武汉城市圈耕地集约利用时空分异特征

为加强对武汉城市圈耕地集约利用时空变化规律的认识,该文从投入强度、利用程度和产出效益3个方面构建了包含10项指标的耕地集约利用评价指标体系;以县级单元作为基本分析尺度,运用全局主成分分析方法,对划分的35个评价单元2002－2009年间的耕地集约利用水平进行综合评价,分析武汉城市圈耕地集约利用的时空分异特征。结果表明：2002－2009年,随着资本投入和科技投入的波动性增长,武汉城市圈耕地集约水平呈现出"稳定上升-平稳发展-阶段下降-迅速上升"的变化过程,平均分值由58.40提高至61.62,整体保持了增长态势;受区域地貌特征、耕作条件的影响,武汉城市圈各地区耕地集约利用水平差异显著,集约度较高的区域主要分布于东西沿江平原一线,南北丘陵山区耕地集约度较低,总体呈现"中间高、两翼低"的空间分异格局;但随着城市圈整体集约度的提高,各地区间耕地利用集约度的差异正在逐步缩小并趋于稳定;研究期内,各地区耕地集约度变化呈现明显的空间分异特征,多数地区耕地集约度变化呈现波动上升趋势,但城市圈中心武汉市区及其周边部分地区,由于耕地产值的大幅下降,耕地集约度有所下降。该文为武汉城市圈耕地集约利用水平的提高提供了科学依据。

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.