Study on land use change and ecological effect in Tailan River watershed in recent 15 years
近15年台兰河流域土地利用变化及其生态效应研究

TM remote data in 1990, 2000 and 2005 were used to explore land use type changes from 1990 to 2005 in Tailan River watershed using GIS. The results indicated that the areas of cropland and sandy land increased by 3.50×104 hm2 and 2.05×104 hm2 respectively while grassland area decreased by 1.43×104 hm2, suggesting the great reclamation over the past years. Five sites with similar natural conditions but different land uses were selected for comparing soil properties, soil organic matter (SOM) and total salt decreased sharply with soil depth, and the effects of land use type on SOM and total salt occurred mainly within 0 - 25 cm depth. The total salt of croped glycyrrhiza land and saline-alkali land were greatly higher than those of the other land use types. SOM contents in topsoils of land use types followed an order of economic forest > farmland > croped glycyrrhiza land > ameliorated sandy land > saline-alkali land. In addition, total salt decreased while SOM increased with the years of farming.