1. manoj ecosystem services apafri workshop on forest hydrology

ASSESSING WATER REGULATORY

SERVICES PROVIDED BY FORESTS OF

UTTARAKHAND: PROPOSED META-

MODELLING FRAMEWORK

*Manoj Kumar1, MP Singh1, Hukum Singh1, Peter A Khaiter2

1Climate Change & Forest Influence Division

Forest Research Institute

PO : New Forest, Dehradun – 248 006, India

2School of Information Technology, The Faculty of Liberal Arts and

Professional Studies, York University, TEL Building # 3044, 4700 Keele

Street, Toronto, Ontario M3J 1P3, Canada

*Email: [email protected], [email protected]

Water Regulatory Services by Forests

Role of land cover in regulating runoff and river

discharge: Provides natural irrigation, drainage,

channel flow regulation, and navigable transportation

Filtering, retention and storage of fresh water:

Provision of water for consumptive use (both quality

& quantity)

(Source: Earth Economics 2013)

Forest goods and services in few studies in India

3

(Source: NPV Report , MoEF, 2013)

2013

Water Regulatory Services

The 2006 NPV Expert Committee refers to the value of

watershed services which included the value of soil

conservation along with hydrological services from secondary

site-specific studies. (NPV Expert Committee Report, MoEF,

govt. of India, 2013)

The review report of NPV suggests that the methodology for

valuation of water regulatory services from forests is still

evolving


The data for average weight of soil per hectare was obtained from

the Forest Inventory data of FSI (FSI 2013). Conservatively

assuming that the in absence of forests, the entire soil will take 100

years to erode, annual soil erosion rates have been estimated have

for all VDF category of all forest type groups. Recognizing the fact

that the capacity of forests to prevent soil erosion depends on a

significant extent to the canopy of forest cover through which

precipitation is intercepted , relative weights for different canopy

density classes have been calculated to estimate their ability to

avoid soil erosion. Based on these relative weights, estimate of soil

erosion prevented has been calculated for the remaining forest

canopy density classes. The quantity of annual soil erosion

prevented by forests is thus estimated for all forest type groups and

canopy cover density classes.


While site-specific estimates for run-off rates as a percentage of

precipitation doesn’t exist for the different forest canopy cover

density classes.

On account of lack of any information to provide estimates for

different forest type groups or canopy cover density classes, the

study by NPV expert committee proposed to use a blanket

estimate of Rs. 2950/ha/year as the economic value of water

purification services for all forest type groups and canopy

cover density classes.

ORIGIN AND NEED OF THE PROPOSAL

7

Updated reviews suggests removal of forest cover results in

higher total stramflow. (Bosch and Hewlett, 1982, Grip,

Fritsch and Bruijnzeel, 2005). These observation may often

mislead that removing forest will augment the water supply.

Many other services provided by forests viz. soil erosion

control, improved water quality Carbon fixation, and the

continuous flow of other forest products suggest for

estimating these services more scientifically with due care.

Role of forests in regulating the global water cycle and global

climate can never be overlooked.

Continued…

Origin and need of the proposal

8

To ensure optimum water quality we need some framework

for its assessment based on actual field observation through

site specific experimental set up and developing suitable

model for simulation under assumed scenarios.

Forest management in the watershed catchments need

scientific basis rather than any misperception.

Different associated services are bound to vary with the

percent removal of the forests, so the question lies what is the

optimal forest cover for a sustained yield of different services?

We propose a meta-modelling framework for the assessment

of water regulatory services provided by forests of

Uttarakhand.

Continued…


Uttarakhand is an Indian State lying in the Himalayan

topography. Most of its area, covering almost more than

ninety percent, is hilly terrain with nearly sixty five percent-

forest cover. People of the region and majority of downstream

population are dependent upon the surface and subsurface

waters retained and transformed by the regional forests.

Therefore, the surface and sub-surface water flows and their

quality, formed on the forested watersheds of the State, need

to be monitored for addressing various forest management

practices and their associated impacts upon the hydrological

regime.

Continued…


There have been several studies undertaken world-wide for

measuring the regulatory services provided by forests on the

watershed areas. However, every forest service varies from

region to region and thus it may not be justifiable to

mechanically transfer the values received in those studies onto

the forests of Uttarakhand. The attempts to evaluate the various

services, including water regulatory services of Uttarakhand,

have often been made by simply multiplying the dollar values

of unit forest area by the total forest cover area of the region.

We propose a meta-modelling framework for the assessment of

water regulatory services provided by forests of Uttarakhand.

Continued…


Theoretical understanding of hydrological processes and resulting

water balance for the forests of Uttarakhand can be achieved by

conducting experimental observations on long- term basis for

different forest types of the State. Monitoring of water flow to

calculate crown interception, evaporation from snow and water,

snowmelt, water release from snow, freezing and thawing of soil-

grounds, infiltration, formation of all kinds of runoff, and

transpiration together with the monitoring of water quality is

suggested for different kinds of forest cover based upon species,

crown density, area and age class.

Simulation and Modelling

Economic Assessment

Management/Control

Meta modelling framework

Conceptual framework for simulating water flow

Methodological Approach

In order to quantify the water regulatory services provided by

forests of Uttarakhand, it is necessary to compare the components

of the water balance in an experimental paired watershed.

However, to compare the results it will require felling of trees to

compare the results for different densities of forests over a time,

often a very long duration.

To overcome these methodological difficulties, simulation

modelling approach will be adopted. Simulation will be done for

the forests of Uttarakhand after obtaining the desired

experimental values; for the simulation run, through a set of

experimental monitoring stations under different forest stands for

a considerable period.

Simulation Model for Uttarakhand Forest Hydrology

Simulation Model for Uttarakhand Forest Hydrology (SMUFH)

of the processes of water transformation in a forested watershed

simulates the processes of forest hydrology, and calculates crown

interception, evaporation from snow and water, snowmelt, water

release from snow, freezing and thawing of soil-grounds, infiltration,

formation of all kinds of runoff, and transpiration. The model

simulates the values of the water balance components, and provides

a quantitative assessment of the hydrological service of the forest.

The SMUFH represents the distribution of precipitation using the

following water balance equation:

PR = EVC + EVF + EVS + QSUR + QSUB + TR + ∆SM + QGR


Where,

PR = Precipitation

EVC, EVF, & EVS = Evaporation from canopy, floor and soil

respectively

QSUR, QSUB = Surface and Subsurface fluxes, respectively

TR = Transpiration

ΔSM = Variation of soil moisture content

QGR = Water recharge to the groundwater table

Continued…

The modelling of water transformation in the SMUFH will be

calculated at three levels (or hydrological niches as proposed by

Voronkov, 1988): 1) Tree crown, 2) Forest floor, and 3) Soil layer of

a given thickness, Z. The balance condition should obviously be

satisfied for each of the hydrological niches:

k

j

k

i

j

i

j

OUTINCdt

dM

Continued…


Where j denotes a hydrologic niche (j = 1, 2, 3); Wj is the water

contents in the jth hydrological niche; t is the time variable;

and are the i th incoming water balance item and

k th out coming water balance item, respectively, for the jth

hydrological niche.

Continued…


)()()(

)()()(

1

tQtQtSM

tQtQtSMQUSE

o

GR

o

SUB

o

T

t

f

GR

f

SUB

f

In order to quantitatively assess the hydrological service of forest,

it must be formally defined. It could be expressed through the

positive influence of forest vegetation on both the richness of

stream flows and the soil moisture content. Given that

traditionally in hydrology, all items from the water balance are

considered as positive (or useful) ones, except for losses to

evapotranspiration and surface runoff, a formalization of the

notion of the hydrological service of a forest and its estimation

ΔQUSE was proposed (Khaiter, 1993) in the form of the

following expression:

Continued…


The computer experiments with the SMUFH will be carried out for

the watersheds representing different forest tree stands and soil

types. The computed estimate of the hydrological service in this

simulation for watersheds will be added to obtain the total

hydrological services provided by forests of Uttarakhand. Two

extreme situations (i.e. forested vs. open watershed) will be

modelled and compared in the simulations. In terms of the forest-

management practices, such a transformation corresponds to

complete clear cutting. Obviously, anthropogenic activities of forest

management will lead to any intermediate scenarios.


Continued…

Forest management interventions will be considered for the

change in soil density; SD, and percent of forested area, F% (i.e.,

SD = SD (u(t)) and F% = F% (u(t)). These two factors will be

used in the building of the response surface, approximating the

data generated by simulation experiments. As a result, the

response function will be obtained to estimate the hydrological

service provided by forests of Uttarakhand.


Continued…

Recommendations

Forest ecosystems generate various services and benefits which are

altered with intervention of forest management practices. For

various practical needs of sustainable management, it is important to

predict and quantify the possible changes in the ecosystem services

such as hydrological regime of a given watershed as a result of

anthropogenic activities. Model will help to estimate the ecosystem

services under different forest management scenarios in advance

before actually perturbing the forests. We have discussed the

estimation of hydrological regulatory services through simulation

model. Similar models are obviously needed to quantify all other

forest ecosystem services and goods which can be applied for

addressing sustainable forest management practices.

Continued…

THANK YOU

1. manoj ecosystem services apafri workshop on forest hydrology

Education

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