Spatiotemporal Distribution and Fragmentation Driving Mechanism in Paddy Fields and Dryland of Urban Agglomeration in the Middle Reaches of the Yangtze River

The spatial-temporal distribution pattern of China's cultivated land has changed dramatically from 1990 to 2020, and the problem of cultivated land fragmentation has become more prominent. However, the existing research lacks a focus on the two specific land use types, paddy fields and dryland. In this study, the spatiotemporal distribution pattern and the fragmentation driving mechanism of paddy field and dryland during the years 1990 to 2020 were identified by using the center of gravity center migration model, standard deviation ellipse, and land-use dynamic model for the urban agglomeration in the middle reaches of the Yangtze River as an example. The results show that there are significant differences in the spatiotemporal distribution characteristics of paddy field and dryland in the MRYRUA. Among the provinces and cities, Hubei province and its Xiangyang city showed the most obvious trend of change. The loss and gain of paddy fields and dryland is related to economic and policy contexts in each period. The main driving factor of paddy field and dryland fragmentation is natural condition, whereas a relatively important factor is the per capita disposable income of rural residents. The effects of each factor on paddy field and dryland fragmentation were not independent; any two factor interactions had a stronger effect on paddy field and dryland fragmentation than a single factor. In general, this study provides guidance and references for the main grain-producing areas undergoing rapid urbanization relating to cultivated land conservation, food security, and sustainable agricultural utilization.