基于正常化差水指数的水应激因子大大提高了对于干旱和半干旱草原的光使用效率模型的准确性
Lei Ding1, Zhenwang Li2, Kang Xu3
1College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Journal of environmental management
|November 17, 2023
概括
一个新的草原特定的光利用效率 (LUE) 模型,GRASS-LUE,显著提高了总初级生产率 (GPP) 模拟的准确性. 这种增强型号在半干旱草原中表现最好,性能优于现有的GPP产品.
科学领域:
- 生态生态学 生态生态学
- 遥感 遥感 遥感 遥感
- 生物地质化学生物地质化学
背景情况:
- 对草原生态系统服务和管理来说,准确模拟原始生产率至关重要.
- 现有的光利用效率 (LUE) 模型显示草原的准确性有限,特别是在干旱和半干旱地区.
研究的目的:
- 开发和验证草原特定的LUE模型 (GRASS-LUE),以提高整个干旱度梯度的GPP模拟精度.
- 为了优化关键参数:吸收光合作用活性辐射 (FPAR) 分数,最佳温度 (Topt) 和水应力因子 (f ((W)).
主要方法:
- 开发了GRASS-LUE模型,优化了草原条件的参数.
- 经过验证的GRASS-LUE与状共变量 (EC) GPP数据在8天,月度和年度尺度上.
- 与五个领先的GPP产品 (PML,MOD17,rEC-LUE,VPM,BESS) 的Grass-LUE性能进行了比较.
主要成果:
- 格拉斯-卢表现出强烈同意欧盟GPP估计 (R2高达0.95).
- 与其他GPP产品相比,该模型表现出优越和稳定的性能,特别是在半干旱草原.
- 灵敏度分析表明,使用规范差水指数 (NDWI) 对f{\displaystyle f} 和压力因子的最小值提高了准确性.
结论:
- GRASS-LUE为模拟草地GPP提供了显著的进步,特别是在水资源有限的环境中.
- 使用NDWI和min(f(W),f(T)) 优化水应力表示对于改善干旱和半干旱草原LUE模型性能至关重要.
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