地下水对银川平原植被生长的影响

植被是反映区域性生态环境状况的重要指标之一，而地下水对植被的生长有着重要的影响。结合MODIS-NDVI遥感数据与地下水位观测数据，从大尺度上研究了银川平原地下水与植被的关系，并结合实测的数据，利用最小二乘法拟合出地下水位埋深与NDVI变化率的关系曲线，定量分析了地下水位埋深对植被生长的影响，并对适宜植被生长的地下水位埋深进行了探讨。研究结果表明：地下水位埋深在3 m时，植被长势最好；而适宜植被生长的地下水位埋深范围是1~5 m；当地下水位埋深超过5 m时，地下水位埋深对植被的影响逐渐减弱；当水位埋深超过8 m时，地下水位埋深对植被的生长没有影响。

Effect of Groundwater on Vegetation Growth in Yinchuan Plain

Vegetation is one of the important indices to reflect the status of regional eco-environment,and the groundwater has significant impact on vegetation growth.Located in arid northwestern area,Yinchuan plain is the important industrial and agricultural base in Yellow River basin,and its condition of natural eco-environment is typical in northwest China.Combined with MODIS-NDVI and groundwater monitoring data,this paper studied the relation between groundwater and vegetation in Yinchuan plain from large scale.The relation curve between depth of groundwater and NDVI change rate was fitted based on least square method.The impact of groundwater on vegetation growth was analyzed quantitatively and the suitable depth of groundwater for the vegetation growth was discussed in this study.The result indicated that the vegetation growth is best as the depth of groundwater is 3 m,the suitable range of depth of groundwater for the vegetation growth is between 1 and 5 m.The impact of groundwater depth on vegetation is gradually weak if the depth of groundwater is larger than 5 m and the impact is zero if the groundwater depth is larger than 8 m.