格尔木河流域山前平原区蒸散量的分布特征

格尔木河流域干旱少雨,蒸发强烈,为格尔木地区经济发展提供水资源保障。蒸散发是干旱内陆地区地表水及地下水排泄的主要方式,准确估算研究区长时间序列的蒸散量时空分布及其影响因素,对研究区水资源合理开发利用及生态环境保护具有重要意义。传统的蒸散量估算方法难以获取大尺度时空范围参数且估算结果误差较大。文章以格尔木河流域山前平原区为研究区,应用连续序列的MODIS数据及GLDAS气象数据基于SEBS模型估算格尔木河流域山前平原区蒸散量,利用线性回归法及Mann-Kendall显著性检验法分析其连续时间序列内的变化趋势,分析其影响因素。结果表明:研究区蒸散量从2001到2016年总体呈增长趋势,盐沼平原及山前戈壁砾质平原大部分地区蒸散量变化在16年间呈稳定不变状态,盐湖区和绿洲平原呈显著增长趋势。研究区16年间不同地貌蒸散量夏季增减幅度均远大于其他三季,冬季变化幅度最小。

Distribution characteristics of evapotranspiration in the valley piedmont plain of the Golmud River Basin

The Golmud River Basin is located in the southwest of the Qaidam Basin in Qinghai Province, which provides guarantee of water resources for the city of Golmud. The basin is characterized by plateau continental climate, drought, less rain and strong evaporation. Groundwater and surface water are mainly drained by evapotranspiration (ET) in arid inland areas. Therefore, it is of great significance to accurately estimate the temporal and spatial distribution of ET and its influencing factors in the long time series in the study area for the rational development and utilization of water resources and ecological environment protection. However, studies of ET and its influencing factors of the Golmud River Basin have been insufficient for many years. Traditional methods of ET estimation are difficult to obtain temporal and spatial parameters on a large scale and have large errors in estimation results. The valley piedmont plain of the Golmud River Basin is taken as the study area, and a spatial and temporal distribution of time series trends of ET are estimated, so as to provide reference for rational development and utilization of water resources in the study area. Based on the SEBS model, the continuous MODIS data and GLDAS meteorological data are used to estimate the regional ET in this paper. Linear regression method and Mann-Kendall significance test are used to analyze the variation trend of continuous time series. The impact factors of ET are discussed in this work. The results show that the regional ET increased in the Golmud River Basin from 2001 to 2016. The ET value is stable in most areas of the salt marsh and the piedmont gobi gravel plain, whereas it increased in salt lake and oasis plain during the 16 years. The increase and decrease of summer ET is much larger than that of other three seasons, and winter ET has the smallest variation in different geomorphic units.