MIKE 11. Reservoir. The Modelling Tool for Optimisation of Reservoir Management, Water Quality Simulation and Impact Assessment WATER & ENVIRONMENT

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1 MIKE 11 Reservoir The Modelling Tool for Optimisation of Reservoir Management, Water Quality Simulation and Impact Assessment WATER & ENVIRONMENT

2 Simulated annual variation in temperature and dissolved oxygen and typical concentration distribution of ammonium, chlorophyll and inorganic phosphorus during spring. MIKE 11 - Reservoir Modelling MIKE 11 Reservoir is designed to describe the hydrodynamic, transport and water quality conditions of reservoirs using a multilayered approach. This makes MIKE 11 Reservoir an ideal tool and an important element in testing and optimising interventions and management solutions to alleviate existing problems in reservoirs, and also in the design and Environmental Impact Assessment of planned reservoirs. Until now, the modelling of reservoirs and the associated catchments has required elaborate and expensive one-off specialist studies. MIKE 11 Reservoir now provides practitioners with the opportunity to undertake comprehensive modelling studies within the MIKE 11 system. MIKE 11 is a professional engineering software package for the simulation of flows, water quality and sediment transport in river and channel networks, in estuaries and other water bodies experiencing unidirectional flow. The MIKE 11 Reservoir model includes full vertical resolution and addresses the need to describe the hydrodynamic, transport and water quality processes in the reservoirs themselves, and also the impact both upstream and downstream. This is possible because the Reservoir Module is developed entirely within the general software frame of MIKE 11. The Reservoir model shares the power of the integrated approach of the MIKE 11 system. With a wide range of facilities available as modules, the modeller can analyse, design, plan, forecast and present information on all aspects of river environments. Welbedacht dam, South Africa, during sediment flushing. Users of the MIKE 11 modelling software will immediately recognise the model and its facilities from river modelling. The Reservoir Module is structured to be directly inserted in existing river networks where needed and the communication with the river model is an integrated facility. Photos: Frontpage: Tasmania, Biofoto.

3 Simulated annual variation in temperature and dissolved oxygen and typical concentration distribution of ammonium, chlorophyll and inorganic phosphorus during spring. The Reservoir Model Features heating/cooling and evaporation processes selective withdrawal (outflows) and inflows siltation reservoir flushing eutrophication vertical oxygen profiles, ie oxygen conditions, in the bottom waters ammonia concentrations The core of the MIKE 11 Reservoir model is a 2-dimensional vertical hydrodynamic flow model, solved in a computational grid adapting to the water surface variation. The model solves the laterally integrated Navier Stokes equation assuming hydrostatic pressure distribution combined with the equation for conservation of mass, salinity and temperature. The model is equipped with advanced turbulence models (eg the two parameter k-ε model). A comprehensive description of surface energy transfer is implemented (radiation, evaporation and convective heat transfer), including a feedback loop from the water quality module providing the light extinction in the water from organic matter (plankton and detritus). Transport and sedimentation of fine particles (wash load) is described via the mass transport equation. The water quality model of MIKE 11 Reservoir includes eutrophication describing plankton, nutrient and oxygen dynamics. The vertical resolution enables simulation of development and degradation of vertical profiles of phyto plankton, nutrient and dissolved oxygen depending on light conditions, water temperature, vertical mixing and external and internal nutrient loads. The organic material produced in the surface water settles and the degradation below the thermocline can create anoxic conditions in the bottom waters. The associated mineralisation of the organic nutrients is responsible for the internal load of nutrients, which can become available for the primary production by vertical mixing. At the same time the chemical properties (redox potential and ph) of the bottom water changes causing a higher solubility of metals like manganese and iron and some heavy metals. The water quality model includes 12 state variables: phytoplankton (C, N, P, chlorophyll-a), zooplankton, detritus (C, N, P), inorganic nutrients (ammonia, nitrate and phosphate) and dissolved oxygen. Model boundary conditions are provided automatically via MIKE 11 and/or as selected water withdrawal at different depths. Integrated reservoir management using MIKE software Reservoirs can have significant environmental impacts within the catchment. Some impacts relate to the reservoir design and operation others to the environmental management of the catchment. MIKE 11 Reservoir is specifically designed to study impacts of catchment inflow and operational strategies on the physical and biological processes within the reservoir. To simulate the complex interaction of the reservoir with its environment requires an integrated approach. Combining MIKE 11 Reservoir with other products from the MIKE software family provides an ideal platform for a complete integrated environmental assessment.

4 is the brand name for quality computational models and hydro informatics systems applicable to the illustration and solution of flow phenomena and flow-related problems in hydraulic and water resources engineering. Today, DHI offers the following generalised modelling packages and software tools: Integrated environmental software tools for reservoir design, operation and management. MIKE 11 - a system for the 1D modelling of rivers, channels and irrigation systems, including rainfall runoff, advectiondispersion, morphology, water quality and two-layer flow modules Documentation Reference manuals are provided for all features in MIKE 11 Reservoir. A User guide is provided via online help which explains how to operate a specific dialog and provides guidance to specific input parameters. Hardware Requirements MIKE 11 Reservoir runs under MIKE 11 utilising a fully Windows integrated Graphic User Interface under Windows 95 or Windows NT. The hardware requirements are: processor: Pentium, 90 MHz or more memory (RAM): 32 MB monitor: SVGA hard disk: 1GB memory on graphic card: 1MB Ram CD-Rom drive: 10 x speed MIKE 21 - a modelling system for 2D free surface flows, including advectiondispersion, water quality, heavy metals, eutrophication and sediment transport and spills of oil and other chemicals in estuaries, coastal waters and seas, as well as extensive short-period wave modelling facilities MIKE 3 - a 3D modelling system for free surface flows, including advectiondispersion, water quality, heavy metals, eutrophication and sediment processes MIKE BASIN - a GIS based modelling tool for integrated water resources planning and representation of water availability, sectorial water demands, multipurpose reservoir operation, transfer/division schemes and environmental constraints MIKE SHE - a distributed, physically based hydrological modelling system applicable to a wide range of water resources problems related to surface and ground water management, contamination and soil erosion MOUSE - a modelling system for pipe networks, such as urban storm drainage and sewer systems. It includes rainfall runoff, hydrodynamic, water quality, sediment and real-time operation modules WATER & ENVIRONMENT Agern Allé 5, DK-2970 Hørsholm, Denmark Tel: Fax: dhi@dhi.dk or mike11@dhi.dk MIKE SWMM - an integrated modelling package for wastewater and stormwater management. MIKE SWMM is built around the U.S. Environmental Protection Agency s (EPA) Storm Water Management Model (SWMM) suite LITPACK - an integrated modelling system for littoral processes and coastline kinetics MIKE INFO - a GIS based series of information management systems for coastal and aquatic systems, including data processing facilities for field measurements MIKE Zero - is the software platform for the new generation of DHI Software products. In addition to generic data editors and a common look-and-feel, the concept also entails an essential backbone of data and parameter file formats and the associated I/O routines, communication protocols, etc Design: Ole Søndergaard. Reprinted by Nofo print, October 2000

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