John W. Nicklow

State of the Art for Genetic Algorithms and Beyond in Water Resources Planning and Management

During the last two decades, the water resources planning and management profession has seen a dramatic increase in the development and application of various types of evolutionary algorithms (EAs). This observation is especially true for application of genetic algorithms, arguably the most popular of the several types of EAs. Generally speaking, EAs repeatedly prove to be flexible and powerful tools in solving an array of complex water resources problems. This paper provides a comprehensive review of state-of-the-art methods and their applications in the field of water resources planning and management. A primary goal in this ASCE Task Committee effort is to identify in an organized fashion some of the seminal contributions of EAs in the areas of water distribution systems, urban drainage and sewer systems, water supply and wastewater treatment, hydrologic and fluvial modeling, groundwater systems, and parameter identification. The paper also identifies major challenges and opportunities for the future, ...

Optimizing Structural Best Management Practices Using SWAT and Genetic Algorithm to Improve Water Quality Goals

A genetic algorithm (GA), an evolutionary optimization technique, is coupled with a semi-distributed hydrologic model, Soil and Water Assessment Tool (SWAT) to find an optimum combination of structural Best Management Practices (BMPs) that meets the treatment goals at a watershed scale. The structural BMPs considered in the study are detention ponds, parallel terraces, filter strips, grassed waterways, and grade stabilization structures which are all applicable in agricultural watersheds. The decision variables in the optimization model are the type, size, and location of BMPs which minimize the construction cost and simultaneously reduce sediment and nutrients to target levels at the watershed outlet. The model is demonstrated on the Silver Creek, a sub-watershed of the Lower Kaskaskia watershed in Illinois. The model is used to compare three different sediment and nutrient reduction cases (i.e. 20%, 40%, and, 60%) at the watershed outlet.

In Situ Permeable Reactive Barriers for Groundwater Contamination

In situ permeable reactive barriers (PRBs) consist of zones of reactive material, such as granular iron or other typically reduced metal, lime, electron donor-releasing compounds, or electron acceptor-releasing compounds, installed in the path of a plume of contaminated groundwater. As the groundwater flows through this zone, contaminants are degraded to innocuous components through chemical and/or biological reactions, adsorbed, or chemically altered so that they form insoluble precipitates. This article represents a summary review of representative literature on permeable reactive barrier technology. It consists of a description of the technology, a list of treatable contaminants, the processes necessary for its implementation, considerations for conducting performance monitoring, a discussion of the positive and negative attributes and costs of the technology, and lessons learned during recent applications. Where conditions are favorable and time factors are appropriate, this technology appears promising. The main characteristic in its favor is the lack of the need to operate pumps or treatment vessels, thereby saving operation and maintenance costs and allowing the economic value of property to be restored during remediation. Its reliance on natural advec-tive processes to move contaminants through the treatment zone, resulting in long treatment time frames, can be a disadvantage under some circumstances. There are also uncertainties about the long-term effectiveness of the reactive media. Regulators need to continue the trend toward being more receptive of this technology, as well as other innovative technologies, so that it can be improved. This receptiveness will benefit all stakeholders involved.

Watershed Management Technique to Control Sediment Yield in Agriculturally Dominated Areas

Abstract Non-point source pollution is recognized internationally as a critical environmental problem. In Illinois, soil erosion from agricultural lands is the major source of such pollution. The erosion process, which has been accelerated by human activity, tends to reduce crop productivity and leads to subsequent problems from deposition on farmlands and in water bodies. Comprehensive watershed management, however, can be used to protect these natural resources. In this study, a discrete time optimal control methodology and computational model are developed for determining land use and management alternatives that minimize sediment yield from agriculturally-dominated watersheds. The solution methodology is based on an interface between a genetic algorithm and the U.S. Department of Agricultures Soil and Water Assessment Tool. Model analyses are performed on a farm field basis to allow capture of different, local stakeholder perspectives, and crop management alternatives are based on a three-year rotation pattern. The decision support tool is applied to the Big Creek watershed located in the Cache River basin of Southern Illinois. The application demonstrates that the methodology is a valuable tool in advancing comprehensive watershed management. The study represents part of an ongoing research effort to develop an even more comprehensive decision support tool that uses multi-criteria evaluation to address social, economic, and hydrologic issues for integrative watershed management.

Examining the Possibilities: Generating Alternative Watershed-Scale BMP Designs with Evolutionary Algorithms

Recent studies in water resources planning and management show a gradual shift in the state of the art from numerous on-site structural stormwater Best Management Practice (BMP) designs to watershed-scale BMP design approaches that meet both target water quantity (peak flow) and quality (sediment reduction) criteria. Such regionally-strategic approaches are not only cost-effective but emphasize comprehensive, holistic watershed-scale management, an idea strongly promoted by the U.S. Environmental Protection Agency (US EPA) since the early 1990s. Implementing a watershed-scale design can prove difficult when decision-makers have differing and sometimes conflicting objectives. We present a methodology that integrates the semi-distributed watershed model Soil and Water Assessment Tool (SWAT) with an evolutionary algorithm, Species Conserving Genetic Algorithm (SCGA). In addition to identifying an optimal watershed-scale BMP design (e.g., type, size, location), SCGA simultaneously produces several near-optimal design alternatives using a user-specified distance metric. We demonstrate this decision-oriented framework on a watershed in southern Illinois. Results of this application yield several high-quality alternative designs appropriate for solving integrated watershed management problems.

Control of Channel Bed Morphology in Large-Scale River Networks using a Genetic Algorithm

Alluvial channels undergo continuous morphological changes caused by relationships between entrained sediment, variable flows and movable boundaries. Excess changes that occur through sediment degradation and deposition, however, tend to threaten the stability of bridges, hydraulic control structures and underground utilities. These changes also reduce conveyance capacity of a channel and diminish reservoir benefits associated with hydropower generation, flood control, and water supply. This article outlines the development of an optimal control methodology for minimizing sediment aggradation and degradation, thus controlling channel bed morphology, in large-scale multi-reservoir river systems. The sedimentation control problem is solved by coupling the U.S. Army Corps of Engineers HEC-6 sediment transport simulation model with an immune genetic algorithm. The simulation model is used to implicitly solve governing hydraulic and sediment constraints, while the genetic algorithm is used to solve the overall control problem. The method is demonstrated first through application to a hypothetical river network from the literature, for which a comparison between the genetic algorithm and alternative optimization technique is made. A second application to an existing hydraulic network illustrates the practical utility of the methodology as a decision-making tool for sedimentation control.

Generating alternative watershed-scale BMP designs with evolutionary algorithms

The first part of a two-step decision-making framework for watershed-scale stormwater runoff control (Kaini et al., 2008, this meeting) involves identification of the most cost-effective combination of structural BMPs that meet target peak flow and sediment reduction criteria. This paper presents the second half of that framework: simultaneous generation of near-optimal alternative design strategies using a Euclidean distance metric. Structural BMPs included in this model include detention ponds, infiltration ponds, field borders, grade stabilization structures, and grassed waterways. Alternative designs are identified by coupling Soil and Water Assessment Tool (SWAT) and a Species Conserving Genetic Algorithm (SCGA). In addition, we demonstrate SCGA’s flexibility and efficiency at generating alternative designs as well as varying numbers of alternatives. The model is demonstrated on Silver Creek watershed, a sub-watershed of the larger Lower Kaskaskia watershed in southern Illinois.

Evaluation of Ground Water Denitrification at a Biosolids Disposal Site

A study was conducted at a sanitary sewage sludge(biosolids) disposal site in Springfield, Illinois, U.S.A. todetermine if biological denitrification played a significantfactor in attenuation of ground water nitrate values. The siteselected for this study is a 23 ha (57 acre) dedicatedbiosolids disposal facility located adjacent to a 75.7 millionliter per day (20 million gallons per day) municipal treatmentplant that uses anaerobic solids stabilization for treatment ofgenerated biosolids material. Biosolids have been disposed of byfixed-point spray applicators at the site since 1976, which hascaused ground water nitrate levels to increase significantlyabove background levels. A method was developed using aconservative chemical tracer to simulate the biosolidsapplication process and monitor the ground water directly beneaththe simulated disposal site. Results demonstrated a net declineof nitrates that could not be attributed to dilution alone.While the monitoring methodology developed for this study didnot directly estimate the denitrification rate, a rate foroverall nitrate reduction was calculated that could be consideredto take into account all transport and reduction mechanisms suchas denitrification, advection, dispersion and dilution.

A short-term assessment of a multi-faceted engineering retention program

A set of formative tools have been designed to assess the short-term progress of a multi-faceted program aimed at improving the overall graduation rate from 37 to 67 percent over a five-year period at a College of Engineering. The holistic program consists of a set of academic and non-academic components designed to improve first- and second-year retention rates to 80 and 90 percent, respectively. Using selective performance indicators, each program component is assessed to determine its impact on the programs short-term progress. The assessment shows that the student support offered by the program components has a positive impact on the number of enrolled engineering majors. Following one year of implementation, the program is approximately half way towards reaching its target retention rates. The program has also unexpectedly and positively impacted student recruitment and campus-wide retention efforts. A key lesson learned through project implementation is that strategic assessment of activities is crucial not only to determine the extent to which the desired objectives have been met but to also refine the program components to achieve the desired retention goals. Furthermore, the efforts which focus on first-year students should not overlook the fact that parental/guardian consent may be required as part of assessment activities.

Artificial Life Algorithm for Management of Multi-reservoir River Systems

The design and operation of civil engineering systems, particularly water resources systems, has been pursued from the perspective of minimizing costs and related negative impacts, maximizing benefits, or a combination thereof. Due to the complex, nonlinear nature of the majority of systems, together with an increase in digital computing capabilities, global search algorithms are becoming a common means of meeting these objectives. This paper employs an artificial life algorithm, derived from the artificial life paradigm. The algorithm is evaluated using standard optimization test functions and is subsequently applied to determine optimal dam operations in multi-reservoir river systems. The optimal dam operation scheme is that which indirectly minimizes environmental impacts caused by short-term water level fluctuations. Optimal releases are sought by coupling an artificial life algorithm with FLDWAV, a one-dimensional, steady flow simulation model. The resulting multi-reservoir management model is successfully applied to a portion of the Illinois River Waterway.