Study On Dynamic Change Of Land Use Pattern Of Dagoutou Small Watershed In Naiman County

The changes of land use and landscape patterns were analyzed, based on land use photo data of Dagoutou small watershed in Naiman County, farming-pastoral zone in 1986, 1997 and 2005, using the methods of GIS, statistical analysis and landscape ecology in this paper. The results show that the land use patterns have changed significantly in this region with the fulfillment of small watershed comprehensive control and the policy of returning farmland to forest from 1980's.Land use structure has been changed in a great manner. Forest area markedly increased by 77.92% and forest had become the main landscape. Cultivited land was decreasing from 50.21% in 1986 to 33.76% in 2005. Under the measures of soil and water control, the area of deserted grass land in the gully was decreasing and patch was gathering, while the areas of houseland and the patch along the gully were not changing markedly. The deserted grassland n the slope disappeared later.As to landscape variation, on the whole landscape level, the index of fragmentation and diversity were obviously increased. The most obvious change took place at forest landscape. With the number of patch markedly increasing, MPS was decreasing, which indicated that forest land was becoming more and more separate and dispersing. The fragmentation degree of cultivited land was increasing, but grassland, houseland and the patch along the gully showed little change, and little influence to land use pattern. AWMSI of forest was increasing year by year, indicating that the shape of forest patch was becoming more and more irregular. AWMPFD values of forest, grassland, houseland, and the patch along the gully appeared the increasing trends, which indicated that these types of land use were influenced by human activity in different degrees. The IJI's were increasing with time, which showed the influence degree of human activity to landscape factors of the watershed was becoming obviously.In view of spatial distribution, at the head of gully, deserted grassland was replaced by forest. Upper slope and the gully end were used as forest land. All the measures of soil and water conservation and desert control as well as the fulfillment of returning-farmland-to-forest policy had played an important role in wind-breaking and sand-fixing effects, and contributed greatly to the decrease of soil erosion. The analysis of the land use pattern of Dagoutou small watershed, on one hand, provides bases for the studies on the force of dynamics of land use pattern, on the other hand, provides scientific data for the reasonable exploitation and use of land resources as well as optimization of land use pattern, and eventually makes the eco-environment and social economy of the whole watershed get a healthy, steady and sustainable development.