生态脆弱草原区地下水位对降水要素变化的响应

发布时间：2018-11-27 20:27

【摘要】：降水是生态脆弱草原区地下水系统的关键补给源,研究地下水位对降水强度、降水次数等降水要素的响应特征对揭示草原生态系统"四水"转化规律具有一定的指导意义。以锡林浩特市典型草原为研究区,基于M-K检验将地下水位长时序变化过程划分为浅埋期和深埋期,通过Poisson分布模型及其改进模型分析降水强度、降水次数等降水要素的时序演变规律,定量研究地下水位对不同降水要素的响应程度。研究结果表明,锡林浩特市各个观测井地下水位呈逐年下降趋势,地下水埋深整体较浅,对降水要素的响应程度由强至弱依次是日均降水强度、降水次数和次雨深,其中农场三队和欣康村监测井的水位对降水要素变化最为敏感;2001年左右,区域地下水位步入深埋期,水位降幅显著,埋深增加导致包气带增厚,延缓了降水入渗补给过程,地下水位对各个降水要素的响应程度也不断减弱。
[Abstract]:Precipitation is the key recharge source of groundwater system in ecologically fragile grassland. It is of certain guiding significance to study the response characteristics of groundwater table to precipitation intensity, precipitation times and other precipitation elements in order to reveal the transformation law of "four rivers" in grassland ecosystem. Taking the typical grassland of Xilinhaote as the study area, based on M-K test, the long time series change process of groundwater level is divided into shallow burial period and deep buried period. The precipitation intensity is analyzed by Poisson distribution model and its improved model. The time series evolution law of precipitation elements such as the times of precipitation and the response degree of groundwater level to different precipitation elements are quantitatively studied. The results show that the groundwater level of the observation wells in Xilinhaote is decreasing year by year, the depth of groundwater is shallow as a whole, and the degree of response to precipitation elements is in the order of daily average rainfall intensity, precipitation times and secondary rain depth. Among them, the water level of the monitoring wells in the third Farm and Xinkang Village is the most sensitive to the change of precipitation elements. In 2001, the regional groundwater level stepped into the deep burial period, the water level decreased significantly, and the increase of the buried depth resulted in the thickening of the aeration zone, which delayed the process of precipitation infiltration and recharge, and the response degree of the groundwater level to the various precipitation elements was also weakened.
【作者单位】：水利部牧区水利科学研究所;中国水利水电科学研究院;
【基金】：国家自然科学基金项目(51609153) 中央分成水资源费项目(1261430122054) 中国水利水电科学研究院科研专项项目(MK2016J11,MK2016J01)
【分类号】：S812

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