银川平原地下水位变化特征及其成因分析

基于2013~2015年地下水的监测资料，通过SPSS聚类分析和土地利用类型，分析银川平原水位动态变化在时间尺度、空间尺度上的变化规律及影响因素。分析发现：银川平原地下水动态分为径流型、灌溉型、降水-蒸发型和开采型4种类型，其中人为影响地下水位动态类型（灌溉型、开采型）分布最广，约占银川平原总面积的1/2。在时间尺度上，受不同因素的影响，4种动态类型变化趋势明显不同，从年内动态趋势看，径流型呈M型变化；灌溉型呈W型变化；降水-蒸发型呈Λ型变化；开采型呈Z型变化，对于开采型，通过模拟，认为夏季开采全年的45%~50%，冬季开采15%~20%是最优开采量。在空间尺度上，受地形因素影响，地下水动态类型自西向东呈径流型-开采型-灌溉型规律变化。在此基础上，探讨了银川平原地下水资源开采的合理方式，为地下水资源的可持续开发利用提供科学依据。

Dynamic Analysis of Groundwater Level in Yinchuan Plain

Based on the groundwater monitoring data from 2013 to 2015, SPSS cluster analysis and land-use-type were used to analyze the variation rules and influencing factors of the dynamic change of water level in Yinchuan plain on the time scale and space scale. It is found that the groundwater dynamics in Yinchuan plain are divided into four types:runoff type, irrigation type, rainfall-evaporation type and mining type. The dynamic types of human-influence (irrigation type and mining type) are widely distributed among them, accounting for about 1/2 of the total area of Yinchuan plain. In terms of time scale, the change trend of the four dynamic types is obviously different because of different influence factors. From the perspective of the dynamic trend of the whole year, the runoff-type shows M-type change. The irrigation-type shows W type change. Rainfall evaporation type shows Λ type change. The mining type shows Z type change. Through simulation, the optimal annual mining volume is 45%~50% in summer and 15%~20% in winter. On the spatial scale, due to the influence of topographic factors, the groundwater dynamic type changed from west to east as runoff type, mining type and irrigation type. On this basis, a reasonable way of exploiting groundwater resources in Yinchuan plain is discussed, which provides a scientific proof for sustainable exploitation and utilization of groundwater resources.