Hydrochemical characteristics and water quality evaluation of shallow groundwater in Suxian mining area,Huaibei coalfield,China

The aim of this study is to evaluate the hydrogeochemical characteristics and water environmental quality of shallow groundwater in the Suxian mining area of Huaibei coalfield,China.The natural formation process of shallow groundwater in Suxian is explored using Piper trilinear charts and Gibbs diagrams,and by examining the ratios between the major ions.United States Salinity Laboratory(USSL)charts,Wilcox diagrams,and the water quality index(WQI)are further employed to quantify the differences in water quality.The results reveal that the main hydrochemical facies of groundwater are HC03-Ca,and that silicate dissolution is the main factor controlling the ion content in shallow groundwater.The USSL charts and Wilcox diagrams show that most of the water samples would be acceptable for use in irrigation systems.The WQI results for each water sample are compared and analyzed,and the quality of groundwater samples around collapse ponds is found to be relatively poor.

Advanced Grey Relational Analysis Method and Its Application in Water Quality Evaluation of the Lake-type Wetland

Grey relational analysis is one of the most important methods in water quality evaluation system. As the traditional grey relational analysis has the defects of homogenization in static resolution ratio, small discrimination in correlation degree, and low precision in the weight of impact factors, this paper proposed an advanced grey relational analysis that used dynamic resolution ratio and comprehensive evaluation indicators. This method has been applied in the MIS software which monitors and evaluates the water quality in the lakes of the Four-Lake Basin. Compared with the traditional grey relational analysis and the cluster-factor analysis, this method could effectively enhance the reliability and accuracy of the results.

FANN-Based Surface Water Quality Evaluation Model and Its Application in the Shaoguan Area

一个模糊神经网络模型被建议评估水质。模型包含二部分：首先，模糊数学理论被用来标准化样品；秒， RBF 神经网络和 BP 神经网络被用来训练标准化样品。建议模型被使用在 2005 在 Shaoguan 区域在 9 条河里估计 16 节的水质。评估结果在在 2005 的 Shaoguan 区域与 RBF 神经网络方法和报导结果的相比。它显示建议模糊神经网络模型的性能在水质评价的应用程序实际上是可行的，它的操作简单。

Water Quality Evaluation in Tidal River Reaches of Liaohe River Estuary, China Using a Revised QUAL2K Model

Rivers in the Liaohe River Estuary area have been seriously polluted by discharges of wastewater containing petroleum pol- lutants and nutrients. In this paper, The Enhanced Stream Water Quality Model (QUAL2K) and its revised model as well as One-dimensional Tide Mean Model (1D model) were applied to predict and assess the water quality of the tidal river reach of the Liaohe River Estuary. Dissolved oxygen (DO), biochemical oxygen demand (BOD5), ammonia nitrogen (NH3-N) and total phosphorus (TP) were chosen as water quality indices in the two model simulations. The modelled results show that the major reasons for degraded rivers remain petroleum and non-point source pollution. Tidal water also has a critical effect on the variation of water quality. The sensitivity analysis identifies that flow rate, point load and diffuse load are the most sensitive parameters for the four water quality indices in the revised QUAL2K simulation. Uncertainty analysis based on a Monte Carlo simulation gives the probability distribution of the four water quality indices at two locations (6.50 km and 44.84 km from the river mouth). The statistical outcomes indicate that the observed data fall within the 90% confidence intervals at all sites measured, and show that the revised QUAL2K gives better results in simulating the water quality of a tidal river.

Agrochemical Concentration Level in Zaria Dam Reservoir and Ground Waters in the Environs

This study examines the effect of agrochemical used for faming in the Galma Dam area on the quality of water in the reservoir and well water around the reservoir. Nine sampling points upstream of the Galma Dam were randomly se- lected for the study. Also, six hand dug wells in use by adjacent communities were identified for ground water samples. The study covered the period July to September 2011. All measurements were in accordance with the Standard Methods for the Examination of Water and Wastewater. The parameters measured and their mean concentrations from the reser- voir are in the order of: Chlorides (0.600 - 0.900 mg/l);Nitrates (0.009 - 0.019 mg/l);Bicarbonates;0.444 - 1.900 mg/l);Total Phosphates (0.173 - 3.077 mg/l);Sulphates (0.617 - 3.587 mg/l);and pH (6.4 - 7.5). For the well water samples, the results ranged from 1.58 - 3.10 mg/l;0.14 - 0.03 mg/l;0.60 - 2.73 mg/l;0.08 - 1.89 mg/l;0.33 - 2.66 mg/l and 6.05 - 7.0 respectively in the order previously listed. The results were statistically analyzed using ANOVA at 95% confidence level. Chlorides showed no significant variation between sampling points but significant variation with dates of sam- pling for surface and well waters. Nitrates variations with both sampling points and dates of sampling were insignificant. Bicarbonates variations with sampling points and dates of sampling were highly significant. Total Phosphates and Sul- phates variations with sampling points and dates of sampling were insignificant and significant respectively. pH values variations with sampling points and dates of sampling were insignificant and highly significant respectively. Generally, the mean concentrations are within the WHO maximum limits of the parameters in drinking water and recommenda- tions were made regarding the use of agrochemicals for farming in the area.

Spatial and Temporal Variation and Trend Analysis of Water Quality in Large Reservoirs in Ji’an City

Based on the water quality monitoring data of 5 large reservoirs in Ji’an City,Jiangxi Province from 2015-2021,the temporal and spatial variation characteristics and trends of water quality of the reservoirs were analyzed by single-factor evaluation method and seasonal Kendall test to evaluate the trophic status of the reservoirs and explore the influencing factors of characteristic pollutants.The results showed that:①the water quality of the reservoirs was good and could meet the water needs of various functions;②the water quality of the reservoirs had generally changed from bad to good in recent years,indicating that the implementation of“river chief system”has achieved certain results;③Kendall test analysis showed that,except for individual projects which showed an upward trend in water quality,other projects showed no obvious change trend or downward trend,indicating that the water quality of the reservoirs is indeed improving;④the causes of water pollution in reservoir area were further analyzed by exploring the natural and human factors of the characteristic pollutant total phosphorus.It is recommended to strengthen supervision in the later stage to control point and non-point source pollution.

Water Quality Analysis of Fuping Section of the Shichuan River Based on Different Evaluation Methods

In order to study the water quality of the Shichuan River basin in Fuping,Shaanxi Province,based on improved Nemerow index method,comprehensive pollution index method and principal component analysis method,eight water quality indexes such as pH,dissolved oxygen(DO),total dissolved solids(TDS),COD,total hardness,total phosphorus,total nitrogen and Zn in three monitoring sections of Fuping section of the Shichuan River in Shaanxi Province were detected and analyzed.The results show that the water quality of the surface water in the Shichuan River basin is gradeⅢorⅣwater,that is,the water is slightly polluted and moderately polluted.It is necessary to monitor the water quality after regulation and clarify the main factors causing the water pollution.

Analysis of Water Quality and Eutrophication Status of Artificial Lakes on Campus:A Case Study in Tibet University

In this paper,the artificial lake on the campus of Tibet University was taken as the research object.By detecting the water quality of the lake,the standard index method and comprehensive pollution index method were used to understand the water quality characteristics,pollution status,and main pollutants of the Siyuan Lake.On this basis,the comprehensive nutritional status index method was used to evaluate the eutrophication status of the Siyuan Lake.The results showed that the overall water quality of the artificial lake was good,showing as still clean,with TN and TP being the main pollution factors of the artificial lake.The main nutritional indicators were TN,TP,and transparency,with a comprehensive nutritional level of middle eutropher.Based on the environmental characteristics of the artificial lake area on the campus of Tibet University,reasonable treatment measures have been proposed.It hoped to prevent and improve the water environment through these measures,and provide reference for the protection and restoration of campus landscape water body.

Entropy method for determination of weight of evaluating indicators in fuzzy synthetic evaluation for water quality assessment

Considering the difficulty of fuzzy synthetic evaluation method in calculation of the multiple factors and ignorance of the relationship among evaluating objects, a new weight evaluation process using entropy method was introduced. This improved method for determination of weight of the evaluating indicators was applied in water quality assessment of the Three Gorges reservoir area. The results showed that this method was favorable for fuzzy synthetic evaluation when there were more than one evaluating objects. One calculation was enough for calculating every monitoring point. Compared with the original evaluation method, the method predigested the fuzzy synthetic evaluation process greatly and the evaluation results are more reasonable.

Evaluation of Farmland Drainage Water Quality by Fuzzy–Gray Combination Method

The complex relationships between indicators and water conditions cause fuzzy and gray uncertainties in evaluation of water quality. Compared to conventional single-factor evaluation methods, the combination evaluation method can consider these two uncertainties to produce more objective and reasonable evaluation results. In this paper, we propose a combination evaluation method with two main parts:(1) the use of fuzzy comprehensive evaluation and gray correlation analysis as submodels with which to consider the fuzzy and gray uncertainties and(2) the establishment of a combination model based on minimum bias squares. In addition, using this method, we evaluate the water quality of a ditch in a typical rice–wheat system of Yixing city in the Taihu Lake Basin during three rainfall events. The results show that the ditch water quality is not good and we found the chemical oxygen demand to be the key indicator that affects water quality most significantly. The proposed combination evaluation method is more accurate and practical than single-factor evaluation methods in that it considers the uncertainties of fuzziness and grayness.

Water quality evaluation based on improved fuzzy matter-element method

For natural water, method of water quality evaluation based on improved fuzzy matter-element evaluation method is presented. Two important parts are improved, the weights determining and fuzzy membership functions. The coefficient of variation of each indicator is used to determine the weight instead of traditional calculating superscales method. On the other hand, fuzzy matter-elements are constructed, and normal membership degrees are used instead of traditional trapezoidal ones. The composite fuzzy matter-elements with associated coefficient are constructed through associated transformation. The levels of natural water quality are determined according to the principle of maximum correlation. The improved fuzzy matter-element evaluation method is applied to evaluate water quality of the Luokou mainstream estuary at the first ten weeks in 2011 with the coefficient of variation method determining the weights. Water quality of Luokou mainstream estuary is dropping from level I to level II. The results of the improved evaluation method are basically the same as the official water quality. The variation coefficient method can reduce the workload, and overcome the adverse effects from abnormal values, compared with the traditional calculating superscales method. The results of improved fuzzy matter-element evaluation method are more credible than the ones of the traditional evaluation method. The improved evaluation method can use information of monitoring data more scientifically and comprehensively, and broaden a new evaluation method for water quality assessment.

Determining the Quality of Mine Gushing and Mixed Water Using Coupled AHP and Fuzzy Comprehensive Evaluation Methods

This study focused on analysis of the chemical characteristics of mine waters. The aim of this study is to correlate the degree of different ionic components in mine water and the influence of their convergence using a combination of the three-scale AHP and fuzzy evaluation methods for the comprehensive evaluation of water quality. Ion chromatography (ICS 1100) has been used to analyze the content of the water sample while portable pH/EC/TDS/Tem- perature meters (SX 811 and SX 813) were used to test physical-chemical parameters. The results of this study show that chemistry of in No.11 gushing mine is dominated by HCO3-Na and HCO3-Ca, and had a pH between 7.1 and 8.00, belonging to neutral or slightly alkaline water. In addition, water were found to have the hardness between 18 mg/L and 542.5 mg/L. Results also show that the TDS of the roof sandstone and goaves water are higher than Cambrian limestone water, while the turbidity of the mixed water is 20 NTU in the sump, again higher than in other samples such as Cambrian limestone water. Total dissolved solids and the total hardness of Cambrian limestone groundwater mainly depend on the content of K+ + Na+, Ca2+, B={b1,b2,…,bj} and SO2-4. Thus, chemical composition changes remarkably after mine water mixing. Results showed that the coal roof sandstone water is class V while that in the sump is class III, and the Cambrian limestone groundwater is class I. In gushing, the quality of water can vary greatly;thus, water from the coal face roof sandstone and the Cambrian limestone should be stored and treated separately before being utilized.

Comprehensive Evaluation of Water Quality of Rivers in Binzhou Based on RAGA-PPCE Model

The water quality of main rivers in Binzhou City,Shandong Province was comprehensively evaluated based on RAGA-PPCE model. Six main factors such as ammonia nitrogen(NH_3-N),total phosphorus(TP),total nitrogen(TN),chemical oxygen demand(COD),dissolved oxygen(DO) and p H were used to establish the evaluation and classification standards of water quality. The results show that the evaluation results of water quality by RAGA-PPCE model and the fuzzy comprehensive evaluation method are basically the same. The evaluation results of RAGA-PPCE model are objective and reasonable and can be applied to the comprehensive evaluation of water quality.

Biological Evaluation Based Quality Management of Water Resources in Small Xingkai Lake

Taking the water ecosystem of Small Xingkai Lake as research object,through the survey and analysis of aquatic organism indicators,this paper established an ecosystem integrity evaluation system with the biological integrity as the criterion layer. Using the index of biological integrity and comprehensive health index,it evaluated the health status of water ecosystem of Small Xingkai Lake.

A Bayesian method for comprehensive water quality evaluation of the Danjiangkou Reservoir water source area, for the middle route of the South-to-North Water Diversion Project in China

Danjiangkou 水库是为在中国的 South-to-North 水转向工程的中间的线路的水来源。因此，它的水质量地位担心大。五水质量指示物(溶解的氧，高锰酸盐索引，氨氮，全部的氮，和全部的磷)，在三点被测量监视地点( Danjiangkou 水库水坝， Hejiawan 和 Jiangbei 桥)，调查变化趋势，并且在到2012年5月的从2006年1月的 Danjiangkou 水库区域的水质量的空间与时间的特征。我们然后使用了一个贝叶斯的统计方法包括地评估水质量。正常分发采样方法被用来计算可能性的，并且熵重量方法被用来为对的兴趣的变量决定指示物重量到学习。结果显示所有五指示物的集中在最后六年期间增加了。另外，在水库的水质量在湿季节期间是更坏的(从 5 月到 10 月) ，比在旱季期间(从 11 月到下一年的 4 月) 。总的来说，水的概率根据为在中国的表面水的环境优秀标准，属于类型 II 的优秀范畴是 27.7%-33.7% ，比它属于另外的四种水质量类型的大。营养素的增加的集中能导致 Danjiangkou 水库的超营养作用。这个方法减少了通常与决定指示物重量和人工的分类被联系的主观，完成更可靠的结果。这些结果显示 interbasin 水转向工程在 Danjiangkou 水库区域实现综合的水质量管理是重要的[出版摘要]

An attribute recognition model based on entropy weight for evaluating the quality of groundwater sources

In our study, entropy weight coefficients, based on Shannon entropy, were determined for an attribute recognition model to model the quality of groundwater sources. The model follows the theory previously proposed by Chen Q S. In the model, firstly, the author establishes the attribute space matrix and determines the weight based on Shannon entropy theory; secondly, calculates attribute measure; thirdly, evaluates that with confidence criterion and score criterion; finally, an application example is given. The results show that the water quality of the groundwater sources for the city comes up to the grade II or III standard. There is no pollution that obviously exceeds the standard and the water can meet people’s needs .The results from an evaluation of this model are in basic agreement with the observed situation and with a set pair analysis (SPA) model.

Evaluation, prediction, and protection of water quality in Danjiangkou Reservoir, China

The water quality in the Danjiangkou Reservoir has attracted considerable attention from the Chinese public and government since the announcement of the Middle Route of the South to North Water Diversion Project(SNWDP), which commenced transferring water in 2014.Integrated research on the evaluation, prediction, and protection of water quality in the Danjiangkou Reservoir was carried out in this study in order to improve environmental management. Based on 120 water samples, wherein 17 water quality indices were measured at 20 monitoring sites, a single factor evaluation method was used to evaluate the current status of water quality. The results show that the main indices influencing the water quality in the Danjiangkou Reservoir are total phosphorus(TP), permanganate index(COD Mn), dissolved oxygen(DO), and five-day biochemical oxygen demand(BOD5), and the concentrations of TP, BOD5, ammonia nitrogen(NH3e N), COD Mn, DO, and anionic surfactant(Surfa) do not reach the specified standard levels in the tributaries. Seasonal Mann e Kendall tests indicated that the COD Mn concentration shows a highly significant increasing trend, and the TP concentration shows a significant increasing trend in the Danjiangkou Reservoir. The distribution of the main water quality indices in the Danjiangkou Reservoir was predicted using a two-dimensional water quality numerical model,and showed that the sphere of influence from the tributaries can spread across half of the Han Reservoir if the pollutants are not controlled.Cluster analysis(CA) results suggest that the Shending River is heavily polluted, that the Jianghe, Sihe, and Jianhe rivers are moderately polluted, and that they should be the focus of environmental remediation.