干旱区研究 ›› 2019, Vol. 36 ›› Issue (2): 395-402.doi: 10.13866/j.azr.2019.02.15

• 天气与气候 • 上一篇    下一篇

基于地表温度和叶面积指数的干湿限研究及区域蒸散发估算

王军1,2,3, 李和平1,2,3, 鹿海员1,2,3, 张瑞强1,2,3, 曹雪松1,2,3   

  1. 1.中国水利水电科学研究院牧区水利科学研究所,内蒙古 呼和浩特 010020;
    2.水利部牧区水利科学研究所,内蒙古 呼和浩特 010020;
    3.流域水循环模拟与调控国家重点实验室,北京 100038
  • 收稿日期:2018-05-24 修回日期:2018-12-18 发布日期:2025-10-18
  • 作者简介:王军(1987-),男,工程师,博士生,研究方向为牧区水资源高效利用与流域水循环模拟. E-mail: slwj1988@163.com
  • 基金资助:
    中国水利水电科学研究院流域水循环模拟与调控国家重点实验室专项(SKL2018TS01);中国水利水电科学研究院科研专项(MK2016J09)

Dry-Wet Edge Based on Land Surface Temperature and Leaf Area Index and Estimation of Regional Evapotranspiration

WANG Jun1,2,3, LI He-ping1,2,3, LU Hai-yuan1,2,3, ZHANG Rui-qiang1,2,3, CAO Xue-song1,2,3   

  1. 1. Institute of Water Resources for Pastoral Area,China Institute of Water Resources and Hydropower Research, Hohhot 010020, Inner Mongolia,China;
    2. Institute of Water Resources for Pastoral Area, Ministry of Water Resources, Hohhot 010020, Inner Mongolia,China;
    3. State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, Beijing 100038,China
  • Received:2018-05-24 Revised:2018-12-18 Online:2025-10-18

摘要: 针对遥感能量平衡方法估算区域蒸散发(ET)存在的空间歧义性问题,本文以METRIC模型为例,基于地表温度(Ts)与叶面积指数(LAI)相关趋势图,按照“Ts频率直方图占比前5%的最高温度区、LAI频率直方图占比后5%的裸土区为‘干点’,Ts频率直方图占比后5%的最低温度区、LAI频率直方图占比前5%的湿地或农田为‘湿点’”的提取方案,综合确定研究区的干湿限,并通过下垫面涡度相关系统实测数据验证了模型估算精度。经检验,校准期和验证期的区域ET估算控制精度平均为15%,与以往研究成果相比,结果相对合理,提取方案在一定程度上可为METRIC模型主观确定干湿限提供帮助。将ET估算结果按土地利用分类提取,研究区不同土地利用类型表现为ET水体>ET林地>ET耕地>ET未开发利用土地>ET城乡工矿居民用地≈ET草地,成果对区域遥感ET精准估算研究具有一定参考意义。

关键词: 蒸散发, METRIC模型, 干湿限, 地表温度, 叶面积指数, 内蒙古

Abstract: The METRIC model was chosen to reveal the spatial ambiguity issue encountered during the calculation of regional evapotranspiration (ET) by remote sensing energy balance method. The study was based on the trend graph of surface temperature (Ts) and leaf area index (LAI). The dry pixel was chosen as the bare soil area where the Ts frequency histogram accounted for the top 5% of the high-temperature region, and the LAI frequency histogram accounted for 5% of the region. The wet pixel was chosen as the wetland or farmland where the Ts frequency histogram accounted for the last 5% of the low-temperature region, and the LAI frequency histogram accounted for the top 5% of the region. After that, the measured data of the eddy covariance system were used to verify the estimation accuracy of the model. The results showed that the average estimation accuracy of evapotranspiration in the calibration period and verification period was 15%, which was relatively reasonable compared with the previous research results. The selection scheme could help the Mapping Evapotranspiration with Internalized Calibration (METRIC) model to subjectively determine the dry-wet edge. The evapotranspiration values of different land use types were calculated, and they were in an order of ETwater>ETforest>ETarable land>ETunused land>ETurban and rural industrial land ≈ ETgrassland, which could be referred in researching the precision estimation of regional remote sensing evapotranspiration.

Key words: evapotranspiration, METRIC model, dry-wet edge, surface temperature, leaf area index, Inner Mongolia