Abstract:
Pilot command area of 7393 acres with a geographical area of about 40 sq. km under
distributaries D1 and D2 of its Left main canal under Talluru lift Scheme of Pushkar canal
system, located in the uplands of the Gandepalli and Jaggampeta mandals in Andhra Pradesh,
is studied for its hydrologic budgeting under changed land use conditions. Seasonal
groundwater balance has been carried out for study area. Groundwater flow model is
conceptualized based on land use, command area and lithology. Modelling is undertaken
using MODFLOW to simulate the impact of surfacewater irrigation on the groundwater
recharge in the command area. Simulated groundwater level scenarios over different
scenarios are analysed.
In this study on Pushkar Canal system the interaction of canal water and groundwater is
established using stable isotope characterization. The groundwater balance is carried out to
estimate the seasonal change in groundwater storages due to rainfall, tube wells and impact of
canal network in the study area. Also, a pilot area of D1 and D2 command area and its canal
system was setup over an area of 10 by 8 km using MODFLOW. Steady state simulations are
done for scenarios of 1980s, 1990s, with canal and with canal and increased pumping
(conjunctive use). Results indicate that the aquifer can be used as potential underground
reservoir to store surplus flows and to rejuvenate existing wells and to increase their yields.
IWRM plans in this direction may be useful in conservation and management of surface
water, canal water and groundwater in this upland command area.
