塔里木河干流中游典型生态闸补水效应研究

Study on Water Replenishment Effect of Typical Ecological Gates in the Middle Reaches of Tarim River

为探究塔里木河流域内生态闸补水效应,运用MODFLOW建立乌斯满断面地下水剖面二维流运动的数值模拟,拟合了区域内4年的地下水流场演变过程,并在此基础上针对有无生态闸输水的两种方案进行了预测与对比。结果表明,两种预测方案下的第5年,使用生态闸输水的方案较单一的主河道输水,研究区小于8 m的埋深面积增加6.62%;生态闸集中恢复了远离主河道生态区域的地下水位,断面北侧的地下水位平均抬升了2~3 m;使用生态闸的方案相比单一的主河道输水,每立方米地下水存储量的增量所消耗的潜水蒸发量减少了24.6%。生态闸解决了传统输水模式下远离主河道生态区域地下水位难以恢复的问题,为中游多处汊口形成的河网地块生态系统的恢复及干流沿线生物多样性的安全带创造了条件。

To study on water replenishment effect of ecological gate in the Tarim River Basin,the MODFLOW was used to establish the numerical simulation of the two-dimensional flow movement of the groundwater profile in the Wusiman section,and to analyze the evolution process of the groundwater flow field in 4 years.On this basis,the two schemes with or without ecological sluice were predicted and compared.The results show that in the fifth year under the two prediction schemes,compared with the single main river channel,the buried depth area less than 8 m in the study area increased by 6.62% by using the ecological sluice water conveyance scheme.The ecological gates restored the groundwater level far away from the ecological area of the main river channel,and the groundwater level on the north side of the section increased by 2-3 m on average.Compared with the single main channel water conveyance,the phreatic evaporation consumed by the increment of groundwater storage per cubic meter was reduced by 24.6%.The ecological sluice solves the problem that the groundwater level is difficult to recover in the ecological area far away from the main river channel under the traditional water conveyance mode,and creates conditions for the restoration of the river network ecosystem formed by multiple branches in the middle reaches and the safety belt of biodiversity along the main stream.