Analysis on the Changing Dynamics of Groundwater Level in the Lower Reaches of the Tarim River, Xinjiang

In this paper,the changing dynamics of groundwater in the lower reaches of Tarim River and thechange of inflow to the lower reaches are researched,and the influences of agricultural irrigation on the changingdynamics of groundwater and the response of desertification to the change of groundwater level before and aftertransfusing stream water to the lower reaches for saving the ecology are also analyzed.The results show that thegroundwater level in the lower reaches of the Tarim River was seriously dropped because the inflow from theupper and middle reaches to the lower reaches of the Tarim River was reduced for many years.In the Aragan andKorgan regions the groundwater level was dropped by 4~6 m in average before transfusing stream watercomparing with that in the 1950s.The volume of salt water drained from the irrigated areas and desalinization intothe Tarim River was significantly increased along with the rapid development of irrigated agriculture in the upperand middle reaches of the Tarim River,and the surface water quality and groundwater quality in the lowerbreaches was deteriorated.Thus,the vegetation composed of the forests of Populus euphratica,shrubs and herbswere seriously degenerated,and the desertification became more serious.The situation,however,is currentlyimproved after transfusing stream water to the lower reaches of the Tarim River,the groundwater level isincreased by 50% in average,the groundwater mineralization along the Yengisu section is dropped from 4.37 g/L before transfusing stream water to 2.93 g/L in November 2000 and 2.25 g/L in November 2001 aftertransfusing stream water,and the ecological environment in the lower reaches of the Tarim River is alsoimproved.