Study On Land-Use/Land-Cover Change And The Ecological Carrying Capacity In Loess Hilly And Gully Region

The ecological carrying capacity is a part of regional sustainable development ability. Both types of land-use and change of land-cover will affect the structure and function of ecosystems, so that leading to changes in ecological carrying capacity. It will help to announce the reason of the ecological carrying capacity and land-use change in Loess Hilly and Gully Region by discussing the effect of the land-use/land-cover change on the ecological carrying capacity. In order to offer scientific basis to regional sustainable development, this study based on the theory of data aimed to analyse the ecological carrying capacity and the effect of the land-use/land-cover change on the ecological carrying capacity of Chakou valley.Firstly, based on the land use status chart which roots in field survey and images dealt with remote sensing software (such as ArcGIS), get the corresponding land use status data through statistics and spacial analysis. On the basis of the land use status data, this paper made an analysis about the dynamic change of land use change in the study regional from four aspects:rangeability,trend ,degree and intensity.Secondly, on the basis of the theory that comprehensive evaluation of ecological carrying capacity, this study constructs a comprehensive evaluation index system of ecological carrying capacity, and made an comprehensive evaluation about Chakou valley’s ecological carrying capacity based on SPSS statistical analysis software and principal component analysis theory. Then made an analysis about the effect of land use change on the ecological carrying capacity from two aspects:the bearing capacity of land resources, and the relationship between the ecological carrying capacity and land use dynamic trend and degree.What’s more, based on MATLAB software and the theory of SVM ,this study made a regression simulation test about the relationship between the bearing capacity and the bearing factors from 2008 to 2013, to predicted the level and change trend about the bearing capacity in the future. Finally, puts forward suggestions for improving the comprehensive bearing capacity of the Chakou valley.Conclusions:(1)The land use of the small watershed is on the development stage and the degree of intensity of land use improves from 2003 to 2013.The main developing kind of land are slope cropland, terraced fields, grassland and forest during the research. Garden plot and forest develop fastest and the land use intensity of grassland, whose land intensitis change is the most drastic, reaches -0.29%.The effect of returning the farmland to forest project and turning hillsides into terraced fields project is remarkable.(2)Ecological capacity improves during the research as a whole. The influence index of the social economy grows fastest and the resource environmental bearing capacity has more influence on ecological capacity among three subsystems.Thereinto, the key impact factors are land reclamation index, forest coverage rate, lost sediment of the runoff, nitrogen and phosphorous content of the runoff, the per unit area yield of grain, population density and per capita income.(3)It satisfies the demand of population carrying capacity of the land based on food security at present, but the demand of the plough has approached the cultivated land. The land use dynamic and the change of ecological carrying capacity are positive correlation, while the index of the land use degree and the index of the ecological capacity are negative correlation.(4)The precision of the regression model based on the support vector regression machine satisfied the request of 90%, and has a high accuracy. It could predict the comprehensive carrying capacity of the small watershed.