输水作用下的地下水水质变化与胡杨林更新——以塔里木河下游英苏断面为例

Change of Groundwater Quality and Restoration of the Forests of Populus euphratica under Transfusing Stream Water to the Lower Reaches of the Tarim River ——A Case Study along Yengisu Section

通过对塔里木河下游地下水化学特征在 4次生态输水后的变化分析 ,揭示英苏断面地下水矿化度对生态输水的时空响应特点。结果表明 ,在空间上 ,每一次输水后地下水矿化度的响应范围都不断扩大 ,但 4次输水对地下水矿化度的影响不超过距离河道 10 0 0m的范围 ;在时间上 ,每次输水后地下水矿化度都有明显响应 ,在受输水影响的初期 ,矿化度明显上升 ,然后逐步下降 ,下降速度先快后慢。在分析胡杨幼苗对地下水质的耐受性的基础上 ,提出生态输水时间的选择对胡杨林更新的重要性 ,并进一步指出胡杨林更新的关键是加强河道整治。

In this paper, the chemical properties of groundwater are studied during four times of transfusing stream water to the lower reaches of the Tarim River for regenerating the ecology so as to reveal the temporal and spatial response of chemical properties of groundwater to implementing the project of transfusing stream water along the Yengisu section. The results show that, spatially, the affecting extent of transfusing stream water to the chemical properties of groundwater is continuously enlarged, the affecting extent was within 250 m in distance away from the river channel after transfusing stream water of first time, extended to 450m after second time, and did not exceed 1 000 m after 4 times; temporally, the response of mineralization and chemical properties of groundwater to each time of transfusing stream water is sensitive, that is the groundwater mineralization was obviously increased at the early stage of stream water transfusion, then it was decreased rapidly but slowly in the late stage. The importance of the time of transfusing stream water to the regeneration of the forests of Populus euphratica, the dominant plant species in the lower reaches of Tarim River, is emphasized because the sprouting of seedlings of Populus euphratica requires the regime of groundwater with high quality, and it is also emphasized that the key of regenerating the forests of Populus euphratica is to strengthen the rehabilitation of river channel in the lower reaches of the Tarim River.