CAJ | 학술논문

随着中国经济的快速发展和人口的不断增加，在各项建设占用大量耕地和生态退耕与环境保护措施的双重影响下，中国的耕地面积在持续减少。对中国耕地随时间变化规律的认识以及其空间分布变化趋势的把握已成为重要的研究内容，这对于研究区域粮食安全和区域可持续发展也有重要的指导意义。该文在中国长时间序列土地利用动态时空数据库的支持下，对中国1987年到2010年的耕地变化过程进行了全面分析，揭示了中国近30 a来耕地变化的时空特征，分析了其变化的主要原因。研究表明，自1987年以来，中国原有耕地不断减少，北方地区为主的新垦耕地持续增加。以2000年为转折点，1987年到2000年耕地总面积略有增加，2000年到2010年耕地总面积逐步减少，近30 a间，耕地总量相对稳定。比较而言，2000年以前的耕地增加速度明显高于2000年以后的耕地减少速度。到2010年全国耕地总面积呈南减北增、减少速率最快的区域集中于长江三角洲、珠江三角洲地区，而增加速率最快的区域集中在新疆、黑龙江以及内蒙古部分地区。建设用地对耕地的占用持续强烈并有加强趋势，生态建设占用耕地是生态脆弱地区耕地面积减少的主要原因，对耕地的占用比例仅次于建设用地。对草地、林地的开垦是全国新增耕地的主要来源，对未利用土地的占用有增强趋势，近年来，包括盐碱地；沼泽地，甚至是沙地、戈壁等未利用土地被改造成耕地，同时也会带来区域水资源和环境等方面的一系列问题，尤应慎重。
수착중국경제적쾌속발전화인구적불단증가，재각항건설점용대량경지화생태퇴경여배경보호조시적쌍중영향하，중국적경지면적재지속감소。대중국경지수시간변화규률적인식이급기공간분포변화추세적파악이성위중요적연구내용，저대우연구구역양식안전화구역가지속발전야유중요적지도의의。해문재중국장시간서렬토지이용동태시공수거고적지지하，대중국1987년도2010년적경지변화과정진행료전면분석，게시료중국근30 a래경지변화적시공특정，분석료기변화적주요원인。연구표명，자1987년이래，중국원유경지불단감소，북방지구위주적신은경지지속증가。이2000년위전절점，1987년도2000년경지총면적략유증가，2000년도2010년경지총면적축보감소，근30 a간，경지총량상대은정。비교이언，2000년이전적경지증가속도명현고우2000년이후적경지감소속도。도2010년전국경지총면적정남감북증、감소속솔최쾌적구역집중우장강삼각주、주강삼각주지구，이증가속솔최쾌적구역집중재신강、흑룡강이급내몽고부분지구。건설용지대경지적점용지속강렬병유가강추세，생태건설점용경지시생태취약지구경지면적감소적주요원인，대경지적점용비례부차우건설용지。대초지、임지적개은시전국신증경지적주요래원，대미이용토지적점용유증강추세，근년래，포괄염감지；소택지，심지시사지、과벽등미이용토지피개조성경지，동시야회대래구역수자원화배경등방면적일계렬문제，우응신중。
With the rapid development of the economy and population since the adoption of an open and reform policy, cultivated land is continually reduced in China under the multiple impact of occupation for construction and the implementation of an ecological restoration and environmental protection project. Understanding the temporal variation of cultivated land and grasping the spatial distribution trends have become an important research topic. This has an important guiding significance for the study of food security and sustainable development. With the support of a long temporal land use dynamic database, this paper analyzed the change process of cultivated land from the end of 1987 to 2010 in China, revealed the spatial-temporal characteristics of cultivated land changes, and analyzed the main causes in the last 30 years. The national dynamic database has was 6 sets of land use data (1987, 1995, 2000, 2005, 2008 and 2010) and 5 sets of dynamic data (1987-2000, 1995-2000, 2000-2005, 2005-2008, and 2008-2010). Remote sensing images with 20-30m spatial resolution (TM/ETM+, CBERS and HJ-1A), visual interpretation, field surveys, and much auxiliary information were applied during construction of the database. We extracted the cultivated land information from the land use database, and analyzed the spatial-temporal change of cultivated land after data statistics and dynamic transfer matrix calculation. The results show that: In the most recent 30 years, the total area amount of Chinese cultivated land was relatively stable. The original cultivated land kept reducing since the end of the 1980s in the whole nation. On the other hand, the newly reclaimed land distributed mainly in northern China kept increasing. The new reclaimed land partly offset the original cultivated land loss, so that the center of new reclaimed land gravity was gradually moving from northeast to northwest. The moving of new reclaimed land gravity caused the productivity of new reclaimed land to be reduced. The year of 2000 was the turning point of the change process, because the total area of cultivated land was increased slightly from the end of 1987 to 2000, but reduced from 2000 to 2010. Because the speed of cultivated land increase was obviously higher than the reduction, the total area of cultivated land was increased from the end of 1987 to 2010. The spatial pattern of the cultivated land change process showed that cultivated land distributed in north China was increased, but those in south China were decreased. The Yangtze River delta and Pearl River delta were the fastest decreased regions in which cultivated land was distributed, and Xinjiang, Heilongjiang and Inner Mongolia were the fastest increased regions. The situation of land use type change showed that construction land occupation was the main reason that cultivated land decreased, and the trend of occupation is still rising. Ecological construction occupied cultivated land was the main reason in the ecologically vulnerable area. Reclaimation of grassland and forest was the primary source of cultivated land increase. In recent years, more and more unused land was reclaimed to cultivated land, such as saline-alkali land, swampland, and even sandy land and Gobi. Because a series of problems of water resources and the environment will become prominent during the process, unused land reclamation should be carried out particularly carefully.