Springshed Management Training Curriculum · Springshed development: the scientific process •...
Transcript of Springshed Management Training Curriculum · Springshed development: the scientific process •...
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Springshed Management Training Curriculum
2016The Springs Initiative
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SESSION TITLE:
Hydrogeology of Springs
SECTION: Understanding the ResourceMODULE: Applied HydrogeologyAUTHORS: Dr Himanshu KulkarniCONTRIBUTING ORGANIZATIONS: AcwadamPURPOSE: To introduce the science of groundwater, geology and hydrology in context of springs IMPACT: Participants understand how springs are formed and what distinguishes them from other groundwater or watershed applicationsTIME REQUIRED: 60-100 minutesMATERIALS: This pptADDITIONAL RESOURCES:
Springshed Management Training Curriculum, Draft 2
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SESSION TITLE:
Hydrogeology of Springs
Overview• Groundwater, importance/dependence• Water cycle review• Relation to watershed management• Aquifers & groundwater in watersheds• Looking below the ground – rock type, structure• Discharge, relating to aquifer characteristics• Source versus resource• Springshed management approach• Hydrogeology as decision support
Springshed Management Training Curriculum, Draft 2
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Global groundwater scenario
www.unesco.org
Groundwater is the world’s most extracted raw material with withdrawal rates currently in the estimated range of 982 km3 /year
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Global groundwater abstraction
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The water cycle…also called hydrologic cycle
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Groundwater is a resource…
• It is a part of a larger system of water resources…the hydrological cycle.
• It is also a part of the larger system of earth resources…THE ENVIRONMENT.
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HYDROSPHERE
LITHOSPHERE
PEDOSPHERE
ATMOSPHEREBIOSPHERE
The environment includes spheres and processes
Precipitation
Infiltration
Transpiration
Percolation
Base flows
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Watershed management
• Recharge to groundwater
• Control surface runoff
• Conserve and recharge groundwater
• Water security
Watershed management is an integrated effort where rain water is conserved, recharged and harvested.
HYDROSPHERE
LITHOSPHERE
PEDOSPHERE
ATMOSPHEREBIOSPHERE
Base flows
Percolation
Precipitation
Transpiration
Evaporation
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Why watershed management?
• Overexploitation of natural resources like• Water
• Soil
• Forest
• Scarcity of water
• Degradation of soil
• Soil erosion
• Frequent flash floodsWatershed management implies to the wise use of soil and water resources.
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Hydrological processes…rivers
UPSTREAM
DOWNSTREAM
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Hydrological processes…rivers and reality
UPSTREAM
DOWNSTREAM
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Watershed approach
Contour trenching, Bunding, CCT, Gabion structures
Check dams,Loose boulder check, percolation tank
Wells, farm ponds
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So, where are the aquifers in this watershed??
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Spring
Spring
Spring
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Hydrogeology helps strategise recharge
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Springs and aquifers: discharge trends –annual cycle
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Apr/15 May/15 Jul/15 Sep/15 Oct/15 Dec/15 Jan/16 Mar/16 May/16 Jun/16
Spring 1 Spring 2 Spring 3 Spring 4
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Describing a spring based on its discharge
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160
Apr/15 May/15 Jul/15 Sep/15 Oct/15 Dec/15 Jan/16 Mar/16 May/16 Jun/16
Spring 1
Spring 2
Spring 3
Spring 4
Low discharge, highly seasonal
High discharge, perennial
Sustained perennial discharge
Widely ranging discharge
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Spring discharge: accumulation and flow in underlying aquifers
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Apr/15 May/15 Jul/15 Sep/15 Oct/15 Dec/15 Jan/16 Mar/16 May/16 Jun/16
Very limited storage, highly local and seasonal connection to surface water
Large storage, rapid flow
Slow flow, moderate to large storage
Low storage, quick transmission, connection to seasonal surface water source
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Spring discharge: mostly likely aquifer types
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Apr/15 May/15 Jul/15 Sep/15 Oct/15 Dec/15 Jan/16 Mar/16 May/16 Jun/16
Very local aquifer
Unconfined / confined
Mostly unconfined
Confined
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Indicator matrix
Recharge zone - proximity to spring
Recharge zone - size
Spring 3 Could be either closeby or far away (large aquifer storage)
Large
Spring 2 At distance Small
Spring 4 At distance (moderate to low transmissivity)
Large
Spring 1 Very close Small, probably negligible
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0
100
200
300
400
500
600
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800
900
10000
50
100
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200
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400
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Rainfall (Melli)
PALLO DHARA
SAUNEY DHARA 1
DAHAL DHARA 1
DWAREY DHARA
…so are springs tapping mountain aquifers
Credit: Mr. Suren Mohra, RM&DD-Sikkim
Baseline= 90 lpm
Impact= 97 lpm
8.33% increase over
the whole year
Baseline= 9.5 lpm
Impact= 10.5 lpm
10.6% increase over
the whole year
Baseline= 16.5 lpm
Impact= 18 lpm
8% increase but over
300 days
Baseline= 11 lpm
Impact= 13 lpm
17% increase but over
80 days
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Movement of water from the atmosphere to great depths…
HCO3
HCO3+ SO4+Na+Mg
Na + Cl
Anion change HCO3 SO4 Cl
Cation change Ca Mg Na
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An “exposed” aquifer…
Springs! But what else??
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?
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The aquifer feeding the springs
Morraine
Clay
Aquifer
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Spring and a well : what is common ?????
AQUIFER
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SourceUsers and uses share a common resource even through different types of sources…
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AccessAccess in many areas is through “common” sources…
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DistributionDistribution is usually about connecting to a source and supplying to an increasing demand…
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What is groundwater?
Groundwater is the water found underground in the cracks and spaces in soil, sand and rock. It is stored in and moves slowly through geologic formations called aquifers.
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What is Hydrogeology?
• Hydrogeology is the science of groundwater.
• It is a branch of geology.
• It is a science that deals with occurrence, movement and distribution of groundwater within the geological framework of rocks.
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GEOLOGY plays a very important role in the formation of aquifers, and consequently, on the accumulation and movement of groundwater..
Geological conditions tend to vary, both laterally and vertically…
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An aquifer is very much like an underground watershed
• Aquifer catchments are areas from where aquifers receive recharge, i.e. groundwater recharge areas or zones.
• Aquifer commands are areas where aquifers send groundwater, i.e. groundwater discharge areas or zones.
• Aquifers are defined by:• Physical (impermeable /
permeable boundaries)• Hydraulic boundaries (constant
/ fluctuating water tables)
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Natural recharge
That part of the rainfall (or any other natural precipitation) that infiltrates the ground surface under natural conditions leading to an addition to the groundwater storage, is called NATURAL RECHARGE. It may also be through:
• Direct infiltration through the soil over the whole or part of a watershed.
• From a ponded stock of water.
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Artificial recharge• Sometimes, rainfall is collected
artificially and channeled into the aquifer by artificial means. This addition is called artificial recharge. ARTIFICIAL RECHARGE maybe:
• Diffuse: Large pondage is created and recharge occurs through large surface areas.
• Point source: Recharge occurs at specific locations (points) where surface water / rainwater is channeled into wells or bore wells or tube wells (or infiltration pits).
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Discharge of groundwater
• Natural: Springs and seeps (baseflow to streams)
• Pumping from wells
• Deep infiltration
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Springs and aquifers as commons
Spring is a natural discharge point and its location is irrespective of type of land
Similarly aquifer boundaries also are irrespective to land
type but governed by
local hydrogeology
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Springshed development : a hydrogeological approach
Drinking, domestic use,
irrigation, industry etc…
Increasing demand and the
changing climate pattern
Hydrogeology as the base
Spring water used for drinking purpose
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Springshed development: conflicts, challenges and
community participation
Lack of data
Lack of awareness of utility of
such data
Geological or aquifer
boundaries rarely coincide
with administrative or
socio-economic boundaries
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Springshed development: the scientific process
• Hydrogeological mapping of springshed
• Classification of the spring
• Secondary data collection and interpretation
• Identification of recharge area based on local geology and
structure
• Setting up a monitoring system for periodic spring discharge,
rainfall and water quality data collection
• Delineation of the mountain aquifer
• Planning of treatment measures in the recharge area with the
help of community participation
• Conceptual layout of spring
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Springshed development: the final product
A Google image
A geological layout
A Geological map created using
Google image as the base
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Springs and its recharged areas marked on a Google image
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Use of Hydrogeology in decision support system
Muthalane in Pune district
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Aquifer IStorage: 67200 m3
Aquifer IIStorage: 1179200 m3
Aquifer IIStorage: 50000 m3
Aquifer storage= Aquifer area * Thickness * Specific yield
Randullabad in Satara district
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Demand-supply management
Randullabad
Rainfall (mm) 600-700
Annual aquifer storage (mm) 151
Annual aquifer recharge(mm)
53
Annual aquifer discharge(mm)
62
Drinking water<1%
Water for livestock<1%
Water for Poultry<1%
Water for domestic use2%
Water for Kharif 17%
Water for Rabi irrigation
81%
Water demand in Randullabad
Efficient use of waterEquitable use of drinking water
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Crop planning in Randullabad
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Strengthening drinking water sources N
Geological cross section
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Geohydrological mapping
Community dialogue
Primary and secondary data collection
Capacity building and communication
Water quality investigation, including past data andHealth data surveys
Estimate groundwater resources availability under various scenarios
Participatory decision making system