Spatial-temporal disparity characteristics of cultivated land intensive use in Wuhan Urban Agglomeration

Abstract: Cultivated land intensive use is a hot topic discussed in China since it is significant to guarantee food security and promote sustainable development of land resource as well as social economy. Wuhan Urban Agglomeration is an important region for crop production in Central China. In this paper, the spatio-time characteristics of cultivated land intensive use were analyzed to better understand the variations of cropland intensive use levels during the year of 2002 to 2009 in Wuhan Urban Agglomeration. An evaluation index system was established at first. According to the data available, the study area was divided into 35 units at county-level. All data used were acquired from statistical yearbooks. Based on the original definition and scholars' discussions, the established index system contained 10 indicators from 3 aspects including intensity of cropland involvement, utilization of cropland and output benefits. The method applied in this paper was Global Principal Components Analysis (GPCA) that combined principle component analysis with sequence analysis. Comparing to other conventional evaluation models, the advantage of this method was able to reveal the sequential and spatial characteristics of cultivated land intensive use of the 35 units objectively, systematically and consistently. Besides, the coefficient of variations (Cv) was also used to describe the changes as well as its spatial reasons. Based on the analysis process, the results reached are as follows: 1) During the period of 2002 to 2009, capital investment and technology input of the cultivated land increased in fluctuation. Base on this, the average score of cultivated land intensive use rose from 58.40 of 2002 to 61.62 of 2009 with wave-like change process. Specifically, it showed rising steadily and keeping stable, then going down occasionally and ascending fast at last. Meanwhile, the sequential changes of coefficient of variation (Cv) for cultivated land intensive use degree experienced double rises and double falls. However, the Cv kept no more than 12% from 2004 to 2009, which was significantly lower than the level of 2002-2003, indicating that the regional disparity of cultivated land intensive use was becoming smaller. 2) During the entire period of research, the relative high level distribution of cultivated land intensive use mainly involved Jianghan Plain and plains in eastern Hubei along the Yangtze River, which basically covered from the west to the east of the study area. The intensive use levels of cropland were comparatively lower in the northern and southern hilly and mountainous region. Generally, the spatial disparity pattern of cultivated land intensive use in Wuhan Urban Agglomeration appeared to be high in the central part and low in the northern and southern side. 3) The changing trends were significantly different in different parts of the study area. The levels of cultivated land intensive use in the majority of the Wuhan Urban Agglomeration went up with fluctuations such as Jiangxia District and Macheng City. On the contrary, small areas such as the town area of Wuhan City and some surrounding units went down with fluctuations mainly effected by sharp descending of cropland output value. The results were able to provide scientific basis for enhancing cropland intensive use in Wuhan Urban Agglomeration.