黄河三角洲浅层地下水埋深动态与降水的时空响应关系

An analysis of the space-time patterns of precipitation-shallow groundwater depth interactions in the Yellow River Delta

为探究黄河三角洲浅层地下水埋深动态对降水的时空响应关系及其驱动因素,基于2006—2010年黄河三角洲14口监测井的浅层地下水埋深数据和气象站降水量数据,利用Kendall’s秩相关、交叉小波变换和小波相干方法,分析黄河三角洲地下水埋深动态和降水之间不同的时空响应模式,结合土地利用、微地貌类型和土壤质地资料,利用地理探测器方法对地下水埋深-降水响应关系进行定量归因研究。结果表明:(1)地下水埋深时间序列与降水量时间序列呈负相关关系,根据降水量对地下水埋深的影响强弱,可划分为3种空间模式:模式1强负相关(-0.45^-0.30)、模式2负相关(-0.30^-0.15)和模式3弱负相关(-0.15^-0.01),空间差异性明显。(2)从模式1到模式3,地下水埋深对降水的响应延迟时间逐渐变小,分别为178.36 d、146.43 d和35.51 d,在所有模式中,地下水埋深对强降水的响应都很敏感。(3)土地利用、微地貌类型和土壤质地对地下水埋深-降水的响应关系都有显著的影响,解释贡献率分别为微地貌类型(0.2807)>土地利用(0.2441)>土壤质地(0.1638),驱动因子之间均表现出非线性增强作用,土地利用和微地貌类型的协同增强作用最大,为0.7490。研究揭示了黄河三角洲浅层地下水埋深变化与降水之间不同的时空响应模式并对其进行定量归因,为黄河三角洲地区水循环过程研究及地下水资源管理和生态保护提供科学依据。

In order to study the spatial and temporal response and driving factors of groundwater depth to precipitation in the Yellow River Delta,based on the time series data of groundwater depth of 14 typical monitoring wells and precipitation of meteorological stations from 2006 to 2010,the Kendall’s rank correlation,Cross-Wavelet and Wavelet Coherence methods are used to analyze the spatial and temporal response patterns of groundwater depth and precipitation.Based on the data of land use types,micro-geomorphic types and soil texture,the quantitative attribution of the relationship between precipitation and groundwater depth was also explored by using the geographical detectors method.The results show that(1)groundwater depth is negatively correlated with precipitation,and the spatial difference of their relationship is obvious.According to the effect of precipitation on groundwater depth,the relationship between groundwater depth and precipitation is divided into three spatial patterns in the study area:pattern 1 withτau ranging between-0.45 and-0.30,pattern 2 withτau between-0.30 and-0.15 and pattern 3 withτau between-0.15 and-0.01.(2)From pattern 1 to pattern 3,the temporal lag of groundwater depth to precipitation is becoming shorter,which is 178.36,146.43,35.51 d,respectively.In all patterns,the change of groundwater depth is very sensitive to heavy precipitation.(3)Land use types,soil texture and micro-geomorphic types have significant effects on the relationship between groundwater depth and precipitation.The contribution rates of interpretation are micro-geomorphic types(0.2807)>land use types(0.2441)>soil texture(0.1638).There are synergistic enhancement effects among the driving factors.The synergistic enhancement effect of land use types and micro-geomorphic types is the greatest,which is 0.7490.Different spatial and temporal patterns of groundwater depth and precipitation in the Yellow River Delta are revealed and a quantitative attribution is also made to them,which provides a scientific basis for the study of water cycle process,groundwater resource management and ecological protection in the Yellow River Delta.