Modeling of spatial distributions of farmland density and its temporal change using geographically weighted regression model

This study used spatial autoregression (SAR) model and geographically weighted regression (GWR) model to model the spatial patterns of farmland density and its temporal change in Gucheng County, Hubei Province, China in 1999 and 2009, and discussed the difference between global and local spatial autocorrelations in terms of spatial heterogeneity and non-stationarity. Results showed that strong spatial positive correlations existed in the spatial distributions of farmland density, its temporal change and the driving factors, and the coefficients of spatial autocorrelations decreased as the spatial lag distance increased. SAR models revealed the global spatial relations between dependent and independent variables, while the GWR model showed the spatially varying fitting degree and local weighting coefficients of driving factors and farmland indices (i.e., farmland density and temporal change). The GWR model has smooth process when constructing the farmland spatial model. The coefficients of GWR model can show the accurate influence degrees of different driving factors on the farmland at different geographical locations. The performance indices of GWR model showed that GWR model produced more accurate simulation results than other models at different times, and the improvement precision of GWR model was obvious. The global and local farmland models used in this study showed different characteristics in the spatial distributions of farmland indices at different scales, which may provide the theoretical basis for farmland protection from the influence of different driving factors.