关键词: HTEM, 蒸散发, 时空格局, 地理探测器, 塔里木河下游

Abstract:

To reveal the spatiotemporal patterns and driving mechanisms of evapotranspiration （ET） and provide theoretical support for ecological conservation planning in the lower reaches of the Tarim River. Based on MODIS data， the Hybrid Dual-Source Triangle Evapotranspiration Model （HTEM） was employed to estimate ET from 2000 to 2022 in the lower Tarim River basin. The spatiotemporal distribution characteristics and trends of ET were analyzed， and the optimized parameter Geodetector was applied to identify factors influenci ET spatial patterns.（1） Simulated water surface evaporation aligned well with calculated values， amodeled ET for Tamarix communities matched field observations. （2） Over the past two decades， ET in the lower Tarim River showed an increasing trend， with a multi-year average of 127.6 mm. Annual ET varied significantly across land cover types： water bodies （906.7 mm）， cropland （482.3 mm）， forestland （282.8 mm）， grassland （144.0 mm）， and desert （48.6 mm）. （3） ET exhibited a "high-north， low-south" spatial pattern. From 2000-2015， high-value zones clustered in the northern Daxihaizi Reservoir， 34th Regiment， and 35th Regiment irrigation areas， while low values occurred in desert regions >1 km from the river channel. In 2015-2022， high ET values expanded to floodplain zones. （4） Vegetation coverage was the dominant driver of ET spatial distribution， followed by waterbody frequency and groundwater depth. Climatic factors （precipitation， temperature） exerted weaker influences. The HTEM model accurately estimates ET in the lower Tarim River. These findings offer critical insights for combating desertification， ecological restoration， and sustainable water resource management in the region.

Key words: HTEM, evapotranspiration, spatiotemporal pattern, geodetector, lower reaches of the Tarim River