Analysis on spatial distribution pattern and change characteristics of cultivated land in Yangzonghai basin in the past fifteen years

【Objective】In order to grasp the quantity of cultivated land in Yangzonghai basin, the temporal and spatial variation characteristics of cultivated land were analyzed, which could provide a reference basis for the sustainable utilization of cultivated land resources and land spatial planning in Yangzonghai basin. 【Method】Based on ArcGIS, Fragstats 4.2 and other software, the RS data from 2005, 2010, 2015 and 2020 were selected to analyze the dynamic variation and spatial distribution pattern of cultivated land in the study area using different methods such as dynamic variation degree, different terrain conditions, transition matrix, geo-informatic atlas, and landscape pattern index. 【Result】From 2005 to 2020, the number of cultivated lands in the study area showed a decreasing trend with a reduced area of 816.45hm² and a dynamic variation degree of -0.66%. From the county (district) scale, Yiliang County showed a continuous decline trend in the past 15 years, while the other three counties (districts) increased and decreased in each period; The topographic conditions had a certain impact on the cultivated land spatial distribution. The cultivated land in the study area occupies a large proportion in the cloudy aspect and semi-cloudy aspect with the altitude < 2300m and slope < 25°; From the perspective of geo-informatic atlas and landscape pattern index, cultivated land increased and decreased in each period from 2005 to 2020. The main types of land increasing are forest land, unused land and construction land, among which forest land accounted for a large proportion, indicating that the local ecological protection measures such as "returning farmland to forest" had achieved certain results. The landscape pattern index changed in each period from 2005 to 2020. Throughout the 15 years, the number of cultivated land patches had increased, and the average patch area and aggregation degree had decreased, indicating that the overall spatial aggregation of landscape pattern had weakened, the trend of landscape fragmentation had been presented. 【Conclusion】Based on the RS data of 2005, 2010, 2015 and 2020, the spatial distribution pattern changes of cultivated land in Yangzonghai basin in recent 15 years were analyzed from different angles by using the methods of dynamic variation degree, different topographic conditions, transfer matrix, geo-informatic atlas and landscape pattern index, so as to provide an important basis for rural revitalization and village planning in the future.