摘要
陕西省延安市作为国家退耕还林生态工程实施重点区、示范区,是我国生态问题集中体现区,研究其土地生态风险时空差异对区域土地可持续发展、差别化国土资源发展政策的制定具有重要意义。首先,依据延安市土地系统的基本特征,选取植被覆盖度指数、降水距平百分比指数、土地利用结构风险指数和土壤侵蚀指数4个风险指标,构建土地生态风险综合评价模型;其次,基于像元尺度测算土地生态风险各因子指数及综合指数;最后,结合探索性空间数据分析方法,分析了延安市2000—2015年间土地生态风险及空间集聚效应的时空演化规律,进而提出土地分区综合治理的建议。研究结果表明,延安市土地生态整体状况良好,各生态因子及综合风险整体呈降低态势,但宝塔区和洛川县较高且高等级综合风险区面积呈小幅增加态势。延安市土地综合生态风险呈现较强的空间集聚状态,热点区包括位于各区县城镇建设区的城镇热点区和分布在子长县、安塞区、延长县、延川县和吴起县5区县的北部热点区,冷点区则主要位于生态环境状况较好的东南部黄龙县、宜川县,西南部黄陵县、富县以及甘泉县西南部等地区。得益于国家退耕还林(草)及封山育林等生态工程的实施,热点集聚程度总体呈逐渐减弱趋势,但宝塔区内城镇热点区面积持续增加,应注意加强生态管理;受气候干旱的影响,富县西北部、宜川县西部冷点区范围呈缩小态势,应注意优化水资源的调配。
As a key and demonstration area for the implementation of the national ecological project of returning farmland to forestry,Yan’an City is a concentrated area of ecological problems in China.It is of great significance to study the spatial and temporal differences of land ecological risks for the sustainable development of regional land and the formulation of differentiated land and resources development policies.According to the basic characteristics of land ecosystem,four risk indicators,namely vegetation coverage,percentage anomaly precipitation,land use structure risk index and soil erosion index,were selected to construct a comprehensive evaluation model of land ecological risk.Then on the basis of pixel scale,each factor index and comprehensive index of land ecological risk were calculated.In combination with exploratory spatial data analysis(ESDA),the spatial and temporal evolution of land ecological risk and spatial agglomeration effect in Yan’an City from 2000 to 2015 was analyzed.Then the corresponding suggestions for comprehensive management of land in different regions were put forward.The results are as follows:The land ecology of Yan’an City is in good condition as a whole,whereas the land comprehensive ecological risk and the risk of the four ecological factors temporally decrease on the whole;nevertheless,the area of Baota District and Luochuan County is higher in this aspect,and high comprehensive risk areas increase slightly.The land comprehensive ecological risk of Yan’an City shows a strong spatial agglomeration.Hot spots include urban hot spots located in urban construction areas and northern hot spots distributed in five districts and counties of Zichang County,Ansai District,Yanchuan County,and Wuqi County.The cold points are mainly located in Huanglong County,Yichuan County,Huangling County,Fuxian County and the southwest area of Ganquan County.Thanks to the implementation of national eco-engineering measures such as returning farmland to forestry(grassland)and closing hillsides for reforestation,the agglomeration degree of hot spots has been gradually weakening.However,the area of urban hot spots in Baota District continues to increase,and hence attention should be paid to strengthening ecological management.As cold spot areas in northwest Fuxian and western Yichuan County has been shrinking because of climate drought,attention should be paid to optimizing the allocation of water resources.
作者
段艺芳
任志远
周晓
孙艺杰
DUAN Yifang;REN Zhiyuan;ZHOU Xiao;SUN Yijie(College of Geography and Tourism,Shaanxi Normal University,Xi’an 710119,China;College of Environment and Planning,Liaocheng University,Liaocheng 252000,China)
出处
《国土资源遥感》
CSCD
北大核心
2020年第1期120-129,共10页
Remote Sensing for Land & Resources
基金
国家自然科学基金项目“我国生态脆弱区能源开发生态效应测评与调控研究”(编号:41371523)资助。
关键词
土地生态风险
探索性空间数据分析
空间集聚
延安市
land ecological risk
exploratory spatial data analysis
spatial agglomeration
Yan’an City
作者简介
第一作者:段艺芳(1980-),女,讲师,博士,主要从事资源环境遥感与GIS研究。Email:duanyifang@snnu.edu.cn;通信作者:任志远(1953-),男,教授,博士生导师,主要从事国土资源开发和生态环境评价相关研究。Email:renzhy@snnu.edu.cn。
