厄立特里亚扎拉河地下水资源评价与可开采潜力分析

Evaluation of Groundwater Resources and Analysis of Exploitable Potentiality in Zara River of Eritrea

为了确保科卡金矿项目可以获得持续性供水,避免过度抽水导致周边地区生态环境失衡,通过抽水试验、地震勘探等方法对地下水资源进行评价,并建立了水均衡模型,探究该地区地下水的可开采潜力。结果表明:该地区含水层具有高渗透性,出水量超过20 L/s,总存储量计算值为5.3 Mm3;较厚的冲积含水层可满足该项目运行8年的用水需求。水均衡分析结果显示,平水年的河道径流可以提供足够的入渗补给,使含水层恢复至最大储量;模拟3种气候条件下,含水层出现的平均降深为2.21~2.65 m,平均地下水位约为15.1 m,且从含水层中抽取水对周围环境并无显著影响。

In order to ensure Koka Gold able to achieve the sustainable water supply and avoid the excessive pumping water leading to the unbalance of ecological environment in the surrounding areas, the groundwater resource is evaluated by the water pumping test and the seismic survey method. And the establishment of water balance model can analyzes the exploitable potentiality of groundwater in this area.The result shows that the aquifer of this area has the high permeability, the water yield exceeds 20 L/s and the calculation value of total storage reserves is 5.3 Mm3. The thicker alluvial aquifer can satisfy the water demand for the 8-year operation of this project. The water balance analysis result shows that the river runoff of normal flow year can provide the sufficient infiltration supply to make the aquifer recover to the maximum reserves. Under the condition of three simulated climates, the average drawdown of aquifer is2.21~2.65 m, and the average groundwater level is about 15.1 m. And the water supply from the aquifer has no appreciable impact on the surrounding environment.