Spatial and Temporal Variation of Water Stress in Bharathapuzha River Basin, Kerala, India

Water scarcity was caused by many factors such as increase in demand of water, decrease in water availability and poor water quality. Bharathapuzha river basin in Kerala was taken for the study as it faces acute water stress during summer months. The water stress was calculated using two indicators: the Falkenmark’s water stress indicator (WSI) and blue water scarcity indicator based on blue water footprint (BWSI). In water stress indicator based on water footprint, three sectors: domestic, industrial and agriculture were considered. Water stress was calculated for 3 decades 1982–1991, 1992–2001 and 2002–2011. Using Falkenmark’s WSI absolute scarcity was increased from zero to 238.8 km 2 and water scarcity from 874 to 1584.27 km 2 in the decades. However, BWSI showed severe water scarcity in 873 km 2 of area in all decades. This region falls on eastern side of the river basin. Comparing the results of the two indicators shows that two subbasins face severe water stress by using both the indicators. This study will help the planner to design proper water conservation measures to alleviate the water scarcity. © 2018, The Institution of Engineers (India).