下辽河平原景观生态安全评价及空间结构分析

Analysis and evaluation of the landscape ecoenvironmental security and the spatial distributive features in the lower reaches of Liaohe River Plain

以东北三省开发强度最大的辽河中下游———下辽河平原为研究对象,根据景观格局与生态安全的关系,通过景观干扰度指数和景观类型脆弱度指数构建景观生态安全指数,并借助地统计学和空间自相关模型分析的理论方法,对下辽河平原景观生态安全的空间分布特征、变异规律及空间结构进行了分析。结果表明:1)块金值C0所占比例在3个年份间有逐步上升的趋势,表明非结构性因素对景观生态安全演变的影响程度不断加深,但结构性因素(地形地貌、水文、土壤植被类型等)仍然对本区景观生态安全的空间分布起决定性作用;5 km采样间距内研究区景观生态安全具有高度的空间相关性;2)1989—2010年下辽河平原景观生态安全总体呈略微下降趋势,各安全分区的面积比例和空间结构均发生了明显变化;3)1989—2010年研究区景观生态安全Moran's I表现为一定程度的正相关,且相关程度呈略微下降趋势,研究区景观生态安全局部空间自相关和显著性水平均发生了明显变化。

The given paper is to introduce our analysis and evaluation of the landscape eco-environmental security and the spatial distributive features in the lower reaches of Liaohe River Plain. As is known, landscape pattern determines the distribution of resources and environment quality of a given area, what we would like to do is to find the profound influence of the environment change on the anti-interference ability, the recoverability, system stability and the biodiversity of our natural living surroundings. Our research has been done based on the landscape pattern, the research which is aiming to introduce our study on the spatio-temporal variation of landscape ecological security. From the point of view of how to properly deal with the relation between the landscape pattern and the ecological security, we have analyzed the lower Liaohe River Plain—the lowest situated plain among the three provinces in the northeast of China while investigating the landscape ecological security indexes in focus of pursuing the landscape disturbance and vulnerability indexes. At the same time, we have also analyzed the space distribution features, the variation patterns and space structures by using the geo-statistical method and the spatial autocorrelation model. The results of our investigation and analysis show that： （1） Through the analysis of the theoretical model, it has been found that the percentage of nugget has gradually increased since 1989, 2001 and 2010, which indicates that non-structural factors deeply affect the landscape ecological security evolution, though the structural factors （the topography, hydrology, soil, vegetation type, etc.） still keep their decisive function on the spatial distribution of the landscape ecological security in this area. The variation value analysis shows that the landscape ecological security of the area under study presents closer spatial correlation within 5 km sampling space. （2） The interpolation results show that the landscape ecological security in the above mentioned Liaohe River Plain presents a slightly descending trend from 1989 to 2010, symbolizing the area＇s declining proportion and spatial structure of each security division. （3） The landscape ecological security of the area under study shows that the positive correlation to some degree by Moran＇s I index and correlation presents a slightly declining trend, though the local spatial autocorrelation and conspicuousness of the landscape ecological security of the area under discussion have noticeably changed.