Estimation of Water Stress and Identification of Priority Areas for
Irrigation over the Drought Prone Semi-Arid Region of India
Abstract
Marathwada division of Maharashtra is one of the semi-arid regions of
India where the agricultural conditions are highly vulnerable to the
scanty rain and severe droughts. Over this area, significantly depleting
groundwater level and low amount of monsoon rains demands for a good
irrigation system for maximum crop cultivation and day-to-day
activities. Therefore, this study estimates the spatio-temporal water
and vegetation stress to make out the sensitive regions of Marathwada
where irrigation network is necessary. The area-specific water
requirement is based on the water demand for crops from that particular
area. The rate of Evapotranspiration (ET) with potential ET (PET)
directly represents the field-specific crop water demands, hence; to
understand their relevance we have analyzed the monthly ET and
Normalized Difference Vegetation Index (NDVI) by the data acquired from
Moderate Resolution Imaging Spectrometer (MODIS) for the period of 2001
to 2017. Water deficiency of particular region is highly dependent on
the rainfall vagaries of that area. Therefore, the monthly rainfall
product from Tropical Rainfall Measuring Mission (TRMM) was also
studied. Station based groundwater data, Soil profile, Land use land
cover etc. were the other datasets considered to prioritize the areas
for building the irrigation facilities. Study area as a whole, a
significant correlation was observed between ET and NDVI. Among the
eight districts of Marathwada, Latur, Parbhani Aurangabad and Hingoli
were the regions where higher water stress was noticed. On the temporal
scale (from last 17 years) maximum water scarcity was noticed over the
year 2002-2003 and 2014 -2015. Ensemble bi-decadal analysis of five
different drought indices with the aid of IMD observations shows water
stress as a proxy variable for drought monitoring. Hence the proven
correlation between ET, NDVI and water stress from this study, gives the
new interdisciplinary approach to deal with the drought hazards and to
priorities the drought-affected area which demands more concern.