Low-cost approaches to problem-driven hydrologic research: The case of Arkavathy watershed, India.

Tuesday, 16 December 2014
Veena Srinivasan1, P. Narayan Ballukraya2, Kirubaharan Jeremiah1 and Apoorva R1, (1)Ashoka Trust for Research in Ecology and the Environment, Bangalore, India, (2)University of Madras (Retd), Applied Geology, Chennai, India
Groundwater depletion is a major problem in the Arkavathy Basin and it is the probable cause of declining flows in the Arkavathy River. However, investigating groundwater trends and groundwater-surface water linkages is extremely challenging in a data-scarce environment where basins are largely ungauged so there is very little historical data; often the data are missing, flawed or biased. Moreover, hard-rock aquifer data are very difficult to interpret.

In the absence of reliable data, establishing a trend let alone the causal linkages is a severe challenge. We used a combination of low-cost, participatory, satellite based and conventional data collection methods to maximize spatial and temporal coverage of data.

For instance, long-term groundwater trends are biased because only a few dug wells with non-representative geological conditions still have water - the vast majority of the monitoring wells drilled in the 1970s and 1980s have dried up. Instead, we relied on “barefoot hydrology” techniques. By conducting a comprehensive well census, engaging farmers in participatory groundwater monitoring and using locally available commercial borewell scanning techniques we have been able to better establish groundwater trends and spatial patterns.