Name Enrollment No.Patel Jimi 131100106029

Patel Viraj 131100106040Patel Yash 131100106042

Shah Ashit 131100106051

DROUGHT MANAGEMENT AND WATER HARVESTING

Guided by :- Prof. Manali Shah Prof. Uttejana Chaudhari

CONTENT

• DEFINITION• TYPES OF DROUGHT• CAUSES OF DROUGHT• DROUGHT CONTINGENCY PLANNING• AUGMENTATION OF WATER • MEASURES FOR WATER CONSERVATION• WATER HARVESTING

DROUGHT

• Drought Is Generally Defined As A Prolonged Period Of Time During Which Precipitation Is Less Than 75 Percent Of Average For A Given Year, Or Poor Distribution Of Precipitation In A Single Year Or Less Than Average Precipitation In Successive Years.

TYPES OF DROUGHT

• These Has A Basically Four Types, Likes..1. Meteorological Drought2. Agricultural Drought3. Hydrological Drought4. Socioeconomic Drought

i. METEOROLOGICAL DROUGHT

• “It deacribes A situation where there is A reduction in rainfall below a specific amount for specific period (days, months, year).”

• On an average India receives 118 cm annual rainfall which is considered to be highest anywhere in the world for the country of comparable size.

• But the uncertain, unreliable & erratic nature of rainfall by south-west monsoon create a Drought condition in different parts of country.

ii. HYDROLOGICAL DROUGHT

• Hydrological drought is associated with reduction of water.• There are two type :-

Surface water Drought o It is concerned with drying up of surface water resources such as rivers, streams, lakes,

ponds, tanks, reservoirs etc etc… Ground water Drought

o It is associated with the fall in the ground water table.

iii. AGRICULTURAL DROUGHT

• Agricultural drought are droughts that affect crop production or the ecology of the rang.

• Agricultural drought links various characteristics of Meterological drought, Hydrological drought to agricultural impacts.

• Focus on …Precipitation shortageDifference between actual & potential EvaporationSoil water deficitsReduce Ground water/reservoirs levels

iv. SOCIOECONOMIC DROUGHT

• When the supply of some Good & Services such as water and Electricity are Weather dependent then Drought may cause shortages in supply of these economic goods.

CAUSES OF DROUGHT

oPrecipitation deficiency

oDry season

oMountains

• Mountains can prevent wind from blowing moisture to needy regions.

Rainy areaArea affected by Drought

Mountain

oErosion & Human Activities

• Human activities can directly trigger exacerbating factors such as..• Over farming• Excessive irrigation• Deforestation

• Erosion adversely imopacts..• The ability of the land to capture & hold the water.

oClimatic Changes

• Drought occur because water vapor is not brought by air current to the right areas at the right time.

• Instead of blowing air from south to north, they blow east to west . when that happen, the water vapor does not leave the Indian ocean and many people suffer from the resulting drought.

oGlobal warmings

• It will result in increased world rainfall along with drought in some areas, flooding & erosion will increase in others

DROUGHT CONTINGENCY PLANNING • To provide contingency plans to manage drought and

emergency conditions.• To continue to deliver a cost effective, adequate, safe and

reliable supply of water.• The provision of credit or cash/food for work• Maintaining water supply for animals and humans• Maintaining cereal availability• Human and livestock health service provision• Support for private sector• Provide fodder for drought affected stock• Flexible taxation systems for affected people

o DROUGHT CONTINGENCY PLANNING ALLOW FOR IMPLEMENTATION OF :

• Mitigation

• Relief

• Rehabilitation

oDROUGHT CONTINGENCY PLANNING FOR IMPLEMENTATION:

Overall drought policy, setting out plans objectives of minimizing the impact of drought

Set plans for specific mitigation, relief and rehabilitation measuresConstruction of dams and additional reservoirs for supply of water.Cloud seeding- artificial rainDesalination of sea water for irrigation or consumption.

• Drought monitoring by total rainfall levels and total usage levels• Land use by carefully planned crop rotation• Outdoor water use restriction• Rainwater harvesting• Recycled water• Relief works• Disease prevention and control

• CONTINGENCY PLANNING DONE BY GOVT. POLICY ISSUES, NATIONAL, REGIONAL AND DISTRICT LEVEL RURAL DEVELOPMENT INFRASTRUCTURE INPUT SUPPLY, MARKETING AND FARM ADVISORY SERVICES

• NON- GOVT.NGO’SRURAL INSTITUTIONSPRIVATE SECTORS

AUGMENTATION OF WATER

It includes methods for providing an entirely new supply of fresh water and techniques for increasing utility of available supplies of water.

New supply of water include weather modification.

Weather modification done to increase precipitation and decrease evapotranspiration.

Cloud seeding done to increase precipitation.

AVAILABLE WATER SUPPLIES INCREASED BY CONSERVATION OF AVAILABLE WATER SUPPLIES.

• Agricultural water requirements can be reduced by reducing conveyance losses, and discouraging wasteful irrigation techniques.

• Technique should be developed to reduce water consumption in home and industry.

• Evaporation losses from small reservoirs can be reduced by providing roofs.

• Reclamation and reuse of waste water can be encouraged.

• Evaporation loss in ground water is less. Use of ground water storage reservoir in conjunction with surface storage reservoirs.

• Infiltration losses can be reduced by sealing the soil surface useful in arid regions.

• Water harvesting done by collecting from roof top, pavements, constructing small storage.

MEASURES FOR WATER CONSERVATION

oGOALS OF WATER CONSERVATION EFFORTS INCLUDE:

• SUSTAINABILITY - ENSURE AVAILABILITY FOR FUTURE GENERATIONS

• ENERGY CONSERVATION - WORLD 15% ENERGY PRODUCTION DEPENDENT ON WATER MANAGEMENT.

• HABITAT CONSERVATION - PRESERVE FRESH WATER HABITAT, MIGRATING WATERFOWL.

oBENEFITS OF WATER CONSERVATION:

• SAVE WATER SAVE MONEY.

• REDUCTION IN EXCESS WATER USE REDUCE WASTE WATER GENERATION, REDUCE OVERFLOWING OF GUTTER.

• ECOSYSTEM AND HABITAT PROTECTION.

• HELPS IN IMPROVING QUALITY OF DRINKING WATER.

oWATER CONSERVATION MEASURES BY:

• DOMESTIC CONSERVATION

• INDUSTRIAL CONSERVATION

• AGRICULTURAL CONSERVATION

DOMESTIC CONSERVATION

• Repair all leaks quickly• Turn off water when not in use• Use conserving appliance which use low volume water for domestic use• Local bodies should install water meter and encourage water pricing.• Only flush the toilet when needed

INDUSTRIAL CONSERVATION

• Use cooling system which use less water.

• Reuse of cooling water for irrigation or other purposes.

• Install in plant treatment measures for treating the waste water or effluent.

AGRICULTURAL (IRRIGATION) CONSERVATION

• Improved irrigation methods such as sprinklers or drip irrigation.

• Water required for agricultural considerably reduced by reducing conveyance loss.

• Infiltration losses reduced by sealing soil surface

• Use of lined canals which reduce seepage and evaporation.

• Use of ground water storage reservoir in conjunction with modern surface storage reservoirs to reduce evaporation loss, in arid regions.

• Price agricultural water to encourage conservation.

• Evaporation losses from small reservoirs can be reduced by providing roofs over them.

o For conservation of water the following structures can be constructed:

• Earthen bund • Gully plugging

• Check dam

• Khet Talawadi

WATER HARVESTING

• Collection of rain water called water harvesting.

• Rainwater harvesting is accumulation and storing of rainwater for reuse, before it reaches aquifer.

• Water collected from roofs of houses, schools, local institutions make important contribution.

• Water collected from ground, called storm water harvesting.

BENEFITS OF RAINWATER HARVESTING

• Increase water availability

• Checks declining water table

• Environmental friendly

• Improves water quality of ground water

• Surface water runoff conservation

• Prevents soil erosion and flooding in urban area

• Improving plant growth by using rainwater for irrigation

o RAINWATER HARVESTING TECHNIQUE

1. Rainwater Collection (Roof Top Rainwater Harvesting)

2. Runoff Collection (Surface Runoff Harvesting)

3. Recharge To Ground Water

4. Runoff Enhancement

ROOF TOP RAIN WATER HARVESTING

• Rainwater captured from roof catchments and stored in sub surface ground water reservoir.

• Objective :- To make water available for future use.

• Useful in dry land, hilly, urban and costal areas.

o COMPONENTS OF ROOF TOP RAINWATER HARVESTING

1) A Collection Area

2) A Conveyance System

3) Storage Facility

4) A Delivery System

• Storage reservoir expensive part, careful design and construction required.

• First rainwater should be flushed or diverted.

SURFACE RUNOFF HARVESTING• Surface runoff harvesting is traditional technique.

• Small dams, ponds, tanks are used.

• Used for irrigation, domestic, livestock use.

SMALL DAMS

• Small dams/check dams constructed in natural channel to impound the runoff water up to certain depth.

• Impounded water slowly infiltrate into soil and recharge ground water.

PONDS AND RESERVOIRS

• Impounding type and dug-cut type ponds constructed.

• Impounding :- a retaining wall or dam is constructed to block the flow of water in a natural storm.

• Dug-cut :- area is excavated to store the runoff.

• Reservoirs requires water storage area, spillways and earth embankment.

STORAGE TANK

• Surface or above ground tank

• Subsurface or underground tank

Storage tanks require

• Solid secure cover

• Coarse inlet filter

• Overflow pipe

• Manhole, sump and drain to facilitate cleaning

• Outlet system, tap or pump

RECHARGE TO GROUND WATER

• Pits • Trenches

• Dug well & Hand Pump • Recharge Well

RUNOFF ENHANCEMENT Can Be Done By Increase Precipitation.Seeding Generally Done To Increase Precipitation.Precipitation Can Be Increased By 10% By Cloud Seeding.Lumb Demonstrated That Increase In Annual Runoff (∆R) Due To Small

Increase In Precipitation (∆P) Is Given By

∆R= ∆P (0.29+1.2 R/P)

where, R= Mean Runoff

P= Mean Precipitation

METHODS FOR RUNOFF ENHANCEMENT

• Cloud Seeding

• Enhancement By Paved Surfaces.

• Surface Of Drainage Basin Effect On Runoff. Bare Surface Give More Runoff.

• Drainage Basin Located On Windward Side Of Mountain Produce More Runoff.

• Runoff Affected By Geology Of Drainage Basin. Pervious Soil Yield Less Runoff.

• Drainage Basin Has Larger No Of Natural Depressions, Which Deposited By Other Material Then Runoff At Basin Increases.

• More Human Activity, More Load On Soil, Reduce Infiltration, Hence Increase Runoff.

REFERENCE

• GOOGLE IMAGE