机井和地下水位对坎儿井水量影响的数值模拟

长期以来坎儿井和机井是吐鲁番地区2种重要的灌溉水源工程,但由于吐鲁番地区机井布局和水源开采缺乏科学规划,造成区域地下水位的下降,直接威胁到了坎儿井的存在.为了探究机井抽水和地下水位对坎儿井水量的影响规律,在研究火焰山山前洪积扇水文地质条件的基础上,结合坎儿井独特的运行机制,建立了坎儿井出水模型,通过施加不同位置和数量的机井,变换抽水量和地下水位等方式以控制影响因素.结果表明:坎儿井水量与机井的距离和抽水量呈负相关,但会因其位置和排布形式的不同而产生不同程度的影响;单井对坎儿井水量的影响十分有限,群井对坎儿井水量的影响较大,其中又以集水段附近设置机井的影响最大;而在所有对坎儿井水量影响的因素中,地下水位起到了决定性作用.因此坎儿井的保护工作应以控制地下水位为主,同时严格控制坎儿井周围的机井数量和抽水量.

Influence of motor-pumped well and underground water level on Karez water quantity by numerical simulation

Karez and motor-pumped wells have long been two kinds of important irrigation infrastructures in Turpan. However, because the motor-pumped wells layout and water resources exploitation are not in a scientific manner, the groundwater level has fallen off below a normal level, treating the existence of Karez. Firstly, the hydrogeological situations of the pluvial fan in front of the flame mountain in Xinjiang are investigated, then the water quantity model of Karez is established according to its unique working mechanism. The influences of location, number and discharge of motor-pumped wells as well as groundwater level on the Karez water quantity are analyzed. The results show that the Karez water quantity has a negative relationship with the distance between a Karez and a well, and the influence depends upon the location and the layout of the wells. A single well has a very limited impact upon the water quantity, while multi-well have more influence. The conservation of Karez should be emphasized on the control of underground water level, meanwhile the number of motor-pumped wells and their discharge should be strictly regulated.