Comparison of Growth Curves and Seasonality Parameters of Main Field crops in a High Elevation Mountain Area based on TIMESAT Program

Time series Normalized Difference Vegetation Index (NDVI) has been shown to provide useful data that can be applied to study vegetable phenologies and crop calendars, and much research has been conducted with it in the main agricultural regions of China. However, few studies using NDVI have been conducted in the Qinghai-Tibet Plateau where agriculture is often limited in the valley and piedmont areas. From the view of agricultural diversity and food security, agriculture (especially grain production) is still very important in this area and thus research is needed. Here we conducted research in a small watershed (Figure 1) in the upper stream of the Huangshui River (which is the largest tributary of the Upper Yellow River and also the main grain production area of Qinghai Province), with the goal of testing the feasibility of extracting seasonality parameters using Landsat Thematic Mapper (TM) images and the TIMESAT Program, and also determining the potential NDVI criteria to discriminate different crop types. Crops in this area are spring wheat, highland barley, rape, potato and broad bean.