The study area is selected in North China region, corresponding to path 123 and row 31 of Landsat ETM+ data. To weaken the influence of Landsat ETM+ gaps on classification accuracy, a rectangle region is subset as the final study area, which lies between approximately 40◦6N to 42◦4N, and 116◦3E to 117◦7E (Fig. 1). The study area mainly consists of Weichang, Fengning, Longhua, Duolun and Luanpin counties of China. It belongs to semi-humid and semi-dry climate region at temperate zone. The annual precipitation is about 500 mm, of which 80% falls in the period of July to September.The annual average temperature is about −1.4 to 4.7◦C, and the annual accumulated temperature above zero is 2000–2200◦C. Four seasons are evident, and wet and hot in the summer, cold in the winter.