青海湖东沙地生态系统蒸散量(ET)的时间变化特征  

Characteristics of Temporal Changes in Evapotranspiration(ET)in the East Desert Ecosystem of Qinghai Lake

作　　者：薛超 田丽慧 金耀涛 XUE Chao;TIAN Lihui;JIN Yaotao(State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University,Xining Qinghai 810016,China;Qinghai Province Engineering Consulting Centre Limited Liability Company,Xining Qinghai 810008,China)

机构地区：[1]青海大学省部共建三江源生态和高原农牧业国家重点实验室,青海西宁810016 [2]青海省工程咨询中心有限责任公司,青海西宁810008

出　　处：《青海农林科技》2025年第1期40-47,共8页Science and Technology of Qinghai Agriculture and Forestry

基　　金：青海省科技厅项目(2023-ZJ-755)。

摘　　要：为了明确青海湖东沙地生态系统蒸散量(ET)的时间变化特征、主要影响因素以及植被恢复对该区域水文过程的影响,本研究采用随机森林分析法对青海湖东沙地生态系统的相关数据进行分析。结果表明:在时间变化特征方面,青海湖东沙地生态系统的ET在季节尺度与日尺度上随时间变化呈现出单峰的变化特征;在年尺度上,随着沙地植被的恢复和生长,ET整体呈现缓慢减少的态势,水分散失得到了有效控制。随机森林分析结果显示:在年尺度上,ET的年变化与日变化主要受到气温(T_(a))的影响;在季节尺度上,春季ET的主要影响因素为T_(a)与饱和水汽压差(VPD),在夏季,秋季和冬季,T_(a)与降水量(P)是主导因素。经过三年的观测研究发现,青海湖湖东沙地的人工固沙植被改变了本区的水文过程,使得ET、土壤含水量(SWC)、土壤温度(T_(s))都发生了变化。在植被恢复过程中,ET与水分收支不断减少,SWC不断增加。To clarify the temporal variation characteristics of evapotranspiration(ET)in the eastern sandy area ecosystem of Qinghai Lake,identify the main influencing factors of ET,and understand the impact of vegetation restoration on the regional hydrological processes,this study employed the Random Forest analysis method to analyze relevant data from the eastern sandy area ecosystem of Qinghai Lake.The results showed that:Regarding temporal variation characteristics,the study found that ET in the eastern sandy area ecosystem of Qinghai Lake exhibited a unimodal pattern of change over time at both seasonal and diurnal scales.At the annual scale,as the sandy vegetation recovered and grew,the overall ET_(s)howed a slow decreasing trend,indicating that water loss was effectively controlled.The Random Forest analysis results showed that,at the annual scale,the annual and diurnal variations of ET were mainly influenced by air temperature(T_(a)).At the seasonal scale,the main influencing factors of ET were T_(a) and vapor pressure deficit(VPD)in spring,while T_(a) and precipitation(P)were the dominant factors in summer,autumn,and winter.Through three years of observational study,it was found that artificial sand-fixing vegetation in the eastern sandy area of Qinghai Lake altered the regional hydrological processes,leading to changes in ET,soil water content(SWC),and soil temperature(T_(s)).During the vegetation restoration process,ET_(a)nd the water budget continuously decreased,while SWC continuously increased.

关 键 词：高寒沙地 涡度相关法 蒸散 随机森林分析 结构方程模型 

分 类 号：X144[环境科学与工程—环境科学]