浑太河流域不同水生态功能区环境要素的分布特征及其与土地利用之间的关系

为深入分析不同水生态功能区土地利用方式对环境要素空间分布特征的影响，于2009—2016年对浑太河流域300个样点的407组数据进行野外监测（包括26种水环境要素数据以及2010年和2015年的Landsat TM遥感影像数据），采用主成分分析、Spearman相关性分析和多元线性回归分析，筛选主要水环境因子，分析流域水质指数（WQI）的空间变化规律，结合水生态功能分区和各样点的土地利用数据，探究了不同水生态功能区土地利用方式对河流主要环境要素的影响.结果表明:①电导率（EC）、溶解氧（DO）、悬浮物（SS）、5日生化需氧量（BOD₅）、化学需氧量（COD_Cr）和铵态氮（NH₄+）是影响浑太河流域水质状况的主要环境要素.②水生态Ⅰ区和Ⅱ区WQI较高，水质状况较好，平均值分别为86.80±6.47和85.57±6.69，其中等级为好的样点占比分别为30.41%和21.70%；水生态Ⅲ区水质较差，WQI平均值为72.92±13.75，其中建设用地和林地是影响WQI的主要土地利用类型；随着林地面积减少，建设用地面积增加，WQI逐渐降低（R_adj2=0.25），其中等级为好的样点占比仅为0.94%，而等级为差的样点占比超过50%.研究显示，土地利用对河流主要环境要素的影响在3个水生态功能区有显著差异，建设用地面积的快速增加和林地面积的大幅降低是影响浑太河流域水生态Ⅲ区水质状况的主要驱动因子. 

Spatial Distribution Characteristics of Environmental Variables and Response to Land Use Patterns in Different Aquatic Ecological Functional Regions of Hun-Tai River Basin

In order to analyze the impact of land use patterns on the spatial distribution characteristics of environmental variables in different aquatic ecological functional areas, a field survey was conducted in the Hun-Tai River Basin from 2009 to 2016. A total of 407 paired data were collected from 300 sampling sites, including 26 environmental variables and the Landsat TM remote-sensing image data in 2010 and 2015. Principal component analysis, Spearman correlation analysis and multiple linear regression analysis were used to select the main environmental factors and analyze the spatial variations of water quality index (WQI) of the basin. Combined with the land use types from different aquatic ecological functional regions and sampling sites, the impacts of land use patterns on the main environmental variables of river were explored. The results showed that electrical conductivity (EC), dissolved oxygen (DO), suspended solids (SS), 5-day biochemical oxygen demand (BOD₅), chemical oxygen demand (COD_Cr) and ammonium nitrogen (NH₄+) were the main environmental variables affecting the water quality of the Hun-Tai River Basin. The WQI in aquatic eco-region andⅡ was higher and the water quality was better with average values of 86.80±6.47 and 85.57±6.69, respectively. The proportions of sampling sites with good grades were 30.41% and 21.70%, respectively. The water quality in the aquatic eco-region Ⅲ was poor with an average value of 72.92±13.75. Among the 6 land use types, construction and forest land were the driving factors that affect the values of WQI. With the decrease in forest land and the increase in the construction land, the WQI gradually decreased (R_adj2=0.25). In the aquatic eco-region Ⅲ, the proportions of sampling sites with good grades were 0.94%, whereas the proportions of sampling sites with poor grades exceeded 50%. The present study shows that the impact of land use on the main environmental variables of the river is significantly different in the three aquatic ecological functional areas. The rapid increase of construction land and the substantial decrease of forest land are main driving factors affecting the water quality in aquatic eco-region Ⅲ of the Hun-Tai River Basin.