摘要
为了研究滨海区地下水中硝酸盐氮(NO-3)的不同来源及其贡献率,以山东莱州市莱州湾东岸地下水为研究对象,分别采用IsoSource、IsoError和SIAR同位素模型,分析围海养殖和地下水库影响下地下水NO-3来源贡献率特征,讨论三种同位素模型在滨海区的适用性。结果表明,在围海养殖区,9月份海水养殖NO-3贡献率最高(45%),1月份NO-3贡献率最低(22%)。生活污水NO-3贡献率季节性差异小,在40%左右。库区内地下水中有机肥的贡献率最大。地下水库减弱了地下水中NO-3的水平迁移,从而使硝酸盐污染源的贡献率季节性差异变小。污染源及受纳水体的同位素范围对IsoSource和IsoError同位素模型的计算结果有较大影响,较大的同位素范围导致其结果的不确定性高。而SIAR模型考虑了污染源和受纳水体中硝酸盐氮氧同位素(δ15N-NO-3和δ18O-NO-3)空间差异性,所以计算结果的不确定性最低,适合本研究区。
In order to study the sources of nitrate and their contribution in groundwater in coastal region,this paper take the groundwater in the east coast of Laizhou Bay as an example,three isotope models(IsoSource,IsoError and SIAR)are applied to calculate the contributions of nitrate sources in the study area affected by reclamation for mariculture and underground reservoir and analyze the isotope models applicability in the eastern coast of Laizhou Bay.The results indicated that in the mariculture zone,the contribution of nitrate derived from mariculture is highest with a value of 45%in September,and lowest with a value of 22%in Januray.Little difference of contributions of nitrate derived from sewage is found between four months with average value of about 40%.The contribution of nitrate derived from manure is highest in groundwater upstream,because of the barrier of underground cutoff walls,horizontal migration of nitrate in groundwater upstream is weaken,which lead to little temporal difference of the contributions of nitrate sources.The range of isotope composition of nitrate source and mix water have large impact on the result calculated by IsoSource and IsoError model.Large range of isotope values leads to high uncertainty of the results.The uncertainty of contributions of nitrate sources calculated by SIAR model is lowest due to considering spatial variability of theδ15N-NO-3和δ18O-NO-3 of nitrate sources and receiving water,which is suited to the study area.In the further study,δ15N-NO-3和δ18O-NO-3 values of different nitrate source should be tested and reported,and uncertainty analysis method of isotope models should be further studied in order to expend the application of isotope models.
作者
康萍萍
许士国
KANG Pingping;XU Shiguo(North China university of Water Resources and Hydropower, Zhengzhou 450046, Henan, China;Institute of Water and Environmental Research, Dalian University of Technology, Dalian 116024, Liaoning, China)
出处
《水利水电技术》
北大核心
2020年第11期155-162,共8页
Water Resources and Hydropower Engineering
基金
国家自然科学基金项目(51709112)。
关键词
硝酸盐氮
污染源贡献率
同位素模型
地下水
nitrate
contribution of pollution sources
isotope mixing model
groundwater
