东南沿海景观格局及其生态风险演化研究——以宁波北仑区为例

以宁波北仑区1990,1995,2000,2005,2010,2015年6期LandsatTM/OLI遥感影像为数据源,提取景观格局数据,进行景观格局及其生态风险区时空演化特征分析.结果表明:(1)研究区的主要景观类型是林地与耕地,景观演化的主要特征表现为建设用地景观面积大量增加,耕地景观面积明显减少,区域景观破碎化愈加明显;(2)25a间,研究区内低生态风险区大量减少,而中、较高和高生态风险区面积大大增加;高生态风险区主要分布于北部平原地区,重心向西南方向移动,人类活动使山麓地带大量低生态风险区转变为较低生态风险区;(3)1990~2015年,研究区内由低等级转向高等级的生态风险区面积占研究区总面积的42.5%;前期以低生态风险区、较低生态风险区转向中生态风险区为主,后阶段以中生态风险区转向较高生态风险区、高生态风险区的比例有所增加;1990~1995年、2000~2005年、2010~2015年3个时间段生态风险转换面积较大.

Research on landscape pattern and ecological risk evolution in southeastern ChinaTaking Beilun district of Ningbo for example

Landsat TM/OLI remote sensing images of Beilun district, Ningbo in 1990, 1995, 2000, 2005, 2010 and 2015 were taking as the data source to extract the landscape pattern data, which can be used to analyze the temporal and spatial evolution characteristics of landscape pattern and its ecological risk area. The results show that:(1) The main landscape types in the study area are forest land and cultivated land, and the main features of landscape evolution are that the landscape area increases significantly but the cultivated land area obviously decreases, and the landscape fragmentation became more obvious. (2) The low ecological risk areas decrease in large area while ecological risk areas of middle, high and higher greatly increase. The high risk ecological areas are mainly distributed in the northern plains. With the center moving to the southwest, human activities make ecological areas in the foothills shifted from low-grade ecological risk zone to lower-grade one. (3) From 1990 to 2015, the area of ecological risk zone shifted from low-grade to high-grade accounts for 42.5% of the total studied area; The ecological area shifting from low and lower grade risk to middle grade risk come into prominence in the initial stage, and the portion of ecological zone turning from middle grade risk to the higher or high ones increases in the latter stage. The ecological risk area changes greatly in the three periods namely 1990-1995, 2000-2005 and 2010-2015.