Study On The Landscape Pattern And Structure Optimization Of Agro-forestry Of Yongshou County In Weibei Loess Plateau

With the wild attention of theory and technology of agro-forestry,its reseach field widening and methods renewing.The landscape pattern is the comprehensive performance of the landscape heterogeneity and the result of nature,society and human effect.Taking Yongshou country in typical Hilly-gully region of Loess Plateau as the study area.Based on the land-use maps of the study area in 1995 and 2005,a transfer matrix of the landscape types was established under the supporting of GIS technology;at the same time,the dynamic analyses of the landscape changes in the study area were done from temporal and spatial perspectives which was associated with the barycentre model and the landscape metrics.The main research contents and results follow:(1) the landscape matrices from 1995 to 2005 were cultivated land,forest land and unused land and the garden land,building land,water area and grass land were inlaid as patches in the matrices. The severest decrease was happened in cultivated land,which was changed to forest land and garden land,as well as decreases in grass land,water area,unused land and the building land. Correspondingly,the increases were happened in forest land and garden land,which were changed from cultivated land and unused land.The forest land has the largest increasing number and the annual change rate.(2) The landscape heterogeneity was changed obviously from 1995 to 2005.The evenness index was in an increasing trend while the dominance index was in a decreasing trend.(3) The study on barycenter transfer model indicates that from 1995 to 2005,the barycenter transfer direction of garden land,forest land and building land was east-north,with the furthest barycenter transfer distance of garden land,and the barycenter transfer direction of cultivated land and unused land was east-south,only the barycenter transfer direction of water area was west-north.(4)The paper regards Yongshou country as studying area,2005 as annual base period.At first, the essential feature and existing problem of the land resource in Yongshou country were analyzed qualitatively according to the area's current situation of land use structure.Then,the population, cultivated land,grain total amount and per unit area yield to 2015 are predicted in Wuqi county according to the county's data over,the past years(2004—2008) by applying the grey predicting model of GM(1.1).Based on this,the grey linear programming model(GLP)was set up,and the land use structure was optimized with I1 variables set up according to feature of the land sources, the demand of society and economy development,management custom and development direction in the future of the county,the maneuverability of relevant data was considered comprehensive as well.To embody the principles of high benefit and low cost of land use and the optimal cllocation of land resources upper limit lower limit and median of the constraint parameters were adopted optional separately and calculated by applying the Lingo software,and three schemes were constructed to the ultimate.The optimum scheme of land use structure of Yongshou country was obtaine AHP to optimize those was applied also.