Integrated Analysis of Water Quality in Artificial Fishponds Using WQI and GIS in South-East Sierra Leone

Artificial fishponds play a pivotal role in global aquaculture, serving as a source of livelihood and nourishment for many communities. Ensuring the sustained health and productivity of Fishes in these environments relies heavily on water quality management. This assessment was done to determine the water quality of ten artificial fishponds in the south-eastern part of Sierra Leone using twelve physicochemical factors (pH, BOD, EC, TDS, turbidity, COD, Fe2+, Mg2+, Ca2+, NH3, , and alkalinity) to find out the Water Quality Index (WQI) and spatial distribution of respective parameters. The assessment of artificial fishponds using WQI and Inverse Distant Weighting (IDW) integration represents a relatively underexplored area within the domain of environmental water resources. The WQI was determined using the “Weighted Arithmetic Water Quality Index’’ method. The results of WQI in the study area range from 65.05 to 147.26. Several locations have water quality deemed unsuitable for consumption, while others range from good to very poor. It is essential to address and improve water quality in locations categorized as unsuitable for consumption and very poor to ensure safe and healthy water sources. It was also clear from the calculation that the smaller the mean concentration value of the pH as compared to the ideal value (7), the smaller the WQI value and the better the water quality. To keep the artificial fishpond water in good condition, mass domestic use should be controlled, and draining of surrounding organic matter should be stopped in ponds Bo_001, Kenema_001, and Kenema_002.

Development of Water Quality Index (WQI) model for the groundwater in Tirupur district, South India

Groundwater quality of the Tiruppur district in Tamil Nadu was investigated in this study to develop a Water Quality Index (WQI) model. Hydrochemical parameters showed tremendous variation in certain location over the seasons. Ionic chemistry of groundwater suggested that textile industries and rock-water interaction are major threats to the water quality. Analysis of Na and Ca concentration indicates that direct as well as the inverse cation exchange controls the natural cation chemistry. NO3 concentration shows that the pre-monsoon samples were affected by the fertilizer usage in agricultural fields. Na-Cl type of the water was dominant throughout the study area except few locations. WQI showed that 55% of the pre-monsoon samples and the 47% of the post monsoon samples were classified as poor/very poor/unsuitable for drinking category. Leaching of the textile waste and their transport to the downstream was well observed during the post-monsoon season. The specific contribution of river Noyyal in the transport of the solutes to the discharge zones was proved by the hydrochemistry of the samples.

Estimating and Plotting of Groundwater Quality Using WQI UA and GIS in Assiut Governorate, Egypt

This paper aims to turn complex groundwater data into comprehensible information by indexing the different factors numerically comparative to the standards of World Health Organization (WHO) to produce Water Quality Index (WQI). Water Quality Index (WQI) has been used to assess groundwater quality and Geographic Information Systems (GIS) has been used to create maps representing the spatial distribution of groundwater categories in Assiut governorate, Egypt. Water Quality Index has been computed by Un-weighted Arithmetic Water Quality Index (WQIUA) method and applied on 796 wells over eight years from 2006 to 2013. The results showed that WQIUA values for drinking purposes were high and most of them reached higher or close to 100, which indicated that the groundwater was polluted and unsafe for drinking. On the other hand, the quality index of groundwater for irrigation purposes in most of the study area ranges between 55.78 and 78.38 (poor and very poor category);this means that groundwater is moderately polluted and rather suitable for irrigation.

Assessment of the Water Quality Index in the Semani River in Albania

Nowadays the human activity has increased the pressure on surface water quality. The purpose of this study is to assess the environmental quality of the Seman River water (in Southern part of Albania) through a 5-year monitoring program of 14 parameters (pH, DO, EC, TSS, Cl-, NO-3, Total-N, Total-P, BOD5, Cu2+, Ni2+, Pb2+, Cd2+ and Temp. °C), that determine the environmental status of this waterbody, as well as the application of WQI (CCME) through a multivariable approach. Based on the cluster dendogram results, it can be concluded that during wet seasons such as winter-spring, there are more sediments which influence other physic-chemical parameters, while during dry seasons (summer-autumn) there are more decomposition reactions of elements released by sediments and influenced by temperature. PCA analysis determines whether the groups of factors correlate strongly or not, depending on the internal structures of the groups and variables “heavy” or latent and vary from season to season with differentiated contributions to the water quality. All three factors influence WQI to the extent of 56% in the summer and spring season and 64% and 40% in the autumn and winter season, respectively.

An Assessment on the Coastal Seawater Quality of the Gulf of Suez, Egypt

The present study focused on water quality assessment of 14 hotspot locations in the Gulf of Suez by measuring the physicochemical parameters seasonally during 2016. The results of investigated area revealed that, the annual mean range of water was: temperature (21.91°C - 29.22°C), pH (7.64 - 7.78), salinity (38.71‰ - 42.74‰), dissolved oxygen (6.09 - 8.78 mgO2/l,) oxidizable organic matter (1.4 - 5.4 mg/l), biological oxygen demand (1.14 - 3.94 mgO2/l), total suspended solids (18.56 - 37.69 mg/l), ammonia (13.51 - 494.41 μg/l), nitrite (1.261 - 151.76 μg/l), nitrate (7.11 - 487.85), dissolved inorganic phosphate (2.22 - 53.26) and silicate (19.83 - 347.61 μg/l). The N:P ratio fluctuated between 4.21 and 1214.61 with the main value of 81.16 indicating that the different sites in the northern part of the Gulf of Suez are P-limited. Based on the Principal Component Analysis Data, the stations locating in the Northern and Southern side of the Gulf of Suez are relatively good water quality;meanwhile, water quality of the other stations locating in the northern side of the Gulf of Suez is found slightly polluted to a different degree co-incided with an increase in the human activities in each of these locations.

A Number Description of Ghanaian Water Quality—A Case Study of the Southwestern and Coastal Rivers Systems of Ghana

The CSIR Water Research Institute undertook water quality monitoring and assessment of the Southwestern and the Coastal Rivers Systems of Ghana from 2005 to 2008 for the Water Resources Commission of Ghana (WRC) under WRIS II Project, a Danish Government Funded Project. The Southwestern and the Coastal Rivers Systems cover approximately 30% of the total drainage basins of Ghana. A total of 19 surface water stations were selected for the monitoring programme. The Adapted Water Quality Index (WQI) was to be used as a tool to classify the overall ambient water quality at the 19 different stations. The index classified water quality into one of four categories: good (Class I, >80), fairly good (Class II, 50 - 80), poor (Class III, 25 - 50), and grossly polluted (Class IV, <25). This paper presents the Water Quality Index approach to the assessment of water quality of the waters in the different stations during the period of study. These ten water quality parameters were used to determine the water quality index (WQI): Dissolved Oxygen (DO % Saturation), Biochemical Oxygen Demand (BOD), Ammonium Nitrogen (NH4-N), Faecal Coliform (FC), pH, Nitrate as Nitrogen (NO3-N), Phosphate as Phosphorus (PO4-P), Total Suspended Solids (TSS), Conductivity and Temperature. Evaluation of the waters with the WQI indicated that most Ghanaian waters are currently in Class II, the fairly good water quality state, but with variations in this range within the seasons and stations, and from one water body to the other. Potroase in the Densu basin had the best water quality during the study period while Nsawam had the poorest. Efforts should be made to prevent further pollution of the waters to improve their quality.

Comparison of Water Quality Status of Disturbed and Undisturbed Mangrove Forest at Awat-Awat Lawas Sarawak

Water quality testing was compulsory for management of safe and reliable water sources. Various sources of pollution and destruction of mangrove forest decrease the quality of river water. Thus a study was conducted to determine the water quality status of mangrove forest river water of Awat-Awat Lawas Sarawak and compare the water quality status of disturbed and undisturbed mangrove forest river in that area. Samples from twelve sampling stations were collected from both mangrove forest river from October 2013 to March 2014. In-situ data collected (pH, temperature, dissolved oxygen (DO), salinity, turbidity, total dissolved solid (TDS), conductivity) and laboratory analysis (biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammoniacal nitrogen (AN), total suspended solid (TSS)) were conducted according to the Standard method of Examination of Water and Wastewater AHPA 2005. Six water parameters: pH, DO, BOD, COD, AN and TSS value were used in calculating the Water Quality Index (WQI). Mean values for disturbed area were follows, pH (7.07), temperature (29.93°C), salinity (15.64 PSU), turbidity (55.13 NTU), DO (4.59 mg/L), BOD (0.73 mg/L), COD (10.16 mg/L), AN (0.14 mg/L), TSS (53.92 mg/L), TDS (23.14 mg/L) and conductivity (2.61 ms/m). Undisturbed area results were, pH (6.84), temperature (28.32°C), salinity (14.65 PSU), turbidity (35.41 NTU), DO (2.39 mg/L), BOD (0.55 mg/L), COD (15.82 mg/L), AN (0.13 mg/L), TSS (53.23 mg/L), TDS (22.82 mg/L) and conductivity (2.34 ms/m). There were no significant differences between two locations except for DO. Both water qualities of disturbed and undisturbed mangrove forest river were found under Class III, which describe that the water bodies are in moderate quality status.

CCME WQI在我国水质评价中的应用

为探讨CCME WQI在我国水资源管理中的适用性,以四个典型水功能区的水质评价为例,对比分析了评价法CCME WQI与我国常用的内梅罗指数和单因子指数评价法的评价效果。结果表明,当无污染物超标时,三种评价方法的评价结果一致;当超标污染物较少时,CCME WQI与单因子指数评价法的评价结果基本一致,且均比内梅罗指数评价法的评价结果严格;当超标污染物较多时,CCME WQI评价法的评价结果比另外两种方法的评价结果严格。总体来看,CCME WQI评价法适用于我国的水质评价。

改进WQI在川中丘陵地区典型流域水质评价中的应用-以琼江流域上游段为例

水质指数(WQI)克服了传统水质评价方法无法同时满足定性评价与定量评价的缺点,但其所需指标较多,无法做到广泛运用。以琼江流域上游段为川中丘陵地区典型流域的代表,对其2018—2019年水质监测数据进行多元线性逐步回归分析,从25个水质指标中筛选出氨氮(NH_(3)-N)、化学需氧量(COD_(Cr))、生化需氧量(BOD_(5))、溶解氧(DO)4个指标建立改进WQI(WQI_(min))模型,该模型评价结果与WQI高度相关,并且具有较好的预测性能(R^(2)=0.81,PE=11.9%)。WQI_(min)评价结果表明:琼江流域上游段WQI_(min)均值为63.1±17.2,水质等级为好;干流WQI_(min)整体上呈沿程升高的趋势,流经安居区时,WQI_(min)明显降低,但能较快恢复至入城区前的水平;WQI_(min)由高至低依次为琼江干流>会龙河>玉丰河>蟠龙河>石洞河,主要支流水质均劣于干流,建议区域水污染治理的重点应逐步放到支流上。

基于熵权的WQI法在鄱阳湖水质评价中的应用

基于2009—2018年鄱阳湖15个监测点位的水质监测数据,采用基于熵权改进的综合水质指数(WQI)法研究10年间该湖水质年际、季节演变特征及空间分布情况。结果表明:鄱阳湖WQI多年平均值为78.41,水质总体处于差等级,其中氮、磷污染较为严重;该湖水质空间分布差异较小,各湖区WQI较为接近,湖区西北部和东南部污染相对较为严重;该湖夏季水质较好,水质与降水量及湖面风浪强度紧密相关;该湖污染物主要来自入湖河流周边的工、矿、企业的废水及采砂造成的污染物释放,建议控制、治理入湖河流水质,提高鄱阳湖较重污染区水质。

基于CCME WQI模型对渭河宝鸡段水质的风险评价

为研究渭河宝鸡段的水质问题及其相应指标的空间分布,选取渭河宝鸡段水体中COD、NH3-N、TP、TN及重金属元素(Cr、Mn、Co、Ni、Cu、Zn、Cd、Pb)和类金属元素As为研究对象,采用单因子污染指数和加拿大水质指数(CCME WQI)对其污染特征进行评价,并对其评价结果进行空间可视化表征.结果表明:①水中NH3-N、TN、TP及重金属元素(Mn、Ni、Co、Cd、Cu、Pb、Zn)变异系数高,受人为影响因素大;②单因子评价中,TN、NH3-N以及As整体超标,超过Ш类水质标准;类重金属元素As在吊桥采样点处达峰值3.093,与该处施工有关;③CCME WQI评价表现为“上游污染轻,下游重”,神农桥至蟠龙桥为中等水质,卧龙桥至虢镇渭河桥为较差水质,同等水质中吊桥评分较低.评价结果空间可视化表明研究区的污染状况为“西高东低”.

综合水质标识指数法(WQI)在永定河石景山段水质评价中的应用

水质标识指数(WQI)能够系统、客观的评价水体的水环境类别、受污染程度等信息,根据单因子水质标识指数(P)创建的综合水质标识指数(WQI)可以全面评价水体的总体水质情况。为全面研究永定河石景山段各不同断面的水环境质量,选取永定河流域3个断面,按照2013—2016年的水断面监测数据,以综合水质标识指数计算各断面污染因子,并详细论述了永定河石景山段水质变化情况。

长江中上游重要渔业水域环境质量评估

为准确评估长江中上游重要渔业水域水环境质量现状及变化趋势,提高水质评价效率,本研究基于11个水质参数,采用水质指数法(water quality index,WQI)对2006-2021年长江中上游三个重要渔业水域水质进行了综合评价,建立WQI min综合评价模型。结果显示:(1)长江中上游重要渔业水域的水温和高锰酸盐指数呈上升趋势;基于地表水环境质量标准(GB38338-2002),单因素水质评价结果表明监测水域内整体水质处于地表水Ⅴ类水标准,部分年份达劣Ⅴ类,主要污染指标为总氮。(2)通过综合评价方法分析,长江中上游重要渔业水域整体为“良”;2006~2021年长江中上游重要渔业水域水质质量呈逐年改善的趋势,且上游保护区的改善较大。(3)基于WQI方法,确定了长江中上游重要渔业水域的关键水质参数为:总氮、高锰酸盐指数、汞、溶解氧、氨氮、悬浮物以及水温,分别构建了上游保护区、中华鲟保护区以及四大家鱼保护区的WQI_(min)模型;考虑权重和不考虑权重的WQI min模型对比分析表明,考虑权重的WQI min模型的水质评价结果更加准确,该方法可有效评估长江中上游重要渔业水域的水质变化特征并可扩展用于其他水域。

伊洛河盆地地下水水化学特征及人类健康风险评价

地下水水质状况与人类的身体健康密切相关,为掌握伊洛河盆地浅层地下水水质状况及水化学特征,选取2015年采集的68组地下水样品,使用WQI水质指数法进行水质评价,水化学特征分析采用Piper三线图、舒卡列夫水化学分类、离子毫克当量浓度比值法以及Gibbs图等;并对硝酸盐指标进行了人类健康风险评估。研究结果表明:按WQI水质等级分类方法,差和极差的水样所占比重为51.5%,主要分布在洛阳市主城区及渑池县、义马市、新安县以及偃师市东等地,硝酸盐权重值最高,是影响水质的关键因子;浅层地下水呈弱碱性,17.65%的地下水为微咸水,82.35%为淡水,地下水水化学类型以HCO_(3)·SO_(4)-Ca型水为主,其次为HCO_(3)-Ca型水;浅层地下水水化学组成的主要影响因素为岩石风化,同时受人类活动的影响;研究区硝酸盐健康风险较高,儿童健康风险值HQ为0.0216~5.6850,成年人健康风险值HQ为0.0116~3.045,经评价而存在健康风险的洛阳市主城区、伊川县、义马市等地的地下水环境问题,尤其是硝酸盐含量的变化,应引起重视。

非点源污染对太湖上游西苕溪流域水环境的影响

水资源短缺是全球性关注的问题水质恶化更加剧了这一问题的严重性定量研究水质变化及其影响因素可为治理水环境提供基础依据. 与实测数据及综合污染指数的对比表明水质指数能够合理反映水质的变化程度和时空变化趋势. 利用西苕溪流域1996-2000年水质监测数据的研究结果如下西苕溪流域水质的空间变化趋势是自上游至下游逐渐恶化时间变化的总体趋势是逐年转好点污染源得到有效控制年份1999年的水质指数比以前年份1996-1998年有所提高但幅度不大说明非点源污染是影响西苕溪流域水质的重要因素流域水污染的主要形式是氮磷污染其主要非点源是农田经济竹林和城镇径流及居民生活污水等.

基于水质综合指数的澜沧江西藏段水质评价及其影响因素

为了解澜沧江西藏段的水质现状及影响因素,于2017-2019年对澜沧江西藏段4个干流站位(曲孜卡、如美、卡若、扎曲)和4个一级支流站位(麦曲、金河、昂曲、热曲)进行了水质监测。监测水质参数包括水温(WT)、溶解氧(DO)、pH、电导率(EC)、透明度(SD)、总悬浮物(TSS)、总磷(TP)、总氮(TN)、氨氮(NH_(4)^(+)-N)、硝酸盐(NO_(3)^(-)-N)、亚硝酸盐(NO_(2)^(-)-N)、磷酸盐(PO_(4)^(3-))和CODcr。采用水质综合标识指数(WQI)对澜沧江西藏段水质现状进行评价。结果显示:(1)澜沧江西藏段的水质参数存在明显的时空波动,主要污染物包括TP、TN和CODcr。(2)澜沧江西藏段WQI均值范围72~80,水质总体良好;春季水质优于秋季,支流站位的WQI均值略高于干流站位的WQI均值,2017-2019年水质呈逐年向好趋势。(3)影响澜沧江西藏段WQI值的水质参数有WT、TP、NH_(4)^(+)-N、CODcr和DO。为更好地保护澜沧江西藏段的水环境,建议完善水质监测网络体系、管控污染型企业进入、加强生态环境保护与水土流失治理。

基于改进综合水质指数法的水库水质特征分析

[目的]对引黄水库水质状况进行分析,提供一种合理有效且有利于比较并适于在水库水质评价中推广的方法。[方法]以山东省滨州市滨城区东海和西海水库为研究对象,以水污染指数(WPI值)为分项指数,以超标倍数法、主成分法和层次分析法进行组合赋权,建立了引入水质标识指数法的改进型综合水质指数(WPSPNQI)评价方法,并对2011年4月至2014年4月时段内两座水库进、出口4个监测断面水质数据进行计算,分析水库水质的总体污染状况及时空变化特征。[结果](1)滨城区水库水质多为Ⅰ类或Ⅱ类水体,总体水质状况较好;(2)在研究期限内,Ⅰ类水体的比例有所增加,但部分污染因子没有得到相应改善;(3)从空间分布特征来看,两座水库的水质差距较小,其出口水质明显优于进口,水库具有一定的自净能力。[结论]经与其他水库水质评价方法对比,改进型综合水质指数(WPSPNQI)评价方法在数据处理、权重赋值等方面都较为优越,评价结果可靠。

浑太河流域不同水生态功能区环境要素的分布特征及其与土地利用之间的关系

为深入分析不同水生态功能区土地利用方式对环境要素空间分布特征的影响,于2009—2016年对浑太河流域300个样点的407组数据进行野外监测(包括26种水环境要素数据以及2010年和2015年的Landsat TM遥感影像数据),采用主成分分析、Spearman相关性分析和多元线性回归分析,筛选主要水环境因子,分析流域水质指数(WQI)的空间变化规律,结合水生态功能分区和各样点的土地利用数据,探究了不同水生态功能区土地利用方式对河流主要环境要素的影响.结果表明:①电导率(EC)、溶解氧(DO)、悬浮物(SS)、5日生化需氧量(BOD_(5))、化学需氧量(COD_(Cr))和铵态氮(NH_(4)^(+))是影响浑太河流域水质状况的主要环境要素.②水生态Ⅰ区和Ⅱ区WQI较高,水质状况较好,平均值分别为86.80±6.47和85.57±6.69,其中等级为好的样点占比分别为30.41%和21.70%;水生态Ⅲ区水质较差,WQI平均值为72.92±13.75,其中建设用地和林地是影响WQI的主要土地利用类型;随着林地面积减少,建设用地面积增加,WQI逐渐降低(R_(adj)^(2)=0.25),其中等级为好的样点占比仅为0.94%,而等级为差的样点占比超过50%.研究显示,土地利用对河流主要环境要素的影响在3个水生态功能区有显著差异,建设用地面积的快速增加和林地面积的大幅降低是影响浑太河流域水生态Ⅲ区水质状况的主要驱动因子.

三峡水库175 m试验性蓄水后库区水质时空变化规律

为了研究三峡水库175 m试验性蓄水运行后的库区水质时空变化规律,基于2008~2019年三峡库区逐月水质监测数据,采用Mann-Kendall非参数检验法和水质质量指数(WQI)综合评估法分析了三峡库区蓄水后水质时空分布特征。结果表明:三峡库区水质主要超标项目为总磷和高锰酸盐指数,上游总磷、高锰酸盐指数超标现象大于下游;2008~2019年高锰酸盐指数、总磷浓度整体呈缓慢下降趋势;2016年是干流总磷浓度变化的突变节点,干流的总磷浓度在2016年之后有显著下降趋势;三峡库区干支流水质质量指数整体处于上升趋势,支流水质质量指数整体低于干流,丰水期水质质量指数低于枯、平水期。研究成果可以为三峡库区水环境保护和管理提供科学依据。

三种常用水质评价方法的对比分析研究

简单介绍了国内常用的评价河流水质的单因子评价法、内梅罗污染指数法以及国际上常用的评价饮用水水质的加拿大水质指数(CCME WQI)法,并以四川省金堂县境内的沱江水系为例,进行实例分析。结果表明:就评价方法而言,单因子评价法和内梅罗污染指数法的评价结果均会受极端指标的影响,而CCME WQI法考虑了"范围、频率、振幅"3个因素的共同作用,能够很好地平抑极端指标的影响,同时,CCME WQI法还能利用水质指数值对水体进行分级,是一种比较全面的水质评价方法;就评价指标而言,不同指标的选择会对评价结果产生一定影响,亟须建立完善的评价指标体系,根据不同的需求选用不同的子指标体系,并由此得到不同的子指数或等级来进行水质评价。