Comprehensive information and knowledge about the QUALITY of WATER resources plays a very important role in preservation plans for WATER resource management. One of the engineering methods used to assess RIVER WATER QUALITY conditions without mathematical and statistical complexity is WATER QUALITY indices. In this method, different WATER QUALITY parameters are analyzed and interpreted in a RIVER WATER QUALITY assessment study. It is one of the most important parts of RIVER QUALITY monitoring plans in which the qualitative indices are converted to a single and dimensionless number. WATER QUALITY classification is undertaken on the basis of the value of the indices comparing with a predefined rated scale. In this study, a monitoring plan is achieved for the 18 stations located along with Gheshalgh RIVER in Kurdistan province in Iran. WATER QUALITY assessment has been conducted using two NSF QUALITY indices of general WATER use and the British Columbia index for drinking and agricultural consumption. Based on the results obtained from these indices, WATER of this RIVER has the worst QUALITY due to agricultural use downstream of the wasteWATER treatment plant of Sanandaj city. Its condition is degraded up to the discharge point of Morghe Par slaughterhouse due to the assimilation capacity of the RIVER. In this location WATER QUALITY is acceptable for drinking purposes and most of the stations have appropriate conditions except for Dare Kuleh and the downstream station which are on the border. Results indicate that the degree of influence of urban pollutant sources such as entry of urban wasteWATER and also of a landfill leachate brook is high, especially in the Gheshlagh bridge area up to the tributaries.

Background and Objective: Increasing the productivity of surface WATER, the unsustainable development of agriculture in the boundaries of RIVERs, and human sewage have reduced the QUALITY of these WATER resources. Therefore, investigating the amount of pollution and its sources is very necessary for regional planning. This study aimed to evaluate the WATER QUALITY of the Golin RIVER using WQI and Liou indexes. Materials and Methods: Sampling of Golin RIVER WATER was performed to check WATER QUALITY based on (WQI) and (Liou) indices in Najjar village station for one year from April 2019 to March 2020. Results: WATER QUALITY, according to the Liou index, during the research period in the sampling station in September and March, was in a good category and other months were slightly polluted. According to the results of the WQI index, WATER QUALITY in September and March were in the excellent descriptive category, with values of 47. 82 and 49. 74, respectively, but in other months it was in a good category. In September and March, WATER QUALITY improved compared to other months because of lower BOD5 due to reduced agricultural activities, and both indicators showed these QUALITY changes well. Conclusion: Due to the lack of stable conditions in WATER QUALITY affected by seasonal changes and its departure from the category of high-QUALITY WATER according to the results of the WQI index and also a little WATER pollution according to the Liou index, the direct use of Golin RIVER WATER for drinking purposes is recommended and for this purpose, regular purification should be done and accurate and continuous evaluations of WATER QUALITY in Golin RIVER are necessary.

Background and Objective: With the industrialization of communities, population increase and use of surface WATER, RIVER pollution has been increased by agricultural, industrial pollutants and urban wasteWATER. Therefore, investigation of RIVER pollution for regional and environmental planning is of great importance. To evaluate surface WATER pollution, a number of surface WATER QUALITY indices have been investigated. Materials and Methods: Iran WATER QUALITY index for surface WATER resources (IRWQISC) approach was used to evaluate the WATER QUALITY of the Mahabadchai RIVER, Iran. Sampling was carried out along the Mahabadchai RIVER based on some criteria such as approximately to drainage areas for landfills/domestic and agricultural effluents. Results: Pearson correlation coefficient between physical, chemical and microbial parameters of WATER showed that fecal coliform, BOD, COD, nitrate, ammonium, phosphate, turbidity and total hardness had a significant positive relationship with each other at 99% confidence. According to this index, upstream samples of the RIVER are classified as good, mid-stations relatively good to moderate category, and downstream samples of the RIVER are classified as relatively bad. Conclusion: Based on the relationship between each variable, fecal coliform, BOD, COD, ammonium, and turbidity were more effective in determining the IRWQISC. Most of the examined variables showed low concentrations in upstream areas of the RIVER while their concentration gradually increased along the RIVER to downstream areas, especially close to urban and industrial districts.

The present investigation has been conducted to assess the status of physico-chemical parameters as well as the concentrations of some selected heavy metals to understand the present scenario of WATER QUALITY at Perak RIVER basin, Malaysia. The temperature, turbidity, pH, EC and DO values of all the examined samples have been within the range of 25. 0 to 30. 5 0C, 39. 5 to 168. 00 NTU, 6. 8 to 7. 33, 30. 3 to 113. 8 μ s/cm and 3. 62 to 7. 01 mg/L, respectively. The concentrations of trace metallic constituents have been determined by means of Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES), giving the following ranges: Cr: 0. 01 to 0. 052 mg/L; Pb: 0. 01 to 0. 03 mg/L; Zn: 0. 11 to 0. 92 mg/L; Fe: 1. 38 to 5. 55 mg/L; Mn: 0. 10 to 0. 25 mg/L and Ca: 2. 55-23. 23 mg/L, respectively. The concentrations of heavy metals at downstream of Perak RIVER WATER were higher than the concentrations of upstream. The order of heavy metallic constituents in the WATER samples was Fe > Zn > Mn > Cr > Pb. R mode Cluster Analysis (CA) suggests that multiple anthropogenic activities like urban runoff, agricultural runoff, discharges of vehicles washing and workshops, land use changes, unplanned settlements, domestic effluents, wasteWATER of livestock husbandry farms etc., are influencing the physico-chemical parameters and heavy metals concentrations of Perak RIVER WATER. The present study is highly significant for providing baseline information of potential hazardous level of heavy metals to human health, environment, and sustainable WATER resources management for economically and environment friendly uses of Perak RIVER.

The Oshmak RIVER is one of the most important RIVERs in Gilan province that passes from Kochesfehan, Lashtenesha and Zibakenar and joins the International Wetland of Boojagh, and then flows into the Caspian Sea through theNational Park of Boojagh. Parameters of Physical, Chemical and Microbial of Oshmak RIVER were measured from spring 2006- winter 2007. For this purpose, according to standard methods, WATER parameters were measured from 6 selected stations seasonally. According to the results, mean of Air Temperature was 19.63oC, mean of WATER Temperature was 65.17oC, mean of Turbidity was 29.40 FTU, mean of Conductivity was 1114.95 micromus/cm, mean of TDS was 678.03 mg/l, mean of TSS was 38.58 mg/l, mean of Total Alkalinity was 77.75 mg/l, mean of Total Hardness was 412.25 mg/l, mean of Ca+2 was 68.14 mg/l, mean of Mg+2 was 60.44 mg/l, mean of Cl- was 133.45 mg/l, mean of So4-2 was 152.64 mg/l, mean of Po4 was 0.08 mg/l, mean of Total Phosphate was 0.63 mg/l, mean of NH4 was 0.34 mg/l, mean of No2 was 0.05 mg/l, mean of No3 was 0.81 mg/l, mean of Dissolve Oxygen was 7.24 mg/l, mean of BOD was 9.83 mg/l, mean of COD was 34.61 mg/l, mean of Salinity was 490 mg/l, mean of pH was 7.75, mean of Acidity was 5.50 mg/l, mean of Free Co2 was 4.48 mg/l, mean of Total Coliform was 33541 no/100 ml/l and mean of Fecal Coliform was 5363 no/100 ml/l.

Introduction: Nowadays WATER pollution is one of the most important problems in the world and environmental concerns are the major sources of surface WATER. Shahrood RIVER is one of the most important RIVERs in Qazvin province. Materials and Methods: Sampling was done in two seasons of November 96 (winter) and July 97 (summer) during two times and three replications from 7 stations including Taleghan, Alamoot, RajaeeDasht, Razmian, Loshan, Loshan 1 and 2. Qualitative parameters included: DO, pH, Total Solids, BOD, Turbidity, Temperature, Phosphate, Nitrate and Fecal Coliform. The data were determined using NSFWQI and WATER QUALITY index of each RIVER section measured. Results: The results showed that the mean TDS was 180. 66 to 329. 33 mg/l, pH 8. 01 to 8. 55, BOD 0 to 2. 8 mg/l, DO 5 to 7. 5, Coliform 1618. 33 to 27300, and Turbidity of 0. 73 to 114. 9 NTU in summer the TDS 184. 66 to 451mg/l, pH 7. 73 to 8. 55, BOD 0 to 1 mg/l, DO 9 to 13. 7, Coliform 162/33 to 1653/333, And the Turbidity is 0. 72 to 262. 66 in winter. Conclusion: The WATER QUALITY status of summer in station 1 was good in other stations moderate and in winter season station 1 and 4 were in good range and in other stations was moderate. As a result, Shahrood RIVER WATER is good and medium QUALITY and due to lower WATER QUALITY of homes, agricultural lands near the RIVER are also causes of increased Nitrate and Phosphate in winter due to agricultural and urban effluents around the RIVER. As a result, RIVER WATER is somewhat suitable for drinking and needs purification and the Industrial agents around the RIVER have no effect on the WATER QUALITY.

Karoun RIVER is one of the most important WATER ways and longest RIVERs of Iran. Because of agricultural farms, industrial units and cities in its vicinity, the Karoun RIVER has a strategical position. Hence, its WATER QUALITY monitoring is essential due to many point and non point sources of pollution. This study was carried out to evaluate Karoun RIVER’s WATER QUALITY in Ahvaz region. For WATER QUALITY data's analysis in various stations, index of WATER QUALITY NSF (National Sanitation Foundation) software from Wilkes University is used. Therefore Dissolved Oxygen, fecal coliform, pH, BOD5, Nitrate, Phosphate, Temperature, Turbidity and Total solids were determined on monthly basis.The monthly WQI in studied stations fluctuates from 57 to 70 that fall within medium category. WATER QUALITY index from first to last station gradually decreased. The results of WQINSF for RIVER bank WATER QUALITY computation during 1 year sampling period show that Koot-Abdollah station (lower part of the RIVER) has the worst situation with yearly index of 62.5 and Kian-Abad station (upper section of the RIVER) has the best QUALITY amongst studied stations (65.25).Because of RIVER bed and self purification, seasonal change has insignificant effects on WATER QUALITY in Pol-e-Siah station. WATER QUALITY (in spring) because of the suitable conditions for growth of fecal coliforms and increased turbidity- has worst situation and in autumn season -because of the incensement of rain and decreasing of contaminations- has best situation.