Evolution and optimization regulation of rural settlements in Jilin Province from perspective of human-land relationship in 1990—2020

Based on rural settlements database acquired by multi-temporal remote sensing images, the spatial pattern and dynamic changes of the settlements were characterized with landscape ecological indices, kernel density and frequency-area scale class models. Furthermore, the decoupling relationship between rural settlements land and rural population in Jilin Province from 1990 to 2020 was analyzed by integrating demographic statistics and decoupling model. The results indicate that: 1) The scale of rural settlements in Jilin Province exhibited a phased change characterized by “increase followed by decrease”; 2) The regional distribution pattern of settlements was pronounced, presenting a stable configuration of “high density and contiguous high-value areas in the central region, with sparse and scattered clusters in the eastern and western regions of Jilin”, and an underlying trend of aggregation was observed beneath this relatively stable appearance by decreasing NNIs at province, partitions and the prefectural-city scale; 3) Small settlements accounted for an absolute majority, and the area-frequency distribution of settlement sizes showed a stable flattened pattern; 4) The settlement-population relationship shifted into comprehensive negative decoupling across multiple scales. The optimization and regulation strategies are as follows: 1) “Shrinking the countryside and expanding the small city and town” in response to rural-urban migration; 2) Priority should be given to the spatial restructuring of settlements in three prefecture-level cities in the central black soil region, in the following order: Changchun, Liaoyuan, and Siping; 3) A spatially hierarchical structure with clear differentiation, consisting of “towns-central villages-administrative villages”, should be established. This study can provide a basis for black soil resource conservation and for formulating urban-rural land-use planning as well as village revitalization planning in Jilin Province.