农牧交错区50年来耕地开发过程及其驱动因素分析——以大庆市杜尔伯特蒙古族自治县为例

Stages and Determinants of Farmland Development and Driving Forcesin Duerbote County During the Past 50 Years

杜蒙县是一个20世纪初开始农业开发的牧区,近50年的农业开发力度较大。在遥感和GIS支持下,用TM、MSS、地形图及相关资料,对1954年～2001年杜尔伯特蒙古族自治县耕地开发过程及驱动机制进行了分析。结果表明该区近50年来耕地急剧增长,耕地增长的土地来源主要是草地和沼泽地,还有部分林地和治理后的盐碱地。耕地也有部分转为林地和城镇及居民用地,其中80年代初实行"退耕还林还草牧"政策,有部分耕地变为草地。其驱动机制有人口的增长,主要是汉族人口的增长;社会生产力的进步,主要是农机具的大量使用,使人们有能力开垦大量的土地;土地政策,对耕地的开发起到宏观调控作用。

Duerbote County is a pasturing region where has been an agriculture-dominated economy from the beginning of the 20th century. Especially during the recent 50 years,the agricultural development within this region has been very intensive. Based on Remote Sensing and GIS,this paper analyzes the spatio-temporal dynamic changes of the farmland and its mechanism according to TM,MSS,topographic map and other data in Duerbote County during 1954 to 2001 were used for the analysis. It is concluded that farmland increased rapidly, and grassland and swampland were the main causes of farmland increase. At the same time partial of the improved saline-alkali land changed into farmland. In the period, grassland changed into farmland mostly, and the conversion was 10.32 percent. Barren land changed into farmland, and the conversion rate increased up to 2.87 percent. Forest changed into farmland and the conversion rate added up to 0.11 percent. The ratio of conversion of farmland changing into forest, town and resident land is 1.62 percent and 0.78 percent respectively. There were some farmland that changed into water body, salty and alkaline land and swampland. At the beginning of the 1980s, 11.58 percent of the farmland changed into grassland because of the policy of 'conversion of farmland into woodland and grassland'. The driving forces of farmland increasing include population increase, social productivity development, especially agricultural machines being introduced, which make people be able to develop a mass of farmland. In addition, land policy affects strongly farmland development.