Assessment of satellite-based approach for the groundwater recharge
estimation in arid regions
Abstract
Estimation of aquifer recharge is a prerequisite for understanding
groundwater systems and sustainable water resources management. In arid
and semi-arid areas, where access to hydrologic data for groundwater
studies is often limited with spatial and temporal inconsistencies, data
collection is difficult. Therefore, in these regions satellite products
of meteorological data series have recently turned into the most
reliable alternative. This study presents a daily groundwater recharge
estimation in the NW part of the Lake Chad Basin using VisualBALAN, a
water-soil-plant distributed model, from two data sources (ground and
satellite-based meteorological data) under non-irrigated and irrigated
land. Precipitation and temperature data from ground-based gauge
stations and the Multi-Source Weighted-Ensemble Precipitation product
(MSWEP), was gathered for the years 2005-2014; average annual values
were 283 and 417 mm and 30 and 29 ℃ for gauges and for MSWEP,
respectively. The estimated mean annual aquifer recharge from
precipitation equals 10.9 and 14.7 mm/yr, while in irrigated areas was
33 and 41 mm/yr, for ground and satellite-based data, respectively,
being always slightly higher for the satellite estimates. Sensitivity
analysis was performed to assess the dependency of input data in final
recharge. Recharge estimates were mainly sensitive to soil type, soil
parameters such as field capacity and wilting point, and to surface
hydrology-related parameters such as curve number.