摘要
干旱区绿洲抗干扰能力弱,开展其生态风险评价具有的重要意义。以景观生态学理论为指导,选取青铜峡市作为研究对象,采用三期遥感数据,运用景观格局指数评估生态风险,并对生态风险指数进行空间化,绘制研究区2006年、2010年、2016年的生态风险空间分布图。在此基础上,结合空间统计法分析了研究区生态风险的聚集模式。结果表明:(1)研究期间,青铜峡市景观格局变化明显。耕地、水域和未利用土地的景观破碎度增加,大斑块破碎化趋势明显,区域的景观稳定性降低。景观格局指数的空间分布显示景观破碎度、损失度较高区分布在人口和经济活动聚集的绿洲核心区。(2)研究区的生态风险时空变化差异较大。其中高风险区面积减少最为显著,并随着风险等级之间的转换,中等风险区成为研究区的主要风险类型。生态风险呈现缓和趋势。(3)研究区的生态风险存在显著空间正相关,"低低"和"高高"聚集是主要的生态风险聚集模式,低值为高值包围或高值为低值包围的空间孤立点表现不显著,高低风险之间严重分化是研究区亟待解决的问题。
It is of great significance to carry out ecological risk assessment because of the weak anti-interference ability of oasis in arid area.Based on the theory of landscape ecology,we selected Qingtongxia City as the research sample,and used remote sensing data in three periods,and the landscape pattern index to assess the ecological risk,and achieved the spatialization of index,as well as made the spatial distribution maps of ecological risk in 2006,2010 and 2016.On the basis above,the accumulation mode of ecological risk in the study area was analyzed by spatial statistics.The results showed that:(1)during the study period,the change of landscape pattern was obvious in Qingtongxia City;the fragmentation of cultivated land,water area and unused land increased,the fragmentation trend of large patches was obvious,and the landscape stability decreased;the spatial distribution of landscape pattern index show that the landscape fragmentation and the loss degree of the higher areas distributed in the oasis core area which was gathered by population and economic activity;(2)the spatial and temporal changes of ecological risk in the study area were different;among them,the reduction of high risk area was the most remarkable,and with the conversion of the risk grade,the medium risk area became the main risk type;ecological risk presented the mitigative trend;(3)there was prominent spatial positive correlation between the ecological risks in teh study area,the ‘low—low'and‘high—high'accumulations were the main ecological risk accumulation mode,the spatial outliers that low values were surrounded by high values or high values were surrounded by low values were not significant,the serious differentiation between high and low risks is the urgent problem to be solved in the study area.
出处
《水土保持研究》
CSCD
北大核心
2017年第5期285-290,共6页
Research of Soil and Water Conservation
基金
国家自然科学基金资助项目"宁夏生态移民安置区生态风险及其空间分异研究"(41461039)
关键词
景观格局
生态风险
干旱区绿洲
风险管理
青铜峡市
landscape pattern
ecological risk
arid area oasis
risk management
Qingtongxia City
