塔里木盆地南缘绿洲地下水时空变异与监测点位优化——以策勒绿洲为例

目的]揭示塔里木盆地南缘绿洲地下水时空变异特征,优化监测点位,为实现水资源的合理利用与绿洲可持续发展提供依据。方法]基于2008—2014年地下水监测数据,首先利用地统计学方法,通过对球状、指数、高斯3种模型的系统分析,确定适宜该地区的最优模型;其次利用该模型定量分析区域地下水时空变异特征,并进行地下水监测点位优化;最后利用Thiessen多边形法计算地下水平均埋深,对绿洲地下水平均埋深变化特征进行分析。结果]高斯模型为最优模型,并且地下水的空间异质性和连通性增强;在不影响监测精度前提下,将原有23个监测点有效减至12个,降低监测成本;绿洲地下水平均埋深变化趋于稳定。结论]绿洲地下水尽管受绿洲扩张影响显著,但因径流补给,目前总体处于安全状况。为保障绿洲健康可持续发展,需在目前绿洲规模基础上适当控制绿洲扩张。

Spatio-temporal Variability of Oasis Groundwater in Southern Rim of Tarim Basin and Monitoring Sites Optimization -A Case Study in Cele Oasis

Objective] The spatio-temporal variation of groundwater in the south rim of Tarim Basin was explored to rationally arrange the monitoring well, and also to realize the rational utilization of water resource and the sustainable development of the oasis. Methods] Geostatistical method was used to analyze the spatio-temporal variation of groundwater based on the data between 2008 and 2014. Firstly, Gauss model, Spherical and Exponential models were compared to determine which one performed best; Secondly, a chose model was used to analyze the spatio-temporal variation of groundwater in study area, and to optimize monitoring well; At last, Thiessen polygons method was used to calculate the average depth of groundwater and get the variation characteristics of groundwater depth from 2008 to 2014. Results] Gauss model was the best model in analyzing groundwater change. The spatial heterogeneity and connectivity were enhanced, and the optimization of monitoring wells could be reduced from 23 to 12. The variation of mean groundwater depth was relatively stable. Conclusion] Groundwater was influenced significantly by the oasis expansion. However, it was still in safe situation counterbalanced by runoff supply. In order to keep oasis development sustainable, it is important to control oasis expanding based on the present oasis scale.