2005-2008年中国耕地变化对区域生产潜力的影响

我国人多地少,粮食安全问题一直是国家关注的头等大事。而耕地资源与粮食生产能力是保障粮食安全的基础,因此,研究中国耕地变化对区域生产潜力产量的影响具有重大的现实意义,可以为国家相关决策提供科学依据。本研究基于2005-2008年最新的气象观测数据和卫星反演数据,并结合2005、2008年耕地数据及其变化数据,从耕地资源的数量变化与质量特征两方面,研究2005-2008年耕地变化对我国全境内光温生产潜力的影响。研究结果显示:在耕地的变化过程中,光温生产潜力增加区与减少区产量变化不对等:增加区增加785.14万t,减少区减少2543.61万t,净减少1758.47万t;增加区与减少区光温生产潜力单产不对等:增加区平均光温生产潜力单产为11.89t/hm²,减少区平均光温生产潜力单产为20.99t/hm²,后者约为前者的2倍;增加区与减少区空间分布不同:增加区主要分布在新疆、黑龙江、内蒙古、宁夏、青海等西北、东北地区,生态用地开垦是其增加的主要原因,占77.25%,减少区主要分布在江苏、安徽、山东、广东等黄淮海平原、长江三角洲、珠江三角洲地区,建设用地占用耕地是其减少的主要原因,占69.20%。

The Effects of Cultivated Land Change on Regional Potential Productivity in China from 2005 to 2008

With a large population and a relatively less cultivated land,China＇s food security has always been a top priority for the country.For cultivated land resources and grain productivity are the basis for food security,researches that focus on effects of cultivated land change on grain potential productivity in China are of great practical significance and can provide scientific grounds for relevant national decision-making.This study,based on latest meteorological observation data and satellite retrieval data from 2005 to 2008,and on quantitative change and quality characteristics of cultivated land resources,combining cultivated land data and change data in 2005 and 2008,focuses on the effects of cultivated land change on light-temperature potential productivity in China from 2005 to 2008.The results showed that： productions of light-temperature potential productivity have both increased zone and reduced zone in the process of cultivated land change.There is non-equivalence of yield variation in increased zone and reduced zone,as increase of 7.8514 million tons in increased zone and reduction of 25.4361 million tons in reduced zone,resulting to a net decrease of 17.5847 million tons.There also is non-equivalence of per unite yield in increased zone and reduced zone,as average values of light-temperature potential productivity are 11.89 t/hm2 in increased zone and 20.99 t/hm2 in reduced zone.The later is almost 2 times more than the former.Increased zone and reduced zone have different spatial distribution： increased zone mainly distributed in Xinjiang,Heilongjiang,Inner Mongolia,Ningxia,Qinghai provinces/autonomous regions,i.e.northwest and northeast of China,and ecological land reclamation is the main reason of its increase,accounting for 77.25%.Reduced zone mainly distributed in Jiangsu,Anhui,Shandong,Guangdong provinces,in other word,the Yellow River-Huaihe River-Haihe River Plain,the Yangtze River Delta and the Pearl River Delta areas,where farmland transferred to construction land is the main reason of its reduction,accounting for 69.20%.