黄河下游湖泊水化学特征与水体营养类型评价

The Assessment of Hydrochemistry Characteristics and Eutrophication Types of Lakes in Lower Reaches of the Yellow River

为了合理开发利用与保护黄河下游湖泊水资源,对黄河下游湖泊中的东平湖、稻屯洼、马踏湖、白云湖湖水化学成分分别进行分析,确定其水化学类型及基本特征,并对水体营养类型进行综合评价。运用与湖泊富营养化关系最为密切的chla(叶绿素)、TN、TP、CODMn和SD(透明度)作为评价参数,对照中国湖泊富营养化评价标准,并参考太湖的以百分数划分湖泊营养方法,采用单项评分和综合记分方法,确定湖水营养类型评价标准。对湖水水质监测数据分析表明:东平湖、白云湖为重碳酸类钠组Ⅱ型水、稻屯洼、马踏湖为氯化类钠组Ⅱ型水,均为偏碱性湖泊;稻屯洼与马踏湖湖水中有机物耗氧量高,平均为9.58mg/L和21.47mg/L,说明水体已受到污染;东平湖与白云湖湖水中有机物耗氧量不高,平均分别为5.06mg/L与4.02mg/L;东平湖与白云湖湖水中N:P比值较高,分别为61与45,说明东平湖与白云湖湖水中氮含量供应充分,植物、藻类的生长受到了磷的限制。对湖水营养类型评价结果表明:东平湖现属中富-富营养型水平,稻屯洼属富营养型水平,马踏湖属重富营养型水平,白云湖属中营养型水平。总体来说,黄河下游湖泊大都受到不同程度的污染,湖水水质已经恶化,水体营养类型已达富营养化水平,白云湖水质较好,需加强保护。

To rationally develope,utilize and protect the water resources in lakes of lower reaches of the Yellow River,hydro-chemical composition of natural water in Dongping Lake,Daotunwa Lake,Mata Lake and Baiyun Lake was analyzed,hydro-chemical types and fundamental characteristics were determined and nutritional types of the water were also comprehensively evaluated.To determine the nutritional type standards of these four lakes,five indexes [chla（chlorophyll）,TN,TN,CODMn and SD（transparency）] were selected as evaluation parameters.Compared with the eutrophic criteria of lakes in China and referd to the method that dividing the Tai Lake nutrient in percentage terms,individual grading and comprehensive grading methods were adopted.The results of water quality monitoring data showed that：the type of water of Dongping Lake and Baiyun Lake was CIINa,Mata Lake and Daotunwa Lake was CIIINa,and they were alkaline lakes.Organic oxygen consumption in Daotunwa Lake and Mata Lake was very high,with an average of 9.58 mg/L and 21.47 mg/L,respectively,which indicated water here had been polluted.Organic oxygen consumption in Dongping Lake and Baiyun Lake was low,with 5.06 mg/L and 4.02 mg/L on average,respectively.The N：P ratio in Dongping Lake and Baiyun Lake was 61 and 45,respectively.The higher N：P ratio demonstrated that nitrogen was fully supplied in these two lakes and growths of plants and algae were limited by phosphorus.The results of nutritional types of the water data showed that：Dongping Lake,Daotunwa Lake,Mata Lake and Baiyun Lake were in mesoeutrophic-eutrophic state,eutrophic state,high eutrophic state and mesotrophic state,respectively.On the whole,most of the lakes at the Lower Reaches of the Yellow River had been suffering from varying degrees of pollution,water quality is deteriorating in recent years,and nutritional types of water had reached the eutrophication level.However,water quality in Baiyun Lake remained stable in good condition,and needed to strengthen the protection.