Land reclamation zoning of Chaohu Lake Basin based on GIS and grey constellation clustering

Abstract: Land reclamation zoning is the premise and foundation for comprehensive land consolidation and planning. It can provide effective guarantee for the work of scientific land renovation. This paper takes Chaohu Lake Basin as an example, based on the analysis of basic conditions of the local conditions, status of land renovation and land use, the principle and the basis for the selection of the evaluating indices are combined. Drawing lessons from previous land regulation indicators and considering the accessibility of index data, 4 factors are considered including natural conditions, location advantages, social economy and land use, and the land consolidation zoning index system includes 13 elements. In order to eliminate the difference between the various index units, the values of the 13 indices are normalized. The entropy method is used to determine the weight for avoiding the influence of subjective factors, and the relevant experts are consulted on the appropriate adjustment of the weight of the index. GIS (geographic information system) platform was employed to build thematic data layers, and spatial distribution characteristics of index system were analyzed using spatial data visualization. Finally, the grey constellation clustering method was used to delineate different land consolidation zones, and 232 villages and towns in the study area were categorized into the semicircle coordinate system of 0-180°. According to the high aggregation degree of X and Y coordinates, different villages and towns were divided into one class, which is called "constellation". According to the results, the Chaohu Lake Basin is divided into 4 types of land consolidation areas. And considering the continuity of spatial distribution, according to the comprehensive index value ranking and the maximum similarity principle, the natural spatial continuity is used to adjust the regional results, and the results of the adjustment and merging are proofed and the results of the clustering are proofed. It shows that the grey constellation clustering method is feasible for the zoning in the Chaohu Lake Basin. Finally, the 232 villages were categorized into 4 land consolidation types, which were: Zone I (area of ecological conservation type), including 21 villages and towns, accounting for 12.49% of the study area, the development and utilization of low hill gentle slope should be emphasized; Zone II (area of urban development type), including 42 villages and towns, accounting for 1.08% of the study area, ecological land consolidation model was recommended, which could serve for the urban area via county park construction; Zone III (area of basic farmland type), including 86 villages and towns, accounting for 42.95% of the study area, high standard prime farmland construction mode was recommended, which was implemented by raising the quantity of cultivated land and improving the quality; Zone IV (area of comprehensive regulation type), including 82 villages and towns, accounting for 43.48% of the study area, land consolidation should be carried out mainly by the relocation of villages, improving the rural agriculture and economy, and reducing the phenomena of the hollow village and land abandonment. The research results can provide a scientific and reasonable basis for making land consolidation plan in the Chaohu Lake Basin, and provide scientific reference for the regulation and control of land consolidation in Chaohu Lake Basin.