近20年塔里木河干流区地下水埋深变化特征及其生态效应研究

基于塔里木河干流区近20年水文生态变化监测资料,研究了其地下水埋深时空变化特征与河道来水的相互关系及其生态效应。结果表明:塔河干流上中游段地下水埋深年度变化呈枯水期3—4月变幅在0.42～0.92 m,汛期7—9月变幅在1.06～3.67 m。经近20年的生态输水,2009—2017年9年间下游段地下水埋深平均抬升了3.75 m,地下水埋深随输水量的变化明显,总体上在输水停止后1月内达到峰值,而后逐渐降低,直至下一次输水才会明显回升。2009年之后的生态输水对下游植被恢复效果明显,下游NDVI平均值由0.05提升至0.15。本研究系统分析了塔里木河干流区生态输水以来区域生态环境对地下水的综合响应,可为区域水资源调控和进一步量化输水效益提供理论依据。

Variation Characteristics of Groundwater Depth and Its Ecological Effect in the Main Stream of Tarim River in Recent 20 Years

The spatio temporal variation characteristics of groundwater depth and the inflow of river and its ecological effect were studied based on the monitoring of hydrological and ecological parameters in the main stream area of Tarim River in recent 20 years.The results showed that the annual variation of ground water depth in the upper and middle reaches of the main Tarim River was 0.42~0.92 m in the dry season from March to April, and 1.06~3.67 m in the flood season from July to September. After nearly 20 years of ecological water conveyance, the groundwater depth in the downstream section had increased by 3.75 m during 2009-2017. The depth of groundwater varied significantly with the amount of water conveyance. Generally, it reached the peak value within one month after the water conveyanced. After that, it gradually decreased until the next water conveyance. After 2009, the ecological water transport has obvious effect on the vegetation restoration of downstream, and the average value of NDVI in the downstream increased from 0.05 to 0.15. This study systematically analyzed the comprehensive response of regional ecological environment to groundwater since the ecological transport of the main stream of Tarim River, which could provide theoretical basis for regional water resource management and further quantification of water transport benefits.