江南四省耕地后备资源调查与评价

耕地后备资源储量调查及适宜性评价能够为耕地后备资源的合理开发利用提供科学依据。本文将3S技术支撑下的室内分析和野外科学考察相结合,从自然适宜性和生态安全性角度构建了江南四省(湖南、江西、浙江和福建)耕地后备资源的自然-生态适宜性指标体系,以“一票否决”和“设置容许度”两种方式对纳入的生态安全性指标进行区分,实现江南四省耕地后备资源的提取和评价。结果发现:江南四省共有未利用土地8 992.30km²,耕地后备资源总量为5 394.70km²,集中连片大面积的耕地后备资源基本上已开垦殆尽。储量少、质量低、分布零散是该地区耕地后备资源的基本特征。小面积耕地后备资源的充分利用已经成为江南四省维持耕地占补平衡的需要。

Suitability assessment of reserve cultivated land resources south of the Yangtze River

Cultivated land in China is diminishing because of urban construction. The evaluation of the quantity and quality of reserve cultivated land resources provides a scientific basis for the application of cultivated land requisition-compensation balance and the expansion of cultivated land. Under the support of 3S technology (remote sensing,geography information systems and global positioning systems),laboratory analysis and field investigation were combined to evaluate the quantity and quality of reserve resources of cultivated land in four provinces south of the Yangtze River(Hunan,Jiangxi,Zhejiang and Fujian). The methods ‘zero for one' and ‘setting tolerance' were used to classify ecological security factors included in the evaluation system. Zero for one is suitable for the elimination of wetland and ecological construction land from reserve cultivated land resources. Setting tolerance is used to get rid of unused land resources with soil erosion and rocky desertification exceeding tolerable levels. We found that in study area,the total area of unused land resources is 8 992.30km² and that reserve resources of cultivated land totals 5 394.70km². The reserve resources of cultivated land with large area suitable for utilization were scant or nearly developed. Small amount,low quality and scattered distribution are the basic characteristics of reserve resources of cultivated land in four provinces south of the Yangtze River. The exploitation of reserve resources of cultivated land with small area is indispensable for the balance of cultivated land loss and gain.