Water Quality Status Of River Research Articles

Evaluating future stress due to combined effect of climate change and rapid urbanization for Pasig-Marikina River, Manila

Considering the finite volume of fresh water resources, managing its quality and quantity sustainably is one of the greatest challenges because of complex global changes. This work strives to predict the combined effect of urbanization and climate change on water quality in Pasig-Marikina River considering its criticalities to develop proactive plan by policy makers working in water sectors. Pasig-Marikina River is an important source of water for different usage viz. domestic, industrial, agriculture and recreation in the National Capital Region (NCR) in Philippines. However, stationarity of this river basin is compromised by global changes and human disturbances viz., climate change, rapid urbanization and weak/non-structured government policies results in severe pollution, makes long section of the river unsuitable for any use in recent past. Therefore, presenting a comprehensive spatio-temporal status of river water quality using transdisciplinary framework will be valuable to guide and implement better management policies within governance structure. In this study, status of water quality of the Pasig-Marikina River was analysed for current and future timescale using population growth, land use change, wastewater production and treatment scenarios. Water Evaluation and Planning (WEAP) model was used to model river pollution scenarios using three indicators for aquatic ecosystem health viz. Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Nitrate (NO3). Comparison of simulated water quality parameters for the year 2015 and 2030 with 2011 (base year) clearly indicates that the water quality at 2030 will rapidly deteriorate and will be not suitable for any aquatic life in terms of major of water quality parameters. Also, even current existing master plan for wastewater treatment plants and policies are not sufficient enough for sustainable water resource management within NCR, Philippines and hence call for immediate and inclusive action.

River water pollution condition in upper part of Brantas River and Bengawan Solo River

Wastewater and solid waste from both domestic and industry have been known to give burden on river water quality. Most of river water quality problem in Indonesia has start in the upper part of river due to anthropogenic activities, due to inappropriate land use management including the poor wastewater infrastructure. Base on Upper Citarum River Water pollution problem, it is interesting to study the other main river in Java Island. Bengawan Solo River and Brantas River were chosen as the sample in this study. Parameters assessed in this study are as follows: TSS, TDS, pH, DO, and hexavalent chromium. The status of river water quality are assess using STORET method. Based on (five) parameters, STORET value showed that in Brantas River, Pagerluyung monitoring point had the worst quality relatively compared to other monitoring point in Brantas River with exceeding copper, lead and tin compared to the stream standard in East Java Provincial Regulation No. 2 in 2008. Brantas River was categorized as lightly polluted river based on monitoring period 2011-2015 in 5 monitoring points, namely Pendem, Sengguruh, Kademangan, Meritjan and Kertosono.

Evaluation Of Water Quality At River Bian In Merauke Papua

River Bian in Merauke Regency has been utilized by local people in Papua (the Marind) who live along the river for fulfilling their daily needs, such as shower, cloth and dish washing, and even defecation, waste disposal, including domestic waste, as well as for ceremonial activities related to the locally traditional culture. Change in land use for other necessities and domestic activities of the local people have mounted pressures on the status of the River Bian, thus decreasing the quality of the river. This study had objectives to find out and to analyze river water quality and water quality status of the River Bian, and its compliance with water quality standards for ideal use. The study determined sample point by a purposive sampling method, taking the water samples with a grab method. The analysis of the water quality was performed by standard and pollution index methods. The study revealed that the water quality of River Bian, concerning BOD, at the station 3 had exceeded quality threshold. COD parameter for all stations had exceeded the quality threshold for class III. At three stations, there was a decreasing value due to increasing PI, as found at the stations 1, 2, and 3. In other words, River Bian had been lightly contaminated.

Water Quality Assessment of Cimanuk River in West Java Using Pollution Index

Cimanuk river is one of the seven rivers in West Java. Cimanuk river pollution is indicated to have suffered as a result of the activity of domestic waste, industrial and agricultural uncontrolled in the riparian area of Cimanuk river. This research aims to analize water quality of Cimanuk river based on water quality standard on Government Regulation of Republic of Indonesia (IDN), Regulation of the Governor of West Java (WJ), World Health Organization (WHO), Enviromental Standard of United Kingdom (UK), Environmental Protection Agency (EPA), Enviromental Quality Standard (EQS), and Department of Environment (DOE). This research used pollution index method. The result is water quality of Cimanuk river not meet water quality standard where the TSS (94.85±84,60 mg/L), BOD (9.61±3.16 mg/L), COD (37.69±14.01 mg/L), DO (5.12±1.22 mg/L), NH3N (0.25±0.24 mg/L). Degradation of water quality of Cimanuk river from upstream to downstream marked by increased pollution index value annually. Pollution index of Cimanuk river ranging from 1.25 to 20.31. Water quality status of Cimanuk river has been from lightly polluted to heavilypolluted.

Development of correlation-regression model between land use change and water quality indices in Ciliwung watershed

Urbanization and industrialization lead to the change of land cover from pervious into impervious. This can impact environmental problems such as water quality degradation that affects human health and water ecosystems. The study aimed to develop a regression-correlation model between impervious cover in Ciliwung watershed and water quality indices in Ciliwung river. The correlation-regression model can be used to predict changes in the status of Ciliwung river water quality due to impervious cover changes. Methods of assessing the indices of water quality are CCME-WQI, NSF-WQI, and STORET within the period of 2005-2016. Monitoring locations from the most upstream to downstream are Atta’awun, Katulampa, Kedung Halang, Pondok Rajeg, Panus Bridge, Kelapa Dua, Condet, Kalibata, MT Haryono and Manggarai. Impervious cover data for each water quality monitoring location is processed using ArcGIS Software. Test of correlation significance between percentage of impervious cover and water quality indices using Pearson Correlation test method. The result of correlation test is significantly a strong inverse relationship between impervious cover and water quality indices. The result of regression test is trend line between impervious cover change and water quality indices that can be used to predict the change of water quality status in Ciliwung River.

Potential Of Best Management Practices (Bmps) Projects For Effective Integrated Water Resource Management

Nowadays, water pollution was viewed as a crucial issue and if not properly managed, it can threaten human health along with environment. Being so, various efforts have been taken by the government of Malaysia to ensure the Integrated Water Resource Management can be effectively implemented. In supporting the effective implementation of this approach, a Best Management Practices (BMPs) projects were carried out. Unfortunately, the implementation of these projects still remains in doubt and was unfamiliar by many parties. Therefore, this paper examined the outcome of BMPs Projects in the perspective of river water quality in Malaysia. By using content analysis technique towards 12 year period of data from the Malaysia Environmental Quality Report, starting from year 2002 to the year 2014, four projects were selected in order to identify is there any difference, especially on the river water quality status before and after BMPs Project have been carried out. The result of the studies revealed that, the BMPs projects have a potential in improving water quality status and there is a need to actively promote this project to the various stakeholders involved so that it can minimize Integrated Water Resource Management issues as well as enhancing the implementation.

A Sub-Catchment Based Approach for Modelling Nutrient Dynamics and Transport at a River Basin Scale

The prediction of nutrient pollution at realistic details is difficult due to lack of proper description of inherent processes in modelling tools. To overcome that this study has adopted a process based approach to build a semi-distributed model to simulate nutrient pollution in changing environment. The model was built to describe: (1) nutrient generation process in the catchment with consideration of different aspects of external and internal sources, (2) nutrient release from surface to the waterways via runoff and soil erosion, and (3) in-stream transport and chemical reaction process. The key novelty of this research is the linking of the nutrient generation process with transport mechanism for modelling nutrient dynamics at a basin scale. A flow capacity based approach was introduced to determine nutrient export from catchment to the waterways, which was useful to achieve the high resolution outputs from the model. The model performed reasonably well to represent the behaviour of nutrient in high flow events as well as in seasonal flow in two catchments located in distinct hydro-climatic regions. The study has shown that the nutrient model is suitable for predicting actual nutrient pollution in rivers for both high flow and seasonal flow under different hydro-climatic conditions. By simulating organic and inorganic nutrients separately, the model allows to estimate river water quality status in detail.

STATUS KUALITAS AIR SUNGAI SEKITAR KAWASAN PENAMBANGAN PASIR DI SUNGAI BATANG ALAI DESA WAWAI KALIMANTAN SELATAN

This study aimed to analyze the water quality of Sungai Batang Alai. Water quality of physics and chemistry properties were analized in location of sand mining and without sand mining. Research conducted at Sungai Batang Alai Village Wawai District of South Batang Alai Hulu Sungai Tengah. Parameters of physical and chemical of water which analyzed were temperature, TSS, TDS, Debit, BOD, COD, DO, pH, Fe, and Mn. The sample were taken at 4 points with 3x replicatation. Status of water water quality were determined by using STORET method, then the results were compared with status of river water quality status of Class I based on South Kalimantan Governor Regulation No. 5 of 2007 on the status of river water quality. The results showed that the sand mining activities negatively impact the water quality of the river Batang Alai than the location there are no sand mining. This can be seen by the river water quality status in the area before the sand mining in the category of Class I to Class III down to the location of the existing sand mining.

River Water Quality Preliminary Rapid Assessment Using Pollution Index

A rapid interpretation of river water quality is a compulsory since river is a dynamic ecosystem, influenced by various activities in the river bank. Hence a preliminary rapid river water quality status determination using pollution index on locations near IPB Dramaga Campus was simulated. Based on grab sampling on 5 sites in River Cihideung, River Ciapus, and Lake of PPLH, all water quality parameter met water quality standard class III for fisheries and animal husbandry as stipulated in Government Regulation No 82/2001. Application of water pollution index towards 5 sampling sites (selected by location map consideration) denotes good water quality status with water pollution index ranging from 0.728 to 0.892.

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.

Estimation of contribution ratios of pollutant sources to a specific section based on an enhanced water quality model.

Because water quality monitoring sections or sites could reflect the water quality status of rivers, surface water quality management based on water quality monitoring sections or sites would be effective. For the purpose of improving water quality of rivers, quantifying the contribution ratios of pollutant resources to a specific section is necessary. Because physical and chemical processes of nutrient pollutants are complex in water bodies, it is difficult to quantitatively compute the contribution ratios. However, water quality models have proved to be effective tools to estimate surface water quality. In this project, an enhanced QUAL2Kw model with an added module was applied to the Xin'anjiang Watershed, to obtain water quality information along the river and to assess the contribution ratios of each pollutant source to a certain section (the Jiekou state-controlled section). Model validation indicated that the results were reliable. Then, contribution ratios were analyzed through the added module. Results show that among the pollutant sources, the Lianjiang tributary contributes the largest part of total nitrogen (50.43%), total phosphorus (45.60%), ammonia nitrogen (32.90%), nitrate (nitrite + nitrate) nitrogen (47.73%), and organic nitrogen (37.87%). Furthermore, contribution ratios in different reaches varied along the river. Compared with pollutant loads ratios of different sources in the watershed, an analysis of contribution ratios of pollutant sources for each specific section, which takes the localized chemical and physical processes into consideration, was more suitable for local-regional water quality management. In summary, this method of analyzing the contribution ratios of pollutant sources to a specific section based on the QUAL2Kw model was found to support the improvement of the local environment.

Water Quality Management Plan for Patalganga River for Drinking Purpose and Human Health Safety

Deteriorating water quality of rivers is of major concern in India; this is especially true for rivers being used as drinking water sources. One such river considered in this study is the Patalganga, which is located about 60 km from Mumbai and is a significant source of water supply for Panvel, Alibaug and Rasayani. This paper aims to determine the polluting sources responsible for the poor water quality of the Patalganga River and to suggest a scientifically sound water quality management plan to improve the same. A total of 14 water samples from different point sources of pollution were collected and tested for physico-chemical parameters (pH, temperature, DO, BOD, COD, TSS, TDS, EC, PO4 3- , NO3-N and NH3-N), metals (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and microbiological parameter using World Health Organization (WHO) and the Bureau of Indian Standards (BIS) standards. Based on, the water quality at most of the sampling stations was found to be unsuitable for drinking. Hierarchical cluster analysis (HCA) classified the 14 sampling stations into three clusters. The HCA identified a uniform source of parameters (physico-chemical and nutrients) for all the sampling stations, excluding two sampling stations (7 and 12) that exhibited anomalous concentrations. Furthermore, as per the WQI, the water quality status of Patalganga River fell under good category, except at the sampling station 7 and 12 where the water quality index were bad (49) and medium (51) category, respectively, and were totally unfit for drinking purpose. Water quality management plan specific to the individual sites has been delineated in the paper.

Detection of River Pollution Using Water Quality Index: A Case Study of Tropical Rivers in Penang Island, Malaysia

A study on the Water Quality Index (WQI) has been conducted among 11 rivers in Penang Island, Malaysia from October 2012 to January 2013. The water quality status of rivers was classified based on the Interim National Water Quality Standard (INWQS) for Malaysia. The six water quality parameters used to determine the water quality index are dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solid (TSS), ammonia and pH value. Based on the WQI assessment, among the 11 rivers studied, none of the rivers were considered as clean. The upstream and middle stream of the Pinang River in Balik Pulau (with WQI = 69 and 70 respectively), the upstream and middle stream of the Kongsi River (with WQI = 67 and 72 respectively) and the upstream of the Betong River (with WQI = 63) were slightly polluted, while the rest of the rivers had a WQI of below 60, which were categorized as polluted rivers. Among the 30 sampling stations, 17 stations were classified as Class III (extensive treatment of water supply required; fish for common economic value, species tolerance, and for livestock drinking), and 13 stations were classified as Class IV water status, which was classified as irrigation according to INWQS. From this study, the WQI and river classification system were considered as a tool for assessing the health status of river water quality. Efficient and sustainable management of rivers in Penang Island should be emphasized in order to protect their aesthetic value for future generations.

Assessment of water quality status of Anjarakandy river in Kannur district of Kerala

The rivers always form the lifeline of nation and society by providing precious resources for development and perpetuation of life. In India, the surface water, especially rivers form an inevitable part of culture and are used as drinking and irrigational water source. The present study focus on the assessment of seasonal changes in water quality of the Anjarakandy River in Kannur District, Kerala during the pre monsoon and monsoon seasons of the year 2013. The physical, chemical and bacteriological attributes of the river water were analyzed, and based on the selected parameters, the Water Quality Index (WQI) was calculated. The results show that there is chemical pollution of river water due to chloride, salinity, total hardness, sulphates, sodium, potassium etc. especially in down stretches of the river, where the severity of saltwater intrusion is common. The upstream portions of the river show high MPN values for total and fecal coliform bacteria, which indicate the organic pollution by excreta of warm blooded animals. From the water quality index values determined, it was found that the river water is ‘Unfit For Drinking’. Based on the values of Sodium Adsorption Ratio and Percentage Sodium determined, it was found that the water of Anjarakandy River is suitable for irrigation.

Water quality status of rivers in the coastal city of Manado, North Sulawesi Province, Indonesia

A study on water quality status of three riverine systems, S. Bailang (SB), S. Maasing (SM), and S. Tondano (ST), in coastal city of Manado, North Sulawesi Province, has been conducted to measure several water quality parameters, to analyse source and quality of wastewater discharge, and to assess the status of the rivers related to the water quality. Measurement of the parameters was conducted using three indicators, i.e. organic (BOD5) and in-organic (N-NO3 and P-PO4), and pathogenic microorganism (Escherichia coli [EC] and total coliform [TC]). The result showed that the level of water quality varied between the rivers. The average level of water quality (based on the observed parameters) in SB, respectively, was 0.317 mg/l, 0.093 mg/l, 2 mg/l, >2420 MPN, and >2420 MPN; in SM, respectively, was 0.029 mg/l, 1.859 mg/l, 17.7 mg/l, >2420 MPN, and >2420 MPN; and in ST, respectively, was 0.299 mg/l, 0.252 mg/l, 3.5 mg/l, >2420 MPN, and >2420 MPN. The level of water quality between the rivers was not significantly different (p>0.05), except based on the parameter of N-NO3 which was significantly different (p<0.01). The status of the observed rivers varied based on the classes of their water utilities (according to the Government Regulation of Indonesia, No. 82, 2001); mostly was "unsuitable". Kajian tentang status kualitas air di 3 perairan sungai di kota pesisir Manado, S. Bailang (SB), S. Maasing (SM), dan S. Tondano (ST), Provinsi Sulawesi Utara, telah dilakukan yang bertujuan untuk mengukur beberapa parameter kualitas air, menganalisis sumber dan kualitas buangan limbah domestik, dan menilai status ketiga perairan sungai tersebut. Tiga indikator digunakan, yaitu: bahan organik (BOD5), bahan anorganik (N-NO3 dan P-PO4), dan mikroorganisme patogenik (Escherichia coli [EC] dan coliform total [TC]). Hasil kajian menunjukkan bahwa tingkat kualitas air perairan tersebut berbeda-beda. Konsentrasi rerata parameter kualitas air (BOD5, N-NO3, P-PO4, EC, dan TC) di SB, berturut-turut, sebesar 0.317 mg/l, 0.093 mg/l, 2 mg/l, >2420 MPN, dan >2420 MPN; di SM, berturut-turut, sebesar 0.029 mg/l, 1.859 mg/l, 17.7 mg/l, >2420 MPN, dan >2420 MPN; dan di ST, berturut-turut, sebesar 0.299 mg/l, 0.252 mg/l, 3.5 mg/l, >2420 MPN, dan >2420 MPN. Konsentrasi kualitas air ketiga sungai tersebut tidak berbeda secara signifikan (p>0.05), kecuali parameter N-NO3 (p<0.01). Secara umum, kondisi kualitas air ketiga sungai tersebut, menurut Peraturan Pemerintah No. 82, 2001) berada dalam status “tidak cocok” untuk peruntukannya.

Development and assessment of an integrated ecological modelling framework to assess the effect of investments in wastewater treatment on water quality.

Worldwide, large investments in wastewater treatment are made to improve water quality. However, the impacts of these investments on river water quality are often not quantified. To assess water quality, the European Water Framework Directive (WFD) requires an integrated approach. The aim of this study was to develop an integrated ecological modelling framework for the River Drava (Croatia) that includes physical-chemical and hydromorphological characteristics as well as the ecological river water quality status. The developed submodels and the integrated model showed accurate predictions when comparing the modelled results to the observations. Dissolved oxygen and nitrogen concentrations (ammonium and organic nitrogen) were the most important variables in determining the ecological water quality (EWQ). The result of three potential investment scenarios of the wastewater treatment infrastructure in the city of Varaždin on the EWQ of the River Drava was assessed. From this scenario-based analysis, it was concluded that upgrading the existing wastewater treatment plant with nitrogen and phosphorus removal will be insufficient to reach a good EWQ. Therefore, other point and diffuse pollution sources in the area should also be monitored and remediated to meet the European WFD standards.

Nutrient-based ecological consideration of a temporary river catchment affected by a reservoir operation to facilitate efficient management

The water quality status of the Kouris river in Cyprus was examined in order to fulfil the requirements for ecological quality as defined by the Water Framework Directive-2000/60/EC. Nitrate concentration (mean value) was increased in the Limnatis (2.8 mg L(-1)) tributary in comparison with the Kryos (2.1 mg L(-1)) and Kouris (1.0 mg L(-1)) tributaries depicting the influence of anthropogenic activities. The total maximum daily nutrients loads (TMDLs) based on the flow duration curves approach, showed that nutrients loads exceeded threshold values (33.3-75.6% in all hydrologic condition classes in the Kouris tributary, and 65-78% in the Limnatis tributary) especially under low flow conditions. The TMDL graph is intended to guide the temporal schedule for chemical sampling in all hydrologic classes. Kouris reservoir is an oligotrophic system, strongly influenced by the river's flash-flood character but also by the implemented management practices. Kouris river outflow, which was reduced to one-tenth in the post dam period altered the wetland hydrologic network and contributed to the decrease of aquifer thickness. Continuous evaluation and update of the River Basin Management Plans will be the basis for the sustainable development of the Kouris basin.

Assessing the relationship between water quality parameters and changes in landuse patterns in the Upper Manyame River, Zimbabwe

For the past 30years, the increases in population pressure and external influences, such as economic growth, have accelerated the demand for land within the Upper Manyame River catchment in Zimbabwe which has caused substantial changes in landuse. The general objective of this research was to assess the impacts of landuse activities on the water quality of the Upper Manyame River which drains the rural and urbanised part of the catchment up to flow gauging station C21. Landcover data for the month of April in years of 1984, 1995, 2003 and 2011 were acquired from available Landsat TM and ETM images and were classified through the maximum likelihood digital image classification using the supervised classification approach. The status of water quality of the Upper Manyame River was also assessed through analyses of historical concentrations and pollution loads for TP, DO, COD, NH3-N, SS, Pb, NO3, BOD5, EC, PO4-P and TN at the Environmental Management Agency (EMA) gauging station CR21 sampling point for 1996, 2000/1 and 2008/9. Water quality of 15 monitoring sites comprising 25 water quality parameters were monitored monthly from January to June 2012. These locations were selected to reflect a wide array of landuse for both the dry and wet seasons. The results indicated that there was an increase in pollution load from 1995 to 2012; for TP from 130kg/day to 376kg/d, and for TN from 290kg/day to 494kg/d. This indicates high pollution levels which have severe impacts on downstream users and also severe sewage contamination. Significant deviations occurred in DO (0.1–6.8) mg/L, COD (11–569) mg/L, BOD5 (5–341) mg/L, PO4-P (0.01–4.45) mg/L, NH3-N (0.001–6.800) mg/L and EC (38–642) μS/cm. Hydrologic Response Unit and buffer analysis were used to determine the dominant landuse which contributes to a certain water quality. Results of digital image classification indicate that woodland/forest, grassland and bareland decreased between years 1984 to 2011 by 24.0%, 22.6% and 31.7% respectively. This was mainly due to expansion or increase of agriculture and urban areas by 24.4% and 41.6% respectively over the same time period. It was concluded that settlements and agricultural areas are the ones mainly affecting the water quality in Upper Manyame River with a Pearson’s Correlation Coefficient of r=0.97 for COD and r=0.78 for TSS respectively. It was also observed that the water quality status of the Upper Manyame River and its tributaries is very poor and the level of pollution generally increases from upstream to downstream. The results obtained provided baseline information which may be used in the development of appropriate water quality management systems in the catchment. Thus the study recommended a combined programme of point source control and landuse modification.

The water quality degradation of upper Awash River, Ethiopia

Benthic macroinvertebrate based assessment of water quality in the upper Awash River, along the river course of about 500 kms was conducted on quarterly bases between September 2009 and August 2010. This paper reports the complete identification of macroinvertebrates together with measurements of physico-chemical parameters and heavy metal concentrations which were considered as a tool for assessing the water quality status of upper Awash river, Ethiopia. Benthic animals and water samples were collected from three different sampling sites located in the upper Awash River, and analyzed to evaluate stressor sources and the general stream water quality. The percentage abundance of families of various macroinvertebrates taxonomic groups was identified from all sites. Accordingly, Koka bridge site of the upper Awash River had low water quality status which is likely to be due to poor farming, untreated effluents from factories and poor provision of sanitation facilities to the riparian communities. Apparently, the concentrations of the selected nutrients and heavy metals did not differ significantly among the sampling sites (ANOVA, P > 0.05), presumably due to pollution of the whole stream reach by the catchment nutrient sources. Ten orders of benthic macroinvertebrates consisting of 36 families were identified. The highest family richness was observed in Ginchi, slightly impacted site (1) whilst the least faunal diversity was observed in Koka Bridge (7 families) indicating the effect of water quality class differences among the sampling sites.Key words: Macroinvertebrates, organic pollution, heavy metals, water quality, anthropogenic impact, upper Awash River

Water Quality Model Parameters Estimation Based on Particle Swarm Optimization Algorithm

Water quality parameter is the basic data of the river water quality mathematical model for forecasting river water quality status. In this paper, the parameter estimation problem of the analytical model, which is used to describe one-dimensional tracing test data of river streams with tracers instantaneously injected, is converted to the function optimization problem. And particle swarm optimization algorithm is applied to solve this problem. The experimental results show that the particle swarm optimization algorithm can estimate the water quality model parameter values regardless of whether the randomly sampling data has noise.