Multiscale spatiotemporal characteristics and influencing factors of intensive cultivated land use in Yangtze River Economic Belt

Abstract: Under the limited reserve resources of cultivated land, it is necessary to change the traditional extensive utilization methods of cultivated land resources, and the road of intensive development is the most effective way to solve the human-land contradiction. The scientific analysis of spatial and temporal differences and influencing factors of cultivated land intensive use in the region is of great practical significance for promoting intensive potential exploitation and efficient utilization of cultivated land resources. Taking the Yangtze River Economic Belt as a case study, evaluation index system of cultivated land intensive use was constructed from the dimensions of input intensity, utilization intensity, output efficiency and sustainability. Projective pursuit model was used to quantitatively measure the level of cultivated land intensive use in the Yangtze River Economic Belt from 1978 to 2016. Based on the multiscale perspective of watershed, province and city, through the coefficient of variation, spatial autocorrelation index, the paper explored multiscale spatial-temporal differences of cultivated land intensive use in the Yangtze River Economic Belt. The influence mechanism of intensive utilization of cultivated land was revealed by using geographic detector model. The results showed that: since 1978, the level of cultivated land intensive use in the Yangtze River Economic Belt has improved at the watershed scale, but in the evolution process, the difference characteristics of "east high west low" have appeared; the intensive use of cultivated land in the Yangtze River Economic Belt at provincial and city scales presents spatial agglomeration characteristics, and the smaller the scale, the more significant the spatial agglomeration. During the period of the study, the types of spatial correlation between provinces and regions were mainly positive correlation, and there was a phenomenon of "club convergence" in cultivated land intensive use in the Yangtze River Economic Belt at city scale. The hot spots are mainly concentrated in Shanghai and Southern Jiangsu, and gradually evolved into Shaoxing-Hangzhou and Lancang; the cold point area was mainly concentrated in the Western Sichuan Plateau area. Natural factors, population growth, economic and social development, and institutional policies can effectively explain the spatial-temporal differences in the intensive use of cultivated land in the Yangtze River Economic Belt; demographic factors and economic and social factors have a significant impact on cultivated land intensive use, while policy factors have a strong driving effect. Finally, suggestions were put forward on how to promote cultivated land intensive use from the aspects of comprehensive land remediation, increasing the input of elements, optimizing and adjusting the structure of cultivated land, and promoting innovation in agricultural science and technology. In addition, it should be pointed out that there are still some deficiencies in this study: only the spatial and temporal patterns of cultivated land intensive use in six time sections since 1978 are analyzed on the time scale, it is also necessary to further reveal the temporal and spatial differentiation of intensive cultivated land use in the Yangtze River Economic Belt at a multitime scale. In terms of the impact mechanism, the factors of farmer households have not been discussed in this study, and the factors of farmer households have an important impact on regional cultivated land use efficiency. How to reveal the micro-mechanism of spatial and temporal differentiation of cultivated land intensive use in the Yangtze River Economic Belt from the perspective of farmers will be the next deepening area and direction of this study.