不同降水情景下天津市地下水位的时空变化特征

为了定量模拟和评价不同降雨情景下天津市不同含水层地下水位时空变化情况,通过对天津市水文地质条件的分析和已获取的资料建立地下水系统的三维数值模拟模型,并利用已知的地下水位动态数据对模型进行拟合与检验,确定模型的可靠性。然后利用模型对常态条件下(地下水开采量维持不变,50%频率下的降水量)和极端气候条件下(地下水开采量维持不变,95%频率下的降水量)天津市地下水位的时空变化特征进行预测和评价,分析不同含水层地下水位对两种情景的动态响应机制。结果表明:两种方案下10 a后的地下水流场特征较为相近,地下水流向也基本一致,地下水位均有所下降,在开采量不变情况下,降水量的减少对承压含水层的影响较为有限。

Temporal and spatial variation characteristics of groundwater level under different rainfall scenarios in Tianjin

In order to quantitatively simulate and evaluate temporal and spatial variation characteristics of groundwater levels in various aquifers under different rainfall scenarios in Tianjin, a three-dimensional numerical simulation model of groundwater system was built based on the analysis of hydrogeological conditions and obtained data. The monitored dynamic groundwater level were used to fit and test the groundwater model to determine its reliability. Then, the model was used to predict and evaluate temporal and spatial variation characteristics of groundwater level under normal conditions (unchanged groundwater exploitation, 50% frequency of precipitation) and extreme climatic conditions (unchanged groundwater exploitation, 95% frequency of precipitation). The results showed that: the characteristics of groundwater flow field are similar after 10 years later under the two schemes, the groundwater flow directions are basically the same, and both the groundwater levels decrease. The effect of precipitation reduction on confined aquifer is relatively limited under constant exploitation.