| 摘要: |
| 水分利用效率是生态系统碳水耦合的关键指标，对流域水资源管理具有重要支撑作用。以右江流域为研究区，基于ERA5-Land与MODIS数据驱动BEPS模型，模拟2019-2022年总初级生产力与实际蒸散，计算生态系统水分利用效率，结合Theil-Sen趋势分析与Mann-Kendall检验揭示其时空变化特征。结果表明：（1）流域多年平均WUE为3.10 g C/kg H2O，整体呈缓慢上升态势，季节上呈冬季＞秋季＞春季＞夏季，非生长季WUE高于生长季，且非生长季变化主导全年WUE的趋势；（2）WUE空间上呈西北高、东南低格局，79.79%区域呈上升趋势，下降区域集中于东南部农业区，且WUE本底值越高增长速率越快；（3）不同土地利用类型内部WUE呈林地＞农田＞灌木＞草地＞荒地的梯度特征，各类型年内均呈单峰变化，7月达峰值、1月为谷值。研究结果可为流域碳水耦合调控与农业水资源高效利用提供科学依据。 |
| 关键词: 右江流域 BEPS模型 水分利用效率 蒸散量 时空变化 |
| DOI： |
| 投稿时间：2026-06-02修订日期：2026-07-12 |
| 基金项目:国家自然科学基金(42571364,42061063)、广西重点研发项目(AB24010076) |
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| Spatiotemporal Variation Characteristics of Water Use Efficiency in the Youjiang River Basin Based on the BEPS Model |
|
zhongzhien, yanyan
|
| (Nanning Normal University) |
| Abstract: |
| Water use efficiency is a key indicator of carbon-water coupling in ecosystems and plays an important supporting role in watershed water resource management. Taking the Youjiang River Basin as the study area, based on ERA5-Land and MODIS data driving the BEPS model, the total primary productivity and actual evapotranspiration from 2019 to 2022 were simulated to calculate ecosystem water use efficiency, and Theil-Sen trend analysis combined with the Mann-Kendall test was used to reveal its spatiotemporal variation characteristics. The results show that: (1) the long-term average WUE of the basin is 3.10 g C/kg H2O, showing an overall slow upward trend. WUE in the non-growing season is higher than in the growing season, and changes in the non-growing season dominate the annual WUE trend; (2) spatially, WUE shows a pattern of high in the northwest and low in the southeast, with 79.79% of the area showing an upward trend, and the decreasing areas concentrated in the southeastern agricultural regions; (3) WUE for different land use types follows the gradient of forest > farmland > shrubs > grassland > barren land, with each type showing a single-peak variation within the year, peaking in July and reaching a minimum in January. The research results can provide a scientific basis for carbon-water coupling regulation in the watershed and efficient agricultural water resource utilization. |
| Key words: Youjiang River Basin BEPS model water use efficiency evapotranspiration spatiotemporal variation |
