A prototype toolset for the ArcGIS Hydro Data Model

Center for Research in Water Resource

A GIS-Based Water Quality Assessment and Pollution Control Planning Approach for Lake Management (WQAPCP)

ABSTRACT Many lakes are receiving large volumes of contaminants from agricultural discharges, industrial emissions and municipal wastewater, which causes significant surface water pollution. The adverse environmental and health effects of lake contamination are a primary concern in environmental management. Water quality assessment methods and pollution control planning models are useful tools for researchers and decision-makers to protect ecological environments and develop local economies. Also spatial information technologies such as Geographic Information Systems (GIS) make it possible to manage water bodies with more detailed location-based information. The goal of this thesis is to develop a GIS-based water quality assessment and pollution control planning approach for lake management (WQAPCP), which includes the following components: (1) evaluation of water quality based on four index methods with inter-comparisons; (2) pollution control planning for a lake system based on an integration of pollutant distribution simulation and optimization models along with water quality index measures; (3) GIS technology to help implementing water quality assessment and lake contamination control optimization by creating displayed maps of the study results to provide spatial support for decisions. Several water quality evaluation methods are first presented in this thesis within the GIS framework to examine water quality index models, including the US Oregon water quality index (OWQI), the Canadian water quality index (CWQI), the Chinese single-factor water quality index (CNWQI-S) and the Chinese comprehensive water quality index (CNWQI-C) methods. These index methods are applied to assess the water quality of a real case. The assessment results are presented in the form of GIS maps containing the spatial distribution of the water quality levels and their ranking. Through an example of sensitivity analysis and comparison of four sets of water quality assessment results, the parameters with the most significant influence on lake water quality are identified and the most suitable method of water quality evaluation is put forward to support future lake management. Subsequently, this thesis develops a simulation-optimization approach by integrating lake water quality simulation and lake pollution control optimization. A contaminant dispersion simulation is first conducted to provide input for the optimization study. Particularly, a single-objective programming (SOP) model and a multi-objective programming (MOP) model are developed, applied, and compared to support effective lake water contamination control planning under different lake management scenarios. Three periods and a set of significant levels are considered in the real case study to provide a comprehensive dynamic modeling and optimization analysis of lake pollution control through the simulation-optimization approach. Based on the developed optimization method and the case study results, the OWQI and CNWQI-C methods are utilized to help formulating the effective measures for lake water quality management. GIS technology is employed in this study to link the water quality assessment approaches and the lake pollution control optimization. By integrating the relevant data and creating visualized maps of the study results, GIS plays an important role in extending the modeling and assessment results for the lake water quality management with spatial geo-references

Recovery of the Mersey Estuary from Metal Contamination

Merged with duplicate record 10026.1/596 on 27.03.2017 by CS (TIS)The Mersey Estuary has received significant quantities of industrial wastes and sewage over several decades. Although contaminant loads are reducing and the estuary is showing signs of recovery, the sediment reservoir remains a repository of historical contamination and still contains high concentrations of trace metals and organic compounds. A combination of hydrodynamic, sedimentary and geochemical processes are responsible for maintaining trace metal concentrations at present-day levels. The distributions of trace metals in bed sediments reflect changes in granulometry, differences in POC content and the magnitude of past inputs rather than the locations of point sources in the estuary. The association of contaminant metals with SPM varies not only with axial changes in salinity and particle concentration but also in response to the relative magnitudes of freshwater and tidal inflows and cyclic variations in water and particulate chemistry that occur on intratidal, intertidal and seasonal timescales. The most influential of these arise from axial changes in dissolved oxygen and the delivery of organic carbon from both external and internal sources which modify the relative degree of sorptive control exerted by Fe, Mn and organic C at different locations in the estuary and at different times. These factors, combined with the efficient trapping o f sediments and possible salting out of neutral metal-organic complexes, assist in the retention and internal recycling of particles and associated metals between the bed and water column. Geochemical reactivity is suppressed in Mersey SPM and metal decontamination is not predicted to occur through the loss of particulate metals to the surrounding coastal zone. Rather, it is envisaged that sediment resuspension and the desorption of metals into fresh and low salinity waters, supplemented by the release of metals from tidally stirred diagenetically modified sediments, are more likely to be important long term cleansing mechanisms, with the latter occurring particularly during the summer months when bacterial numbers and the degradation of accumulated organic detritus becomes more pronounced. Future declines in metals from bed sediments have been estimated using two methods and two independent data sets. Resulting values are not only metal-dependent but also vary with sediment location. Losses of Cd, Co, Cu, Hg, Ni and Zn are predicted to take up to 40 years, whilst removal of substantially elevated concentrations of Pb in sediments in the upper estuary could span hundreds of years.UK Environment Agency (North West Region

Object-orientation and integration for modelling water resource systems using the ACRU model.

Doctoral Degree. University of KwaZulu-Natal, Pietermaritzburg.Water is a limiting resource in South Africa, with demand in many catchments exceeding supply, necessitating transfers of water between catchments. This situation requires detailed and integrated management of the country’s water resources, considering environmental, social and economic aspects as outlined in the National Water Act (Act 36 of 1998). Integrated water resources management (IWRM) will require better data and information through monitoring and integrated water resources modelling. The ACRU hydrological model is an important repository of South African water research and knowledge. In recent years there have been technological advances in computer programming techniques and model integration. The thesis for this study was that the valuable knowledge already existing in the ACRU model could be leveraged to provide a better hydrological model to support IWRM in South Africa by: (i) restructuring the model using object-oriented design and programming techniques, and (ii) implementing a model interface standard. Object-oriented restructuring of the ACRU model resulted in a more flexible model enabling better representation of complex water resource systems. The restructuring also resulted in a more extensible model to facilitate the inclusion of new modules and improved data handling. A new model input structure was developed using Extensible Markup Language (XML) to complement the object-oriented structure of the ACRU model. It was recognised that different models have different purposes and strengths. The OpenMI 2.0 model interface standard was implemented for ACRU, enabling ntegration with other OpenMI 2.0 compliant specialised models representing different domains to provide a more holistic IWRM view of water resource systems. Model integration using OpenMI was demonstrated by linking ACRU to the eWater Source river network model. A case study in the upper uMngeni Catchment in South Africa demonstrated: (i) the benefits of the object-oriented design of the restructured ACRU model, in the context of using ACRU to create modelled catchment-scale water resource accounts, and (ii) the integration of ACRU with another model using OpenMI. The case study also demonstrated that despite the improvements to the ACRU model, the simulations are only as good as the model input data