基于RS和PRA的横山县耕地质量综合评价研究

Comprehensive evaluation of cultivated land quality based on RS and PRA:A case study in Hengshan county

为了解该县目前的耕地质量现状及其发展趋势,为当地的耕地资源保护提供参考撰写此文。采用PRA技术进行农户调查,得到农户普遍关注的耕地质量因素有坡度、灌溉条件、土壤质地、产量、肥料投入、作物长势、沙化和水蚀程度,将这些因素通过基于遥感数据的SVMI、MSAVI、SARP等指标反映出来,构建耕地质量评价指标体系;基于压力——状态——响应模型(PSR),借助地理信息系统(GIS)构建生产压力指数、耕地状态指数以及农户行为指数,从不同角度分别描述耕地质量,并进行耕地质量综合评价。结果显示,当地将近70%的耕地质量现状较差,并且其中大部分耕地面临巨大的退化危险;60%以上的耕地其社会经济条件和管理行为是不可持续的。最后,针对不同等级耕地提出了政策建议。

This study was carried out with the objective of developing comprehensive land quality evaluation based on 2002 ETM ＋ image, 2003-2004 household survey data and 2000-2002 social-economic statistics data for Hengshan County in Northern Shaanxi province. It would be helpful to understand the status and trends of euhivated land quality, and useful information would be provided for land managers. Based on PRA, it was found out that farmers evaluated cultivated land quality by slope, water availability, soil texture, yields, amount of fertilizer, cro Pperformance, sandy and water erosion degree, these factors were reflected by SVMI, MSAVI, and SAR Petc. then a indicator system was developed. Data from satellite and surveys were integrated with socio-economic statistic data using geographical information system （GIS） and three indexes, namely Production Press Index （PPI）, Land State Index （LSI） and Farmer Behavior Index （FBI） were proposed to measure different aspects of land quality. Results suggested that local cultivated land had a poor quality （70%） and most of them run the risk of getting degraded. More seriously, 60% cultivated land faced unsustainable land managements and social-economic conditions. At last, beneficial information for management decisions was supplied according to different euhivated land ranks.