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Water quality models are important decision support system tools for water pollution control, study of the health of aquatic ecosystems and assessment of the effects of point and diffuse pollution. However, water quality models are usually comprehensive software, which are usually not easy to learn and apply. Thus extensive training is needed before scientists and engineers can use most of the water quality models effectively. In this study; a new, easy to use and simple stream water quality modelling software is developed. The model underwent and extensive testing period that includes education/training oriented applications and a real world application as well. The software is easy to learn and the model is simple enough to be used in advanced undergraduate and introductory graduate level courses in aquatic sciences and environmental science, engineering or management programmes. It can also be used for institutional training in state offices that are dealing with water pollution control and integrated water management as well. All the modelling system is developed according to free/open software philosophy so that advanced level users such as trainers are able to modify it according to the training/institutional needs.

The water resources management and eutrophication control problem in the Federal District of Brazil including the capital, Brasilia is outlined. Procedure and criteria of the assessment are discussed together with model developments (static and dynamic models for total phosphorus as well as a three-compartment P-cycle model for estimating future algae biomass levels). Population scenarios, sewage treatment options and alternatives of the future Sao Bartolomeu Reservoir for fulfilling drinking water demands for the coming 25 years are summarized. As the best compromise solution the medium size reservoir upstream to the confluence of the River Paranoá and River Sao Bartolomeu is selected. Future sewage treatment conditions are defined in order to keep trophic state at the desired level.

The paper highlights the increasing international public concern relating to hydro-environmental issues and cites examples of some of the water quality problems now being considered by hydraulic engineers on a regular basis. The limitations and restrictions of both physical and numerical hydraulic models are discussed and concern is expressed with regard to the increasing use of numerical models being made by non-specialist engineers or scientists - often with little understanding of hydraulics and numerical methods - to assist in the planning and/or design of water quality related studies. General details are given of numerical models used for flow and water quality concentration predictions in coastal and inland hydraulic basins and two example research projects are described. In the first of these studies comparisons are made between dynamically and non-dynamically linked nested models, with the results indicating that in some circumstances nondynamically linked models can give inaccurate velocity fiel...

The sewage from the Greater Athens area is discharged without treatment to the nearby Saronicos Gulf. Recently the Greek government decided to implement an appropriate treatment and disposal scheme, on the basis of a study of the hydrodynamic behaviour of the Gulf and the fate of the discharged pollutants. The study was conducted with the aid of suitable hydrodynamic and water quality models for a number of alternative treatment schemes, ranging from primary treatment to biological treatment with seasonal nitrogen removal, combined with outfalls of different lengths. The results indicate that, although none of the examined schemes will lead to an immediate substantial impact, the scheme that includes biological treatment with seasonal nitrogen removal can eliminate the danger of serious ecological disturbances at a reasonable cost.

The Manzanares River, located in Madrid (Spain), is the main water supplier of a highly populated region, and it also receives wastewater from the same area. The effluents of eight Waste Water Treatment Plants (WWTPs) downstream of the river, which represent 90% of the flow in the middle and lower parts of the river, are the primary sources of water pollution. Although the situation has improved slightly in the last two years, the water in the river is highly polluted, making it uninhabitable for aquatic life. Water quality modelling is typically used to assess the effect of treatment improvements in water bodies. In this work, the GESCAL module of the Aquatool Decision Support System Shell was used to simulate water quality in the Manzanares River. GESCAL is appropriate for modelling in an integrated way water quality for whole water resources systems, including reservoirs and rivers. A model was built that simulates conductivity, phosphorous, carbonaceous organic matter, dissolved oxygen, organic nitrogen, ammonia, and nitrates. The period from October 2006 to September 2008 was selected for calibration due to the many treatment modifications that occurred during this time. An earlier and longer period, from October 2000 to September 2006, was used for validation. In addition, a daily model was used to analyse the robustness of the GESCAL model. Once the GESCAL model was validated, different scenarios were considered and simulated. First, different combinations of nutrient elimination among the different WWTPs were simulated, leading to the conclusion that investments have to focus on three of the proposed WWTPs. Moreover, these treatments will not be sufficient to maintain fish habitat conditions at all times. Additional measures, such as the increment of the flow in the river or oxygen injection, were simulated. Incrementing the flow of the Manzanares River has been shown to be an efficient means of increasing water quality, but this implies an increment in the risk of water scarcity situations in the Madrid water supply system. © 2010 Elsevier B.V. All rights reserved., This work has been supported by the Spanish Ministry of Science and Innovation through the project Consolider-Ingenio 2010 CSD2009-00065.

The paper presents a case based reasoning (CBR) tool designed for the identification of crucial information for the modelling of pollutant transport in rivers. The developed CBR tool is using a case base comprising published information. This information regards pollutant transport modelling work carried out for different rivers. The models from the case base are designed for a specific river reach. For an unstudied reach it is possible to find a model for pollutant transport based on the comparison between the characteristics of that river reach with the characteristics of the already studied reaches, stored in the case base. The reaches of Somes River were compared against the reaches in the case base, and information for pollutant transport modelling was identified. The developed tool is also applicable in the case of other rivers were no detailed concentration measurements are available and the mathematical models for pollutant transport are needed.

Bu çalışmanın amacı detaylı bir havza modeli uygulayarak iklim ve arazi kullanımı değişiklerinin, seçilen havzanın hidrolojisi ile havzadaki yayılı kaynaklardan gelen kirleticiler üzerindeki etkilerini belirlemektir. Diğer bir amaç ise gelişmekte olan ülkelerdeki araştırmacılara veri erişilebilirliğini, veri toplama maliyetini ve model performansını dikkate alan, veri gereksinimi, model sonuçları, maliyet konularında eşik seviyeleri gözeten, maksimum fayda sağlamak için optimize edilmiş, amaca hizmet eden bir havza modellemesi projesinin tasarımında rehberlik etmektir. Bu çalışmada Köyceğiz havzası için havza hidrolojisi ve yayılı kirlenme karakterizasyonu ile iklim ve arazi kullanımı değişikliklerinin havzanın hidrolojisi ve yayılı kaynaklardan gelen kirletici yükleri üzerindeki etkilerini belirlemek amacıyla Better Assessment Science Integrating point and Non-point Sources (BASINS) ve Hidrolojik Simülasyon Programı-Fortran (HSPF) kullanılmıştır. En İyi Profesyonel Yargı (Best Professional Judgment, BPJ) yöntemi ve literatür taraması sonuçları kullanılarak, veri, maliyet ve Model Performans İndeksi arasındaki ilişkiler belirlenmiştir. Bu ilişkilerin belirlenmesinde kanıtın ağırlığı (Weight of Evidence, WoE) analizi baz alınmıştır. Gelişmekte olan ülkelerde kullanmak amacıyla, minimize edilmiş veri gereksinimi, göreceli olarak düşük maliyet ve model sonuçlarının kabul edilebilirliğini içeren BASINS/HSPF uygulamasını kapsayan bir hipotez geliştirmek için nesnel kanıtlar ileri sürülmüştür. The aim of this study is two folds. The primary aim of the study is to apply a detailed watershed model for the quantification of climate and land use change impacts on the hydrology and NPS pollution in the case study watershed in a developing country. Secondly, it aims to develop a pathway for researchers in developing countries that takes into account the data availability, cost of data collection and model performance to design a watershed modelling project tailor made to the specific modelling objectives based on a threshold level of data requirement, model results and cost, optimized for maximum benefit. In this study Better Assessment Science Integrating point and Non-point Sources (BASINS), and Hydrological Simulation Program-FORTRAN (HSPF), are used for the characterization of watershed hydrology and diffuse pollution and quantification of the effects of land use and climate change on the hydrologic regime and NPS pollutant loads in the Koycegiz watershed, Turkey. Based on the Weight of Evidence (WoE) analysis; Best Professional Judgment (BPJ) in modeling experience and literature review are used to define the relationships between Data, Cost and Model Performance Index and objective evidences are put forth to develop a hypothesis incorporating an application scenario for BASINS/HSPF application in a developing country identifying the minimum data requirement, corresponding relative cost and acceptability of model results, respectively. 184

Sapanca Gölü Türkiye'nin Kuzeybatısına içme suyu sağlayan önemli su kaynaklarından biridir. İçme suyunun kalitesini belirlemek çok önemlidir. Su kalitesini değerlendirmek için birçok metot vardır. Son yıllarda su kalitesinin araştırılmasında matematiksel modeller çok yaygınlaştı. Bu araştırmada ötrofikasyon için önemli olan sınırlayıcı madde azot fosfor oranı kullanılarak belirlendi. Bunun yanında Sapanca Gölü'nün trofik karakterini belirlemek için Vollenweider metodu ve olasılıklı yaklaşım kullanıldı. Fosfor ve klorofil a arasındaki ilişkiyi görmek için doğrusal olmayan regresyon uygulandı. Termal katmanlaşma gölün sıcaklık profili kullanılarak incelendi daha sonra epilimnion ve hipolimnion derinlikleri belirlendi. Son olarak, PAMOLARE adı verilen dinamik bir model Sapanca Gölü'nün su kalitesinin değerlendirilmesinde kullanıldı. PAMOLARE gölün gelecekteki karakterini geçmiş verileri ve göle giren yükleri kullanarak hesaplayan bir modeldir. İki tip model kullanılmıştır; bunlar ismen :tek tabakalı ve çift tabakalı modellerdir. Tek tabakalı model gölün tam karıştığını ve tabakalaşma olmadığını kabul eder. Tek tabakalı model tahminini gölün morfolojisini kullanarak ve sabit besi yükü kabul ederek yapar. Çift tabakalı model karmaşık bir modeldir. Bu model gölü epilimnion ve hypolimnion olarak iki tabakaya böler. Matematiksel formüller bu iki katmana farklı uygulanır. Bunun yanında çift katmanlı model günlük verileri kullanır ve gelecekteki verileri bu geçmiş verileri kullanarak elde eder. Modelin inşası sürecinde, gölün genel yapısı belirlendi. Eksik veriler curve fitting programlarıyla elde edildi. Güneş ışığı şiddeti, sıcaklık dağılımı gölün fiziksel özelliklerinden belirlendi. Model gölün gelecekteki karakterini tahmin etmek için uygulanmıştır. Ve farklı senaryolar için farklı sonuçlar elde edilmiştir.Sonuç olarak, Sapanca Gölü'nün su kalitesi incelenmiştir ve PAMOLARE modeli gelecekteki göl içi parametrelerinin belirlenmesinde başarılı bir şekilde uygulanmıştır. Lake Sapanca is one of the major water resources supplying drinking water of northwestern Turkey. The determination of water quality of drinkable water resources is so crucial. There are lots of methods to estimate the water quality. In recent years, mathematical models become so popular for investigation of the water quality. In this research, limiting element which is so important for eutrophication is determined by using nitrogen and phosphorus ratio. Beside that, Vollenweider method and probabilistic approaches used to determine trophic character of Lake Sapanca. To see the relation between phosphorus and chlorophyll-a non linear regression is applied. The thermal stratficiation is investigated by using temperature profile of lake then epilimnion and hypolimnion depth is determined. Lastly, dynamic model named as PAMOLARE used for evaluation water quality of Sapanca Lake. PAMOLARE is a model which is estimating future characteristics of lake by using past data and input loads. Two types models were used; namely: 1-Layer PAMOLARE model and 2-Layer PAMOLARE model. 1-Layer Model assumes that lake is well mixed and no stratification occurs in lake. 1-Layer Model makes estimation by using lake morphology and assuming a constant nutrient loading. 2-Layer Model is more complex model. This model separates lake to two layers as hypolimnion and epilimnion. The mathematical formulas are applied differently to two layers. Beside that 2-Layer Model uses daily environmental data and estimates future data by using these past environmental data. In the construction process of model, general behavior of lake was described. Missing data was obtained by curve fitting programs. Solar intensity, epilimnion and hypolimnion layers depth were described by the physical properties of lake. And different results are obtained according to different scenarios.As a conclusion, water quality of Sapanca Lake is investigated and the PAMOLARE models have been successfully applied to determine future in-lake parameters. 125

Biyolojik oksijen ihtiyacı (BOİ), su kalitesinin yönetimi ve planlamasında en önemli parametrelerden biri olarak gösterilmektedir. Fakat son derece önemli olan bu parametrenin ölçümü zordur ve ölçüm sonuçlarının elde edilmesi beş gün gibi uzun bir süre almaktadır. Ölçümlerin zorluğu ve zaman alması ölçümlerin maliyetini de arttırmaktadır. Bu tür zorlukların üstesinden gelmek için bilim adamları bazı metotlar geliştirme yoluna gitmişlerdir. Bu metotlardan birisi de son zamanlarda literatürde sıkça kullanılan yapay zeka modelleridir. Bu çalışmada bir atıksu arıtma tesisinin girişindeki BOİ yapay zeka metotlarından olan yapay sinir ağları (YSA) ile tahmin edilmeye çalışılmıştır. YSA modelinin kurulmasında atıksu arıtma tesisinin girişindeki günlük kimyasal oksijen ihtiyacı (KOİ), günlük su debisi (Qw), günlük askıda katı madde (AKM), günlük toplam azot (N) ve günlük toplam fosfor (P) parametreleri girdi olarak kullanılırken günlük BOİ parametresi ise çıktı olarak kullanılmıştır. Ayrıca, en iyi sonucu veren modelin araştırılmasında çeşitli girdi kombinasyonları kullanılarak BOİ tahminleri yapılmıştır. YSA modellerinin çıktılarının performansları, determinasyon katsayısı (R2), ortalama mutlak hata (OMH) ve ortalama karesel hata (OKH) gibi hata performans fonksiyonları kullanılarak değerlendirilmiştir. Ayrıca YSA sonuçları çoklu regresyon analizi (ÇRA) sonuçları ile de karşılaştırılmıştır. Performans sonuçlarına bakıldığında YSA modelinin BOİ tahmininde ÇRA' dan çok daha etkili bir model olduğu ve gerçeğe çok yakın sonuçlar verdiği görülmüştür. Biological oxygen demand (BOD) has been shown to be an important variable in water quality management and planning. However, BOD is difficult to measure and needs longer time periods (5 day) to get results. Artificial Neural Networks (ANNs) are being used increasingly to predict and forecast water resources variables. The objective of this research was to develop artificial neural networks (ANNs) model to estimate daily biological oxygen demand (BOD) in the inlet of wastewater biological treatment plant. The plantscale data set (364 daily records of the year 2005) were obtained from a local wastewater treatment plant. Various combinations of daily water quality data, namely chemical oxygen demand (COD), water discharge (Qw), suspended solid (SS), total nitrogen (N) and total phosphorus (P) are used as inputs into the ANN so as to evaluate the degree of effect of each of these variables on daily inlet BOD. The results of the ANN model is compared with multiple linear regression model (MLR). Mean square error, average absolute relative error and coefficient of determination statistics are used as comparison criteria for the evaluation of the model performances. The ANN technique whose inputs are COD, Qw, SS, N and P gave mean square errors of 708.01, average absolute relative errors of 10.03 %, and determination coefficient of 0.919, respectively. Based on the comparisons, it was found that the ANN model could be employed successfully in estimating the daily BOD in the inlet of wastewater biological treatment plant. 49

安東ダムの水質は点的および面的汚濁源によって汚染され, 富栄養化の現象が利水上で問題視されている。安東ダムの水質保全のために, 外部汚染源の削減および内部汚染を抑制する総合的対策を検討する必要がある。そこで, 本研究では, 安東ダムの富栄養化への対策と制御法を合理的に選定するために, 簡単な河川と潮水の物質循環モデルを構築し, 点的および面的汚濁源の発生負荷量の積算結果と水域の諸元を入力することにより, 水質の予測を試みた。河川モデル式による計算値の水質と測定値の水質はよく再現しているが, 湖沼モデル式による水質推定値は再現性があまりよくない。今後の安東ダムの水質の保全のためには, 各排水区域の点的汚染源を処理すると同時に安東ダムへの流入水の窒素とリンを除去するべきものである。

Istanbul, the largest metropolis of Turkey and one of the most crowded metropolises in the world, is facing the risk of water scarcity. Analyses indicated that one of the alternative solutions coping with this problem is water transfer from a watershed that is located outside the administrative boundaries of Istanbul. Due to its water potential and relatively less degraded water quality, Buyuk Melen Watershed was considered to be the most feasible option. As the result of analyses, State Hydraulic Works (DSI) has planned construction of a reservoir in the Buyuk Melen Watershed to supply the required amount of water for Istanbul also in low flow seasons. Since the reservoir will be located at the downstream region of the watershed, its water quality will be affected by human-induced activities, thus measures need to be taken to prevent pollution prior to reservoir construction. Quantifying the response of the planned reservoir to external pollution loads is an important step in the planning and management of the watershed. Mathematical modelling is a useful tool for estimating the future water quality and understanding the possible responses of the reservoir to various pollution loads. In this study, a water quality model capable of simulating hydrodynamics, transport and water quality in reservoirs is used for preliminary estimation of possible impacts of several management options in the watershed. Model results indicated that, all of the point sources in the watershed must be controlled by advanced wastewater treatment and should be diverted from the streams and the planned reservoir. Model results also indicated that reduction of agricultural diffuse loads by 30–40% is expected to have a perceptible improvement of reservoir water quality.

Downstream of Capim Branco I hydroelectric dam (Minas Gerais state, Brazil), there is the need of keeping a minimum flow of 7 m3/s. This low flow reach (LFR) has a length of 9 km. In order to raise the water level in the low flow reach, the construction of intermediate dikes along the river bed was decided. The LFR has a tributary that receives the discharge of treated wastewater. As part of this study, water quality of the low-flow reach was modelled, in order to gain insight into its possible behaviour under different scenarios (without and with intermediate dikes). QUAL2E equations were implemented in FORTRAN code. The model takes into account point-source pollution and diffuse pollution. Uncertainty analysis was performed, presenting probabilistic results and allowing identification of the more important coefficients in the LFR water-quality model. The simulated results indicate, in general, very good conditions for most of the water quality parameters The variables of more influence found in the sensitivity analysis were the conversion coefficients (without and with dikes), the initial conditions in the reach (without dikes), the non-point incremental contributions (without dikes) and the hydraulic characteristics of the reach (with dikes).

Bu çalışmada, Köyceğiz ? Dalyan Lagünü'ne, Water Quality Analysis Simulation Program (WASP), adlı su kalitesi modeli uygulanmış ve bu tip hassas ekosistemlerde su kalitesi modellemesi yapacak araştırıcılara yardımcı olabilmek amacıyla karşılaşılan zorluklardan bahsedilerek bir kılavuz oluşturulmuştur. Su kalitesi modelleme çalışmaları sırasında, sistemdeki süreçlerin ve mekanizmaların daha iyi anlaşılabilmesi amacıyla simülasyonlar basitten başlayıp, karmaşığa doğru gerçekleştirilmiştir. Bu amaçla, simülasyonlar 5 adımda yapılarak, her adımda bir veya birkaç durum değişkeni ilave edilmiştir. Birinci simülasyon adımında, tuzluluk simülasyonları gerçekleştirilmiştir. Tuzluluk sonuçlarına göre, öngörülen konsantrasyonların çoğu izleme çalışmalarında ölçülen değerlerle uyum göstermektedir. Simülasyon sonuçları; modele tanıtılan akımların, akım yollarının ve difüzyon katsayılarının su kalitesi simülasyonlarının gerçekleştirilebilmesi için yeterli doğrulukta olduğunu göstermektedir. İkinci simülasyon adımında, WASP modelinde yer alan bütün azot türleri ve fitopalnkton, üçüncü simülasyon adımında ise, fosfor türleri, azot türleri ve fitoplankton birlikte simüle edilmişlerdir. Dördüncü simülasyon adımında, üçüncü adımda yer alan durum değişkenlerine çözünmüş oksijen, KBOİ, detrital karbon ve tuzluluk parametreleri ilave edilmiştir. Beşinci simülasyon adımında, noktasal ve yayılı yüklerin sistem üzerindeki etkilerinin analiz edilebilmesi için, yük senaryoları geliştirilmiştir. Simülasyon sonuçlarına göre, fosfor sistemdeki kısıtlayıcı element olarak gözükmektedir. Fosfor türleri simülasyonlara eklendiklerinde toplam klorofil-a konsantrasyonlarında önemli değişiklikler meydana gelmiş, bu da azot türlerinde konsantrasyon değişimlerine neden olmuştur. In this study, Water Quality Analysis Simulation Program (WASP) was applied and adapted to Köyceğiz ? Dalyan Lagoon, and a guideline was proposed for researchers studying water quality modeling of such complex systems by emphasizing on the difficulties faced during the study. During the modeling studies, the simulations were run from the simplest complexity level to higher complexity levels in order to better understand the processes and mechanisms that occur in the system. Therefore, the simulations were carried out in 5 steps. One or more state variables were added in each simulation step. In Simulation Step 1, salinity simulations were conducted for analyzing the flows and exchanges defined to the model. According to the salinity simulation results, most of them are in high compliance with monitoring data. The simulation results indicate that the flow rates, pathways, exchanges and exchange coefficients, are estimated satisfactorily to run water quality simulations. In Simulation Step 2, all the nitrogen species and phytoplankton, in Simulation Step 3, nitrogen species, phosphorus species and phytoplankton are simulated together. In Simulation Step 4, dissolved oxygen, CBOD, detrital carbon and salinity parameters were added to Simulation Step 3. In order to analyze the effects of point and diffuse pollutant loads on the system, load scenarios were developed. According to the simulation results, phosphorus seems to be the limiting nutrient in the system. When phosphorus species were included into the simulations significant changes were observed in total chlorophyll- a concentrations, which also affected the concentrations of nitrogen species. 257

Preface. Acknowledgements. Introduction. I. E. Gonenc and B.Toktoraliev.- Watershed Management In Various Countries. Watersheds and Water Management System in Algeria M. Messahel.-Advances in Managing Austria's Water Resources M. Schonerklee.- Problems and prospects of water resources management in the Azerbaijan Republic A.Aliev.-Water Resources Management System Of Kyrgyzstan M.Amanaliev.-Watershed Management Practices in the Philippines, The Tigum-Aganan Watershed Case J. C. Sala.- Watershed Management System in Poland and Its Implications for Environmental Conditions of the Baltic Sea: An Example of the Vistula River Watershed E. Andrulewicz.- Water Resources Management in Romania: Challenges and Opportunities A.Vadineanu and E. Preda.- Watershed Management in the Russian Federation and Trans-boundary Issues by Example of Kaliningrad Oblast (Russia).- B.Chubarenko.- Overview of Water Management in Turkey: Issues, Constraints, Achievements Prospect S.Burak.- Watershed Management in the U.S.A. R. C. Russo et al.-Decision Support Tools, Models and Case Studies.Multilevel Participatory Model for Decision Making on Regional Hydro-System Basis: Serbian Case Study B.Srdjevic and Z.Srdjevic.- Supporting Tools For Decisional Process Within Water Framework Directive: From EU Context to Modelkey Perspective S.Gottardo et al.- Application Of Water Quality Modelling as a Decision Support System Tool For Planned Buyuk Melen Reservoir and Its Watershed A.Erturk et al.- The Use of Numerical Modeling in Italian Watershed Management G.Umgiesser et al.- Sustainable Development Of Watersheds: Using Sturgeon Species As An Indicator in Integrated Trans-Boundary Water Management in The Ural River Basin V.Lagutov.- Lagoon Ecosystem Study Trough Two Cases: Oualidia (Atlantic) and Nador (Mediterranean) - Morocco A. Orbi et al.- Coastal lagoons in the context of water management in Spain and Europe A. Perez-Ruzafa.- Water Framework Directive: Defining TheEcological Quality Status In Transitional And Coastal Waters S.Gamito. The Role of Ecological Endpoints in Watershed Management B. Rashleigh.-- Bioidentification of Xenobiotics as a Basis of Water management V.Tonkopii et al.- GIS analysis of sustainable development indicators for coastal watersheds in the South-Eastern Baltic B. Chubarenko and D. Domnin.- Combined Use of Watershed Models to Assess the Apportionment of Point and Non Point Load Sources to Surface Waters A.Azzellino et al.- Development Of National Action Plan To Address Pollution From Land Based Activities In Turkey A. Gulsen. Et al.- Reduction of the Land-Based Discharges to the Curonian Lagoon in a View of a Climate Change Perspective A. Razinkovas et al.- The Study of Hydro-Mineralogical and Ecological Regime of Kara-Bogaz-Gol Lagoon O. Geldiyew.- Comparative Analysis of Water Management Practices in Mediterranean Countries S.Burak.- Chesapeake Bay Program - A Watershedf Approach to Management J.P. Wolflin.- Conclusions and Recommendations. Decision Support Systems and Tools R.Neves et al.- Land-based sources and water quality and management A.Vadineanu et al.-Decision Making, Policy And Financing J. Wolflin et al.-List of Participants

A general methodology is presented for stating and solving model calibration problems in a global optimization framework. The approach is illustrated by examples related to water quality modelling.

The North Sea is highly polluted by nutrients and toxics. By extensive data collection and analysis, coupled with hydrodynamic and water quality modelling, the behaviour of toxics in the North Sea is quantified. This is illustrated by simulation of the cadmium concentration pattern in the North Sea. Special attention is given to the consequences of various measures of dumping/storing dredged material from Rotterdam harbour on the water quality of the North Sea.

Diffuse pollution is hard to analyze, control and manage by its nature. Watershed models and Geographical Information Systems (GIS) are recently developed tools that aid analysis of diffuse sources of pollution. However, their applications are not always easy and straightforward. Turkey is a typical example of a mountainous country rich in rivers and streams. Due to the complex geomorphology, land-use and agricultural practices in most of the watersheds in Turkey, modelling, analyzing and managing diffuse pollution has been a challenge. The complex watershed structure forces the modellers to work with spatially high resolution data. Apart from the data, the models themselves may also cause operational problems. These issues and their probable solutions form the basis of the discussions in this paper. It acts as a guideline for modelling and analyzing diffuse pollution by emphasizing the referred problems and difficulties. Design of an Information Technology-based system tool for watershed and/or water quality modelling, which would be suitable for countries having watersheds with similar structure and problems to those of Turkey, is also outlined.

Relatively simple compartmental models of transport of radioactive substances by a uniform flow are quite often successfully used for assessment of concentrations of radionuclides in water, bottom sediments and flood plains of rivers. However, one should take into account specificity of contamination of a river to be simulated. In this work the results of modelling of Sr, Cs, and Pu migration in the Techa River were compared with observed data. As a result of the comparison the authors have supposed that taking into account of the process of mass exchange between the main stream of a river and underflow is important for the adequate modelling of migration and accumulation of radionuclides (and other contaminants with similar physical and chemical properties) in rivers that were polluted during a long period of time. It is known that underflow of a river can reach 30% of the main stream. The performed analysis of comparison of the modelling results with the observed data has enabled an evaluation of numerical values of parameters by means of which the interaction between the main stream and the underflow may be described. The choice of the Techa-river as an example was not casual. For more than 50 years the “Mayak” plant was fulfilling its important defense mission and discharged contaminated effluents to the Techa-river. As a result the whole river and its basin have become contaminated by long-lived radionuclides. The issues of the Techa-river contamination by radionuclides and simulation of their transport have been given attention over decades by many scientists.

In tale pubblicazione, riprendendo l’approccio lagrangiano proposto in una memoria presentata a IDRA 2006 (Mucherino, C., Palumbo, A., Bruno Francavilla, C.M., e Pianese, D. (2006). “Modellazione delle variazioni spazio-temporali delle caratteristiche di qualità dei corsi d’acqua naturali”) per la simulazione della propagazione di contaminanti in corsi d’acqua naturali, si effettua un confronto con i principali modelli di qualità presenti in letteratura mettendo in luce l’efficienza, la validità e l’accuratezza del modello proposto. Il confronto è stato effettuato focalizzando l’attenzione sul problema della riduzione della dispersione numerica nel termine della convezione. portando a soluzioni del profilo di concentrazione altamente accurata.

There are many sources of uncertainty in modelling systems including uncertainty due to parameter estimations, input data and structure of the system. In this paper, modelling system structure is understood to be the algorithms and equations used to describe and calculate processes. Specific attention is given to the uncertainty in the equations, which link models interactively in a modelling system and algorithms, which pass information between the models. This paper places emphasis on structural uncertainty in modelling systems since this topic has received very little attention in research compared to the wealth of literature on parameter and input data uncertainty. This imbalance is partly due to the difficulty in quantifying structural uncertainty and an example is given showing how this may be done. The modelling system used for this study incorporates the coupling of three models from the WASP5 package (Water quality Analysis Simulation Program) developed by the US Environmental Protection Agency: DYNHYD (hydrodynamics), EUTRO (dissolved oxygen, nutrient and phytoplankton dynamics) and TOXI (transport and transformation of sediments and micro-pollutants). The three models were coupled in the high level architecture (HLA) platform to enable interactions between the models during simulations. This platform allowed ease of implementing Monte Carlo simulation runs, which were used for the uncertainty analyses. The modelling system structure focuses on the exchange of data between EUTRO and TOXI in simulating two processes: (i) sorption of heavy metals to suspended solids as a function of the fraction of organic carbon constituting the solids and (ii) phytoplankton growth limitation by light extinction through the water column as a function of the concentration of suspended solids and chlorophyll a in the water. Both processes are described by empirical relationships using regression curves derived from field data. The variance in the y -axis interceptions of the curves (also called regression uncertainty) is taken to be the uncertainty bounds for the Monte Carlo simulations used for the uncertainty analyses. The results show that structural uncertainty can be more significant than parameter and input data uncertainty, especially if the processes are very sensitive to the state variables.

A key question related to climate change projections is how will aquatic systems respond to changes in variables such as temperature and precipitation? This thesis uses GWLF, a simple catchment scale model to explore potential impacts of climate change on water quantity and quality. River discharge and nutrient loads were modelled for several warmer world scenarios. For one catchment in New York, USA changes in annual dissolved phosphorus loads decreased along with annual streamflow, and particulate phosphorus loads increased for a single future climate scenario. For the Galten catchment of Lake Mälaren, Sweden, the spring melt peak observed historically was reduced for six future scenarios. Peak runoff and dissolved phosphorus and nitrogen load maxima occurred in winter rather than early spring. A synthesis of model results for dissolved inorganic nitrogen (DIN) loadings for five European catchments showed changes in the timing and magnitude of peak DIN load for several future scenarios. In northern Europe, changes were largely due to increased winter streamflow and reduced snow pack and spring melt runoff. In western Europe, DIN loads increased in winter or early spring due to increased precipitation. The biological response for a warmer future scenario was modelled for the Galten basin of Lake Mälaren using GWLF coupled to a lake phytoplankton model and a physical lake model. An increase in cyanobacteria biomass accompanied by a decline in diatom biomass resulted from changes in the timing of nutrient export from the catchment. The projected increase in lake temperature favored an overall increase in total phytoplankton biomass. Lastly, a method based on hourly measurements of colored dissolved organic matter (CDOM) fluorescence provides the appropriate data for dissolved organic carbon (DOC) model parameterization and may also be used for surveillance of organic matter inputs to lakes.

International audience; To achieve the objectives of the European Water Framework Directive (EWFD), the Seine basin Water Authority has constructed a number of prospective scenarios forecasting the impact of planned investments in water quality. Paris and its suburbs were given special attention because of their impact on the river Seine. Paris sewer system and overflow control is of major concern in future management plans. The composition and fate of the urban effluents have been characterized through numerous in situ samplings, laboratory experiments and modelling studies. The PROSE model was especially designed to simulate the impact on the river of both permanent dry-weather effluents and of highly transient Combined Sewer Overflow (CSO). It was also used to represent the impact of Paris at large spatial and temporal scales. In addition to immediate effects on oxygen levels, heavy particulate organic matter loads that settle downstream of the outlets contribute to permanent oxygen consumption. Until the late 90s, the 50 km long reach of the Seine inside Paris was permanently affected by high oxygen consumption accounting for 112% of the flux upstream of the city. 20% of this demand resulted from CSO. However, the oxygenation of the system is strong due to high phytoplankton activity. As expected, the model results predict a reduction of both permanent dry-weather effluents and CSOs in the future that will greatly improve the oxygen levels (concentrations higher than 7.3 mgO(2) L-1, 90% of the time instead of 4.0 mgO(2) L-1 in the late 90s). The main conclusion is that, given the spatial and temporal extent of the impact of many CSOs, water quality models should take into account the CSOs in order to be reliable. (c) 2006 Elsevier B.V All rights reserved.

This study is based on water quality monitoring work of water resources within the Abaya-Chamo basin. The methods, method validation and analysis results have been presented and discussed. Seansonal variation and trends as well as associated water quality management issues are discussed. A water quality monitoring system based on an integrated partial physical orthogonal model has been designed based on data generated within the water resources of the Abaya-Chamo drainage basin. Abstract common factors were extracted by the application of principal component and factor analysis. By overlaying real factors with abstract common factors the underlaying causes for the water quality variations hace been explained. Surface flow factors, sub surface flow factors, leaching flow factors, effects of soil matrix, rainfall magnitude and intensity, discharge, catchment area and slope, in stream pollution and point sources of pollution, evaporative storage and precipitation chemistry all showed up in such integrated model. This model can be extended by including further physical factors as well as natural and anthropogenic pollution sources and factors. This model can be extended to lakes and ground water sources as well. Design of water quality monitoring intervals was accomplished with the help of spectral analysis. Spatial monitoring spacing for lake water quality was determined after hierarchical cluster analysis. The possibility of modelling the various water quality parameters was investigated. Auto regressive modelling fits well variables that have seasonally evened variation. Variables with short-term fluctuation were modelled with spectral level regression. State-space method was satisfactorily applied for relating the time series between two sampling points located on different rivers. Discharge-base contaminant modelling was modified to compensate for error by establishing a pattern of relationship between calculated and observed contaminant loads.

The River Ouse forms a significant part of the Humber river system, providing the largest UK fresh water source to the North Sea and a valuable habitat for fish. It suffers from dissolved oxygen sag over summer months, especially downstream of industrial effluent discharges at Selby. The Environment Agency (EA) therefore proposed implementing stricter environmental limits for industries and sewage treatment works. The effectiveness of other management options is evaluated through a one-dimensional water quality model, QUESTS1D. Significant improvements in water quality from alternative options are predicted by simulation using QEUSTS1D, in comparison to tightening effluent consents. The Transfer Coefficients Matrix of BOD5 is derived in this paper to indicate the relative impacts on water quality of using different discharge locations. An integrated river policy taking into account both effluent discharges and water abstraction on the basis of their effects suggests a combined water management framework could be applied to ensure the required water quality.

With the development of computing technology, numerical models are often employed to simulate flow and water quality processes in coastal environments. However, the emphasis has conventionally been placed on algorithmic procedures to solve specific problems. These numerical models, being insufficiently user-friendly, lack knowledge transfers in model interpretation. This results in significant constraints on model uses and large gaps between model developers and practitioners. It is a difficult task for novice application users to select an appropriate numerical model. It is desirable to incorporate the existing heuristic knowledge about model manipulation and to furnish intelligent manipulation of calibration parameters. The advancement in artificial intelligence (AI) during the past decade rendered it possible to integrate the technologies into numerical modelling systems in order to bridge the gaps. The objective of this paper is to review the current state-of-the-art of the integration of AI into water quality modelling. Algorithms and methods studied include knowledge-based system, genetic algorithm, artificial neural network, and fuzzy inference system. These techniques can contribute to the integrated model in different aspects and may not be mutually exclusive to one another. Some future directions for further development and their potentials are explored and presented.

The dynamic behaviour of pesticides in river systems strongly depends on varying climatological conditions and agricultural management practices. To describe this behaviour at the river-basin scale, integrated hydrological and water quality models are needed. A crucial step in understanding the various processes determining pesticide fate is to perform a sensitivity analysis. Sensitivity analysis for hydrology and pesticide supply in SWAT (Soil and Water Assessment Tool) will provide useful support for the development of a reliable hydrological model and will give insight in which parameters are most sensitive concerning pesticide supply towards rivers. The study was performed on the Nil catchment in Belgium. In this study we utilised an LH-OAT sensitivity analysis. The LH-OAT method combines the One-factor-At-a-Time (OAT) design and Latin Hypercube (LH) sampling by taking the Latin Hypercube samples as initial points for an OAT design. By means of the LH-OAT sensitivity analysis, the dominant hydrological parameters were determined and a reduction of the number of model parameters was performed. Dominant hydrological parameters were the curve number (CN2), the surface runoff lag (surlag), the recharge to deep aquifer (rchrg_dp) and the threshold depth of water in the shallow aquifer (GWQMN). Next, the selected parameters were estimated by manual calibration. Hereby, the Nash–Sutcliffe coefficient of efficiency improved from an initial value of −22.4 to +0.53. In the second part, sensitivity analyses were performed to provide insight in which parameters or model inputs contribute most to variance in pesticide output. The results of this study show that for the Nil catchment, hydrologic parameters are dominant in controlling pesticide predictions. The other parameter that affects pesticide concentrations in surface water is ‘apfp_pest’, which meaning was changed into a parameter that controls direct losses to the river system (e.g., through the clean up of spray equipment, leaking tools, processing of spray waste on paved surfaces). As a consequence, it is of utmost importance that hydrology is well calibrated while––in this case––a correct estimation of the direct losses is of importance as well. Besides, a study of only the pesticide related parameters, i.e. application rate (kg/ha), application time (day), etc., reveals that the application time has much more impact than the application rate, which has itself a higher impact than errors in the daily rainfall observations.

This paper illustrates the coupling of water quality model components in High Level Architecture (HLA), a computer architecture for constructing distributed simulations. HLA facilitates interoperability among different simulations and simulation types and promotes reuse of simulation software modules. It was originally developed for military applications but the platform is finding increasing applicability for civilian purposes. The models from the Water Quality Analysis Simulation Program (WASP5) were implemented in HLA to extend its Monte Carlo uncertainty analysis capabilities. The models include DYNHYD (hydrodynamics), EUTRO (phytoplankton and nutrient dynamics) and TOXI (sediment and micropollutant transport). The uncertainty analysis investigated the impact of errors in the hydrodynamic parameters (weir discharge and roughness coefficients) and boundary conditions (upstream and tributary discharge) on the uncertainty in the water quality output variables. It was found that the contribution of the hydrodynamic parameter error to the water quality output uncertainty is comparable to that obtained from the error in the water quality parameters. The error in the boundary condition input data is also an important contributor to model uncertainty.

Integrated urban drainage modelling and environmental impact assessment require sewer emission models to be linked with submodels for treatment infrastructure and receiving rivers. The uncertainty in current water quality modelling is, however, huge, and environmental impact assessment looses more and more credibility. Based on an integrated modelling case for a combined sewer \342\200\223 WWTP \342\200\223 river system, it is shown in the paper that the integrated model does not produce more accurate results in comparison with the random simulation of emission concentrations from a frequency distribution. This should, however, not pose a serious problem as in most applications of impact assessment model results are not needed in real time but in statistical terms. Further investigation makes clear that detail/sophistication in water quality modelling is not so important, but that more focus has to be given to long-term simulations, the use of parsimonious models and model validation based on concentration frequencies.

Understanding the process controls on episodic fluxes of faecal indicator organisms (FIOs) is becoming increasingly important for the sustainable management and accurate modelling of water quality in both recreational and shellfish harvesting waters. Both environments exhibit transitory non-compliance with microbiological standards after rainfall episodes despite significant expenditures on control of sewage derived pollutant loadings in recent years. This paper demonstrates the role of wave propagation in the entrainment of FIOs from river channel beds as a contributor to episodes of poor microbial water quality. Previously reported data is reviewed in the light of relationships between wave and mean water travel velocities. High flows and rapid changes in river flow, driven by releases of bacterially pure reservoir water, resulted in elevated FIO concentrations and transient peaks in concentration. The new interpretation of these data suggest three modes of entrainment: (i) immediate wave-front disturbance, (ii) wave propagation lift and post-wave transport at mean flow velocity, and (iii) stochastic erosional mechanisms that maintain elevated bacterial concentrations under steady high flow conditions. This is a significant advance on the previously proposed mechanisms. Understanding these mechanisms provides an aid to managing streams intended for recreational use and emphasises the need to control the timing of high flow generation prior to use of the water body for e.g. canoeing events. In addition the processes highlighted have relevance for the protection of shellfish nurseries, drinking water supply intakes and episodes of poor bathing water quality, and associated health risks.

Management of water quality in karst is a specific problem. Water generally moves very fast by infiltration processes but far more by concentrated flows through fissures and openings in karst. This enables the entire surface pollution to be transferred fast and without filtration into groundwater springs. A typical example is the Jadro spring. Changes in water quality at the spring are sudden, but short. Turbidity as a major water quality problem for the karst springs regularly exceeds allowable standards. Former practice in problem solving has been reduced to intensive water disinfection in periods of great turbidity without analyses of disinfection by-products risks for water users. The main prerequisite for water quality control and an optimization of water disinfection is the knowledge of raw water quality and nature of occurrence. The analysis of monitoring data and their functional relationship with hydrological parameters enables establishment of a stochastic model that will help obtain better information on turbidity in different periods of the year. Using the model a great number of average monthly and extreme daily values are generated. By statistical analyses of these data possibility of occurrence of high turbidity in certain months is obtained. This information can be used for designing expert system for water quality management of karst springs. Thus, the time series model becomes a valuable tool in management of drinking water quality of the Jadro spring.