摘要
为深入探究不同空间尺度以及不同水情条件下,长三角地区水质空间格局与土地利用类型关系,选取了 2021年316个测站的溶解氧浓度、pH值、总氮浓度、总磷浓度、高锰酸盐指数、水温、氨氮浓度、电导率和浊度等9个水质指标月平均数据,以测站为中心,划分500、2 000m缓冲区及子流域缓冲区,采用综合因子评价法、Pearson相关性分析和冗余分析等方法研究水质空间分布特征及土地利用类型影响.结果表明:(1)长三角整体水质较优,为Ⅱ级,主要污染物为氮磷和有机物,其中西南地区总磷浓度高,东北地区低;(2)同时,该区域水质枯水期和丰水期差异明显,表现为枯水期电导率、总氮和溶解氧均高于丰水期;(3)土地利用类型对水质影响明显,小尺度上,影响水质的主要土地类型为农业用地;此外,林地对水质影响在枯水期较丰水期强.在大尺度上,林地对区域水质影响较大.因此,小区域尺度上开展合理的农业措施管理和大区域尺度实施退耕还林还湖等措施对长三角地区水体生态治理具积极意义.
Abstract
This study aimed to explore the relationship between the spatial distribution of water quality and land use types in the Yangtze River Delta region.Monthly average data for nine key water quality indicators,including dissolved oxygen concentration,pH value,total nitrogen concentration,total phosphorus concentration,permanganate index,water temperature,ammonia nitrogen concentration,conductivity,and turbidity,were collected from 316 monitoring stations in 2021.Buffer zones of 500 meters and 2000 meters,as well as sub-basin buffers centered around the stations,were established for analysis.The research employed a combination of methods including the comprehensive factor evaluation approach,Pearson correlation analysis,and redundancy analysis.The findings of this study revealed the following:(1)The overall water quality in the Yangtze River Delta region was of high quality,categorized as Grade Ⅱ.Key pollutants included nitrogen,phosphorus,and organic matter.Notably,total phosphorus concentration exhibited regional variations,with higher levels observed in the southwest and lower levels in the northeast.(2)Distinct variations between dry and wet seasons were evident,with conductivity,total nitrogen,and dissolved oxygen concentrations being higher during the dry seasons compared to the wet seasons.(3)Land use types exerted a significant influence on water quality.At a smaller scale,agricultural land was identified as the primary driver of water quality variations.Additionally,the impact of forested land on water quality was more pronounced during the dry seasons than the wet seasons.At a larger scale,forested areas played a substantial role in regional water quality.In light of these insights,this study underscored the positive implications of implementing both targeted agricultural management practices at the local scales and broader measures such as afforestation and wetland restoration at the regional scales for effective water ecological management in the Yangtze River Delta region.
基金项目
国家自然科学基金项目(42171346)
江苏省高等学校基础科学(自然科学)研究项目(21KJB570006)
NETL
NSTL
万方数据