Spatial Effects Of Qingjiang River Basin Structure On Landuse And Human Activity Patterns

Watersheds have a profound impact on urban construction,agricultural production activities,economic development,and civilization development.Understanding the spatial distribution characteristics of land use and human activities on the watershed structure,and quantitatively analyzing the impact of watershed structure on land use and human activity patterns can enrich people’s understanding of the formation of land use and human activity patterns,and also provide a basis for watershed planning,It provides a certain scientific basis for management,protection and restoration,and sustainable development.With the support of geographic information system and remote sensing technology,this paper interprets the image data of landsat8 in October2018 and November 2020 to obtain the land use distribution map of the Qingjiang River Basin,and preprocesses the 12.5m ALOS DEM elevation data to obtain distribution map of all levels of watershed,terrain,slope,terrain relief,and surface cutting depth.On this basis,the characteristics of the watershed structure,the characteristics of the land use and human activity pattern under the watershed structure,the influence of the watershed structure on the land use and human activity pattern and its quantitative relationship are analyzed and studied.The research on the characteristics of the watershed structure is mainly based on the construction of a watershed structure characteristic index system.The number of watersheds,the average area of the watershed,the watershed shape coefficient,the watershed separation index and the aggregation index,the watershed river network density,the watershed terrain type,the watershed slope,and the watershed terrain relief are selected.,The surface cutting depth of the watershed is expressed by a total of 10 indicators.The research on the characteristics of land use and human activity patterns under the watershed structure mainly uses the number,density,average area and percentage of land use type patches,land use distribution index,land use type shape index,land use type separation index,and land use type aggregation.The index,the human activity intensity index,and the scale of human activities are represented by a total of 10 indicators.Aiming at the research on the impact of watershed structure on land use and human activities,we mainly find significant correlation factors through correlation analysis,and then use common function models to perform regression analysis on the spatial relationship between watershed structure and land use and human activities to find the best fit function.Conclusion（1）The watershed structure indicators of different levels have hierarchical characteristics.The average area,aggregation index,shape index,and river network density of the watershed increase step by step in the 1-6 watersheds,and the number of watersheds and the separation index decrease step by step.The area and percentage of topographic structure indicators are in descending order:(low and medium mountains > low mountains >hills > plains > hills > high mountains,slopes > steep slopes > sharp slopes >dangerous slopes > slightly flat slopes > flat slopes,small undulations > slight undulations > medium Ripple>flat>big wave,cutting depth20m-40m>40-60m>0-20m>60-80m>100m.（2）As the watershed grade increases,the land use type and the scale,shape complexity and aggregation degree of human activities show an increasing trend;There is a gradual downward trend,and the type of land use gradually transitions from the type with strong human activities to the type with partial natural effect.（3）From the perspective of the watershed hierarchy,the average area,shape and dispersion degree of the watershed are significantly correlated with the scale,shape and dispersion degree of land use and human activities.The best fitting function of the watershed hierarchical structure to the spatial interaction relationship of land use type and area scale is a logarithmic function,and the best fitting function to the spatial interaction relationship of land use type,human activity land shape,and human activity scale is a linear function.The best fitting function for the spatial separation and aggregation degree of land use types is a polynomial function（4）From the topographic structure of the watershed,topographic types and slopes are significantly correlated with land use patterns and human activity intensity.The best fitting function of the influence of the topographic type structure of the watershed（ie altitude）on the land use type and the spatial distribution of human activity intensity is a linear function.The best fitting function for the distribution of the dominant distribution of the watershed slope structure on land use types and the intensity of human activities is the logarithmic function..