四川省湿地类型变化的自然-社会经济驱动力分析

利用Landsat系列遥感影像对四川湿地进行遥感制图,通过GIS空间叠加分析获取2000—2015年间2期(2000—2010年和2010—2015年)湿地变化时空数据库,选取平均风速、降雨量、平均气温、平均日照时间、平均相对湿度、国内生产总值、人均国内生产总值、农业生产总值和人口数量9个自然和社会经济影响因子,采用典型相关分析(CCA)方法,对四川省湿地类型变化的驱动力进行研究。(1)从2000年到2015年,四川省湿地变化面积705374 hm~2,沼泽和河流湿地是每期湿地面积变化的主体,库塘是变化最大的湿地类型,湖泊湿地最为稳定,主要的湿地变化类型是沼泽转化为非湿地、河流和非湿地转变为库塘。(2)平均气温、国内生产总值和人口数量分别解释湿地类型变化的16.6%、30.7%和2.1%,而降雨量和平均相对湿度仅能解释0.6%和0.3%,表明国内生产总值、平均气温和人口数量是四川省湿地类型变化的主要驱动因子。(3)四川不同湿地类型变化的驱动因子存在差异。具体表现为,随着国内生产总值的增加,沼泽湿地转化为非湿地的量减少,而且国内生产总值越高,非湿地和河流湿地转变为库塘的量越多;随着平均气温的增加,沼泽湿地转化为非湿地的面积增加。研究结果说明社会经济的快速发展对四川湿地面积的保护和增加起到了积极作用,但全球变暖仍然导致沼泽湿地在不断减少,因此在全球变化的背景下,加强对沼泽湿地的保护和恢复,对于稳定四川湿地资源具有重要的作用。

Natural and social economy driving forces of wetland types changes in Sichuan Province

Landsat series remote sensing images were used to map the wetlands in Sichuan, and the GIS spatial overlay analysis was used to obtain wetland change spatio-temporal database in two periods (2000-2010 and 2010-2015). We chose nine natural and socio-economic factors including average wind speed, precipitation, average temperature, average sunshine duration, average relative humidity, gross domestic product, GDP per capita, gross agricultural output and population, and adopted the Canonical Correlation Analysis (CCA) method to analyze the driving forces of changes of wetland types in Sichuan Province. The results showed that (1) from 2000 to 2015, the changeable areas of the wetland in Sichuan Province were 705374 hm². Swamps and rivers were the main changeable wetland areas in each period. The ponds were the most changeable wetland type, and lakes were the most stable. The main types of change were swamps transformed into non-wetlands, rivers and non-wetlands changed into ponds. (2) The average temperature, GDP and population explained 16.6%, 30.7% and 2.1% of changes in wetland types respectively, while precipitation and average relative humidity could only explain 0.6% and 0.3%. So, GDP, average temperature and population were the main driving factors for the change of wetland types in Sichuan Province. (3) There were differences in driving factors for different wetland types in Sichuan. Specifically, as the GDP increased, the amount of swamp wetlands converted to non-wetlands decreased, and the higher the GDP, the more non-wetlands and river wetlands were converted into ponds; with the increase of average temperature, the area of swamp wetlands converted into non-wetlands increased. The results show that the rapid development of society and economy has played a positive role in protecting and increasing the area of Sichuan wetlands, but global warming still leads to the continuous reduction of swamps. Therefore, in the context of global change, strengthening the protection and restoration of swamps will play an important role in stabilizing Sichuan wetland resources.