Pattern,Mechanism And Effect Of Multi-Scale Rural Land Use Transformation In Karst Trough Valley Area

With the vigorous promotion of urbanization and industrialization,China’s countryside has entered a new stage of transformation and development,and the territorial system of rural human-land relations has been evolving under the background of land use transformation and rural population migration.The transformation of rural land use has become an important part of rural transformation,and it is important to deepen the study of rural land use transformation to optimize the allocation of rural land use and promote rural revitalization and the construction of livable,workable and beautiful villages.This paper selects Langxi trough valley in karst trough valley as a case study,takes land use transformation theory as a guide,and explores the process,driving mechanism and effect of land use transformation in karst trough valley from multi-scale and long time series with the help of image interpretation data,county and township socio-economic statistics,and village and farm household survey data,and summarizes the land use transformation model in karst trough valley,so as to provide a better understanding of land use transformation in karst trough valley.This study provides scientific support and decision basis for optimal land use allocation and rural transformation development in karst troughs and valleys.The main conclusions of this study are as follows:(1)This paper constructs a multidimensional and multi-scale research framework for rural land use transformation.Based on the topographic gradient and economic gradient differences,land use transformation research is carried out on the basis of three scales:valley-village area-farm households,with the complete trough and valley landform unit as the research object.The land use transformation at different scales is measured by the indicators of "explicit transformation-implicit transformation-functional transformation".The explicit transformation aims to explore the quantitative and spatial transformation of land use,while the implicit transformation is based on the transformation of production factors,land inputs,land management methods and land use efficiency,and the functional transformation is based on the measurement of the transformation of the three life functions and the multifunctional transformation of land use.The three dimensions are progressive to each other,and finally the transformation of land system is regulated through land function.(2)On the trough and valley scale,the number of explicit land use transformation in the Langxi trough and valley over the past 50 years has shown a transformation process of "scale expansion-scale reduction-scale expansion".The transition speed shows the evolutionary characteristics of "dramatic-slow-dramatic-slowing down".In terms of topographic relief,the transformation of arable land,garden land,industrial and mining land,residential land and abandoned land mainly occurs in flat and slightly undulating areas,while the transformation of forest land and grassland mainly occurs in small,medium and high undulating areas,and the transformation of transportation land and bare rock occurs in the whole region.The implicit pattern shows that the arable land area per resident population tends to decrease and then increase,the utilization intensity tends to gradually weaken,and the land per resident site tends to be roughly utilized.The operation main body has changed from small farmers’ operation to multi main body operation.In terms of functional form,the three functions of land use show a trend of "slow decline followed by continuous improvement".The abrupt change point of the transformation of explicit and functional forms occurred in 2005,and the abrupt change point of the transformation of implicit forms occurred in 2015.(3)At the village scale,the explicit transformation presents that the slot dam-diversified industrial development village and slot dam-slot slope transitional-diversified industrial development village have the most significant transfer of garden land,the slot slope single industrial village development village has the most significant transfer of cultivated land to forest land,and the slot top-easy migration relocation village has the most significant transfer of forest land.The implicit transformation shows that the operating subjects of trough dam village diversified industry development village,trough slope single industry village development village and trough top-easy migration relocation village are in order of pure farming type + part-time type + new operating subjects to the operating subjects mainly new operating subjects.The three life functions of typical villages show a gradual increase,but the growth rate varies,with trough dam village-diversified industrial development village increasing the fastest,trough top-easy migration relocation village increasing the slowest,trough dam trough slope transitional-diversified industrial development village and trough slope-easy migration relocation village village village between the two.The functional transformation of trough dam-diversified industrial development village is transformed to production and living function,trough slope single industrial village development village is transformed from production and living function to ecological production function,and trough top easy migration relocation village is transformed from production and living function to ecological production function.The abrupt change point of the transformation of the explicit and functional forms appeared in 2005,and the abrupt change point of the transformation of the implicit form appeared in 2015,which is consistent with the trough valley scale.(4)The drivers of land use transformation in the study area have multi-scale characteristics.This paper discusses the factors causing land use transformation from three scales,so as to explore the causes of land use transformation.From the long time series,the land use transition is the result of the combined effect of natural,socio-economic,locational conditions and policy system.The impact of socioeconomic and policy factors is more important in the transition from the traditional to modern agricultural development stage.This paper applies actor network theory to explore the development mechanism of land use transition from the perspective of actor networks.It is argued that endogenous factors driving land use transformation are farm households,new management agents,village committees,and industrial development,as well as external assistance dynamics government and policy,technology and capital,markets and enterprises,and ecological construction,which are the factors driving land use transformation at the village level.The factors to explore land use transformation at the farm household level are mainly the livelihood status of farm households,contracted land of farm households and their land quality status.(5)Multi-scale land use transformation effects and farmers’ response.In this paper,the ecological and socio-economic effects of land use transformation are discussed at the trough scale and the village scale.The ecological and environmental quality at the trough and village scales showed an improvement trend after 2005.The responses of livelihoods,livelihoods output and livelihoods space at the farmer scale were mainly explored,indicating that farmers responded most strongly to the changes in livelihoods caused by land use transformation.(6)The multi-scale land use transition analysis reveals the land use transition patterns in karst trough and valley areas.The land use transformation models at the trough and valley scale mainly include"production supply + livelihood service enhancement land use transformation model","ecological restoration + livelihood supply enhancement land use transformation model","ecological restoration +production service enhancement land use transformation model",and"ecological restoration + livelihood service enhancement land use transformation model".+The land use transformation model with enhanced production and service functions".At the village scale,there are mainly land use transition models of ecological-economic and life-shifting land use transition in slot dam-diversified industrial development villages;ecological-shifting land use transition model in slot slope monoculture industrial development villages and production and ecological-shifting land use transition model in slot top easy migration relocation villages.And the land use optimization transformation path is proposed according to the model characteristics.