青海湖流域生长季土壤水分空间分布特征研究  

Spatial distribution characteristics of soil moisture during growing season in Qinghai Lake Basin

作　　者：张梦雅 马育军 谢婷 ZHANG Mengya;MA Yujun;XIE Ting(School of Geography and Planning,Sun Yat-sen University,Guangzhou 511400,Guangdong,China)

机构地区：[1]中山大学地理科学与规划学院,广东广州511400

出　　处：《水利水电技术（中英文）》2023年第3期85-95,共11页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(41771026,41730854)。

摘　　要：【目的】土壤水分作为水文循环过程的重要环节,是影响青藏高原生态环境演变的关键因素之一。青海湖是维系青藏高原东北部生态安全的重要水体,了解青海湖流域土壤水分空间分布特征对于维护区域生态系统稳定具有重要意义。【方法】本研究基于2019—2021年7~8月青海湖流域75个采样点的土壤水分实测数据,分析了不同植被类型和海拔高度的土壤水分空间分异,辨识了不同深度土壤水分变化的主要影响因素。【结果】结果表明:(1)青海湖流域土壤水分平均值及其变异系数在垂直方向上均随深度增加而减小,深层(60~100 cm)土壤水分空间分布更均匀。(2)不同植被类型和海拔高度下的土壤水分垂直分布表现出不同的特征。四种典型植被类型土壤水分平均值由高到低依次为高寒草甸、灌丛、高寒草原、温性草原;除高寒草甸土壤水分平均值随深度增加逐渐减小外,其余三种植被类型均呈先增大后减小趋势。土壤水分随海拔升高而增大,3600 m以上地区土壤水分变异系数呈“W”型变化。(3)不同环境条件下土壤水分变化的主要驱动因素各不相同。高寒草原和温性草原土壤水分受气温影响较大,两者在60~80 cm深度同气温相关系数分别为-0.509和-0.703,受降水和NDVI影响较小;高寒草甸和灌丛则与之相反。低海拔地区主要受气温影响,土壤水分含量较低;高海拔地区则在气温、降水等多种环境因子共同作用下,土壤水分含量较高。【结论】总体上,青海湖流域土壤水分受气温、降水和NDVI等多因素影响,呈现明显的空间异质性,垂直方向上土壤水分随深度的增加而减小,水平方向上高寒草甸土壤水分高于其余三种植被类型,高海拔地区土壤水分高于低海拔地区。[Objective]As an important process of hydrologic cycle,soil moisture is one of key parameters affecting the evolution of ecological environment.Qinghai Lake is an important water body to maintain the ecological security in the northeast of the Qinghai-Tibet Plateau,and its spatial distribution varies with the change of topography,soil and vegetation in the whole basin.Therefore,understanding the spatial distribution of soil moisture in the Qinghai Lake Basin is of great significance for maintaining the regional ecosystem stability.[Methods]Based on the soil moisture data measured at 75 sampling sites from July to August between 2019 and 2021 in the Qinghai Lake Basin,we analyze the spatial variation of soil moisture under different vegetation types and altitudes,and further identified the main environmental drivers of soil moisture variation at different depths in the basin.[Results]The results show that:(1)In the whole basin,both the mean value and variation coefficient of soil moisture decrease with the increase of soil depth in the vertical direction,and the spatial distribution of soil moisture in the deep layer(60~100 cm)is more uniform.(2)The vertical distribution of soil moisture show different characteristics under different vegetation types and altitudes.The mean value of soil moisture of four typical vegetation types from high to low correspond to alpine meadow,shrub,alpine steppe and temperate steppe,respectively.The soil moisture of alpine meadow decrease with the increase of depth,while the other three vegetation types show a trend of increasing first and then decreasing.The soil moisture increased with altitude,and the variation coefficient of soil moisture above 3600 m show a“W”shape change.(3)The main driving factors of soil moisture variation under different environmental conditions are different.Soil moisture in alpine steppe and temperate steppe is mainly affected by air temperature,and the correlation coefficients between soil moisture and air temperature at 60~80 cm depth are-0.509 and-0.

关 键 词：土壤水分 空间分布 垂直变化 环境因子 青海湖流域 

分 类 号：K903[历史地理—人文地理学]