Study On Dynamic Evolution Of Shelterbelt Pattern In Hongmenchuan Basin Of Miyun County

This paper has taken 1:10000 topographic map as the map work, based on the satellite image data of Hongmenchuan basin in 1995, 2000 and 2005, used remote sensing images and land-use data of Hongmenchuan basin of the three periods, made a image processing by using ERDAS software, delineated land-use types, set up the spatial database and the attribute database of the basin by using ArcGIS3.2 software. With the combination of field survey, produced the land use pattern maps of the three periods. Used landscape index and the Patch Analyst, the expansion module of landscape analysis of ArcView3.2 software to calculate landscape pattern indices of Hongmenchuan basin, analyzed dynamic changes in the characteristics of watershed landscape pattern, made transfer matrixes of landscape area of the period of 1995~2005 by using Arcview and excel software. Selected suitable nature factors and socio-economic factors, analyzed the correlation between the factors and the shelterbelt landscape pattern change by using gray correlation analysis, to determine the driving force factor that affected the shelterbelt landscape pattern change, and to analyze the mechanism that affected the shelterbelt landscape pattern change. Main conclusions of the study are as follows: (1) the areas of shelterbelt landscape types of Hongmenchuan basin increased generally, the areas of coniferous forest, broadleaf forest and shrub increased, the area of mixed forest decreased; the areas of non-forest landscape types decreased generally. (2) the plaques of the landscape of Hongmenchuan basin had a tendency to break and disperse, the distribution of all landscape types had a tendency to be balance. The significant change of landscape index occurred at the end of the study, it tallied with the changing trend of the driving factors of landscape pattern change. (3) of all the driving factors that has selected, the correlation degree between annual lowest temperature and the change of shelterbelt pattern was not high. The socioeconomic factors were the direct motivity of the change of shelterbelt pattern.