Advances in the field of geospatial technologies have resulted in the growth in the application of such methods and techniques to a wider range of challenges and issues associated with urban water resources. The use of remote sensing, geographic information science (GIS), spatial analysis, global positioning systems (GPS),
digital mapping, online electronic data resources, and processing techniques are now common tools in addressing urban water quality, storm water, flooding, water supply issues, and overall management of water resources and watersheds in urban communities and urbanizing landscapes. In this volume, the authors address many of the complex concerns and impacts associated with human and natural changes
facing urban water resources through their use of a variety of geospatial techniques and tools. The aim of the volume is to present the reader a mix of examples of the evolving use of geospatial methods and applications now utilized in many urban areas to assist decision-makers, planners, and communities in making sound judgments as to how best manage their water resources for both human use and to minimize impacts to the natural environment.
It is our hope that through presenting these examples and case studies that readers will gain a broader understanding of the emerging field of the use of geospatial technologies to address urban water issues at a time during which these resources are under great threat from natural and human stresses, such as climate change, declining freshwater supplies, drought, excessive water demand and use, cost pressures associated with urban water infrastructure, natural and technological hazards, growing urban populations, and competing water uses.
The chapters are intended to provide a range of insights into the development of the geospatial tools and technologies and their applications to a variety of issues and localities. With these presentations the reader is intended to gain a better appreciation for the range of methods now available to address many urban water challenges and consider how geospatial technologies are advancing our understanding and efforts to address the many complex urban water issues now facing our society.
In his introductory chapter to this volume, Seth provides a comprehensive overview of the types of geospatial technologies and tools available to address urban water issues, including GIS, digital data sets, and spatial analysis techniques.
The author outlines the typical types of spatial data often utilized with GIS platforms with specific discussion on those most applicable to urban water issues. Seth also identifies the key data sets necessary to integrate into water resource projects such as land use, digital elevation model (DEM) outputs, hydrological conditions, soil information, and landscape characteristics. The author focuses on the importance of data acquisition and the preparation of metadata in order best organize and present such spatial data.
Seth discusses the standard GIS operational frameworks essential for such work including data overlay and manipulation, geocoding and georeferencing, and the preparation of map coordinate system. This chapter also presents several examples of how GIS can be used to assist in resolving urban water management by community planners and others by the preparation of storm water runoff models, simulations of sewer systems to address wastewater collection and treatment infrastructure operations and needs, and linking GIS to urban water resource management models to facilitate community decision-making. Seth provides an excellent summary and assessment of the opportunities and challenges in the use of geospatial techniques to address a wide range of urban water resource issues and as such has provided a welcome and important start to this volume.
With water conservation such a critical issue in many urban areas located in more arid climates, Larson and colleagues consider the use of a spatial approach to addressing water conservation at the neighborhood scale in Phoenix, Arizona. The chapter outlines an innovative method to integrate individual household metered water use with social survey data by use of GIS techniques. The aim is to be able to understand how various socio-spatial relationships are linked to water use, perceptions of water availability and demand, and relationships to water demand within neighborhoods.
The results highlight issues of the lack of understanding and poor perception of the value of water conservation efforts and the misunderstandings residents have regarding their own high water consumption. The study points to several critical challenges with urban water conservation efforts and the use of GIS to better understand the complex social dynamics associated with individual and neighborhood water use and conservation efforts – important lessons that can be better understood through geospatial techniques.
This chapter highlights the important utility of using such methods to better understand the potential for various water conservation efforts needed to address the important issue of water use and supply in major urban areas where water availability is a concern.
How can one utilize the understanding and roles of community members to better understand and address water uses is a question raised in the chapter by Cutts. The chapter outlines a participatory mapping approach intended to examine cumulative actions of water information providers across metropolitan Phoenix, Arizona.
The transfer of basic information from local water municipal providers to water users is a critical aspect for better water use management, especially in regards to supply, demand, cost, and conservation issues. Such information can help individual water uses, in this case homeowners, with the necessary tools to make sound decisions regarding their water use and potential for conservation efforts. Participatory GIS is used to assess the roles of various local water providers to map the cumulative water information landscape – how information on water usage and conservation was being provided to water users. The local water providers were then interviewed to validate the information gathered and to assist in the identification of issues with data collection and management.
The results of the survey were examined in order to identify the range of types of information provided on various water conservation methods and the provision and communication of such information to water users. Such research is of fundamental importance in addressing municipal scale efforts to inform and encourage the utilization of a range of water conservation efforts by users so as to address the often inequity between water supply and demand, all too common in major urban areas, especially those located in arid climates.
Goetz and Fiske examine the important connections between changes to urbanization within a region and its impacts to the ecosystem health of a stream as measured by the biotic diversity of species. The chapter presents an overview of research conducted for numerous small streams located in the southern New England region of the eastern United States to examine how land use changes are altering overall ecological aquatic health of these ecosystems. General additive models (GAM) and step-wise multiple linear regression (MLR) are used to assess relationships between land cover types and a series of stream biological indicators.
The 2001 National Land Cover Database, developed from the classification of 30 m Landsat Thematic Mapper satellite imagery, was used to create a uniform land cover mapping for each watershed unit within the study area. The major land cover types of impervious surfaces, grass, crops, and forest were analyzed for proximity to streams within individual watersheds. The statistical analysis using the GAM and MLR models was applied to examine three biotic indices and a comparison of differing scales of impacts from various upstream scaled areas.
The results indicate that watershed size was not often a significant predictor of biotic conditions, but that the variations in land cover can be important in assessing overall aquatic ecosystem health in the streams. The results of such research can provide important information to assist with more closer examination of land cover changes in watersheds (such as reducing impervious cover) to reduce impacts to stream water quality and overall ecosystem biotic health of these systems.
In urban areas the variety of land uses within urban centers present significant storm water concerns with the resulting runoff from surfaces creating issues of water quality and flooding, issues that Goldshleger and colleagues seek to address.
The chapter examines the concerns of changing land uses along the coastal region of Israel where the rapid conversion of open areas and agricultural lands has resulted in major urban development in the forms of residential neighborhoods, commerce, and industry. Techniques from remote sensing and GIS are applied to study land cover/land use changes and their impacts on overall water quality and water quantity. Data collected and analyzed include rain measurements, runoff, and various water quality parameters. During the study period 2007–2009, increases in the urban runoff coefficient were noted along with various impacts of water quality showing higher concentrations of microbes, fecal E. coli and coliforms from all land uses.
Concerns with water quality were higher associated with industrial areas when compared to residential areas, especially in regards to organic and fuel related compounds. The results also indicated that few water concerns were found with residential runoff, thus suggesting the possibility for storm water capture from these areas and potential reuses. As our landscape becomes more urbanized the study of the associated land cover/land use changes and their impacts on water supply and water quality will become increasingly relevant leading to a key role for the use of geospatial data sets and tools to improve our understand and ability to respond to these challenges.
In their chapter, He and colleagues studied the application of GIS based models to improve understanding of the location and impacts of pollution loadings from municipal combined sewer outfalls and other nonpoint sources in the Saginaw Bay watersheds of Michigan, USA. A spatially distributed water quality model was developed in order to simulate the spatial and temporal distributions of point and non-point sources. The watershed was divided into 1 km2 cells which are arranged as a serial and parallel cascade of water from cells to simulate the basin storage structure. The model addresses moisture inputs and outputs from the system including potential evapotranspiration and the interactions of surface and subsurface flows. The hydrological model is interfaced into a GIS platform by use of ArcView to process the related runoff parameters of meteorological data, soils, topography, land cover/land use, and hydrography. Results indicated that point sources from municipalities, industries, and commercial locations contribute significant amounts of the total phosphorous into Saginaw Bay, Lake Michigan.
Fertilizer applications from non-farmland activities were also an important contributor. Such models of watershed systems are increasingly valuable for basin planning and management efforts in order to better understand and address the complex issues associated with land cover/land use changes occurring so rapidly in many regions and resulting in often complex, interrelated, and serious environment impacts to regional and local water resources.
Eiseman and colleagues present the creation of a GIS based model employed within two urbanizing watersheds in the Toledo metropolitan area in northern Ohio in order to assist a local community effort to identify the highest priority areas for river and wetland habitat restoration. Numerous geographic data sources were collected and compiled, including land cover/land use, surface water networks, forest and vegetation types, topography, soils, and land ownership.
The aim was to assess the potential for restoration within the watershed based on physical conditions and the current land management and conservation arrangements already in place at or in proximity to properties. A predictive model was developed that weighted the most important factors to be considered in determining the viability of restoration for streams, wetlands, and streams with adjacent wetlands.
The assessment and identification of potential restoration sites was also divided into three main regions within the watersheds to cover forested, urban, and agricultural areas. The initial analysis revealed a large number of sites of which the top 30 % were selected within each region for more detailed assessment and mapping.Upon field verification and clustering of high value sites, the model resulted in the selection of 33 final restoration sites for which concept plans were developed.
The use of geospatial data sets, integrated into a GIS format, and subject to selection criteria, provided for a detailed and validated method for identifying priority stream and wetlands restoration sites.
The challenges of addressing land use changes at the watershed scale are discussed by Czajkowski and Lawrence in their chapter that highlights the creation of remote sensing and GIS based products to assist management within the Maumee basin in northwest Ohio. Landsat satellite imagery, along with field data, was used to determine the predominate land cover/land use types with the watershed on an annual basis for a 5-year study period.
In addition, agricultural crop types were identified in order to assess the amount and variation in planting cycles within the watershed as crops have different impacts on the processes of soil erosion and the presence of crop amendments in local streams and creeks, including sediment and nutrients from non-point rural runoff process. The land cover/land use and crop type data was built into a comprehensive online GIS data base prepared for the entire watershed area with the intent to create one source for the essential spatial data sets needed to assist federal, state, and local agencies and decision-makers in addressing the many water resource issues facing the Maumee watershed.
Additional work included efforts to document and classify the use of conservation tillage techniques used by farmers throughout the watershed to reduce soil erosion. The development of the various geospatial products provided for an important data set and basis for additional studies and management approaches such as modeling of soil erosion, addressing flooding concerns, examining impact of land cover/land use changes on water quality, and the coordination of regional efforts for watershed planning. This work highlights the important role that geospatial technologies can play in assisting with the many efforts by a diverse number of agencies and organizations to deal with complex water resource issues and the need for centralized and organized data sets and associated spatial product to support such efforts.
The development of so many GIS based data and information sources raises questions as to the utility and use of these digital and often online resources by local and regional planners having to address watershed management concerns within their jurisdictions, which is the focus of the chapter presented by Rousseau and Lawrence. As part of the Maumee Watershed GIS Project (highlighted in Chap. 8 of
this volume), a study was undertaken to survey the use of GIS among regional land managers and planners to determine their level of expertise and interest in using GIS to address water resource issues and determine whether the geospatial products prepared by the Maumee Watershed GIS Project were of use and sufficient for their needs. An online survey was conducted by a selected sample of individuals and agencies involved in some capacity with regional planning and water management within the watershed. Results indicated that although there was a great interest in GIS and other spatial data sets, the understanding and application of these to assist with watershed issues was not always clear or extensive.
Potential users of the data sets valued the ability to be able to access key information at one online site and also the ability to view and create a variety of many products. Surprisingly over40 % of the respondents indicated that they did not foresee using the online data site for watershed planning efforts, results that suggest further work is needed to better bridge the gap between the development of geospatial products intended for watershed planning and the users of such data. The study reveals both the opportunities and challenges for connecting those working in the fields of water resource management and watershed planning to the potential important and useful geospatial products available or that could be produced and consider carefully how such data and information could be most useful to assist with decision-making for addressing urban water issues.
Gerwin and Lawrence discuss how GIS driven databases on water quality and ecosystem health indicators for urban streams can be compared to changing land uses in areas of increasing residential and industrial land uses in order to determine the significance of impacts from these changes on stream conditions. During a study of several small streams that drain into Lake Erie, research was conducted to
determine whether the trend of urbanization in these watersheds was resulting in declining aquatic ecosystem health. Landsat imagery was used to classify the major land cover/land use types with specific interest in the growth of the urban class. Spatial analysis was then completed within ArcGIS to classify the predominate land cover/land use adjacent to the stream channels, which were linked to the locations where stream sampling had been conducted to assess the condition of the stream ecosystem by use of standard quantitative measures developed by management agencies. Multiple regression analysis was completed to determine whether there was any significant relationship between land cover/land uses adjacent to the streams and their environmental conditions. Although the results of that analysis
were inconclusive, a number of other factors related to stream conditions were also examined that indicated key issues in management that are of concern in regards the aquatic ecosystem health of the streams, including excessive channelization, up-stream sources of bacteria, sediment and nutrients, and overall lack of aquatic vegetation in the streams. Such studies of the impacts of land cover/land use changes in historically rural landscapes will be increasingly important in many regions of the world where such current and future changes potentially place large numbers of streams, important for drinking water and habitat for natural species, at greater risk.
A growing concern in many water bodies is the potential for the harmful impacts that would result from the contamination of water resources following an oil spill disaster. Dean and Lawrence illustrate the preparation of an emergency response plan for just such an event in the Western Basin of Lake Erie, part of the Great Lakes Basin in the United States and Canada. This chapter outlines the steps necessary to build an online interactive and digital plan for the use during an oil spill emergency where information on infrastructure, equipment, access, site conditions, and environmental factors would be critical to a timely and successful response.
In working with the key federal, state, regional, and local agencies and organizations charged with the preparation and – if needed – implementation of oil spill responses in the Western Basin of Lake Erie, the study utilizes the organization of existing geospatial data sets including transportation networks, lake andshoreline physical characteristics, weather and climate, navigation data, along with aerial and satellite imagery in proposing for an integrated online GIS based model for emergency responses. Numerous data layers are identified and compiled as the basis for such a plan which would include information and data on the shoreline environmental sensitivity, land management arrangements, key infrastructure such as marinas, water intakes, pipelines, shipping facilities, and boat launches.
The data are organized into a series of digital files that represent the key components of a protection strategy for the western basin of Lake Erie in the contingency of an oil spill event. The chapter also provides examples of a protection and response strategy for a selected site within the basin by illustrating steps that would need to be taken to protect a critical habitat area and demonstrates the utility of a geospatial tool for oil spill response planning through providing an example of its use during a simulated oil spill scenario event. The work highlights the important role that GIS and spatial data can play in addressing appropriate and responsive actions necessary following major environmental disasters and how such technologies are increasingly becoming important and applicable to these events.
As a collection, the chapters in the volume provide an assemblage of ideas, concepts, methods, and results that illustrate how various geospatial technologies can be applied to many typical water challenges in urban and urbanizing areas.
As these advances in techniques continue, their application can be considered in examining and better understanding practical and helpful solutions to the management and planning for the valuable water resources in our cities, towns, municipalities, and communities during a period of time in which human populations are rapidly expanding in urban areas worldwide, presenting a myriad of concerns and challenges we as a society so importantly need to address.
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