Estimation of land surface evapotranspiration (ET) using remote sensing is increasingly becoming an effective approach to approximating the moisture and heat exchanges between soil and atmosphere systems. The ET in the western Chinese Loess Plateau is comprehensively estimated by inputting NOAA/AVHRR data-derived parameters into surface energy balance system (SEBS) model. The observed data in the western Chinese Loess Plateau are used to verify the estimates of input variables. ET estimation in this research shows that ET in the western Chinese Loess Plateau is primarily determined by vegetation coverage. Topography also plays an important role in controlling the estimated ET spatial distribution. This study also demonstrate the remote sensing-aided surface energy balance model can be used to estimate ET in semiarid areas.

This study deals with desertification and its impacts on environment in the source region of the Yellow River. Our objectives were to reveal and quantify desertifcation changes from 1990-2000 by remote sensing and GIS, and discuss its impacts on carbon cycle. The results indicate that the study area is one of the most desertified regions in northeast Qinghai-Tibetan Plateau. The study area is now a carbon source. The desertification would have contributed to CO2 emission from grasslands of Qinghai-Tibetan Plateau. Otherwise, there are great potential to resequestration carbon through controlling grazing, restoring ecosystem, and reducing desertification.