A study of the distribution of evapotranspiration at forested areas using remote sensing.

利用遥感技术研究森林地区蒸散发的分布。

• 批准号: 06660190
• 负责人: EBISU Nobuhiro
• 金额: $ 1.28万
• 依托单位: Ehime University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06660190/
• 关键词: Evapotranspiration; Remote sensing; Forested arears; Mapping of evapotranspiration; Surface temperature; Image data; Infrared radiation thermometer; ヒートパルス速度; 熱収支

The first purpose of this study is to estimate the distribution of evapotranspiration at forested areas using the image data of surface temperature by an infrared radiation thermometer and the energy balance data (Surface Temperature method). The second purpose is to observe what causes the distribution of evapotranspiration. Therefore, values of soil water and heat pulse velocities were measured and a relation with distribution of evapotranspiration was analyzed. The results of this study are listed below :(1)The surface temperature, energy balance data and heat pulse velocities were observed at hinoki trees of Ehime university forest. The heat pulse velocity was high at the trees where the transpiration was large. The estimated evapotranspiration by Surface Temperature method had high values when the heat pulse velocity was high.(2)The surface temperature, energy balance data, heat pulse velocities and values of soil water were observed at sugi and hinoki trees of Amenomori experimental site. Amenomori is located in Takatsuki town, Shiga prefecture. There was an obvious difference between the evapotranspiration at the sugi trees and that at the hinoki trees both estimated by Surface Temperature method. At a comparison with the sugi trees, evapotranspiration at the hinoki trees was large in the morning and low in the afternoon. Furthermore, the difference of heat pulse velocities between the sugi and hinoki trees was corresponded to the difference of evapotranspiration. There was rain of 42 mm during the observation period, and the value of soil water changed. The influence of soil water to distribution of evapotranspiration was not recognized in this observation period.

本研究的第一个目的是利用红外辐射测温仪的地表温度图像数据和能量平衡数据（地表温度法）估算森林地区的蒸散发分布。第二个目的是观察是什么导致了蒸散的分布。因此，测量了土壤水和热脉冲速度值，并分析了与蒸散发分布的关系。研究结果如下：(1)对爱媛大学森林的白木进行了表面温度、能量平衡和热脉冲速度的观测。蒸腾量大的树木热脉冲速度高。地表温度法估算的蒸散量在热脉冲速度较大时值较大。(2)观测了杉木和白木试验场的地表温度、能量平衡数据、热脉冲速度和土壤水分值。阿莫森位于滋贺县高摫镇。地表温度法估算的杉树和白木的蒸散量存在明显差异。与杉木相比，白木的蒸散量上午大，下午小。此外，杉木和白木热脉冲速度的差异对应于蒸散量的差异。观测期间有42 mm的降雨，土壤水分值发生了变化。在这一观测期内，土壤水分对蒸散分配的影响尚未得到确认。