中国岩溶2025，Vol.44Issue(2)：274-282,9.DOI:10.11932/karst20250206
西南某城区地下水"三氮"空间分布及风险管控研究
Research on the spatial distribution and risk control of"three forms of nitrogen"in groundwater in an urban area of southwest China
摘要
Abstract
Since the implementation of drought-resistant water exploration and well-drilling work,the utilization of groundwater in the karst areas of Southwest China has been increasing.While groundwater has generated much attention,the problems of groundwater pollution have also come to light,particularly concerning the"three forms of nitrogen"pollution in water.The sources of nitrogen pollution are complex,and its pathways are varied.Under the special hydrogeological conditions of karst areas,surface pollutants are more likely to infiltrate into the ground.Given the concealment and mobility of groundwater,pollutants continuously migrate with the groundwater flow.Once contaminated,the difficulty of restoration and remediation is extremely high. Taking an urban area in Southwest China as an example,this study conducted hydrogeological surveys and water sample testing.Based on data such as springs,boreholes,and water quality,this study utilized the method of Inverse Distance Weighting(IDW)to interpolate and analyze the"three forms of nitrogen"in groundwater.Combined with the field model of groundwater flow,the spatial distribution of"three forms of nitrogen"was analyzed.Furthermore,the areas for risk control were delineated through overlay analysis.The results show that there were differences in the spatial distribution of"three forms of nitrogen"in the study area.Urban boreholes and sewage treatment plants had a greater impact on NH4+-N concentration,while agricultural and residential areas significantly influenced NO3--N levels.The overall situation regarding NO2--N was favorable,with no significant pollution detected.Additionally,there were notable differences in the concentrations of the"three forms of nitrogen",with the highest concentration of NO3--N reaching 96.00 mg·L-1,which was much higher than the concentrations of NH4+-N(8.00 mg·L-1)and NO2--N(0.500 mg·L-1).This variation is attributed to the characteristics of karst areas.Under conditions of adequate oxygen content,NH4+-N and NO2--N were converted into NO3-N.With the use of the Class Ⅲ water index specified in the Standard for Groundwater Quality(GB/T 14848-2017)as the control boundary,the study area is divided into three zones through ArcGIS overlay analysis,key control area(Class Ⅳ-Ⅴ),secondary control area(Class Ⅲ),and general area(Class Ⅰ-Ⅱ).In key control areas,the focus is on controlling sewage discharge and leakage,as well as nitrogen loss from agricultural activities.Specific measures include strengthening control of pollution emission in densely populated residential areas,ensuring the impermeability of residential water wells,sewage pipelines,and wastewater treatment plants.In agricultural-intensive areas,the implementation of scientific fertilization and rational allocation of fertilizers should be prioritized to prevent the migration of"three forms of nitrogen"at the source.In secondary control areas,the emphasis is on preventing further pollution and optimizing water quality indicators.Specific measures include optimizing the sewage systems in residential areas,further controlling pollution emissions,enhancing regional soil and water conservation capacities,and improving vegetation absorption efficiency.Additionally,measures such as crop rotation,optimizing crop irrigation methods,ecological breeding,and reducing random sewage discharge should be implemented to comprehensively improve the regional ecological space.In general areas,the focus is on maintaining the current status and preventing pollution.关键词
城区/地下水/三氮/空间分布/风险管控Key words
urban area/groundwater/three forms of nitrogen/spatial distribution/risk control分类
资源环境引用本文复制引用
黄艳采,金波,曾牡丹,向刚..西南某城区地下水"三氮"空间分布及风险管控研究[J].中国岩溶,2025,44(2):274-282,9.基金项目
贵州省地矿局局管地质科学研究项目(黔地矿科合[2020]5号) （黔地矿科合[2020]5号）
