摘要
目前热红外遥感监测土壤水分含量的方法主要有热红外法、热惯量法和温度植被指数法。其中,热红外法简单易行,在缺乏昼夜温差数据时可用白天下垫面温度反演土壤水分,但其仅考虑某一时刻土壤水分对土壤温度的影响,故其反演精度不够理想;热惯量法物理意义明确,估算精度高,简单易行,但也存在诸如只适用于裸露或植被覆盖度低的地区以及卫星数据难于获取等局限性;温度植被指数法物理意义也较明确,适用性广,但计算过程较复杂,且某些参数难于及时获得。相对来说,植被稀疏区宜采用热惯量法,植被郁闭区则宜采用温度植被指数法。在未来,随着遥感传感器性能的改进,多种技术的综合应用,特别是热红外技术与微波技术的结合应用,将会显著提高土壤水分含量遥感监测的精度。
At present, the thermal IR remote sensing assisted methods for monitoring soil moisture content mainly includes thermal infrared method, thermal inertia method and temperature/vegetation index method. A- mong them, the thermal infrared method is relatively simple and easy to use, and is possible to retrieve soil moisture content from the data of ground temperature at daytime and especially in the condition of lacking the data of temperature range between day and night. Nevertheless, because the effect of soil moisture condition on soil temperature is considered only at a given time period, the accuracy of retrieval for soil moisture content by this method is usually not so ideal. The thermal inertia method has some advantages, such as clear physical meaning, higher accuracy in estimating soil moisture condition and also simple and easy to use. However, it also has some limitation. For example, this method can be used only in the regions with no or little vegetation cover and, in addition, the satellite data suitable used in this method are rather difficult to obtain timely. As to the temperature/vegetation index method, it also has clear physical meaning and can be used in many conditions. However, its calculation process is quite complicated and the data of some parameters used in the calculation are difficult to collect. In future, with the improvement of remote sensors and comprehensively application of different techniques, especially the combined use of thermal infrared technique and microwave one, the monitoring accuracy of soil moisture content with remote sensing will be greatly improved.
出处
《干旱地区农业研究》
CSCD
北大核心
2006年第6期168-172,共5页
Agricultural Research in the Arid Areas
基金
国家自然科学基金(40371081)
关键词
遥感
热红外
土壤水分含量
监测
研究进展
remote sensing
thermal infrared
soil moisture content
monitoring
progress
