THE ESTIMATION OF GROUNDWATER EXCHANGE IN AYDARKUL−ARNASAY LAKE SYSTEM BY A LAKE WATER BALANCE MODEL

Abstract

In this paper, a unique lake water balance (LWB) has been proposed as a key component for the sustainable groundwater (GW) management in arid/semi arid region, particularly in Aydarkul-Arnasay Lake System (AALS), Uzbekistan. The uniqueness of LWB here is by incorporating GW distribution and its interaction. Meanwhile, the evaporation is also locally trimmed for arid/semi arid area. It is a monthlybased calculation by introducing the lake surface area as function of observed lake water level. The result shows that from March to July, GW recharge is higher than GW discharge as indicated by positive GWexchange ranging from 0.13 to 0.83 km3/month. From August to February, GW discharge is higher than GW recharge (a negative GW-exchange). It’s about -0.05 to -0.51 km3/month. Verified with the observed data, this approach seems to serve as a reliable method for the reconstruction of GW-exchange into/out from the lake as well as useful information towards the sustainable GW management.