Study On Restoration Of Groundwater And Vegetation In Lower Reaches Of Tarim River After Intermittent Water Transportation

The lower part of the Tarim river located in the inland of the Eurasia continent is atypical arid and desert region. Due to the large scale land reclamation in the upper and middleriver reaches, the runoff of downstream became decreased year after year from 1950s. Thevolume of water was stored in Daxihaizi Reservoir since 1972. As a result, the runoff was cutoff. The populus euphratica forests were lost and the environment became worse and worse.These problems had aroused concern by the government and then the decision of watertransportation was made. The local government transfer water six times and total quantity ofwater achieved 1.76bil cubic meters from 2000 to 2004.This article investigated the movement of surface water, groundwater water and soilwater by use of the ways of water balance and hydrology after water transportations. Theresults indicate that the groundwater was primary replenishment between Daxihanzi andAlagan. The raising width of groundwater achieve 1km by the water transportation. Thedegree of mineralization of groundwater near river had became lower and lower.The feature of response of groundwater table was analyzed. This paper based onBoussinesq Equation and deduced 1D transient groundwater flow of intermittent watertransmitting in the case of souse and sink. The principle of groundwater movement wasunderstood and then the numerical model of 3D-groundwater modeling was established byModflow. The area of depth between 0~4m and 4~6m increased from 0.8km2 and 13.4 km2 to42.5 km2 and 91km2.According to the theory of restoration ecology and the data of vegetation sample, the author analyzedthe process of generative community. Along with the water transportation, the trend of ecology decline hadkept within limits. The research presents that the growth ring of populus euphratica's branch in Yinsusection was 2.24mm annually after water transportation. It was 3.0 times than 2000. The rulecan be discovered in the whole lower reaches. In the end, the writer forecast that therestoration area of populus euphratica is 209km2 as the runoff is 3.5 bil cubic meters annualy.