| With the rapid development of urbanization and industrialization,the relationship between man and land has become increasingly tense.In order to ensure food security and economic and social development,the development of unutilized land in hilly areas has become an important way to expand the new space of agricultural land under the new situation.However,the eco-environment in hilly areas is fragile,and the unreasonable development and utilization of unutilized land will cause serious damage to the regional ecological environment.Therefore,it is particularly urgent to study the ecological risk of unutilized land development in hilly areas.In this paper,the comprehensive index evaluation model is used to construct the ecological risk assessment system of unutilized land in hilly areas,and Tang County,a typical hilly area,is taken as the research area for empirical study.By analyzing the temporal and spatial evolution of ecological risk of unutilized land development in 2007-2016,functional zoning of unutilized land is carried out,and according to different functional zones,targeted control suggestions are given.The purpose of this study is to provide reference to the development of unutilized land in Tang County.The main conclusions are as follows:(1)Based on the mountain characteristics of hilly areas,this paper constructs the ecological risk assessment model of unutilized land development in hilly areas.The model includes two levels:landscape fragmentation,landscape fragility,landscape separation,landscape dominance and landscape fragmentation;vegetation coverage,soil erosion intensity,land use intensity and ecosystem service value.Finally,ArcGIS software is used to analyze the ecological risk distribution and temporal and spatial evolution of unutilized land in hilly areas.(2)During the study period,the area of unutilized land in Tang County decreased from 544.83 km~2 to 274.14 km~2,with a decrease of 49.68%,mainly for agricultural land.Among them,the unutilized land in the southeastern part of the county is mainly exploited as farmland,forest land and grassland;the unutilized land in the central part of the county is mainly exploited as farmland;the unutilized land in the northwest part of the county is mainly exploited as residential land;only a small amount of unutilized land in the northern part is exploited as forest land and cultivated land.(3)The ecological risk of unutilized land in the study area is mainly moderate,with an area of 281.72 km~2,accounting for 51.71%.During the study period,the ecological risk of unutilized land changed from low-level risk to high-level risk,and the transfer from low-risk area to medium-risk area was up to 47.22 km~2.The spatial distribution pattern of ecological risk of unutilized land was low in the northwest,high in the East and central areas,and the ecological risk of eastern and central areas showed an upward trend,while that of northern areas.Ecological risk is relatively stable.(4)Based on the spatial and temporal evolution characteristics of ecological risk of unutilized land development in the study area and the main causes of ecological risk,the unutilized land development area in Tang County is divided into four ecological risk control zones:cultivated land adjustment and optimization zone,unutilized land ecological development zone,forest and grassland ecological protection zone and unutilized land development and restoration zone.On this basis,the natural environment characteristics of Tang County are discussed.From the perspective of social and economic conditions,the regulation measures to reduce ecological risk are put forward for different functional areas.This study can provide a reference for the study of ecological risk of unused land at county level in hilly areas,and also provide a basis for the ecological risk management and control of unutilized land in Tang County. |
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