塔里木河下游地下水变化动态分析

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

由于塔里木河下游地下水位不断下降,而来水量却连年减少,与20世纪50年代相比平均下降了4～6m。随着大面积发展灌溉农业,排水洗盐改良土壤进程加快,相应地排入塔里木河的咸水也大大增加,塔河下游地下水水质也发生相应的变化。通过对塔里木河下游地下水变化动态以及来水量、农业灌溉对地下水的分析,也对沙漠化发展和分布对地下水的响应关系进行了探讨。

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.