Topographic gradient differentiation of cultivated land and driving factors of its change in the dry valley of Anning River
In order to provide scientific reference for rational utilization of cultivated land and agricultural de-velopment planning in dry valleys,based on high-precision land data,kernel density analysis,landscape index,topographic gradient classification ( altitude,slope,aspect,landform) and PLUS model were used to study the spa-tiotemporal distribution,aggregation and fragmentation driving mechanism of topographic gradient differentiation and its changes of cultivated land in Anning River Basin from 1980 to 2018.The results showed that:(1) The cultivat-ed land accounting for approximately 24% of the total watershed area,mainly concentrated in the narrow valley are-as on both sides of the mainstream of Anning River.The cultivated land in Anning River Basin continued to de-crease,with a total reduction of 61.77 hm2 from 1980 to 2018,mainly transferred out as forestland,grassland,wa-ter area,and construction land.(2) The cultivated land showed a spatial distribution pattern of more in the valleys and less in the mountain land,with the fluctuation of spatial aggregation degree decreasing and the degree of frag-mentation increasing during the research period.(3) The distribution of cultivated land within the watershed had significant vertical zonality (993～1879 m altitude,0～15° slope,three aspects of east,southeast and south,three landforms of plain,hill and small undulating mountains were the dominant positions in the distribution of cultivated land) .More than 55.72% of cultivated land highly concentrated in the flat valley plain zone and the sunny slope zone of the moderately undulating mountain area,which also decreased significantly in these areas.(4) Economic factors such as population density,GDP,and distance from roads,as well as natural factors such as slope,altitude and distance from water area had a profound impact on cultivated land change.The contribution of population densi-ty is the highest,reaching 0.13.The cultivated land of Anning River Basin had significant topographic gradient dif-ferentiation.Under the constraints of natural conditions such as altitude,slope and water area,and the action of e-conomic factors such as population,GDP,and road conditions,the area of cultivated land was continuously decrea-sing,and the fragmentation phenomenon was intensifying.
cultivated land changetopographic differentiationspatial distributiondriving factorsdry valleyAnning River Basin
万方数据
维普
