Modeling DO Conditions in Streams with Dispersion

Koussis, Antonis D.; Kokitkar, Prashant B.; Mehta, Adosh

doi:10.1061/(asce)0733-9372(1990)116:3(601)

Cited by 18 publications

(12 citation statements)

References 4 publications

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“…First Cunge (1969) analysed such a scheme for flood routing; Koussis (1975Koussis ( , 1978Koussis ( , 2009Koussis ( , 2010) also linked storage routing to the diffusion-wave model. The good performance of Matched Artificial Diffusion (MAD) schemes in forward routing has been verified in flood [e.g., Koussis, 1975;Weinmann, 1977;Perkins and Koussis, 1996] and in pollution routing in streams Koussis et al, 1990). The same holds for the MAD-based solution component of longitudinal transport in groundwater (Syriopoulou and Koussis, 1991;García-Delgado and Koussis, 1997;Koussis et al, 2003).…”

Section: Formulation Of the Reverse Routing Problemmentioning

confidence: 90%

“…The recovery entails reverse computation of mass transport to the source by stepping back in time. Dispersion can be appreciable under ordinary transient loadings and is important in spills (e.g., Li, 1972;Koussis et al, 1990). The StreeterPhelps textbook-solution of the BOD-DO problem considers only the dominant advection for computational convenience.…”

Section: Character Of the Reverse Routing Problemmentioning

confidence: 99%

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Reverse flood routing with the inverted Muskingum storage routing scheme

Koussis

Mazi

Lykoudis

et al. 2012

Nat. Hazards Earth Syst. Sci.

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Abstract. This work treats reverse flood routing aiming at signal identification: inflows are inferred from observed outflows by orienting the Muskingum scheme against the wave propagation direction. Routing against the wave propagation is an ill-posed, inverse problem (small errors amplify, leading to large spurious responses); therefore, the reverse solution must be smoothness-constrained towards stability and uniqueness (regularised). Theoretical constrains on the coefficients of the reverse routing scheme assist in error control, but optimal grids are derived by numerical experimentation. Exact solutions of the convection-diffusion equation, for a single and a composite wave, are reverse-routed and in both instances the wave is backtracked well for a range of grid parameters. In the arduous test of a square pulse, the result is comparable to those of more complex methods. Seeding outflow data with random errors enhances instability; to cope with the spurious oscillations, the reversed solution is conditioned by smoothing via low-pass filtering or optimisation. Good-quality inflow hydrographs are recovered with either smoothing treatment, yet the computationally demanding optimisation is superior. Finally, the reverse Muskingum routing method is compared to a reverse-solution method of the St. Venant equations of flood wave motion and is found to perform equally well, at a fraction of the computing effort. This study leads us to conclude that the efficiently attained good inflow identification rests on the simplicity of the Muskingum reverse routing scheme that endows it with numerical robustness. Character of the reverse routing problemThe forward calculation of the propagation of a flood wave in an open channel, known as flood routing, is a problem of applied hydrology that has been studied extensively. The relevant methods of solution, all within the framework of one-dimensional free-surface flow, span the spectrum from numerical solutions of the hydraulic equations of Barré de Saint-Venant to storage routing models of the diffusion-wave type (Koussis, 2009), and have utility in such applications as flood warning, river training and urban storm drainage design. On occasion, however, flood related questions are posed in the reverse sense, such as, e.g., in signal identification (hydrologic forensics): "Which inflow created the outflow observed at cross-section X, or the observed flood profile along reach Y?" We may be also interested in operating a reservoir (optimal outflow control) to minimise downstream flood damage (Szöllósi -Nagy, 1987). Bruen and Dooge (2007) point out that reliable solution techniques of the latter problem would be valuable in handling of urban flash flooding.Yet reverse routing is an inverse problem and as such not well posed. A problem is well-posed when its solution exists, is unique and stable (Bronstein and Semendjajew, 1964), that is, small changes in the initial condition (forcing) cause small changes in the response. The reverse routing solution clearly exists, but must be co...

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Section: Formulation Of the Reverse Routing Problemmentioning

confidence: 90%

Section: Character Of the Reverse Routing Problemmentioning

confidence: 99%

Reverse flood routing with the inverted Muskingum storage routing scheme

Koussis

Mazi

Lykoudis

et al. 2012

Nat. Hazards Earth Syst. Sci.

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“…Adrian et al (1994) developed an approximate analytical solution for a sinusoidal variation in the waste discharge concentration. Numerical solutions have been applied to describe more complicated initial and boundary conditions (Dresnack & Dobbins, 1968;Siemens, 1970;McBride & Rutherford, 1984;Koussis et al, 1990). Jolankai (1997) proposed a generalized model for BOD-DO computation, in which: (i) longitudinal variation of the mass flux is expressed, (ii) the DO equation is written for dissolved oxygen (termed here C ox ); (iii) non-point input loads are considered in terms of concentrations of BOD and DO in the lateral inflow; and (iv) photosynthesis and respiration of aquatic plants are considered.…”

Section: Literature Reviewmentioning

confidence: 99%

Critical appraisal of BOD and DO models applied to a highly polluted river in India

Jha¹,

Ojha

Bhatia³

2007

Hydrological Sciences Journal

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Most commonly used biochemical oxygen demand (BOD) and dissolved oxygen (DO) models have been tested for their applicability in the River Kali, which is one of the most polluted rivers in India. A total of 732 field data sets were generated during field survey from March 1999 to February 2000. The modelling of BOD and DO in the River Kali involves derivation and solution of the governing equations that describe concentration change with time and space brought on by advective, decay, settling and loading functions. However, due to continuous discharges (e.g. from wastewater treatment plants) and steady-state flow conditions in the River Kali, the dispersion effects are found to be insignificant. In the analysis, the model parameters used in BOD-DO models were optimized using the Newton-Raphson technique and the performance of different models was evaluated using correlation statistics (r 2 ) and error estimation, viz. standard error (SE) and mean multiplicative error (MME). The results indicate that the BOD-DO models developed after Camp (1963) yielded the best agreement with the observed values as compared with several other approaches. Mots clefs demande biochimique en oxygène (DBO

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“…Progressively of progress of the scientific research, the models were become more complex by integrating a growing number of factors like dilution, sedimentation, adsorption, dispersion, the advection and of the re-aeration of the atmosphere (Fischer et al 1979;Koussis 1983; Koussis et al 1983Koussis et al , 1990McBride and Rutherford 1984). … at the same time one increased, on the one hand, the difficulties of using them in practice (Snowling and Kramer 2001) and on the other hand the error between simulations and the total sensitivity of the model increases and consequently the most complex model is not necessarily the most "useful" (Lindenschmidt 2006 In Algeria, the water resources of surface are very limited and difficult to exploit, this is why any risk of contamination or of pollution deserves to be underscored, forwarded and modeled.…”

Section: Introductionmentioning

confidence: 99%

Study of Self-Purification Capacity in the Semi-Arid Zones: Case of Wadi Cheliff, (Northern Algeria)

Maamar¹,

Djillali²,

Amine³

2014

Curr World Environ

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The aim of this paper was to study and predict the self-purification capacity of wadi Cheliff (in the section Oum Drou -Chlef). This was done primarily by measuring the Dissolved Oxygen (DO) downstream of a pre-selected pollution discharge point on wadi Cheliff and then predicting the same using the modified Streeter-Phelps equations. Twelve sampling stations are chosen, on a section of approximately 8.5 km of the wadi Cheliff (Oum Drou -Chlef), to collect data with knowing the Biochemical Oxygen Demand (BOD), pH, stream velocity, stream depth and distance. Predicted DO deficit trend lines were first fitted by retaining the original re-aeration coefficient component, k 2 , of the modified Streeter-Phelps equation (United States Geological Survey equation) and subsequently by substituting it with our reaeration coefficient model. It was found that the latter displayed better predictive capacity. Results also demonstrated that the self-purification capacity of the river which is already limited by the relatively low DO saturation level is further threatened by the wastes being discharged into it at varying intervals. Some of these wastes are non-biodegradable which slows down the self-purification processes of the wadi. To preserve the underground layers of the area and to ensure a water of good quality for the irrigation, the Wadi Cheliff must be, necessarily, to protect from any pollution.

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Modeling DO Conditions in Streams with Dispersion

Cited by 18 publications

References 4 publications

Reverse flood routing with the inverted Muskingum storage routing scheme

Reverse flood routing with the inverted Muskingum storage routing scheme

Critical appraisal of BOD and DO models applied to a highly polluted river in India

Study of Self-Purification Capacity in the Semi-Arid Zones: Case of Wadi Cheliff, (Northern Algeria)

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