地理科学进展 ›› 2008, Vol. 27 ›› Issue (2): 53-59.doi: 10.11820/dlkxjz.2008.02.008

• 遥感与模式应用 • 上一篇    下一篇

遥感蒸散模型的时间重建方法研究

熊隽1, 吴炳方1, 闫娜娜1, 胡明罡2, 孙敏章3   

  1. 1. 中国科学院遥感应用研究所农业与生态遥感研究室,北京100101;
    2. 北京市水利水电技术中心,北京100049;
    3. 水利部中国灌溉排水发展中心,北京100038
  • 收稿日期:2007-12-01 修回日期:2008-02-01 出版日期:2008-03-25 发布日期:2008-03-25
  • 通讯作者: 吴炳方(1962-),男,江西玉山人,博士,研究员,主要从事遥感与地理信息系统应用及生态环境监测等研究. E- mail: wubf@irsa.ac.cn E-mail:wubf@irsa.ac.cn
  • 作者简介:熊隽(1981-), 男, 贵州人, 毕业于南京大学城市与资源学系, 地理信息系统专业, 现于中国科学院遥感应用研究所攻 读博士学位, 主要研究方向为地表通量定量反演及应用研究.E- mail: suredream@163.com
  • 基金资助:

    世界银行GEF 项目(海河流域水资源水环境综合规划)资助.

Resear ch on Tempor al Reconstruction of Evapotr anspir ation by Using Remote Sensing

XIONG Jun1, WU Bingfang1, YAN Nana1, HU Minggang2, SUN Minzhang3   

  1. 1. Institute of Remote Sensing Applications, Chinese Academy of Sciences, Beijing 100101;
    2. Beijing Water Technology Center of Beijing Water Authority, Beijing 100073, China;
    3. China drainage Center, Minister of Water Rsources, Beijing, 100038. China
  • Received:2007-12-01 Revised:2008-02-01 Online:2008-03-25 Published:2008-03-25

摘要:

本文提出的遥感蒸散模型的时间重建方法考虑了逐日蒸散可能的变化情况, 在阻抗- 彭曼单层模型的基础 上, 将图像去云处理与时间重建结合在一起, 先使用SEBS 能量平衡余项模型获得晴好日的地表阻抗信息, 选择了 叶面积指数LAI 作为反映植被表面阻抗的参量, 通过时间序列谐波分析(HANTS)获得逐日逐像元的LAI 信息, 将晴 好日的阻抗信息扩展至待定日, 并使用因子函数表达了极端温湿条件对植被叶面阻抗的限制作用。使用中科院禹 城站2003 年作物季的大型蒸渗仪数据对模型所得逐日蒸散结果进行了验证。在作物生长季, 模型结果相对于实测 结果表现出了良好的相关性(R2≈0.7), 远优于作为对比的蒸发比不变法。受单层模型假设局限, 方法在裸地及稀疏 植被上的结果还存在着较大的误差。

关键词: MODIS, 地表蒸散( ET), 时间重建, 遥感反演

Abstract:

Temporal reconstruction of evapotranspiration (ET), which means deriving continuous, complete annual ET from fragmentary satellite measurement, is a problem full of uncertainty in remote sensing application. Traditionally, evaporative fraction (LE/H) is simplified as constant in a short period so that weekly or long term ET could be estimated from a single clear satellite image. In this way, variation of daily ET is often neglected and the amount of ET is hard to compare with those at the same time in another year. The objective of this research is to develop a new reconstruction algorithm to retrieve continuous and actual ET dataset and provide valuable temporal profile for agriculture and ecology application. This algorithm considers both the spatial and temporal discontinuity, and is a combination of SEBS (Surface Energy Balance System) and Penman- Monteith model: SEBS model is used to derived latent heat in clear days, and then surface resistance is inverted from PM equation; Leaf area index (LAI), is interpolated and smoothed to daily term by using HANTS (Harmonic Analysis of Time Series) method. Then surface resistance of the cloudy days is related to those from neighboring clear days with a function of LAI, minimal air temperature and vapour pressure deficit. Daily ET estimation is compared to lysimeter measurements recorded in Yucheng agriculture site and shows a good correlation coefficient in crop growing season (R2≈0.7). Model result is not satisfactory on bare and sparse land because of the limitation of the one- layer assumption in PM equation, which requests that an independent component of soil evaporation should be added into the algorithm.

Key words: MODIS, regional evapotranspiration(ET), remote sensing, retrieve, temporal reconstruction