Particle Swarm Optimization for Automatic Calibration of Large Scale Water Quality Model (CE-QUAL-W2): Application to Karkheh Reservoir, Iran

Abstract

An automatic calibration of water quality model is developed in this research. Automatic calibration as the process to determine the parameters appearing in the equations of a 2-dimensional, hydrodynamic, and water quality models (CE-QUAL-W2) is carried out with Particle Swarm technique as an optimization tool. In the calibration of the CE-QUAl-W2 model, evaporation as a significant parameter influences the thermal profile and water surface elevation in reservoir, simultaneously. Therefore to consider the simultaneous effects of the water temperature variations on water surface elevation in the reservoir, a multi objective technique is used to minimize the weighted sum of total deviations of temperature from field data at check points on monitoring days and those of water surface elevation on daily monitoring period. The proposed approach overcomes the high computational efforts required if a conventional calibration search technique was used, while retaining the quality of the final calibration results. The automatic calibration approach is applied in temperature and water budget calibration of Karkheh reservoir in Iran. Applying the proposed automatic calibration approach, shows the produced results by the CE-QUAL-W2 model with the calibrated coefficients agree closely with a set of field data.

Assessment of the Impacts of Climate Change on the Water Quality of a Small Deep Reservoir in a Humid-Subtropical Climatic Region

“…The model has the capabilities of simulating free surface elevation, pressure, density, vertical and horizontal velocities, and constituent concentration and transport [34]. W2 has been under continuous development since 1975 [33], and was particularly popular in simulating basic eutrophication processes in stratified water systems [25,26,33,35,36], such as the relationships between temperature, dissolved oxygen and algae in a natural lake [26]; and the association between organic matter and sediment in a man-made reservoir [35]. In recent years, this model has been used to evaluate the impacts of climate change on reservoir water quality to make adaptation and planning decisions for optimized water treatment plant operations [14,24].…”

“…Several simulation models have been widely used to study freshwater ecosystems [16,17,[25][26][27], such as the integration of one-dimensional Dynamic Reservoir Simulation Model and Computational Aquatic Ecosystem Dynamics Model (DYRESM-CAEDYM), the applications of two-dimensional water quality and hydrodynamic model supported by the U.S. Army Corps of Engineers (CE-QUAL-W2), and the three-dimensional Hydrodynamic Model Water Modeling System (MOHID) developed by Technical University of Lisbon, Portugal. The projected changes in future climate, especially those on a regional scale, are the most important information that is needed to predict the effects of climate change on reservoir water quality.…”

Reservoir Operation Rules for Controlling Algal Blooms in a Tributary to the Impoundment of Three Gorges Dam

“…In Section 2, the study area is introduced in detail. From consideration of remarkable vertical flow structure of TGR as a river-type reservoir, a hydrodynamic and water quality model for the mainstream of TGR and tributary XXR (TGR-XXR model) is developed and calibrated based on the CE-QUAL-W2 model that has been applied successfully to many lakes, estuaries and reservoirs [29][30][31][32][33][34]. In Section 3, water movement and algal bloom process in XXR are simulated and analyzed under 11 different scenarios of short-term daily water discharge fluctuations or medium-term water level variations using chlorophyll a as the indicator for algal blooms.…”

Enhanced Two Dimensional Hydrodynamic and Water Quality Model (CE-QUAL-W2) for Simulating Mercury Transport and Cycling in Water Bodies

“…Allison and Allison [41] provided a range of 10 2 -10 6 L·kg −1 . From a study of several Wisconsin lakes conducted by Rice et al [50], the partitioning coefficient of Hg ranged from 8 × 10 4 to 3.4 × 10 5 . Suggested values for both methylation and demethylation rates are 10 −5 -10 −2 d −1 [41].…”

“…This model has been continuously developed and maintained by the U.S. Army Corps of Engineers (USACE) and Portland State University since late 80s [1,2]. Since its first release in 1986, the W2 model has been successfully applied to hundreds of rivers, lakes, reservoirs and estuaries throughout the world for thermal and water quality investigations [3][4][5][6][7][8]. U.S. governmental agencies including USACE, U.S. Bureau of Reclamation (USBR), U.S. Geological Survey (USGS), U.S. Environmental Protection Agency (USEPA), and Tennessee Valley Authority (TVA) as well as numerous states, county, and local agencies have used this model as a management tool to evaluate the impacts of point and nonpoint pollution sources including organic wastes, nutrients, and temperature in water bodies.…”