洮儿河冲洪积扇地下水库天然调控能力评价

Evaluation of Natural Regulation Ability of Groundwater Reservoir in Tao'er River Alluvial Fan

洮儿河冲洪积扇为一相对独立的大型储水构造，含水层为砂砾石，厚度10-43m，储、导水能力强；表土层较薄，极易接受大气降水人渗补给和河流渗漏补给，具有较强的调蓄能力，可视为大型天然地下水库。在水文地质条件概化的基础上，建立了研究区地下水流二维平面非稳定流数学模型．在模型识别和验证的基础上，应用该模型模拟了地下水库以现状开采强度持续开采地下水资源的条件下，从现状年到2020年研究区内地下水位的动态变化过程，进而确定了地下水库多年平均意义上的最大天然调控能力为4．30×10^8m^3／a，并且指出地下水库的天然调控能力并不是一个单一确定数值，具有随着区域水资源开发利用条件的不同而变化的特点。

Tao＇er River fan is a large water storage structure independently, the aquifer is gravel and sand which thickness is 10-43 m and the ability of water storage and conductance is suitable. The surface soil layer is relative thin, and the groundwater can received the recharge of precipitation and river seepage. Therefore, the river fan has a good regulation for water resources and can be thought as a large natural groundwater reservoir. According to the summary of hydrogeology conditions, the two-dimensional plane transient groundwater flow model was built, recognized and validated. The model was used to simulate the groundwater regime from the actuality year to year 2020, maintaining the status quo mining intensity of groundwater resources. The perennial average maximum natural regulation ability of groundwater reser- voir was calculated as 4. 30×10^8m^3/a. The natural regulation ability is not an only certain value because it can be changed with the regional groundwater development conditions.