生态脆弱草原区地下水位对降水要素变化的响应  

Response of Groundwater Level to Variation of Precipitation Factors in Ecologically Fragile Grassland Areas

作　　者：崔英杰[1,2] 魏永富[1] 郭中小[1] 廖梓龙[1,2] 龙胤慧[1] 

机构地区：[1]水利部牧区水利科学研究所,呼和浩特010020 [2]中国水利水电科学研究院,北京100044

出　　处：《节水灌溉》2017年第9期60-64,共5页Water Saving Irrigation

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)

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。Precipitation is a key source of recharge of groundwater systems in ecologically fragile grassland areas. The study of the response characteristics of groundwater level to precipitation factors such as precipitation intensity and precipitation frequency is of great significance to reveal the transformation rule of ＂four water＂ in grassland ecosystem. This paper takes the typical grassland of Xilinhot as the research area. Based on the M-K test, the process of long-term change of groundwater level is divided into shallow periods and deep periods. The timing evo- lution rule of precipitation factors, such as precipitation intensity and precipitation frequency, is analyzed by using the Poisson model and its improved model. Response degree of groundwater level to different precipitation factors are studied quantitatively. The result shows that the groundwater level of each observation well in Xilinhot City is decreasing year by year, the groundwater depth is shallow as a whole, and the degree of response to the precipitation elements is from strong to weak, i.e., the average daily precipitation intensity, precipitation frequency and the depth of a rainfall. The water level of the 3rd teams of the farm and the Xinkang village monitoring wells are most sensitive to the change of precipitation factors. In 2001, the regional groundwater level entered the deep-depth period, the water level decreased significant- ly, the increase of the depth caused the thickening of the unsaturated zone, delayed the infiltration recharge process, the groundwater level of the various precipitation factors were also weakened.

关 键 词：生态脆弱草原区 地下水位 降水强度 降水次数 次雨深 响应特征 

分 类 号：S342.3[农业科学—作物栽培与耕作技术] P641.8[农业科学—农艺学]