Characterization of spatial and temporal distribution of evapotranspiration in the Dawen River Basin and analysis of driving factors

Abstract

In this study, the ET in the Dawen River Basin for the year 2021 was estimated using the SEBS model, combined with meteorological data and Landsat 8 remote sensing images. By analyzing representative remote sensing images from spring, summer, autumn, and winter, the temporal and spatial distribution characteristics of ET in the region, as well as its patterns of change, were studied. The results indicate that ET in the study area exhibits a distinct seasonal variation, with the highest levels occurring in summer, followed by fall, spring, and winter. ET peaked in July and gradually decreased to its lowest point in January. Although different land cover types showed similar seasonal variation in ET, the differences were particularly pronounced in summer, with the highest ET observed in water bodies and the lowest in built-up areas. A one-way analysis revealed that elevation was the most significant factor influencing ET, with an explanatory power of 0.272, followed by mean annual temperature and land type. This study provides a scientific basis for optimizing water resource management in the Dawen River Basin and offers new insights into the spatial and temporal dynamics of ET and its driving mechanisms in the region.