Improved modeling of groundwater recharge in agricultural watersheds using a combination of crop model and remote sensing
Résumé
For improved water management and efficiency of use in
agriculture, studies dealing with coupled crop-surface water-groundwater
models are needed. Such integrated models of crop and hydrology can
provide accurate quantification of spatio-temporal variations of water
balance parameters such as soil moisture store, evapotranspiration and
recharge in a catchment. Performance of a coupled crop-hydrology
model would depend on the availability of a calibrated crop model for
various irrigated/rainfed crops and also on an accurate knowledge of soil
hydraulic parameters in the catchment at relevant scale. Moreover, such
a coupled model should be designed so as to enable the use/assimilation
of recent satellite remote sensing products (optical and microwave)
in order to model the processes at catchment scales. In this study we
present a framework to couple a crop model with a groundwater model for
applications to irrigated groundwater agricultural systems. We discuss the
calibration of the STICS crop model and present a methodology to estimate
the soil hydraulic parameters by inversion of crop model using both
ground and satellite based data. Using this methodology we demonstrate
the feasibility of estimation of potential recharge due to spatially varying
soil/crop matrix.