Impact of agriculture water management interventions on hydrological
processes in a fragile watershed of Western India
Abstract
Water management interventions play an important role in ensuring
sustainable food production and mitigating climate risks. This study was
carried out in a watershed located in low rainfall (400-600 mm) region
of western India. The paper analyses the changes in hydrological
processes with the implementation of various rainwater harvesting (RWH)
interventions using field measurements and SWAT simulation. The model
was calibrated using the runoff gauging, storage levels, soil loss and
groundwater measurements between 2000 and 2006. Various agricultural
water management interventions have helped to enhance groundwater
recharge from 30 mm to 80 mm, reduced surface runoff from 250 mm to 100
mm and enhanced base flow. The structures were filled 2 to 3 times
depending on rainfall variability and total precipitation. The RWH
interventions were found to build system resilience by enhancing
groundwater availability even in dry years, which was the main reason
for crop intensification and protected the landscape from heavy erosion.
Sediment erosion reduced more than 75 percent compared to
non-intervention stage. Moreover, 100-150 ha fallow land was brought
under cultivation with high value crops such as horticulture, vegetables
and fodder. The household income increased manifolds compared to
non-intervention stage. The study showed about 50 percent reduction in
downstream water availability, which could be the major concern.
However, there are number of ecosystem trade-offs such as improved base
flow and reduction in soil loss. The study is useful for larger scale
decision making about optimal water harvesting for achieving sustainable
development goals.