Authors: Xianfeng Chen*, Slippery Rock University of Pennsylvania, Jack Livingston, Slippery Rock University of Pennsylvania
Topics: Arid Regions, Geographic Information Science and Systems, Global Change
Keywords: Field sampling, Fractional vegetation cover, GIS, GPS
Session Type: Paper
Presentation File: No File Uploaded
Although the desert has very sparse vegetation and less diverse ecosystem than its counterpart does in wet climate region, its vegetation plays an essential role in the physiological and biogeochemical function of arid and semi-arid ecosystem. Fractional vegetation cover extracted from remotely sensed data has be used as an indicator to environmental disturbance such as overgrazing and desertification, and climate change. The biggest challenge to this sort study is to collect ground truth data to verifying the remote sensing model. In this study, we examined a field survey strategy integrating geographic information system (GIS) and global positioning system technology. Our study area locates at the transitional zone between mountainous steppe of Tian Shan Mountain and Gurbantünggüt Desert near Shihezi, Xinjiang China. A total twenty 200-meters transects were covered from sand dune to mountainous steppe. The camera was mounted 2 meter above the ground to yield an image field-of-view around 1.5 m x 2.5 m. image was taken every 5 meter along the center line of transect. The location of each photo was pinned with GPS device. The differential analysis of GPS data was performed to improve location accuracy around 1 m. All photo samples were digitized manually using random point samples and classified automatically using minimum distance and spectral angle mapper. Statistic test and correlation analysis were applied to the sampling results.