Analysis of spatial distribution pattern and evolutionary characteristics of cultivated lands based on spatial autocorrelation model and GIS platform— A case study of Longquanyi District, Chengdu, China

Cultivated lands are among the most fundamental resources for the existence and development of mankind. Scientific analysis of the spatial distribution patterns and evolutionary characteristics of cultivated lands is highly useful in the protection and resource optimization of cultivated lands. Working on such research project, this paper extracted cultivated land data from the 2005, 2009 and 2013 land use data of the Longquanyi District of Chengdu, China, and calculated the kernel density, concentration index of cultivated land and conducted spatial autocorrelation analysis by using GIS platform. The results suggested that: 1) the evolution of cultivated lands in 2005–2013 in the study area was driven by aggregation. Spatially, cultivated land densities in the northwestern and northern regions were higher than those in the southern and central regions. Regions with higher cultivated land density apparently expanded from northwest to southwest, while regions with lower cultivated land density sporadically expanded from urban to rural area. 2) For distribution of cultivated lands, feature land density in the north was generally higher than that in the south. The distribution of cultivated lands was relatively concentrated, with more concentrated years in terms of the time series, but with more significant variation in the spatial differentiations among the regions. 3) There was a significant spatial autocorrelation for global distribution, with strengthening heterogeneity for local distribution of cultivated lands in the study area. Spatial units with higher proportion of cultivated lands was concentrated in the northern and northwestern regions and reduced westwards from year to year. The units with lower proportions of cultivated lands were more distributed at built-up areas and suburbs surrounding the urban centers, with two stages of expansion and contraction. Because of urban expansion and rural land consolidation in 2005–2013, there were hot spots and cold spots in different localities of the distributed cultivated lands. This study provided the theoretical methods and references for determining the dynamic evolution of regional cultivated lands and developing relevant policies for protection and resource optimization of cultivated lands.