Strengthening Agro-Met Services in...

Strengthening Agro-Met Services in Bhutan

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Disclaimer:

All analyses presented in this report is based on data obtained during the course of this assignment.

The accuracy of results is limited to the quality of original data. With the exception of some basic

data integrity checks, no systematic quality control of data has been carried out. All climate data

was obtained from the Department of Hydro Met Services. The annual agricultural survey data was

obtained from the Department of Agriculture in Bhutan. The agricultural statistics presented in this

reports for each year is the production and area of each crop for the previous year. As most farmers

do not keep actual records, the data gathered is based on a person’s memory and should be treated

as best estimate only.

Copyright © WB 2016

All rights reserved

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LIST OF ABBREVIATIONS AND ACRONYMS ....................................................................................................... 7

ACKNOWLEDGMENTS ...................................................................................................................................... 9

EXECUTIVE SUMMARY ................................................................................................................................... 10

1 BACKGROUND............................................................................................................................................. 14

1.1 INTRODUCTION .......................................................................................................................................... 14

1.2 OBJECTIVE ................................................................................................................................................... 14

1.3 METHODOLOGY .......................................................................................................................................... 14

1.4 REPORT STRUCTURE ................................................................................................................................... 15

2 AGRICULTURE IN BHUTAN .......................................................................................................................... 16

2.1 GEOGRAPHY ............................................................................................................................................... 16

2.1.1 AGRO-ECOLOGICAL ZONES ................................................................................................................. 16

2.1.2 SOILS AND TOPOGRAPHY .................................................................................................................... 18

2.2 AGRICULTURE ............................................................................................................................................. 19

2.3 MAIN CULTIVATED CROPS .......................................................................................................................... 21

2.4 PRODUCTION RISK ...................................................................................................................................... 30

2.5 KEY MESSAGES ............................................................................................................................................ 31

3 WEATHER AND CLIMATE RISK ..................................................................................................................... 32

3.1 CLIMATOLOGY ............................................................................................................................................ 32

3.2 FUTURE CLIMATE RISKS .............................................................................................................................. 44

3.3 CLIMATE DATA COLLECTION AND RAINFALL NETWORK ............................................................................. 46

3.4 KEY MESSAGES ............................................................................................................................................ 49

4 VULNERABILITY OF AGRICULTURAL PRODUCTION TO CLIMATE .................................................................. 50

4.1 MAJOR CLIMATIC RISKS IN AGRICULTURAL PRODUCTION .......................................................................... 50

4.1.1 PEST AND DISEASES............................................................................................................................. 50

4.1.2 DROUGHT ............................................................................................................................................ 52

4.1.1 FLOODS AND EXTREME EVENTS .......................................................................................................... 52

4.2 SENSITIVITY OF AGRICULTURAL PRODUCTION TO CLIMATE. ...................................................................... 53

4.3 CLIMATE RISK MANAGEMENT: STRATEGIES TO DEAL WITH CLIMATE RISK. ............................................................ 58

4.4 VULNERABILITY ASSESSMENTS ................................................................................................................... 60

4.5 KEY MESSAGES ............................................................................................................................................ 61

5 DEVELOPING A NATIONAL FRAMEWORK FOR CLIMATE SERVICES .............................................................. 63

5.1 INSTITUTIONAL ARRANGEMENTS ........................................................................................................................ 63

5.2.1 Department of Hydro Met Services (DHMS) ....................................................................................... 63

5.2.2 Department of Agriculture .................................................................................................................. 65

5.3 FROM CLIMATE OBSERVATION TO CLIMATE SERVICE DELIVERY ................................................................................. 68

5.3 DEVELOPMENT OF AGRO-MET SERVICES IN BHUTAN .............................................................................................. 69

6 FARMER’S WEATHER AND CLIMATE RELATED INFORMATION NEEDS ......................................................... 73

6.1 METHODOLOGY .......................................................................................................................................... 75

6.2 RESULTS ...................................................................................................................................................... 75

6.2.1 SECTION A - Demographic Information ............................................................................................... 75

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6.2.2 SECTION B- Information currently used by farmers in agricultural decision making. ......................... 80

6.2.3 SECTION C- Climate and Weather Information Currently Received from Various Sources ................. 81

6.2.4 SECTION D- Climate Information and Services .................................................................................... 82

6.2.5 SECTION E- Constraints in Agricultural Production ............................................................................. 86

6.3 KEY MESSAGES ............................................................................................................................................ 89

7 RECOMMENDATIONS FOR DEVELOPMENT OF AGRO-MET ADVISORY SERVICES IN BHUTAN ...................... 90

8 REFERENCES ................................................................................................................................................ 92

9 APPENDIX – A CLIMATE SURVEY QUESTIONNAIRE ...................................................................................... 97

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FIGURE 2-1 AGRO-ECOLOGICAL ZONES OF BHUTAN, AND THE DZONGKHAGS. ................................................................17

FIGURE 2-2. CULTIVATED AREA OF MAJOR CEREAL CROPS IN BHUTAN. ..........................................................................24

FIGURE 2-3 PRODUCTION (MT) OF MAJOR CEREALS IN BHUTAN DURING 2004. .............................................................24

FIGURE 2-4. AVERAGE DISTRICT YIELD (KG/ACRE) OF MAJOR CEREALS IN BHUTAN. ..........................................................25

FIGURE 2-5. AREA GROWN TO VEGETABLES CROPS ACROSS BHUTAN. ...........................................................................26

FIGURE 2-6. PRODUCTION OF MAJOR VEGETABLE CROPS ACROSS BHUTAN.....................................................................27

FIGURE 2-7. YIELD OF VEGETABLES CROPS ACROSS BHUTAN. .......................................................................................27

FIGURE 2-8. NUMBER OF BEARING FRUIT TREES ACROSS BHUTAN. ...............................................................................29

FIGURE 2-9.PRODUCTION OF FRUIT CROPS ACROSS BHUTAN. ......................................................................................29

FIGURE 2-10 YIELD PER BEARING FRUIT TREES ACROSS BHUTAN. .................................................................................30

FIGURE 3-1. AVERAGE MONTHLY DISTRIBUTION OF RAINFALL ACROSS DIFFERENT AGRO-ECOLOGICAL ZONES IN BHUTAN. ALL

DATA ARE SHOWN ON SAME SCALE FOR COMPARISON. ......................................................................................33

FIGURE 3-2.THE SEASONAL RAINFALL VARIABILITY FOR KEY LOCATIONS ACROSS BHUTAN. .................................................36

FIGURE 3-3. RELATIONSHIP BETWEEN MONSOON DURATION AND CLIMATE DRIVERS. THE AMOUNT OF RAINFALL (MM) IS

INDICATED BY THE SIZE OF THE CIRCLES AND IS POSITIVELY CORRELATED TO MONSOON DURATION (R = 0.0483 D +71.62

; R2= 0.43). DAILY RAINFALL DATA FOR PUNAKA 1990-2014.IOD TIME SERIES FROM

WWW.JAMSTEC.GO.JP/FRGC/RESEARCH/D1/IOD/DATA/DMI.MONTHLY.TXT. ......................................................40

FIGURE 3-4 MONTHLY DISTRIBUTION OF MINIMUM AND MAXIMUM TEMPERATURE (OC) FOR PUNAKHA IN CENTRAL BHUTAN .42

FIGURE 3-5 TIME SERIES OF MONTHLY MINIMUM AND MAXIMUM TEMPERATE (1990-2014) IN DIFFERENT AGRO-CLIMATIC

ZONES OF BHUTAN. THE STATISTICS OF THE DOTTED TREND LINES ARE IN TABLE 3-4................................................45

FIGURE 3-6 AVAILABILITY OF RAINFALL DATA. MISSING DATA ARE SHOWN AS WHITE (OR YELLOW) COLOURS. ......................47

FIGURE 4-1 DROUGHT ANALYSIS FOR SIX AGRO-CLIMATIC REGIONS IN BHUTAN. .............................................................53

FIGURE 6-1. DISTRIBUTION OF HOUSEHOLD MEMBERS WHO COMPLETED THE QUESTIONNAIRE. .........................................76

FIGURE 6-2. EDUCATIONAL ATTAINMENT OF HOUSEHOLDS. ........................................................................................76

FIGURE 6-3. AGE DISTRIBUTION BY GENDER PER HOUSEHOLD. .....................................................................................77

FIGURE 6-4. INFORMATION CURRENTLY USED TO INFORM DECISION MAKING. 1- SEASONAL CONDITION AND OR INDIGENOUS

KNOWLEDGE; 2- TRADITIONAL CROPPING CALENDAR; 3- PERSONAL EXPERIENCE; 4- FOLLOW OTHER SUCCESSFUL

FARMERS; 5- ADVICE FROM DEPARTMENT OF AGRICULTURE; 6- CLIMATE AND WEATHER FORECAST; 7 VILLAGE OFFICIALS;

8 ADVICE FROM FARMER’S GROUP. ...............................................................................................................81

FIGURE 6-5.PERCENTAGE OF RESPONDENTS RECEIVING OR NOT RECEIVING VARIOUS CLIMATE INFORMATION. ......................82

FIGURE 6-6. CONSTRAINTS IN AGRICULTURAL PRODUCTION BASED ON CROP TYPE. .........................................................87

TABLE 2-1 CHARACTERISTICS OF VARIOUS AGRO-ECOLOGICAL ZONES OF BHUTAN IN THE CONTEXT OF AGRICULTURAL

PRODUCTION. SOURCE: DRAFT NATIONAL BIODIVERSITY STRATEGIES AND ACTION PLAN OF BHUTAN, 2014. ..............18

TABLE 2-2 . A CROPPING CALENDAR OF MAJOR CROPS IN DIFFERENT AGRO-CLIMATIC ZONES. SOURCE (MR CHHIMI RINZIN,

MOA). ....................................................................................................................................................22

TABLE 2-3. ANNUAL PRODUCTION, AREA AND YIELD OF MAJOR CEREALS GROWN IN BHUTAN. DATA COMPILED FROM VARIOUS

MOAF ANNUAL STATISTIC REPORTS. ..............................................................................................................23

TABLE 2-4. ANNUAL PRODUCTION, AREA AND YIELD OF MAJOR VEGETABLES GROWN IN BHUTAN DATA COMPILED FROM

VARIOUS MOAF ANNUAL STATISTIC REPORTS. .................................................................................................26

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TABLE 2-5. MAJOR FRUIT PRODUCTION IN BHUTAN. DATA COMPILED FROM VARIOUS MOAF ANNUAL STATISTIC REPORTS. ...28

TABLE 3-1 MONTHLY MEAN, MINIMUM AND MAXIMUM RAINFALL (MM) FOR DIFFERENT AGRO-CLIMATIC ZONES OF BHUTAN. 34

TABLE 3-2 AVERAGE ANNUAL RAINFALL (MM) AND RAINFALL VARIABILITY ACROSS DIFFERENT AGRO-CLIMATE ZONES OF BHUTAN.

.................................................................................................................. ERROR! BOOKMARK NOT DEFINED.

TABLE 3-3 MINIMUM, AVERAGE AND MAXIMUM TEMPERATURE (OC) DISTRIBUTION ACROSS DIFFERENT AGRO-CLIMATIC ZONES

OF BHUTAN. .............................................................................................................................................43

TABLE 3-4 ANNUAL COEFFICIENT OF LINEAR TREND IN MINIMUM AND MAXIMUM TEMPERATURES AND THE CORRESPONDING

CHANGE IN TEMPERATURE OC IN DIFFERENT AGRO-CLIMATIC ZONES SINCE 1990. ..................................................43

TABLE 3-5 SUMMARY OF CLIMATE DATA FOR BHUTAN. .............................................................................................48

TABLE 4-1. A DROUGHT HISTORY REPORT FOR BHUR (TOP), DAGANA DZONG (MIDDLE), AND PUNAKHA (BOTTOM). .............54

TABLE 4-2 GENERAL SENSITIVITIES OF BHUTAN'S AGRICULTURAL SECTOR. SOURCE: (NEC 2000) ......................................56

TABLE 4-3 THE CLIMATE SENSITIVITY OF BHUTAN'S KEY AGRICULTURAL PRODUCE. ...........................................................57

TABLE 4-4. A SELECTION OF STRATEGIES THAT FARMERS AND INDUSTRY USE TO ADDRESS CLIMATE INFLUENCES ON BHUTAN'S KEY

AGRICULTURAL PRODUCTION. .......................................................................................................................59

TABLE 6-1. DISTRIBUTION OF CLIMATE SURVEY IN VARIOUS DISTRICTS (DZONGKHAGS) AND SUB-DISTRICTS (GEWOGS) OF

BHUTAN...................................................................................................................................................74

TABLE 6-2. HOUSEHOLD POSSESSIONS AND FARM CHARACTERISTICS. ...........................................................................78

TABLE 6-3. FARM SIZE BY DIFFERENT LAND UTILIZATION. ............................................................................................78

TABLE 6-4. TYPE OF CLIMATE INFORMATION CURRENTLY RECEIVED BY USERS, FREQUENCY, SOURCE, LEAD TIME AND HOW THIS

INFORMATION HAS BEEN USED IN DECISION MAKING. THE PERCENTAGE REPOSES ARE THOSE WHO INDICATED THEY HAVE

RECEIVED INFORMATION, NOT THE WHOLE SAMPLE. RESULTS ARE COLOR CODED FOR EASIER CROSS REFERENCING........84

TABLE 6-5 TYPE OF CLIMATE INFORMATION CURRENTLY RECEIVED BY USERS, FREQUENCY, SOURCE, LEAD TIME AND HOW THIS

INFORMATION HAS BEEN USED IN DECISION MAKING. THE PERCENTAGE REPOSES ARE THOSE WHO INDICATED THEY HAVE

RECEIVED INFORMATION, NOT THE WHOLE SAMPLE. . RESULTS ARE COLOR CODED FOR EASIER CROSS REFERENCING. .....85

TABLE 6-6. MAJOR CLIMATE RELATED EVENTS EXPERIENCE BY HOUSEHOLD IN THE PAST 5 YEARS. .......................................88

List of abbreviations and acronyms

ADB Asian Development Bank

AWS Automatic Weather Station

CPT Climate Prediction Tools

CV Coefficient of Variation

DEM Digital Elevation Model

DHMS Department of Hydro Met Services

DOA Department of Agriculture

DAO District Agricultural Officer

DOI Department of Irrigation

DDM Department of Disaster Management

DPNet Disaster Preparedness Network

DRR Disaster Risk Reduction

ECHAM European Centre/Hamburg Model

ENSO El Niño Southern Oscillation

ECMWF European Centre for Medium-Range Weather Forecast

EPC Environment Protection Council

EU European Union

FAO Food and Agriculture Organization

GCM General Circulation Model

GDP Gross Domestic Products

GEF Global Environment Fund

GLOF Glacial Lake Outburst Flood

GTS Global Telecommunication System

FGD Focus Group Discussion

ITCZ Inter Tropical Convergence Zone

ICACS International Centre For Applied Climate Sciences

IOD Indian Ocean Dipole

IRI International Research Institute for Climate and Society

ISM Indian Summer Monsoon

MOEA Ministry Of Economic Affairs

MOU Memorandum of understanding

MOAF Ministry Of Agriculture And Forest

NAPA National Adaptation Program of Action

NPPC National Plant Protection Centre

SMS Short Message Service

SD Standard Deviation

SOI Southern Oscillation Index

SST Sea Surface Temperature

SSTA Sea Surface Temperature Anomaly

USQ University Of Southern Queensland

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UNDP United Nations Development Program

WB World Bank

WMO World Meteorological Organisation

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ACKNOWLEDGMENTS

The report Strengthening Agro-Met Services in Bhutan was prepared in collaboration between

the Departments of Agriculture and Hydromet Services of the Royal Government of Bhutan and

the World Bank. This activity is a part of a broader regional program “Hydromet Modernization,

Disaster Risk Management and Climate Resilience” for which the overall objective is to

strengthen disaster preparedness and hydromet services in South Asia.

We are sincerely grateful to Mr Karma Tsering, Director; Mr Phuntsho Namgyal, Chief;

and Mr Tayba Buddha Tamang, Senior Meteorologist from the Department of Hydro Met

Services (MoEA) for helpful discussions and the provision of climate data; Mr Chhimi Rinzin,

Chief Agriculture Officer, Department of Agriculture, MoAF; Ms Yeshey Dema, Program Director,

NPPC (National Plant Protection Centre); Dr Thinlay (Plant Protection Specialist), and Ms Tenzin

Wangmo of the National Environment Commission Secretariat. Many other staff from various

agencies gave their generous time to provide information, advice and references and their

support and cooperation is greatly appreciated. (Names of district officials and other staff to be

added). Special thanks to Mr Peter Davis, Research Fellow at ICACS for helping with data

preparation and producing GIS outputs and Dr Allyson Williams with editing and review of the

report.

This report was prepared by a team including Poonam Pillai, Senior Environment Specialist (Task

Team Leader); Dechen Tshering, Disaster Risk Management Specialist (co-Task Team Leader) of

the Disaster Risk & Climate Change Unit, South Asia region, Yahya Abawi (Lead consultant) and

Dr Sonam Wang and his team (Wang Research and Consultancy). Peer reviewers

include…(names to be added)

We are grateful to GFDRR including the Government of Japan and the European Union for their

generous funding.

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EXECUTIVE SUMMARY (will be revised)

Agriculture is the dominant sector in Bhutan, providing livelihood, income and employment to

approximately 55% of the population. The majority of famers are subsistence farmers with

average land holdings ranging from 1 to 4 acres. The farming community is the most vulnerable

group to climate impacts as farm productions is predominately dryland and influenced by

increasing climate variability and climate extremes. Despite the vulnerability of the agricultural

sector to climate risks, there is no systematic assessment of how delivery of agro-weather

information or services to farmers can help mitigate climate related risks. Understanding

farmer’s needs, knowledge and practices is essential to ensuring effective agro-climate services

and that products and research outputs meet user’s requirements.

Objective: Main objective of this report is to ……add provide recommendations that will result

in improved farmer and sector-wide resilience to climate variability and change, and improved

agro-meteorological services in Bhutan. The specific objectives of this report are to;

undertake a baseline assessment of climate related risks facing farmers in different agro

ecological zones in Bhutan;

assess institutional and organizational processes at the national and sub-national level

for delivering climate and weather related information to farmers;

assess farmer’s information needs and priorities in different agro-climatic zones;

provide recommendations on how agro-weather services can be strengthened and

institutionalized in Bhutan.

Methodology (to be added)

Process of Preparation (to be added)

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KEY FINDINGS

Although climate service delivery is a priority within the national agenda, Bhutan does

not have a National Framework for Climate Services. Current capability of DHMS is

limited to observation, storage and maintenance of hydro-meteorological data and does

not extend to the provision of climate services. According to the WMO Global

Framework for Climate Services classification Bhutan meets most but not all of the

requirements for Basic Level of services (Category I).

Currently there is no capacity within DHMS to provide climate forecasts. DHMS only

issues 24-hour weather forecast and annual forecast of monsoon sourced from

international agencies (IRI). Developing an operational seasonal climate forecast is a

high priority for agro-met service delivery. However, this is compounded by a lack of

research capacity, limited climate data, complex topography and the lack of an

identifiable climate driver for Bhutan.

An extensive literature review revealed only a few studies assessing drivers of rainfall

variability in Bhutan due to poor data availability. Indeed, the sparse and short

observational climate datasets do not meet the standards set by WMO for statistically

meaningful analyses. While there are similarities in climatology and geography with

other Himalayan regions and north east India, the differences are great enough to

warrant caution when extending climate risk analyses from other regions to Bhutan.

However, the regional extent and strength of ENSO relationships with rainfall across

north-east India indicate significant seasonal and intra-seasonal forecasting potential in

Bhutan for many aspects of identified climate risks. Further research is required using

gridded or proxy data.

Currently in Bhutan due to lack of observational network and the complicated

topography of the Himalayas, full climate prediction capability is yet to be developed

and may take time to do so. However given the priority for agricultural climate service

delivery it is strongly recommended that climate products and forecasts from Global

Producing Centres and Regional Climate Centres be used to fill the gap until a specific

seasonal climate forecasting system is developed for Bhutan. For that to happen there

needs to be strong capacity building for staff in DMHS to understand forecasts and

limitations and be able to communicate these to the public.

A number of agro-climatic products such as drought analysis, extreme event, frost

prediction, heat stress index, trend analysis and general climatology information can be

developed using the current data. This will be extremely useful for agricultural

applications. However, with the lack of a clear mandate for agro-met service delivery it

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is unclear which organization (DHMS or DoA) is responsible for these developments. A

clear mandate and regulatory framework is required to clarify the role of these

departments in the delivery of agro-met services.

Effective climate services need strong involvement by stakeholders from various disciplines. The user needs to engage information providers to understand what climate information is available, how to interpret it correctly as well as understanding its underlying assumptions and limitations. Current partnerships are non-existent or very weak in Bhutan. Strong partnerships need to be pursued through a formal MoU between DHMS and DoA and other sectors where needed.

Analysis of agricultural production data highlighted the significant spatial and temporal

variation in the production of all crops. The risk of agricultural production varies

between agro-ecological zones. However there is little information available on the

specific climate sensitivities of the various production systems in Bhutan and how this

varies across agro-ecological zones. A vulnerability assessment of the agricultural sector

to climate variability and climate change is a high priority.

Research activities in the department of agriculture are mainly carried out through the

four Research and Development Centres located in strategic locations with specific foci.

However most research is predominately related to field trials and crop improvement

programs. There is little analytical research (crop modelling or Decision Support

Modelling) to examine the effect of climate (climate variability and climate change) on

production risk of crops across different agro-ecological zones. This capability needs to

be developed in partnership with international researchers.

RECOMMENDATIONS

The primary objective of providing agro-meteorological services is to facilitate the Government’s

capacity to manage climate risk and increase agricultural productivity. This goal is currently

challenged by the overarching restriction of limited resources and institutional capacity for

seasonal and long term climate risk assessments and subsequent development of climate risk

management policies and programs. To achieve this goal the following recommendations are

made to strengthen agro-meteorological services in Bhutan:

DEVELOPING A NATIONAL FRAMEWORK FOR CLIMATE SERVICES IN BHUTAN The climate survey

conducted as part of this study clearly highlights a significant demand from a range of sectors for

climate services. Whilst observations and monitoring networks are in place and being

developed, there is an urgent need through collaboration with other sector agencies for

developing research capacity for climate services, development of a historical climate database

and real time observation network, developing climate services information systems, and a user

interface platform.

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DEVELOPING PARTNERSHIPS BETWEEN DHMS AND DOA AND OTHER SECTORS

Effective climate services need strong involvement by stakeholders from various disciplines. A

Memorandum of Understanding will provide a formal channel for engagement to identify

climate needs of various sectors and to develop products specific to the needs of these sectors

(climate service delivery). To achieve this it is recommended that an externally led visioning

process should be conducted to ensure that there is mutual understanding and alignment of

objectives across organizations (DoA and DHMS). This process would pull together key personnel

across the board to ensure that issues raised in this report are understood by all and a collective

goal is established whilst at the same time maintaining the integrity and value of each of the

parts within the whole. This will ensure efficiency and establish a shared working vision as the

basis for effective collaboration and communication.

STRENGTHEN CAPABILITY AND HUMAN RESOURCE CAPACITY through capacity building (recruitment of

staff) and capacity development (training of existing staff) in both DHMS and Department of

Agriculture. In DHMS capacity needs to be improved In the areas of weather and climate

forecasting, numerical weather prediction, interpretation of climate products including

limitations and uncertainties, identification of user needs, development of sector specific

products, and partnership creation and communication.

A comprehensive capacity building initiative is also needed within the DoA in the following key

areas:

Development and training in the use of climate concepts for the agricultural sector

Development of analytical and crop simulation capability

Vulnerability assessments of agricultural production due to impacts from climate

variability and climate change.

Before initiating any capacity building exercise, a training needs assessment should be

undertaken to ensure high priority areas are targeted first.

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1 BACKGROUND

1.1 INTRODUCTION

Agriculture is the dominant sector in Bhutan, providing livelihood, income and employment to

approximately 55% of the population. The majority of famers are subsistence farmers with

average land holdings ranging from 1 to 4 acres. The farming community is the most vulnerable

group to climate impacts as farm productions are predominately dryland and influenced by

increasing climate variability and climate extremes. Despite the vulnerability of the agricultural

sector to climate risks, there is no systematic assessment of how delivery of agro-weather

information or services to farmers can help mitigate climate related risks. Understanding

farmer’s needs, knowledge and practices is essential to ensuring agro-climate services and that

the products and research outputs meet user’s requirements.

1.2 OBJECTIVE

The goal of the TA is to provide recommendations that will assist to improve farmer’s resilience

to climate variability and climate change, and assist to strengthen the Government’s capacity for

delivering agro-meteorological services in Bhutan.

The specific objectives of this study are to:

undertake a baseline assessment of climate related risks facing farmers in different agro

ecological zones in Bhutan;

assess institutional and organizational processes at the national and sub-national level

for delivering climate and weather related information to farmers;

assess farmer’s information needs and priorities in different agro-climatic zones;

provide recommendations on how agro-weather services can be strengthened and

institutionalized in Bhutan.

1.3 METHODOLOGY

The following tasks were carried out using the following approach;

an extensive literature review of scientific literature and technical documents,

meetings with government and other relevant stakeholders such as key informants,

farmer group leaders, community representatives and development partners,

design and analyze the results of a survey assessing the climate information needs of

farmers.

The main counterpart agencies contacted were the Department of Hydro-Met Services (DHMS)

and the Ministry of Agriculture and Forests (MoAF). In addition several agencies including the

Department of Geology and Mines, National Soil Services Centre (MoAF), the Department of

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Disaster Management, Plant Protection Centre (MoAF) and the National Environment

Commission (NEC) were consulted.

1.4 REPORT STRUCTURE

This report is organized into seven chapters:

Chapter 1 introduces the study and its objectives.

Chapter 2 provides a background to agriculture in Bhutan: the climate, soil, topography and

agro-climatic characteristics. The agriculture sector is summarized, identifying the main crops

and the level of productivity in each Dzongkhag. This includes a brief review of major constraints

to agricultural production.

Chapter 3 details the climate risk to Bhutan in both a temporal and spatial context. Drivers of

climate variability are discussed with the intent of identifying possible forecasting skill.

Chapter 4 reviews the vulnerability of groups across the agricultural sector who are most

vulnerable to weather/climate events in Bhutan. Coping and adaptation strategies that farmers

and other stakeholders use to manage weather and climate related risks are identified.

Chapter 5 discusses institutional and policy arrangements for effective delivery of agro-met

services including recommendation for capacity development and research.

Chapter 6 presents a climate survey to assess farmer’s information needs and priorities

including the analysis of results and recommendations.

Chapter 7 summarizes the key recommendation from this report.

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2 AGRICULTURE IN BHUTAN

This chapter provides an overview of the agricultural sector of Bhutan. This will offer the basis

for climate risk analysis of the agricultural sector in later Chapters.

Bhutan is a small landlocked country situated in the south-eastern Himalayas between latitudes

260 40’ and 280 20’ N and longitude 880 45’ and 920 7’ E and is surrounded by the Tibetan

Plateau in the north, and by the alluvial plain of the Brahmaputra to the south, Arunachal

Pradesh in the east and the Darjeeling and the Sikkim Himalaya in the west. It covers a total area

of 47000 square kilometers with an estimated population of 735,000. The terrain is among the

most rugged and mountainous in the world. The topography varies from an elevation of about

100 meters above sea level in the south to more than 7,500 meters above sea level in the north.

The main features of the Bhutan landscape are aligned roughly north-south (in contrast to the

east-west alignment of the Central Himalayan topography) and the country is divided into three

geographic regions: eastern, central and western, with six, seven and seven administrative

districts (Dzongkhag) in each region respectively.

Agriculture in Bhutan has a dominant role in the economy of the country. Approximately 70% of

the population of Bhutan are involved in the agricultural sector and 56% are farmers. Bhutan’s

GDP per Capita has grown from $US2337 in 2000 to $US7075 in 2012 (World Bank 2013).

Although the contribution of the agricultural sector to GDP has declined from about 35.9% in

2000 to about 17.1% in 2013, agriculture remains the primary source of livelihood for the

majority of the population. Bhutan’s dependence on the climate-sensitive agricultural

production systems makes it vulnerable to climate risk; a threat from both climate variability

and climate change.

2.1 GEOGRAPHY

2.1.1 AGRO-ECOLOGICAL ZONES

The climate is dominated by the Indian Summer Monsoon (ISM) which moves north from the Bay of Bengal. This brings approximately 75% of annual rainfall to Bhutan between June and September. In winter, the climate is cool and dry as it is significantly influenced by the Tibetan high pressure system and not as affected by the westerlies that drive winter rain in the Western Himalayas (Mani 2003, Norbu et al.2003a). The range in altitude and topography produces a wide range of climatic conditions. The climate ranges from subtropical, through temperate and alpine, to arctic, all within 100 km. Annual mean temperatures vary from above 20oC in the piedmont in the south to below zero in the High Himalaya. Temperature is most influenced by altitude with a decrease of 0.5-0.6oC per 100m of altitude (Eguchi 1991). A detailed discussion of spatial and temporal variations in rainfall and temperature is given in Chapter 3.

http://en.wikipedia.org/wiki/Economy_of_Bhutanhttp://en.wikipedia.org/wiki/Bhutanhttp://en.wikipedia.org/wiki/Demographics_of_Bhutan#Population

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Figure 2-1 Agro-ecological zones of Bhutan, and the Dzongkhags.

Bhutan is divided into six major agro-climatic zones ( alpine, cool temperate, warm temperate, dry sub-tropical, humid sub-tropical and wet sub-tropical), each with similar climatic conditions that are influenced by latitude, elevation, temperature , seasonality and rainfall amount that determine their ability to support various form of agriculture as shown in Figure 2-1 and Table 2-1. Annual rainfall varies from less than 650 mm in the Alpine region to more than 5500 mm in the Wet Sub-tropical region.

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Table 2-1 Characteristics of various Agro-ecological zones of Bhutan in the context of agricultural

production. Source: Draft National Biodiversity Strategies and Action Plan of Bhutan, 2014.

Agro-Ecological Zone Altitude

(masl)

Annual Rainfall

(mm)

Farming Systems, major crops and

agricultural produce.

Alpine 3600-4600

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Information on Bhutan’s soil is very limited despite significant demand for soil information

(especially inherent fertility) from planners, farmers, NGO’s and agricultural specialists. The only

published information is the Land Cover Atlas of Bhutan (1:250,000, Ministry of Agriculture and

Forests, Royal Government of Bhutan, 2011), prepared by the National Soil Services Centre

(NSSC) and Policy and Planning Division, Ministry of Agriculture and Forests. Geologically, most

of Bhutan consists of crystalline sheets with large masses of tertiary granite intrusions in the

north. Approximately 27% of Bhutan is classified as either cambisols or fluvisols. Cambisols are

most common in the medium-altitude zone, while fluvisols mostly occur in the southern belt.

Less fertile acrisols, ferrasols and podzols are estimated to cover 45% of the country. About 21%

of the soil-covered area suffers from shallow depth with mostly lithosol occurring on steep

slopes. An overall typical feature of Bhutanese soils is their high levels of variability over a short

distance and regolith heterogeneity.

The most extensive arable areas in Bhutan are the moderately graded lower hill slopes (the

“Inner Valleys”) at about 2500masl. These valleys are upstream of major ‘Knick points’ in large

rivers where there are concave sections with floors up to 1km wide of alluvial terraces and soils

(Baillie and Norbu 2000). These regions have been settled for long periods of time and

cultivated, and hence are considered the demographic, economic and cultural centre of Bhutan

(Baillie and Norbu 2004).

The level of land degradation is generally low. Approximately 10% of Bhutan’s arable land is

subject to some degradation (Young 1994). Norbu et al.(2003b) provide the first reliable account

of the different types of land degradation within the country with special attention to their

occurrence, causes and interactions. In situ degradation due to soil organic matter depletion is

identified as the main degradation process. Generally the soil fertility in Bhutan is on the

decline, due to inadequate input of organic matter and fertilizer, soil erosion and limited

adoption of crop rotation systems such as legumes. Some conservation measures such as

contouring have helped reduce the declining soil fertility.

There are no records of famine in Bhutan (Banskota et al.1992). This most likely reflects high

levels of indigenous knowledge that have enabled effective small-scale subsistence farming. The

techniques utilised in indigenous land use strategies (for example shifting cultivation, crop

rotation, intercropping, contour ploughing, preparation of manure and its regular application,

and low plant population densities) are less effective as the population grows because the

significant fallow periods of 15-20 years that are required to maintain its sustainability are no

longer achievable.

2.2 AGRICULTURE

Among the agricultural lands in Bhutan, an estimated 28% are wetland or irrigated (Chhuzhing),

60% are dryland (Kamzhing) 6.5% are used for orchards, and 3.7% are areca nut and cardamom

plantations (source: Statistical Yearbook of Bhutan 2015, National Statistics Bureau). In 1996

shifting cultivation (tsheri) accounted for 28% of agricultural, however this practice is now

http://en.wikipedia.org/wiki/Dryland

P a g e | 20

discouraged by the government (source: Statistical Yearbook of Bhutan 2005, National Statistics

Bureau).

Most farming is subsistence with some integration of crops, forests and livestock. Until the mid-

1980s most agriculture was subsistence, however, more recently there has been a trend to

commercial farm cash crops, some of which are exported such as oranges, areca nut and

cardamom in the subtropical south of the country, apples in the more temperate southern

regions.

Despite the high proportion of the population being involved in agriculture, Bhutan is not self-

sufficient in terms of food production. Food insecurity persists mostly in rural areas, especially in

the eastern and southern parts of the country. Current coping mechanisms against food

insecurity include, off farm activities, sale of vegetables, fruits and nuts, labor exchange, sale of

livestock products, cash remittance from employed family members and borrowing from

neighbors. In addition, Bhutan has been a net food importer, particularly of grains.

The agricultural sector in Bhutan faces significant challenges including:

1. Limited agricultural land. Only 2.9% of arable land is currently used for agriculture of

which 31% are on slopes with a gradient of more than 50%. This is further compounded

by the strong policy of environmental conservation with 70% of the land under

permanent forest cover, thus limiting agricultural expansion.

2. High vulnerability to climate hazards and natural disasters. Bhutan is highly vulnerable

to natural hazards such as floods, landslides, cyclone and droughts. Despite high rainfall

and an abundance of water resources, most agricultural production is rain-fed making it

vulnerable to climate variability and climate extremes.

3. Crop damage from wild animals. In a survey conducted by the Department of

Agriculture in 2012, about 67% of farmers identified damage by wildlife as a major

constraint to agricultural productivity. In the climate survey of the 1205 households

conducted in this study (Chapter 6) damage from wide life was ranked 4.6 on a scale of 1

to 5 ( 1- least important to 5- most important), well ahead of climate, soil, water, labor

and other constraints.

4. Shortage of labour. The increasing shortage of farm labour, due to rural to urban

migration, coupled with competition from growing imports of cheaper food is a constant

constraint impacting on internal food production and agricultural development. Almost

61% of households surveyed, identified labour shortage as a major constraint (MoAF,

2012) to agricultural productivity.

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5. Access to Markets. Poor road network and rugged terrain, increases the cost of

commodities and is a significant barrier to producing competitive products particularly

for the international markets.

6. Lack of Irrigation Infrastructure. The main rivers provide water mainly for hydropower

generation, tourism, recreation and ecology, with sparse use for irrigation. Tributaries

and streams are the main source for most water users, with headwater streams used for

irrigation and water supply. Agriculture accounts for around 90 percent of consumptive

water demand, which is mostly through traditional irrigation conveyance systems that

are small and gravity-fed with few properly engineered headwork or feeder canals.

7. Climate Change. Climate projections for Bhutan suggest that the mean annual

temperature in Bhutan will likely increase by ~0.8oC by 2039 and the mean annual

precipitation will likely increase by ~6% over the same period (Second National

Communication to the UNFCCC - National Environmental Commission). Agriculture is

already vulnerable due to increases in temperature and extreme events (e.g. cyclones

Aila, and Phailin), flash floods, hailstorms, windstorms, droughts, pests and diseases.

Although increasing temperature and CO2 due to climate change may have some

positive impacts on some crops (e.g. potatoes), others like rice and maize will see a

decline in yield in the short term. A 1 oC increase in minimum temperature is likely to

reduce rice yield by some 10%. The positive impact of climate change may be offset by

the increasing incidence of pest and diseases and extreme variability in rainfall.

2.3 MAIN CULTIVATED CROPS

The major crops grown in Bhutan are Rice, Maize, Wheat, Millet, Barley, Potatoes, Mustard and

Legumes. These crops are grown in the different agro-climatic zones of Bhutan often in rotation

through the year. A cropping calendar of major crops in different agro-climatic zones is shown

in Table 2-2.

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Table 2-2 . Cropping calendar of major crops in different agro-climatic zones. Source (Chhimi

Rinzin, DoA)

Jan Feb March April May Jun July August Sep Oct Nov Dec

Rice

Maize Maize- Fallow Sowing Harvesting

Potato-Wheat Harvesting Sowing

Winter Wheat-

Buckwheat

Harvesting Sowing

Barley Potato-Wheat Harvesting Sowing

Millet

Mustard Potato-Mustard Sowing Harvetsing

Legumes

Potato Potao- Fallow Planting Harvesting Marketing Marketing Marketing

Rice- Fallow Nursery Nursery T/planting T/planting Harvesting

Rice-Wheat Fodder Nursery Nursery T/planting T/planting Harvesting Harvesting

Rice- Oat Nursery Nursery T/planting T/planting Harvesting Harvesting

Maize- Fallow Sowing Harvesting Harvesting

Maize+bean (relay) Sowing Harvesting Harvesting

Wheat Maize -Wheat Harvesting Sowing

Barley Maize- Barley Harvesting Sowing

Millet

Mustard Potato-Mustard Harvesting Harvesting Sowing

Legumes

Potato-Mustard Planting Planting Weeding Harvesting Marketing Marketing Marketing

Potato- Turnip Planting Planting Weeding Harvesting Marketing Marketing Marketing

Rice -Wheat Nursery Nursery Nursery T/planting T/planting T/planting Harvesting Harvesting

Rice- Mustard Nursery Nursery Nursery T/planting T/planting T/planting Harvesting Harvesting

Rice- Vegetables Nursery Nursery Nursery T/planting T/planting T/planting Harvesting Harvesting

Maize Maize - legumes Sowing Sowing Weeding Harvesting Harvesting

Wheat Rice-Wheat Harvesting Sowing

Barley Maize - Barley Harvesting Sowing

Millet Millet- Fallow Nurserry June Harvesting

Mustard Maize-Mustard Harvesting Harvesting Sowing Sowing Weeding

Legumes Maize - Legumes Sowing Harvesting

Potato- Wheat Planting Planting Weeding Harvesting Harvesting Marketing Marketing Marketing

Potato- Buckwheat Planting Planting Weeding Harvesting Harvesting Marketing Marketing Marketing

Potato-Rice (wetland) Planting Harvesting

Rice

Rice--Fallow Nursery Nursery&

T/planting T/planting

Harvesting Harvesting

Rice (first crop) Rice-Rice Nursery Nursery T/planting Harvesting Harvesting

Maize Maize - Millet Sowing Sowing Weeding Harvesting Harvesting

Maize second crop (

dryland)

Maize - Maize Sowing Harvesting

Maize in wetland

(Spring maize)

Maize -Rice

Sowing Sowing Weeding Harvesting


Barley Maize- Barley Harvesting Sowing

Millet Maize- Millet Nursery T/planting Harvesting Harvesting

Maize- Mustard (dryland) Harvesting Harvesting Sowing Sowing

Rice - Mustard (wetland) Harvesting Harvesting Sowing Sowing

Legumes Maize- Rajma beans Sowing Harvesting

Potato Potato- Maize Harvesting Marketing Planting

Rice Rice- Fallow Nurserry T/planting Harvesting Harvesting

Rice (first crop)

Rice-Rice Nursery Nursery &

T/planting

T/planting Harvesting

Maize (dryland) Maize - Millet Sowing Sowing Weeding Harvesting Harvesting

Maize in wetland

(Spring maize)

Maize -Rice

Sowing Sowing Weeding Harvesting


Barley

Millet Maize- Millet Nursery T/planting Harvesting Harvesting

Maize-Mustard ( dryland)

Rice - Mustard (wetland) Harvesting Harvesting Sowing Sowing

Legumes Maize- Urd beans Sowing Harvesting Harvesting

PotatoPotato- Rice (wetland)

HarvestingPlanting

Mustard

Wet sub-tropical (150 m to 600 m asl)

Cropping Sequence Months

Warm temperate (1800 m to 2600 m amsl)

Dry Sub-tropical (1200 m to 1800 m asl)

Humid sub-tropical (600 m to 1200 m asl)

Cool temperate (2600 m to 3600 m asl)

Mustard

Maize

Rice

Rice

Potato

Potato

Wheat

Crops

P a g e | 23

Cereals

The major cereals grown in Bhutan are Rice (Paddy), Maize, Wheat, Buckwheat and Millet. The

staple food of the Bhutanese people is rice, followed by maize.

Total rice production is approximately 71,630 t grown over an area of 56677 acres. The average

rice yield in Bhutan is 1282 kg/acre with significant variation across the region (Figure 2-4). Rice

is grown mainly in the western region (Thimphu, Paro, Punakha and Wangdue districts) and the

southern region (Sarpang, Tsirang and Samtse districts). The highest yielding districts are Paro,

Thimphu Punakha and Wangdue averaging (1992 Kg/ ha) and the lowest yield are in

Pemagatshel, Samdrupjongkhar, Zhemgang and Gasa averaging 1132 kg/acre. Rice production

has been relatively constant over the past decade with an annual coefficient of variation of 10%

(Table 2-3). While yield has increased over this period, this has been offset by a slight reduction

in the cultivated area.

Rice production on a commercial scale is limited largely due to a shortage of arable land and

farm labour, low cropping intensity, inadequate irrigation and crop losses to pests, especially

wild animals. Domestic production and supply is less than the rising demand. At present self-

sufficiency in rice is about 48%. From the total supply of about 75,229 t of rice in the country in

2013, a significant proportion of domestic demand was met by imports from India.

Year 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Mean SD CV

Paddy

Area (Acres) 46586.0 62458.0 67568.0 67565.0 47834.7 58607.0 56375.3 59167.0 52252.1 48361.0 56677.4 7812.7 0.1

Production (Metric Tonnes) 54326.0 67607.0 74380.0 74439.0 77313.0 65766.0 71636.6 77576.0 78014.0 75229.0 71628.7 7354.6 0.1

Yield (Kg/acre) 1166.1 1082.4 1100.8 1101.7 1616.3 1122.2 1270.7 1311.1 1493.0 1555.6 1282.0 204.4 0.2

Maize

Area (Acres) 53939.0 75859.0 75413.0 71002.1 67278.9 70603.0 61475.9 66021.0 63488.2 58338.1 66341.8 7175.8 0.1


Yield (Kg/acre) 1679.1 1238.7 942.3 870.3 992.6 866.3 938.0 1115.4 1150.2 1297.9 1109.1 250.7 0.2

Wheat

Area (Acres) 7585.0 21826.0 17515.0 16981.0 7877.7 7708.0 5566.6 5447.0 5539.6 5440.0 10148.6 6160.0 0.6


Yield (Kg/acre) 552.7 515.3 547.3 522.9 717.0 477.2 875.6 1067.7 909.5 787.7 697.3 204.9 0.3

Millet

Area (Acres) 7326.0 16986.0 20977.0 21485.0 8696.3 10124.0 8454.0 9162.0 6462.1 5054.5 11472.7 6041.0 0.5


Yield (Kg/acre) 323.1 409.3 418.9 408.5 577.7 417.9 481.0 641.9 613.6 583.6 487.6 108.6 0.2

Buckwheat

Area (Acres) 6288.0 16062.0 21413.0 21701.0 8493.0 9524.0 7503.8 9184.0 6851.5 6590.0 11361.0 6056.3 0.5


Yield (Kg/acre) 399.2 435.9 436.8 373.4 605.0 405.1 526.5 657.3 628.1 552.5 502.0 104.8 0.2

Major Cereals Production in Bhutan

Table 2-3. Annual production, area and yield of major cereals grown in Bhutan. Data compiled

from various MoAF annual statistic reports.

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Figure 2-2. Cultivated area of major cereal crops in Bhutan.

Figure 2-3 Production (Mt) of major cereals in Bhutan during 2004.

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Figure 2-4. Average District yield (kg/acre) of major cereals in Bhutan.

Vegetables

A variety of vegetables are cultivated in Bhutan. Most are produced for household consumption

on a subsistence basis but a few are also sold in the market. The major vegetables crops are

Potatoes, Chillies, Cabbage, Turnip and Radish.

Annual production, area and yield of major vegetables for the past ten years in Bhutan is shown

in Table 2-4. Major vegetable growing regions by production and area are shown in Figure 2-5,

Figure 2-6, and Figure 2-7 respectively.

Potatoes are the most important cash crop in Bhutan. The major potato production regions of

Bhutan are in Wangdi, Mongar, Tasigan, Chhukha and Samdrup districts. Around 30000

households, are dependent on potato production for a significant portion of their livelihood.

Most potato farmers meet their demand of annual supply of rice and household needs using the

cash earned from selling potatoes. The cash crop thus has one of the important influences on

the socio-economic conditions of the poor rural households of the country.

Production of vegetable crops remain highly variable with annual coefficient of variation ranging

from 20 percent (potatoes) to 50% (Turnip).

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Table 2-4. Annual production, area and yield of major vegetables grown in Bhutan. Data

compiled from various MOAF annual statistic reports.

Figure 2-5. Area grown to vegetables crops across Bhutan.

Year 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Mean SD CV

Chili

Area (Acres) 3060.0 5639.0 5971.0 5288.0 9454.4 5684.0 6984.6 6044.0 7797.3 5170.0 6109.2 1702.5 0.3


Yield (Kg/acre) 1455.6 1852.1 1943.7 1582.5 773.5 1563.3 958.7 937.8 990.8 1609.3 1366.7 416.9 0.3

Cabbage

Area (Acres) 704.0 1575.0 2024.0 2151.4 1189.0 863.4 1472.0 2676.9 2427.0 1675.9 689.8 0.4


Yield (Kg/acre) 2683.2 2123.8 2123.5 2084.9 1492.9 1504.6 2036.7 1275.0 1632.5 1884.1 439.9 0.2

Radish

Area (Acres) 2381.0 4711.0 4014.0 3651.2 3166.0 2739.7 2934.0 3371.0 806.1 0.2

Production (Metric Tonnes) 5628.0 12658.0 10218.0 10539.3 5977.1 5674.0 3882.1 5244.5 4534.0 7150.6 3127.7 0.4

Yield (Kg/acre) 2363.7 2686.9 2545.6 2886.5 1792.2 1417.0 1545.3 2176.7 585.8 0.3

Turnip

Area (Acres) 962.0 2028.0 2112.0 2729.0 2139.0 1080.1 1616.2 1809.5 630.0 0.3

Production (Metric Tonnes) 4139.0 8469.0 12915.0 15104.0 5079.9 9366.0 2638.2 7993.6 9758.7 8384.8 4041.2 0.5

Yield (Kg/acre) 4302.5 4176.0 6115.1 5534.6 4378.7 2442.7 6038.2 4712.5 1298.7 0.3

Potato

Area (Acres) 8455.0 14481.0 17632.0 14780.0 13738.5 12154.0 9266.0 11390.0 12548.0 13391.0 12783.6 2690.7 0.2


Yield (Kg/acre) 5606.7 3701.1 3859.4 4136.3 3854.8 3798.0 4750.1 4338.8 3426.8 3763.0 4123.5 639.5 0.2

Major Vegetable Production in Bhutan

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Figure 2-6. Production of major vegetable crops across Bhutan.

Figure 2-7. Yield of vegetables crops across Bhutan.

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Fruit

The major fruits grown in Bhutan are citrus (mandarins, oranges), apples, pears, banana and

areca nuts. Most fruit produced is exported to India and Bangladesh. Agricultural exports to

countries, other than India, constitute 50 to 70 percent of total exports. In 2010 oranges were

the top ranked export commodity (by value), followed by cardamom, and potatoes; in 2014

oranges were ranked second after potatoes (Bhutan RNR Statistics 2015, MoAF).

Table 2-5. Major Fruit Production in Bhutan. Data compiled from various MOAF annual statistic

reports.

Year 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Mean SD CV

Apple

Total Trees 773.9 425.7 477.1 372.8 321.2 395.4 659.4 698.3 306.2 322.1 475.2 172.6 0.4

Bearing Trees 492.2 338.5 379.0 278.9 245.5 315.9 570.4 557.6 244.0 236.1 365.8 129.8 0.4

Production (Metric Tonne) 11834.4 10420.0 7407.0 7074.2 5410.4 15085.1 17371.4 20751.0 7666.1 8031.5 11105.1 5085.7 0.5

Yield (Kg/Bearing Tree) 24.0 30.8 19.5 25.4 22.0 47.8 30.5 37.2 31.4 34.0 30.3 8.3 0.3

Arecanut

Total Trees x 1000 1410.9 863.1 989.7 1597.2 1736.9 1703.2 1801.1 1751.3 1128.4 1234.8 1421.7 346.7 0.2

Bearing Trees x 1000 33.6 32.0 31.7 49.0 48.4 58.6 71.9 87.3 67.3 62.4 54.2 18.7 0.3



Mandarin

Total Trees x 1000 3662.6 1969.3 2297.4 3252.2 1971.5 2804.3 2939.7 3167.7 2076.4 2087.4 2622.8 619.1 0.2

Bearing Trees x 1000 1966.8 1310.1 1353.1 2015.4 1121.0 1570.4 1554.1 1765.5 1104.9 1046.9 1480.8 352.9 0.2



Banana

Total Trees x 1000 290.9 214.8 436.2 719.1 594.8 558.4 328.7 449.0 182.9 0.4

Bearing Trees x 1000 132.5 124.2 201.8 268.9 165.8 162.9 116.6 167.5 53.5 0.3

Production (Metric Tonne) 2870.2 2376.0 3412.0 3974.0 2181.0 2208.4 2432.0 4.0 1493.0 2327.8 1136.1 0.5

Yield (Kg/Bearing Tree) 21.7 19.1 16.9 14.8 13.2 13.6 12.8 16.0 3.4 0.2

Pear

Total Trees x 1000 27.3 36.5 58.7 75.2 21.6 32.5 31.3 50.8 39.8 49.1 42.3 16.3 0.4

Bearing Trees x 1000 18.9 34.5 37.4 48.8 18.6 17.3 16.3 26.4 19.8 20.7 25.9 10.9 0.4



Major Fruit Production in Bhutan

P a g e | 29

Figure 2-8. Number of bearing fruit trees across Bhutan.

Figure 2-9.Production of fruit crops across Bhutan.

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Figure 2-10 Yield per bearing fruit trees across Bhutan.

2.4 PRODUCTION RISK

The preceding section has presented maps and tables showing the mean statistics including the

variability of agricultural production (yield and area panted) over the past decade in Bhutan.

This variation is reflective of the risk faced each year by farmers. This production risk is a

function of many factors, including extreme weather events, drought, pests, diseases, fire,

management (including planting and harvesting), labour amongst others. These risks all have the

potential to affect the quantity and quality of the crop production.

A simple tool to assess the relative levels of risk in agricultural production is the coefficient of

variation (CV). The CV is defined as the ratio of the standard deviation to the mean. The relative

variability of each of the productivity measures considered (area planted and yield) can be

examined by the CV, and ranges from 10% to 60% (Tables 2.3-2.5). The higher the CV, the

greater the variability relative to the mean. For example, of the cereal yields considered, wheat

yield is most risky. It has a CV of 30% which means that about 67% of the time, yield varies +/-

30% from its long term average. Rice yield varies by slightly smaller amount (20%). The area

planted of rice and maize varies little, however the area of wheat, millet, and buckwheat have

CVs of between 50-60%.

There is also a range of riskiness across the difference fruit species. Mandarin yield has a CV of

only 10%; this is the least varying of all fruit yields. Areca nut yield in the most risky (CV is 40%)

P a g e | 31

and apples, one of the largest export earners (Bhutan RNR Statistics 2015, MoAF), along with

pears, they have a high level of variability (50%).

2.5 KEY MESSAGES

Agriculture in Bhutan has a dominant role in the economy of the country with over 70%

of the population involved in the agricultural sector and 56% are farmers. Agriculture

contributes to about 17% of GDP in Bhutan.

Despite abundant water supplies, most agriculture is rain-fed due to steep topography

and lack of irrigation infrastructure. This makes agricultural production highly vulnerable

to the impact of climate variability and climate change.

The major cereals grown in Bhutan are Rice (Paddy), Maize, Wheat, Buckwheat and

Millet. The average rice yield in Bhutan is 1282 kg/acre with significant variation across

the region. The highest yielding districts are in the western region and the lowest

yielding districts are in the southern region. Paddy production is relatively stable with an

annual coefficient of variation of 10% followed by Wheat (20%). However area and

production of Wheat, Buckwheat and Millet varies significantly from year to year with

coefficient of variation between 40-60%. This variability is most likely due to the

exposure of these rain-fed crops to climate variability in Bhutan particularly in the warm

temperature and humid sub-tropical agro-climatic zones where the annual coefficient of

variation of rainfall is between 40-60%.

A vulnerability assessment of the agricultural sector to both climate variability and

climate change needs to be carried out to assess the exposure of different crops to

climate and to assist in developing adaptive capacity for the sector.

http://en.wikipedia.org/wiki/Economy_of_Bhutan

P a g e | 32

3 WEATHER AND CLIMATE RISK

This chapter provides an overview of the climate of Bhutan including variability across different

agro-ecological zones and identifies key drivers of this variability. The climatology of Bhutan is

summarized and challenges for the development of an effective climate forecasting system

which is essential for the delivery of agro-met services in Bhutan are discussed.

3.1 CLIMATOLOGY

Using daily meteorological data from the Department of Hydro-Met Services (DHMS), weather

and climate profiles for the nation are produced. Of the 92 weather stations, there are 20 “Class

A” stations (Table 3-5). Most of these extend from 1996 to present and are used in analyses in

this report. The climate data collection and rainfall network are summarised at the end of this

Chapter and provide details on data quality. It must be noted that the data used in this report

are “raw data” and not corrected for homogeneity or continuity. Therefore, the results

presented in chapter should be treated with a degree of caution.

The mean annual rainfall in Bhutan is 2000 mm, with more than 75% of annual rainfall occurring

between June and September (Figure 3-1). The climate is dominated by the June-September

monsoon season with a dry winter and autumn. The climatic conditions are influenced by

topography, elevation and rainfall patterns. There is year round snow in the north. Southwards,

closer to India, the weather is hot and humid in summer and cool in winter. Annual average

rainfall ranges from 650 mm in the alpine and cool temperate region to more than 5500 mm in

the wet subtropical region. Monthly distribution of rainfall for several districts (Dzongkhag) and

agro-ecological zones are shown in Figure 3-1. The data show a strong seasonal cycle with the

greatest amounts occurring in June and July.

In general there is a strong relationship between altitude and climate (Table 3-1). It gets colder

and drier with height and wetter and warmer as altitude decreases. However there are

important differences to this relationship due to Bhutan’s physiography (Norbu et al.2003). The

inner valleys of central Bhutan are dry valleys in which cloud cover are suppressed by strong up-

valley winds (Whiteman 2000). Poor data coverage and quality lends itself to some uncertainties

regarding the precise spatial distribution of rainfall in Bhutan. Although it is clear that the

southern foothills of Bhutan both in the west and the east have a wet climate (annual rainfall up

to 7000 mm), there is some debate as to the degree of rainfall decrease from west to east.

Many researchers consider that the rain shadow effect of the Meghalaya Plateau in north east

India is highly significant for the eastern regions of southern Bhutan (e.g. Biswas et al. 2007;

Adlakha et al.2012, Bookhagen and Burbank 2010); others consider the effect to be limited and

characterise all of Southern Bhutan as having a wet monsoonal climate (Baillie and Norbu 2004).

River flow data indicate that the main rivers generally all have similar flow regimes and that

Eastern Bhutan is not significantly drier than western Bhutan (Baillie and Norbu 2004). Some

geomorphological indicators suggest that part of the eastern valleys are somewhat wetter than

the rest (e.g. Van der Poel and Tshering 2003). This is a good example of the importance of

P a g e | 33

high-quality climate data so that a proper assessment of rainfall variability across different

regions can be made.

Figure 3-1. Average monthly distribution of rainfall across different agro-ecological zones in

Bhutan. All data are shown on same scale for comparison.

P a g e | 34

Table 3-1 Monthly mean, minimum and maximum rainfall (mm) for different agro-climatic zones

of Bhutan.

EXTREME EVENTS

Heavy rainfall, 1-day extreme events, are particularly important from a risk management

perspective as it is often these events which lead to severe floods, landslides and infrastructure

damage (Nandargi and Dhar 2012). They are most likely to occur in July, August, and September

and are associated with particular meteorological patterns, namely:

monsoon depressions: these move north from their origin in the Bay of Bengal causing

heavy rainfall in the Himalayan foothills ( (Dhar and Nandargi 2000),

monsoon breaks within the monsoon season (Gadgil and Joseph, 2003, Wang et

al.2005): intra-seasonal oscillations of the break and active periods of the monsoon that

are primarily driven by the Madden Julian Oscillation (MJO) usually occur in the mid-late

monsoon months of July and August, and occasionally in September. A break in the ISM

refers to a cessation of the monsoon over much of India as the monsoon trough shifts to

the Himalayan foothills. While the monsoon breaks are the driving force of below

average rainfall anomalies across much of India, it is during these breaks that extreme

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Maximum 78.2 199 310 998 803 1670 2422 1882 1009 590 85.3 77.2

Median 10 17.2 60.9 221 378 942 1267 964 569 166 7.7 2

Mean 17.5 29.8 79.1 254 441 1021 1298 964 633 213 18 10.4

Minimum 0 0 6.6 0 224 566 425 429 169 16.8 0 0

Maximum 38.2 34.7 81.5 146 176 157 277 238 179 191 81.4 50

Median 0.7 8.6 27.9 57.3 85.6 114 149 146 80.2 42.8 1.4 0

Mean 6.5 11 31.1 63.7 87.6 102 147 138 85.9 56.1 6.7 4.1

Minimum 0 0 0 31 35.9 38.5 40.9 24.3 34.4 5.6 0 0

Maximum 60.2 196 102 334 570 839 705 908 864 352 85.4 55

Median 10 21.9 40 59.6 126 316 351 291 256 90 1.1 0

Mean 17.2 38.9 41.5 104 191 332 360 321 275 115 8.4 5.1

Minimum 0 0 5.9 10.8 12.9 85.4 66.3 11.5 39 7 0 0

Maximum 34 82.3 109 151 291 488 425 303 329 254 40.2 20

Median 1.4 9.3 25.8 82.4 90 135 206 200 86.4 64 2.6 0

Mean 7.3 13.5 34.5 74.7 104 158 210 179 104 73.4 5.6 3.4

Minimum 0 0 0 9.8 0 73.6 85.6 6.4 24.6 0 0 0

Maximum 134 304 72.2 150 317 769 410 296 202 130 18.5 20.1

Median 3.4 7.7 9.6 35.1 69.4 116 161 149 110 43.3 1.4 0

Mean 15.3 26.1 15.4 44.1 89.1 152 161 153 103 48.1 4.4 4

Minimum 0 0 0 8.8 7.9 11.8 63.4 6 20 0 0 0

Maximum 54.6 172 242 912 1055 2028 1914 1806 1059 364 164 64.8

Median 20.3 28.6 61.2 289 585 1024 1277 912 650 212 17.8 5.2

Mean 21.2 43.3 95.3 339 609 1062 1297 1065 662 217 28.6 16.9

Minimum 0 0 1.2 24.2 252 395 830 699 297 63.8 0 0

Bhur- Wet Subtropical Longitude 90.4 E Latitude 26.9 N Elevation 375 m asl

Dagana dzong - Warm Temperate Longitude 89.9 E Latitude 27.1 N Elevation 1460 m asl

Punakha - Dry Subtropical Longitude 88.9 E Latitude 27.6 N Elevation 1236 m asl

Sipsu - Wet Subtropical Longitude 88.9 E Latitude 27.0 N Elevation 550 m asl

Chamkhar - Cool Temeprate Longitude 90.8 E Latitude 27.5 N Elevation 2470 m asl

Mongar- Humid Sub-tropical Longitude 91.2 E Latitude 27.3 N Elevation 1600 m asl

P a g e | 35

precipitation occurs in the Himalayan foothills of Bhutan and northern India, including

flooding of rivers. This period of enhanced rainfall during the monsoon breaks appears

to only happen during the first few days of the break period and produces a threefold

increase in precipitation compared with active monsoon conditions.

INTER-ANNUAL VARIABILITY

The following section discusses the inter-annual variability of rainfall in Bhutan and the influence

of remote drivers (such as the El Niño Southern Oscillation, ENSO, the Indian Ocean Dipole, IOD,

and the Pacific Decadal Oscillation, PDO) with a view to building capacity in seasonal or decadal

climate forecasting. The inter-annual variability of rainfall is high across Bhutan as shown in Fig.

3-2 and Table 3-2. This variability is across all seasons, but is especially evident in the months of

high monsoon rainfall. This ‘riskiness’ of rainfall varies across Bhutan: coefficient of variation of

annual rainfall ranges from 13% in the cool temperate region to about 42% in the humid sub-

tropical and 50% in the warm temperate region (Table 3-2).

.

Table 3-2 Average annual rainfall (mm) and rainfall variability across different agro-climate

zones of Bhutan

As mentioned previously the seasonality of rainfall is primarily driven by the Indian Summer

Monsoon (ISM) originating from the Bay of Bengal. The variability of the amount of monsoon

seasonal rainfall is driven by the variability of the onset and retreat of monsoon, the intensity,

and the frequency of active and break periods. The monsoon onset is associated with the

changes in the direction of seasonal winds and the shift in the position of the Inter Tropical

Conversion Zone (ITCZ).

P a g e | 36

Figure 3-2.The seasonal rainfall variability for key locations across Bhutan.

ENSO has been established in the literature as a primary driver of the ISM (Webster et al.1998,

Kumar et al.2006). In general, for all-India rainfall, ENSO accounts for approximately 30% of

inter-annual Indian monsoon rainfall variability: rainfall decreases in a warm ENSO phase (an El

Niño where sea surface temperatures in the central Pacific Ocean are warmer than the long

term average) and increases in a cool ENSO phase, the La Nina where SSTs are cooler than

average (e.g. Shukla and Paolino 1983, Yasunari 1990). This relationship has provided the

foundations for seasonal climate risk management in many parts of India. However the

literature is less clear on the role of ENSO as a driving force of inter-annual rainfall variability in

Bhutan where climatological observations rarely extend beyond 30 years.

The relationships discussed below are developed from tree ring analyses (Sano et al. 2013) and

gridded rainfall data sets (Prevez and Henebry 2015), both of which have restricting caveats.

There is evidence that annual area-averaged rainfall of Bhutan has the same relationship with

ENSO as North East India (Yadav 2012), so conclusions may be drawn from studies in that region.

However, caution must be used when examining regional scale effects or extrapolating results

from other areas of India or the Himalayas.

P a g e | 37

More explicitly, the monsoonal rainfall (June-October) in Bhutan shows an ENSO signal but it is

quite regionalized using 0.5 x 0.5 degree gridded rainfall (Pervez and Henebry 2015). During a La

Nina event there are positive rainfall anomalies in the south west of the country and no signal

elsewhere. During an El Niño event there is decreased rainfall in the southwest and a small

region in the north east of positive rainfall anomalies. This is corroborated by tree ring evidence

(Sano et al.2013) from a single location which also shows that El Niño events are generally linked

to dry conditions in central Bhutan, and La Nina events are related to wet conditions. It is

important to note the spatial nature of relationship: the correlations between rainfall and ENSO

indicators weaken moving east across the western Himalayas and northern India through to the

eastern Himalayas and Bangladesh.

The rainfall-ENSO relationship in Bhutan is not strong, nor is it linear or stationary. It is

modulated by the IOD (Pervez and Henbry 2015). A positive IOD (warmer sea surface

temperatures in the western Indian Ocean relative to the east; an event often associated with El

Niño) is associated with lower than normal rainfall in eastern Bhutan. A negative IOD has no

effect in Bhutan or over much of the Himalayas. The strongest signal in Bhutan is when a

negative IOD event occurs simultaneously with a La Nina event: above average rainfall occurs

across the country. There is little effect when an El Niño occurring with a positive IOD (Pervez

and Henbry 2015).

The La Nina-negative IOD events modify the rainfall in the months of June-July-August the most,

and most importantly increase the frequency of extreme rainfall events (Pervez and Henebry

2015).

There is also evidence of other drivers of multi-decadal modulations of the ENSO-ISM rainfall

relationships in Bhutan, such as the PDO (Sano et al.2013). Tree-ring studies suggest that the

meteorological extremes of flooding and drought in NE India have multi-decadal shifts and these

may be associated with the PDO: a warm phase of the PDO is associated with a weak ISM

(Krishnan and Sugi 2003). It has been shown that Indian monsoon rainfall more often tends to

be below (above) normal when El Niño (La Niña) events occur during positive (negative) phases

of the PDO [Berelhammer , Krishnan and Sugi 2003). The ENSO-rainfall relationship appears to

be consistent only during positive phases of the PDO (Sano et al.2013).

In terms of stationarity, the ENSO ~ monsoon relationship in Bhutan appears to have remained

stable during the 1971-2011 period (Sano et al.2013), however there are reported changes over

recent decades in the strength of ISM~ENSO~rainfall relationships in nearby north-east India

and elsewhere in India (Kumar et al.1999, Torrence and Webster 1999, Clark et al.2000). There

is debate over the nature of the change however, as other studies using different proxies of the

P a g e | 38

Indian monsoon suggest the relationship with ENSO is still significant (Gershunov et al.2001,

Goswami and Xavier 2005, Van Oldenborgh and Burgers 2005).

ENSO appears to affect the ISM rainfall totals through its effect on the duration of the monsoon,

and more specifically through the lengths of active and break spells (Dwivedi et al.2015). In

India, during El Niño years the frequency of longer breaks of the ISM and shorter active spells

increase significantly. This affects the extreme rainfall events as mentioned in the previous

section.

There is lack of clarity in the literature as many researchers mistakenly compare results of

ENSO~ rainfall relationships from various regions, or use an all-Indian rainfall total, or compare

relationships from different time periods, or do not distinguish between the Indian Summer

Monsoon and the North East Monsoon. From an agricultural risk management perspective it is

critical to use climate data for the region in which the farming system is located, and be aware

of possible fluctuations in relationships through time.

Although the rainfall records of Bhutan are not long enough for a statistically significant analysis,

it may still be possible to identify some indications of the above relationships. Here we analyze

20 years of daily rainfall data for Punakha, to determine any patterns in the onset and duration

of monsoon from 1990-2014. After a thorough analysis assessing many possible criteria, the

onset of the monsoon was defined as the first date after 1 June when more than 40 mm of rain

occurred over a 10 day period. Similarly end of monsoon was defined as the first date after 1

September when accumulated rainfall over 10 days was less than 20 mm. The results are

presented in Table 3-3.

P a g e | 39

Table 3-3 Onset and duration of monsoon (1990-2013) using daily rainfall data for Punakha in

Bhutan.

The mean duration of monsoon over the 1990-2014 period was 96.8 days ranging from 62 to

135 days. The average start date of monsoon was 16 June and the average end date of

monsoon was 15 September. There appears to be increased variability in the onset and duration

of monsoon particularly since 2005 with the shortest duration occurring in 2005 and 2012.

The effect of ENSO on the monsoonal onset, duration and rainfall amount in Punakha are shown

in Figure 3.4. The strongest relationship is between monsoon rainfall amount (duration) and

ENSO phase. There appears to be more rainfall in El Niño phases and a slight trend towards

longer duration. Interestingly, across Bhutan as a whole, the 2006 El Niño was a drought year

(Khandu 2015); however as shown in the data from Punakha, 2006 was an anomalously wet

year. Our analysis shows that the drought actually occurred in 2005 with the shortest monsoon

duration (see also section 4.2.1). Perhaps 2006 is incorrectly attributed as a drought year using

crop statistics in 2006 which actually reflects the 2005 production data.

Start date End date Duration (days) Difference from mean (days)

1/06/1990 4/10/1990 125 28

10/06/1991 21/09/1991 103 6

26/06/1992 27/09/1992 93 -4

1/06/1993 3/09/1993 94 -3

3/06/1994 16/09/1994 105 8

9/06/1995 18/09/1995 101 4

27/06/1996 15/09/1996 80 -17

29/06/1997 1/09/1997 64 -33

10/06/1998 12/09/1998 94 -3

1/06/1999 14/10/1999 135 38

18/06/2000 14/09/2000 88 -9

1/06/2001 6/09/2001 97 0

11/06/2002 24/09/2002 105 8

1/06/2003 11/09/2003 102 5

1/06/2004 12/09/2004 103 6

30/06/2005 1/09/2005 63 -34

1/06/2006 10/10/2006 131 34

3/06/2007 21/09/2007 110 13

12/06/2008 21/09/2008 101 4

1/06/2009 8/09/2009 99 2

29/06/2010 29/09/2010 92 -5

20/06/2011 1/09/2011 73 -24

24/07/2012 24/09/2012 62 -35

1/06/2013 13/09/2013 104 7

Average Duration (days) 96.8

La Nina El Nino Neutral

P a g e | 40

Figure 3-3. Relationship between monsoon duration and climate drivers. The amount of rainfall

(mm) is indicated by the size of the circles and is positively correlated to monsoon duration (R =

0.0483 D +71.62 ; R2= 0.43). Daily rainfall data for Punaka 1990-2014.IOD time series from

www.jamstec.go.jp/frgc/research/d1/iod/DATA/dmi.monthly.txt.

The influence of the IOD on the onset and duration at Punakha was more difficult to assess as

there have only been 2 negative IOD events since 1990 (Figure 3.4): 1992 which was a neutral

ENSO phase and 1996 a La Niña. These 2 years have slightly shorter and drier monsoons. It is the

La Nina events in positive IOD years that have the shorter monsoons, and the El Niño and

neutral ENSO events in positive IOD years that have the longer wetter monsoons (Figure 3.4).

This is different to the Pervez and Henbry (2015) study which suggests that there is little effect

when an El Niño occurring with a positive IOD (using gridded rainfall for the period 1901-2010).

In summary, southern Bhutan has greater inter-annual rainfall variability than central/northern

regions. There is variability in different aspects of the monsoon rainfall including the total

amount of rain, the onset and duration of the monsoon period, and also the frequency and

length of active and break periods within the monsoon period. The relationship of these

monsoon parameters with ENSO provides confidence in the prospects of seasonal predictions

and risk assessments.

LONG TERM TRENDS AND CHANGES IN RAINFALL RISK

-40

-30

-20

-10

0

10

20

30

40

50

-0.60 -0.40 -0.20 0.00 0.20 0.40 0.60 0.80 1.00

Mo

nso

on

du

rati

on

(an

om

alo

us

day

s)

IOD

Relationship between monsoon duration, ENSO and IOD

El Niño

La Niña

Neutral

http://www.jamstec.go.jp/frgc/research/d1/iod/DATA/dmi.monthly.txt

P a g e | 41

Although the rainfall data from Bhutan is not long enough to draw significant long-term trends,

trends have been identified in regional neighbours such as Nepal and NE India. In NE India

annual and seasonal rainfall between 1971-2007 has either decreased or has had no trend,

depending on the specific location (Patle and Libang 2014). There have been no increasing

trends in annual or seasonal rainfall.

For longer time periods decreasing trends in monsoon rainfall have been observed

(Krishnakumar et al.2009, Choudhury et al.2012, Kothyari and Singh 1996). Most studies find

post-monsoon rainfall has increased but the level of statistical significance varies. For rain-fed

agricultural systems the post-monsoon rainfall is important for crop intensification and also the

fruit and vegetable production of the following winter season (Choudhury et al.2012).

There has been an increase in extreme rainfall frequency from 1951 onwards. From 1971-2000

extreme 1-day rainfall events in Nepal has increased (Shrestha 2005). However there is a

notable decrease in extreme events during the 2000-2007, a period when the monsoon was

weak.

TEMPERATURE RISK

Temperature varies significantly across different agro-climatic zones and time of the year

ranging from a minimum of -13oC to a maximum of 38.8oC. July and August are the warmest

months and January is the coolest month. In the south and eastern districts temperatures are

significantly warmer than the northern regions of Bhutan. Average monthly minimum,

maximum and mean temperatures for several agro-climatic zones of Bhutan are shown in Table

3-4. The seasonal temperature risk can be further examined by, for example, assessing the

seasonal distribution of monthly minimum and maximum temperatures for Punakha (Dry

Subtropical, Figure 3-4). In addition to the clear seasonal cycles, there is clearly a much stronger

seasonal cycle in the minimum temperatures; there is nearly a 20oC range between summer and

winter.

Although there is not a long enough time series to assess the long-term changes in temperature,

we can still assess changes since 1990, the starting point of our key stations. The analysis of

minimum and maximum temperature data (1990-2014) for six stations in different agro-climatic

zones show a difference in trend between minimum and maximum temperatures. At all

locations minimum temperature has decreased during this period; the largest decline is at

Mongar (-0.23oC or -0.01 oC year-1).

P a g e | 42

Figure 3-4 Monthly distribution of minimum and maximum temperature (oC) for Punakha in

central Bhutan

In general there is an increase in maximum temperatures in most agro-climatic zones with the

largest increase being in Mongar (0.25oC), Punakha (0.2oC) and Sipsu (0.14oC) over this period

(Table 3-4 and Figure 3-5). Bhur and Dagana Dzong , on the other hand show a decrease in

maximum temperatures of -0.26 oC and -0.022 oC respective

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