School of Geography Science, Inner Mongolia Normal University, Hohhot, China.
Inner Mongolia Key Laboratory of Remote Sensing and Geographic Information Systems, Inner Mongolia Normal University, Hohhot, China.
PLoS One. 2021 Sep 10;16(9):e0256981. doi: 10.1371/journal.pone.0256981. eCollection 2021.
Surface evapotranspiration is a water exchange process between the atmosphere, biosphere, and hydrosphere. Accurate evapotranspiration estimations in arid and semi-arid regions are important for monitoring droughts and protecting the ecological environment. The main objective of this study is to build an evapotranspiration estimation model suitable for an effective scientific and objective evaluation of water consumption in the arid and semi-arid regions of the Xilin River Basin based on comprehensive parameters, including meteorological parameters, vegetation coverage, and soil water content. In this study, the community evapotranspiration model was initially constructed using field data, which was then expanded for applicability to the Xilin River Basin based on Geographic Information System technology and spatial heterogeneity characteristics of remote sensing data; both models were significant at the 0.05 level. The monthly evapotranspiration values in July during 2000-2017 and those from April to September (growing season) during the dry, normal, and wet years were calculated using the model at the basin scale. The evapotranspiration showed a generally increasing trend, which was consistent with the fluctuation trend in precipitation in July during 2000-2017. The trend curve for evapotranspiration was gentle during the growing season in dry years, but steep during wet years. The evapotranspiration was the lowest in April, with negligible spatial variations throughout the Xilin River Basin. During May-July, the evapotranspiration was higher than that in other months, in the following order: upper reaches > middle reaches > lower reaches; this was consistent with the vegetation coverage. The evapotranspiration declined and spatial variations were not evident during August-September. The results of this study provide a reference for evapotranspiration model construction and a scientific basis for evaluating regional water resources and protecting the ecological environment.
地表蒸散是大气圈、生物圈和水圈之间的水分交换过程。在干旱半干旱地区准确估算蒸散量，对于监测干旱和保护生态环境具有重要意义。本研究的主要目的是构建一个基于综合参数（包括气象参数、植被覆盖度和土壤含水量）的蒸散量估算模型，该模型适用于对锡林河流域干旱半干旱地区的耗水量进行科学客观的评价。本研究采用野外实测数据构建了社区蒸散模型，利用地理信息系统技术和遥感数据的空间异质性特征对模型进行了扩展，使其适用于锡林河流域，两个模型在 0.05 水平上均显著。利用该模型计算了 2000-2017 年 7 月和枯、平、丰水年 4-9 月（生长季）的流域蒸散量。结果表明，2000-2017 年 7 月流域蒸散量呈增加趋势，与同期降水波动趋势一致。枯水年生长季蒸散量变化趋势较平缓，丰水年较陡峭。4 月蒸散量最低，流域内空间变化不明显。5-7 月蒸散量高于其他月份，顺序为：上游＞中游＞下游，这与植被覆盖度的空间分布一致。8-9 月蒸散量呈下降趋势，空间变化不明显。本研究为蒸散量模型的构建提供了参考，为评价区域水资源和保护生态环境提供了科学依据。
