Water Quality Modelling for Rivers and Streams

✍ Scribed by Marcello Benedini, George Tsakiris

• Publisher: Springer
• Year: 2013
• Tongue: English
• Leaves: 290
• Series: Water Science and Technology Library 70
• Category: Library

✦ Synopsis

The main objective of the Water Framework Directive in the European countries is to achieve a “good status” of all the water bodies, in the integrated management of river basins. In order to assess the impact of improvement measures, water quality models are necessary. During the previous decades the progress in computer technology and computational methods has supported the development of advanced mathematical models for pollutant transport in rivers and streams. This book is intended to provide the fundamental knowledge needed for a deeper understanding of these models and the development of new ones, which will fulfil future quality requirements in water resources management. This book focuses on the fundamentals of computational techniques required in water quality modelling.
Advection, dispersion and concentrated sources or sinks of contaminants lead to the formulation of the fundamental differential equation of pollutant transport. Its integration, according to appropriate initial and boundary conditions and with the knowledge of the velocity field, allows for pollutant behaviour to be assessed in the entire water body. An analytical integration is convenient only in one-dimensional approach with considerable simplification. Integration in the numerical field is useful for taking into account particular aspects of water body and pollutants.
To ensure their reliability, the models require accurate calibration and validation, based on proper data, taken from direct measurements. In addition, sensitivity and uncertainty analysis are also of utmost importance.
All the above items are discussed in detail in the 21 chapters of the book, which is written in a didactic form for professionals and students.

✦ Table of Contents

Water Quality Modelling for Rivers and Streams......Page 3
Preface......Page 7
About the Authors......Page 11
Contents......Page 13
1.1 The Progress in Water Resources Management......Page 18
1.2 The Water Framework Directive......Page 20
1.3 EU Directives Related to Water Quality Issues......Page 21
1.4 From Pressures to Impacts......Page 23
References......Page 26
2.1 Modelling and Water Quality Problems......Page 27
2.2 How to Interpret the Water Quality......Page 28
2.3 Water Resources Exploitation and Water Quality......Page 30
2.4 What to Model in the Water Quality Problems?......Page 32
2.5 The Most Common Way of Modelling......Page 33
2.6 General Features of the Mathematical Models......Page 35
2.7 Need of Data......Page 36
2.8 The River as the Main Water Body for Water Quality Protection......Page 38
2.9 A Fertile Field......Page 40
References......Page 41
3.1 The Water Pollution......Page 43
3.2 The Advection Transport......Page 45
3.3 The Dispersion Transport: Fick Law......Page 46
3.5 In-Water Transformations......Page 48
References......Page 49
4.1 The General Equation of Pollutant Transport in Water......Page 50
4.2 Nonconservative Pollutants......Page 53
4.3 Combined Processes......Page 54
4.4 Hydrodynamic Aspects......Page 56
4.5 A Simplified Interpretation......Page 58
References......Page 62
5.1 The Importance of Dispersion......Page 63
5.2 Evaluation of the Dispersion Coefficient......Page 64
References......Page 67
6.1 The Most Frequent Type of Pollution......Page 71
6.2 The BOD......Page 72
6.3 The Decay of BOD......Page 74
6.4 The Reaeration Coefficient......Page 76
6.6 Local Oxygenation Sources......Page 78
References......Page 80
7.2 The Oxygen Cycle......Page 82
7.3 Algae Activity......Page 84
7.4 Sediment Oxygen Demand......Page 86
7.5 Ammonia Oxidation......Page 87
7.7 The Nitrogen Cycle......Page 88
7.7.2 Ammonia Nitrogen......Page 89
7.7.3 Nitrite Nitrogen......Page 90
7.8 The Phosphorus Cycle......Page 91
7.10 The Significant Constants......Page 93
7.11 Other Kinds of Pollutants......Page 94
7.13 Future Perspective and Research Needs......Page 96
References......Page 97
8.1 Temperature Adjustment......Page 99
8.2 Heat Budget......Page 100
References......Page 101
9.1 An Analytical Solution......Page 102
9.1.1 Continuous Source of Infinite Duration......Page 104
9.1.2 Source of Finite Duration......Page 106
9.2 Some Comments......Page 108
9.3 Computing Procedures......Page 109
References......Page 112
10.1 The Fundamental Equation in One-Dimensional Approach......Page 113
10.2 The Nondispersive Flow......Page 114
References......Page 117
11.1 Discrete Systems......Page 118
11.1.2 Dispersion......Page 121
11.1.5 The Demarcation Cross Sections of the Reaches......Page 123
11.1.6 The Fundamental Equation......Page 124
11.1.7 Combined Processes......Page 125
11.2 An Example......Page 126
11.3 Additional Comments......Page 131
References......Page 133
12.1 Outlines of the Most Common Numerical Methods......Page 134
12.2 The Finite Difference Method (FDM)......Page 135
12.3 Basic Concepts of the Numerical Approach......Page 136
12.4 Numerical Schemes: Stability Criteria......Page 138
12.5 Boundary Conditions......Page 140
12.6 An Example: Pure Advection Transport......Page 141
12.7 Crank-Nicolson Numerical Scheme (CTCS)......Page 144
12.8 The BTCS Numerical Scheme......Page 146
12.9 Explicit Numerical Schemes......Page 150
12.10 Final Comments on the FDM......Page 156
References......Page 157
13.1 Fundamental Aspects......Page 158
13.2 The Basic Algorithm for a Continuous Pollutant Injection......Page 159
13.3 The Ritz-Galerkin Approach......Page 169
13.4 An Application......Page 176
13.5 The Pollutant Wave......Page 180
13.6 Additional Comments on the Finite Element Method......Page 185
References......Page 187
14.1 Basic Concepts......Page 188
14.2 Additional Comments......Page 191
References......Page 192
15.1 The Two-Dimensional Case......Page 193
15.2 Examples......Page 197
15.3 An Outline of the 2D-Finite Element Method......Page 201
References......Page 204
16.1 The Discharge of Hot Water......Page 206
16.2 The Basic Equations......Page 207
16.4 The Injection of a Hotter Flow......Page 209
16.5 Other Forms of Heat Injection......Page 210
16.6 Heat Exchange Between the River and Its Environment......Page 211
16.6.1 The Air-Water Heat Exchange......Page 212
16.6.2 Heat Exchange with the River Bed......Page 213
16.6.3 Heat Exchange with Sediments......Page 214
16.7 An Example......Page 216
References......Page 218
17.1 The Optimal River Management......Page 220
17.2 The Linear Programming Model......Page 221
17.3 Some Characteristics of the Linear Programming Models......Page 222
17.4 An Example of Linear Programming Model......Page 223
17.5 Post-optimal Analysis......Page 225
17.7 The Role of Programming Models......Page 226
References......Page 228
18.1 Calibration......Page 229
18.2 Verification......Page 231
18.3 Quantitative Model Performance Assessment......Page 232
References......Page 234
19.1.1 Definite Methods......Page 236
19.1.4 On-line Monitoring Methods......Page 237
19.2 Traceability......Page 238
19.3.2 Sampling Variance Significant-Measurement Variance Insignificant......Page 239
19.3.4 Sampling Variance Significant-Measurement Variance Significant......Page 241
19.3.5 Uncertainty of Measurement......Page 242
19.3.6 Estimation of Total Uncertainty......Page 243
19.4 Quality Assurance and Quality Control......Page 244
19.6 Sediment and Suspended Solids......Page 245
References......Page 246
20.1 The Effects of Parameter Variability......Page 249
20.2 A More Refined Analysis......Page 251
20.3 Uncertainty Analysis......Page 255
20.4 The Monte Carlo Analysis......Page 259
20.5 New Trends and Future Developments......Page 265
References......Page 266
21.1 New Developments......Page 268
21.2 Future Trends......Page 270
21.3 Epilogue......Page 273
References......Page 274
MONERIS......Page 276
MIKE-11......Page 277
QUAL2K......Page 279
TOMCAT......Page 280
TOPCAT-NP......Page 281
DRAINMOD......Page 283
IWA River Water Quality Model......Page 284
References......Page 285
Index......Page 287