黄河三角洲人类干扰活动强度变化及其景观格局响应

本研究以湿地变化较为剧烈的黄河三角洲为研究对象,基于RS技术和GIS空间分析方法,利用人为干扰度模型,结合区域人工沟渠建设情况,从区域和局地两个尺度直观揭示人类干扰强度时空分异特征,并探究区域景观格局对人类干扰活动的响应,以期为黄河三角洲滨海湿地生态保护与人类活动调控提供决策支持。结果表明：① 1995-2015年现代黄河三角洲区域人为干扰度和人工沟渠密度均明显增加,空间分布呈现从西南部向东部、北部,自内陆向沿海的扩展趋势;② 随着人类活动强度增强,研究区自然湿地面积减少,区域景观多样性和空间异质性增加,景观整体连通性减弱,景观复杂性降低;③ 景观格局对人类干扰强度变化的响应关系呈现出地区和时间差异;人类干扰活动强度相对较低的保护区受人工沟渠建设的影响,也呈现出斑块团聚程度降低、景观多样性增加和景观复杂性降低的变化趋势;④ 人为干扰度指数和人工沟渠密度指标互为补充,互相印证,可以较为全面、客观地反映黄河三角洲地区人类干扰活动强度。

Intensity Change of Human Disturbance and Its Response to Landscape Pattern in the Yellow River Delta

The coastal wetlands of the Yellow River Delta is the most integral, broadest and youngest wetland ecosystem in the warm temperate zone of China. Also, it has unique ecological landscape as well as important ecological service functions. With the increase in population and the intensification of high-intensity development and construction activities, the sensitivity/fragility of the area is highlighted, which poses a great threat to the sustainable development of coastal areas. Aiming at the unique geographic location and resource characteristics of the Yellow River Delta, based on RS and GIS, the hemeroby model as well as the man-made ditches density were used in this study to intuitively reveal the temporal and spatial characteristics of human disturbance intensity in 1995, 2004 and 2015 at the regional and local scales. The response of the wetland landscape pattern to human interference activities was explored as well. A grid analysis method was used to calculate the hemeroby index and man-made ditches density. The data source included the following: Landsat TM、ETM⁺ and OLI Remote Sensing Data (30 m resolution) in 1995、2004、2015, SPOT image of 2004(5m resolution) , GF-1 image of 2015 (2 m resolution) and topographic map. This study aims to provide decision support for ecological regulation and spatial control on human activities in coastal wetlands of the Yellow River Delta. The results showed that: (1) From 1995 to 2015, both the hemeroby index and the density of artificial ditches in the Yellow River Delta had increased significantly, and its spatial distribution showed a trend of expansion from the southwest to the east and north, and from inland to coastal areas; (2) With the increase of human activities, the area of natural wetlands in the study area have been decreased from 3232.11km² in 1995 to 2165.48km² in 2015, the landscape diversity and spatial heterogeneity increased, ecological connectivity weakened, the plaque shape tended to be regular and simplistic. (3) The response of landscape pattern to hemeroby index varies regionally and temporally. In the Kenli Agricultural Area, Hekou Agricultural Area and Shengli Oil Field Area, where the intensity of human interference activities had been relatively high, the intensity increased significantly, and the regional landscape pattern changed obviously in different phases. In the Yiqianer Management Station and the Yellow River Estuary Management Station area, where the intensity of human interference activities had been relatively low, due to the increase in the density of artificial ditches, the landscape pattern had presented a decreasing trend in landscape diversity, patch complexity and ecological connectivity from 2004 to 2015. (4) The indices of hemeroby and the density of man-made ditches supplement each other and confirm each other, which can reflect the degree of human disturbance activities in the Yellow River Delta more comprehensively and objectively.