贵州省粮食安全与耕地压力时空动态变化及驱动因素分析

运用耕地压力指数模型、粮食平衡系数和主成分分析的研究方法，对贵州省及9个地市1989—2005年的粮食生产、耕地压力指数、粮食平衡系数作动态变化分析，及对粮食生产的综合条件进行了主成分分析，分析研究结果表明：①贵州粮食产量迅速增加。从1989年的708．25万t增加至2005年的1288万t，通过主成分分析，贵州的粮食产量与投入粮食生产的资本、技术和劳动与粮食产出密切相关。②人口增长与耕地面积减少的矛盾突出。人口数量呈直线型增长，从1989年的3134．94万人增加至3931．12万人，16a间增加了800万人；耕地面积呈减少趋势，从1989年的185．38万hm^2减少至175．35万hm^2。③耕地压力指数下降，从1989年的1．77降至2005年的1．22，主要原因是耕地综合生产力提高的结果，粮食平衡系数相应提高，但仍低于临界水平1，区域粮食生产相对全国平均水平未能自给。④各个地区的耕地压力减小，遵义市耕地压力系数最小，近年来小于1；粮食平衡系数上升，除遵义市外，其他地区仍小于1，人均粮食占有量为达到全国平均水平，同时各地区之间的粮食安全与耕地压力存在差异性。图4，表1，参16。

Temporal and Spatial Dynamics Change and Driving Factors of Guizhou Grain Security and Cropland Pressure

Using cultivated land pressure index model and the research method of grain balance coefficient, dynamic change analysis was made for the grain production, the pressure index of cultivated land and grain balance coefficient of Guizhou province and its nine cities from 1989 to 2005, and principal component analysis was also made for comprehensive conditions of grain production. The research results showed that： ① The grain output increased rapidly from 708.25 × 10^4t in 1989 to 1288 × 10^4t in 2005. The grain output was closely related to the capacity, technology and labor involved in the grain production through the principal component analysis. ②The contradiction between population growth and cultivated land area reduction was obvious. The growth of population was linear, from 31. 349 million in 1989 to 39.311 million in 2005. The area of cultivated land was a declined trend from 185.38 × 10^4hm^2 in 1989 to 175.35 × 10^4hm^2. ③The pressure index of cultivated land decreased from 1.77 in 1989 to 1.22 in 2005, mainly because of the increase of cultivated land integrated productivity . The grain balance coefficient increased, but still less than 1 （the critical level）, meaning that the regional grain production was not self-sufficient, compared to the na- tional average level .④The pressure index of cultivated land in various regions decreased, and that of Zunyi city was the smallest, which was less than 1 in recent years. The grain balance coefficient increased, while all the cities were still less than 1 expect for Zunyi city. The per capital share of grain reached to the national average level, and there were still differences between the pressure index of cultivated land and grain security in various regions.