摘要
特定空间尺度下的景观格局能够反映水体中非点源污染物的来源及地表景观消纳能力.为探明不同圆形缓冲区尺度下景观格局对排水沟水质的影响,以宁夏回族自治区引黄灌区第四排水沟为研究对象,基于2022年的土地利用数据和2021~2022年26个采样点的动态水质监测数据,设置100、200、500、1000和2000 m等5个圆形缓冲区尺度,采用景观格局分析、Spearman秩相关分析和冗余分析这3种方法筛选出解释水质变化的最佳缓冲区尺度及相应关键景观指标,并解析了排水沟水质与景观特征间的响应关系.结果表明:①宁夏回族自治区引黄灌区第四排水沟主要受到较高的氮污染,全年中70%以上点位的TN指标超过Ⅴ类水标准限值,而TP指标全年未超过Ⅲ类水标准限值,污染较轻;②200 m圆形缓冲区尺度下的景观特征与两个时期的水质指标关系密切,且该尺度下休耕期和耕作期解释率均为最高,分别为45.76%和44.14%,是判别第四排水沟水质的最佳缓冲区尺度;③耕地是最佳缓冲区范围内的主要“源”土地利用类型,是影响排水沟中污染物变化的主要因素,蔓延度指数、聚集度指数、散布与并列指数和香农均匀度是影响水质变化的主要景观因子.因此,采用优化景观格局法进行排水沟水污染监测治理时,建议在200 m圆形缓冲区范围内严格控制耕地等“源”土地利用类型面积占比,同时提高景观的多样性、连通性和聚集度.研究结果可为宁夏回族自治区引黄灌区排水沟水质监测分析提供新的思路和解决方案.
Landscape patterns at specific spatial scales can respond to the sources of non-point source pollutants in water bodies and the surface landscape's ability to absorb them.To investigate the influence of landscape patterns on the water quality of the drainage ditch at different circular buffer scales,the fourth drainage ditch of the Ningxia Yellow River Irrigation Area(YDIA)was taken as the research object,and based on the land-use data in 2022 and the dynamic water quality monitoring data of 26 sampling points from 2021 to 2022,five circular buffer scales,including 100,200,500,1000,and 2000 m,were set up,and three methods.Landscape pattern analysis,Spearman rank correlation analysis,and redundancy analysis were used to filter the water quality of the drainage ditch.Landscape pattern analysis,Spearman rank correlation analysis,and redundancy analysis were used to screen out the optimal buffer scales and corresponding key landscape indicators to explain the changes in water quality and to analyze the response relationship between the water quality of the drainage ditch and landscape features.The results showed that:①The fourth drainage ditch in Ningxia Huang Irrigation Area was mostly polluted by high nitrogen,and more than 70%of the TN indexes exceeded the standard limit for ClassⅤwater throughout the year,while the TP indexes did not exceed the standard limit for ClassⅢwater,which was less polluted.②The landscape characteristics at the scale of the 200 m circular buffer zone had a close relationship with the water quality indexes of the two periods,and the explanation rates of the fallow period and the cultivation period at that scale were the highest,45.76%and 44.14%,respectively,and the explanation rate was the highest,47.63%and 45.83%,respectively,which was the best buffer scale for discriminating the water quality of the fourth drainage ditch.③Cultivated land was the main‘source’land use type within the optimal buffer zone,which was the main factor affecting the change of pollutants in the drainage ditch.Followed by the spreading index,aggregation index,scattering and juxtaposition index,and fragrance uniformity,which were the main landscape factors affecting the change of water quality.Therefore,when optimizing the landscape pattern method for monitoring and controlling water pollution in drainage ditches,it is recommended to strictly control the proportion of arable land and other‘source’land-use types within the 200 m circular buffer zone,and at the same time,improve the diversity,connectivity,and aggregation of the landscape.The results of this study can provide new ideas and solutions for monitoring and analyzing the water quality of drainage ditches in Ningxia's Yellow River Irrigation District.
作者
马纪龙
马琨
谢铁娜
马建军
李虹
岳翔
韩林蒲
齐勇杰
高嘉琪
贾彪
MA Ji-long;MA Kun;XIE Tie-na;MA Jian-jun;LI Hong;YUE Xiang;HAN Lin-pu;QI Yong-jie;GAO Jia-qi;JIA Biao(School of Agriculture,Ningxia University,Yinchuan 750021,China;School of Ecology and Environment,Ningxia University,Yinchuan 750021,China;Research Institute of Science and Technology,Ningxia University,Yinchuan 750021,China;Agricultural Environmental Protection Monitoring Station of Ningxia Hui Autonomous Region,Yinchuan 750002,China)
出处
《环境科学》
北大核心
2025年第7期4251-4263,共13页
Environmental Science
基金
宁夏自然科学基金项目(2023AAC03075,2023AAC03151)
国家自然科学基金项目(32360432)。
