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为了解大沽河下游地区在建设地下截渗墙之后对地下水位、水质及地表植被的影响,在野外调查、观测及资料收集的基础上,利用地学理论、数理统计方法及3S技术,对该地区浅层地下水位、水质时空变化及其对NDVI指数的影响等进行了深入分析。结果表明:1)大沽河下游地区年内地下水位呈现出单峰单谷曲线,最高水位发生频率最高的时期是9~10月,最低水位发生频率最高的时期是6~7月。截渗墙明显起到了涵养水源的作用,抬升了截渗墙北侧的地下水位,平复了截渗墙的地下水漏斗。2)至2011年截渗墙北侧地下水中Cl-含量下降明显,水质变好。3)研究区域NDVI总体呈逐渐增加的态势,一定程度上表明区域植被覆盖状况明显增加。
In order to understand the influence of underground water table, water quality and surface vegetation after construction of underground cutoff wall in the downstream area of Dagu River, based on field investigation, observation and data collection, using geo-theory, mathematical statistics and 3S techniques, Regional shallow groundwater table, temporal and spatial variation of water quality and its impact on the NDVI index were analyzed in depth. The results show that: 1) During the year, the groundwater table in the downstream area of Dagu River has a single peak and single valley curve. The period with the highest occurrence frequency is from September to October and the period with the lowest frequency occurs from June to July. The cut-off wall obviously played a role in conserving water, raised the groundwater level on the north side of the cut-off wall and smoothed the groundwater funnel at the cut-off wall. 2) The Cl- content of groundwater in the north side of the cutoff wall dropped significantly by 2011, and water quality improved. 3) The overall NDVI in the study area shows a gradual increase trend, indicating to some extent that the vegetation cover in the area has significantly increased.