摘要
为了解三亚河营养盐污染状况,于2018年6月-2019年5月对三亚河流域进行逐季调查,分析水体中氮磷营养盐的时空分布特征及影响因素,评估河流富营养化状况,并进一步估算三亚河营养盐入海通量.结果表明,三亚河水体中营养盐浓度季节变化显著,三亚河水体中DIN的浓度范围为0.028-2.096 mg·L-1,平均浓度为(0.700±0.279)mg·L-1,冬季＞秋季＞夏季＞春季,NO3--N 和NH4+-N 是水体中DIN的主要存在形式.DIP浓度范围为0.007-0.442 mg·L-1,平均浓度为(0.140±0.066)mg·L-1,夏季＞春季＞冬季＞秋季.空间分布上,N、P营养盐均呈现出上游及入海口河段浓度低,中下游河段浓度高的特点.河段环境特征、人为活动、降雨、潮汐作用是影响三亚河营养盐分布的主要因素.综合富营养盐指数(EI)结果显示,各季节三亚河上游及入海口河段均处于中富营养化状态,中下游河段均处于富营养化和重富营养化状态.春、夏、秋季N/P值表明河流多处于N限制状态,冬季大部分河段适合藻类生存,有发生藻华的风险.根据营养盐浓度和三亚河年平均径流量估算出,DIN、NO3--N、NO2--N、NH4+-N、DIP 年入海通量分别为 118.37、70.93、11.18、38.67、23.75t.
Abstract
To understand the nutrient pollution status of Sanya River,a seasonal survey was conducted in the Sanya River basin from June 2018 to May 2019 to analyze the spatial and temporal distribution characteristics and influencing factors of nitrogen and phosphorus nutrient salts in the water column.The state of eutrophication was evaluated,and further the flux of nutrients into the sea through Sanya River was estimated.The results show that the seasonal variation of nutrient concentration in Sanya River is significant.The concentrations of DIN ranged from 0.028 mg·L-1 to 2.096 mg·L-1,with an average concentration of(0.700±0.279)mg·L-1,with a sequential increase in spring,summer,autumn and winter NO3--N and NH4+-N are the main forms of DIN present in the water column.The concentrations of DIP ranged from 0.007 mg·L-1to 0.442 mg·L-1,with an average concentration of(0.140±0.066)mg·L-1,with a sequential increase in autumn,winter,spring,and summer.The spatial distribution of N and P nutrients was similar,with low concentration in the upstream and estuaries and high concentrations in the middle and downstream.The environmental characteristics of river sections,anthropogenic activities,rainfall and tide are the main factors affecting the nutrient distribution in the Sanya River.The results of eutrophication index(EI)evaluation showed that the upper reaches and estuaries of Sanya River are moderately eutrophic in all seasons,while the middle and lower reaches are eutrophic and heavily eutrophic.The N/P in spring,summer and autumn indicate that most rivers are in nitrogen limitation,and most of the river were suitable for algal survival in winter,with the risk of algal blooms.Based on nutrient concentrations and the average annual runoff of Sanya River,it was estimated that the annual flux of DIN,NO3--N,NC2--N,NH4+-N and DIP into the sea are 118.37,70.93,11.18,38.67 and 23.75 t,respectively.
基金项目
海南省自然科学基金青年基金(419QN241)
海南省自然科学基金(420MS058)
海南热带海洋学院博士研究生科研启动项目(RHDXB201622)
海南热带海洋学院青年专项基金(RHDQN201816)
NETL
NSTL
万方数据