A Geospatial Investigation of Water Availability and Water Stress in India Lorraine M. Beane Collaborators: Ellen M. Douglas, Stephen H. Boles, Charles J. Vörösmarty, Xiangming Xiao Supported by UNH EOS/NASA Research and Discover Program

Overview Rationale Goals Tools and Methods of Analysis Climate based data Remote sensing data Ground based data

RATIONALE

Previous Studies Vörösmarty et al (2003) study of geospatial indicators of water stress for Africa using river discharge, climatic indicators, and water demand Melloul and Collin (2002) water management and sustainable development of Israel's coastal aquifer Khazaei, Spink, and Warner (2003) estimating groundwater recharge in arid and semi-arid regions of Iran Vörösmarty et al (2000) the effects of climate change, population growth, and other human impacts on global water resources

Research and Water Resources in India India has recently become a focal point for hydrologic research India has been recognized as a country under water stress by UN agencies and many academic organizations Population is single largest contributing factor (>1 billion) Water stress is particularly evident in rural areas where 80% of drinking water and more than 50% of irrigation waters come from groundwater supplies (UNEP) India leads the world in total irrigated area Land irrigated by surface water doubled in area from 1950 to In same period of time groundwater irrigation increased 113-fold (Sampat, 2000)

Climate India’s climate is monsoonal –Two major periods of rain South-west monsoon from June and September affect the central region North east monsoon from October to November affect the northern and southern regions Average annual precipitation is 1.05 m Spatial and temporal distribution restrict utilization of precipitation as a source of freshwater

CMI Climatic moisture index (CMI) is defined as: PPT/PET–1 if PPT<PET OR 1–PPT/PET if PPT>PET where PPT is potential precipitation and PET is potential evapotranspiration Moist climates have positive CMI values while dry climates have negative CMI values Sub-humid Arid Semi-arid Humid Annual average CMI calculated from monthly data

Monthly CMI Monthly CMI data averaged from 1960 to 1995

Cropland and Climate Since most crops are grown in arid and semi- arid regions and most agriculture in India is irrigated instead of being rain fed, then a significant portion of freshwater resources are being used for irrigation Arid cropland Semi-arid cropland Sub-humid cropland Humid cropland Water Usage Agriculture Domestic Industry 87% 8% 5% (FAO-AQUASTAT)

Goals –To apply a method for identifying irrigated areas using remote sensing data to India –To delineate the source of irrigation (groundwater versus surface water use) –To evaluate sustainable versus unsustainable irrigation in India

Tools and Methods of Analysis

MODIS Moderate resolution imaging spectroradiometer NASA satellite Analysis of two tiles (H25 V06 and H25 V07) –1/1/02 to 12/31/02 –Spatial resolution of 500 m –Revisit time is daily –Eight day composite product Filtered for cloud coverage and permanent water bodies Converted to geographic projection H25 V07 on November 1, 2002 Indexes calculated to identify rice fields and irrigation patterns – Use combination of near IR, short wave IR, blue and red wavelengths to detect and enhance reflectance of water and vegetation

NDVI EVI LSWI Index Profile from Region of interest #8 H25 V06 and H25 V07 rice map composite Normalized difference vegetation index OR NDVI = (nir – red)/(red + nir) Land surface water index OR LSWI = (nir – swir)/(nir + swir) Enhanced vegetation index OR EVI = (2.5*(nir – red))/(nir + 6*red – 7.5*blue + 1) (Huete, A.R. et al, 1997) (Xiao, X. et al, 2002)

Irrigation and Agriculture Irrigated Agriculture Irrigated Intensive Agriculture Rainfed Agriculture Slope Agriculture Used Global Landcover 2000 (GLC2000) as a comparison to actual land cover More generalized picture of agriculture for all of India

Water Balance Q = 1261 km 3 /yr 1222 km 3 /yr becomes surface water 418 km 3 /yr becomes groundwater, with 380 km 3 /yr being shallow baseflow 418 km 3 /yr – 380 km 3 /yr= 38 km 3 /yr as deep recharge 1% of annual precipitation becomes recharge for deep aquifers FAO AQUASTAT:

Sources of Water Supply for Irrigation In some areas of India enough water is supplied by rivers and dug irrigation canals due to India’s extensive river network India’s river network

Irrigation Irrigation need = (PET – ET)/Irrigated cropland = 441 km 3 /yr countrywide for India –41% of average annual renewable freshwater is needed for irrigation –In 1995 water used for irrigation = 558 km 3 /yr 80 % efficiency 1995 irrigation water use In other areas groundwater is needed to supplement surface water to fulfill irrigation needs May lead to exploitation of groundwater resources Per km 2

Aquifers of India Aquifer Type Yield ( m 3 /d) Alluvium3500 Alluvium and sandstone 2100 Limestone1300 Crystalline1700 Basalt900 Hilly regions80 Unclassified

Summary and Conclusions –Freshwater supplies are not distributed evenly in India. There is substantial spatial and temporal variation of the CMI. –India is consuming more freshwater than is annually renewable in certain regions. The deficit is greatest in the Northwest where it is most arid and the population is densest. –The groundwater supply is spatially variable. We suspect that usage of groundwater as a supplement to surface water for agricultural use is not a sustainable practice in many areas. –Remote sensing data can be used effectively to identify flood irrigated crops and to show precise timing of large-scale irrigation events.

Future Work Careful mapping of domestic and industrial supply Groundwater and surface water inputs to obtain a better understanding of sustainability Incorporate aquifer map As an end-user of NDWI/EVI MODIS irrigation identification methods continue to apply and assess impact on water resources Complete retrospective analysis ( ) and future projections (present-2025) of water supply in India Refine study to higher resolution (6’)