艾比湖区域景观格局空间特征与地表水质的关联分析

Correlation analysis between the spatial characteristics of land use/cover-landscape pattern and surface-water quality in the Ebinur Lake area

为进一步明确区域土地利用/覆被—景观格局对河流水质影响的空间尺度。选择新疆艾比湖区域为研究对象,以25个水质采样点为中心,建立5种尺度的河流缓冲区并提取不同尺度下的土地利用/覆被-景观格局数据。首先,通过主成分分析获得水环境的主要水质变量。其次,利用冗余分析(RDA)方法探讨研究区不同宽度缓冲区土地利用/覆被—景观格局对河流水质的影响,获得水质管理的有效缓冲区。最后,引入突变点分析方法进一步寻找导致水质变量沿景观梯度突变的特定位置。结果表明:(1)土地利用/覆被—景观格局在不同宽度缓冲区内对河流水质的影响不同。4 km缓冲区土地利用/覆被—景观格局对区域水质有较强的分异解释能力,因此4 km缓冲区的景观格局合理配置对河流水质管理尤为重要。(2)通过偏RDA分析发现4 km缓冲区中,影响区域水质的主要环境变量为景观水平斑块密度、类型水平耕地斑块密度和森林聚集度。(3)在偏RDA分析的基础上,对4 km缓冲区内的景观指数进行突变点分析研究,发现区域景观水平斑块密度为90—105 m/hm^2,类型水平耕地的斑块密度ED值在90—110 m/hm^2、林草地的AI值在70%—90%,是艾比湖区域水质保护的最佳突变值,该值为艾比湖区域水质保护的阈值。本研究从多个角度对新疆艾比区域的土地利用/覆被—景观格局对区域水质的影响进行定量分析,揭示该地区景观生态变化的规律,为区域景观格局优化和土地合理规划提供理论依据,并对改善"丝绸之路经济带"生态环境、实现资源可持续利用具有重要的现实意义和理论价值。

To understand the effect of land use/cover-landscape on water quality, this study selected the Xinjiang Ebinur Lake region as the study area. We took 25 water sampling points to build five buffer zones, and combined land use/cover types with water-quality monitoring data, selected land-use types, and landscape index （landscape level） to monitor water quality. We tried to study the effects of a wide range of buffer land use/cover-landscape patterns on water quality indexes using the redundancy analysis method. Subsequently, we analyzed the specific location of the water-quality variables along the landscape gradient using the change-point analysis method. The results indicated ： （ 1 ） the landscape pattern has different effects on the river--water quality indexes in different buffer zones. A 4 km buffer of land use/cover landscape pattern seems to be a threshold for differentiating the regional water quality. （2） The major environmental variables affecting the water quality of the lake area are the patch density, the patch density, and the degree of aggregation in a buffer of g km. （3） When the edge density （ ED）, of cultivation was 90--105 m/hm2, and the aggregation of forest and grassland index of water was 70%--90%, and the water quality in this region appeared to be better protected. This study performed the quantitative analysis of the land use/landscape pattern changes from multiple perspectives in the Ebinur Lake area, revealing the main regularities of the landscape ecology variation in the region. This study provides the theoretical basis for the optimization of regional landscape pattern and reasonable land planning. It improves the ＂ Silk Road Economic--One Belt and One Road＂ initiative of the ecological environment and sustainable utilization of resources in the Ebinur Lake area in Xinjiang.