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Development of a web-based spatial decision support system (WSDSS) for river restoration

A framework contributing to the implementation of the EU Water framework Directive (WFD) in Austria

Masterarbeit 2008 66 Seiten

Geowissenschaften / Geographie - Geologie, Mineralogie, Bodenkunde

Leseprobe

Content

Preface and acknowledgements

Statement of originality

Abstract

List of figures

List of tables

Glossary & Abbreviations

1 Introduction
1.1 Goal and background of - and need for - this thesis
1.2 The EU Water Framework Directive
1.3 The implementation of the EU-WFD in Austria

2 Development of a strategy for river restoration in Austria – the MIRR project
2.1 Data research and analysis
2.1.1 Relevant datasets
2.1.2 GIS analyses
2.1.3 Relevant spatial (pressure) criteria and their quantitative relationship to fish

3 Background information on decision making, web based spatial decision support and open source/free GIS products
3.1 Decisions and decision making
3.2 Decision support systems
3.2.1 Spatial decision support systems
3.2.2 Web based spatial decision support
3.3 Open Source and free Web-GIS Software

4 Conceptual development of the WSDSS
4.1 Translating the MIRR project into a DSS framework
4.2 Pre-processing of existing datasets
4.3 Important components of the WSDSS architecture
4.3.1 Entity relationship model (ERM) of the WSDSS database
4.3.2 General description of the data processing within the WSDSS
4.3.3 Detailed description of the data processing within the WSDSS

5 Conclusions

6 Literature

Preface and acknowledgements

For me as a landscape ecologist and scientist strongly related to river systems and fish in the last years Geographical Information Science & Systems have increasingly become a part of my everyday work within the last years. Retrospectively therefore it was a crucial step for me to start the UNIGIS MSc studies at the Paris-Lodron University in Salzburg, especially to be up to date with recent developments of spatial management related to environmental issues at both, a global and European scale. Therefore I want to thank the whole UNIGIS team for the good and co-operative support throughout the whole time of my studies, and the high quality of information that was offered to us. Especially I want to thank Cornelius Roth, Michael Fally and Erika Blaschke for their very friendly and obliging efforts to guide me to the end of my studies. Special thanks also go to Josef Strobl, the “heart” of the UNIGIS-movement, assessor of this thesis. I also want to thank Stefan Schmutz, the project leader of the MIRR project (“Model based Instrument for River Restoration”) forming an important basis for the work presented here, for co-supervising this thesis. Mainly the challenging spatial analyses of different available datasets on multiple ecologically relevant scales that had to be resolved within the MIRR project were the reason for beginning my UNIGIS studies at Salzburg. Furthermore I want to acknowledge Arnulf Christl, member of the Where Group, for supporting the development of the framework for the Decision Support System based on open source tools. Special thanks go also to my partner Bettina and my son Alwin, who had to spend many weekends without my active presence within the last two and a half years due to my studies, especially for their support and motivation. I also want to thank my mother Ulrike Kurahs who laid the foundation for my ability to consequently conduct and manage self directed learning efforts. Special thanks also go to my father Dietmar Zitek for all the hours that he spent with me and brother in nature, which formed the basis for my unremitting interest in keeping and restoring good relationships between humans and their surrounding natural, cultural and social landscapes. I strongly believe that only a holistic understanding of our existence in time and space allows us to develop a deeper and respectful contact to everything that exists. Geographical Information Science & Systems, when creatively used, due to their ability to structure, present and communicate all types of information related to a spatial object might be able to significantly contribute to connecting people with people and people with their physical and biological environment, an indispensible basis for a real sustainable development and liveable future.

Statement of originality

Hereby I state, that this thesis is the product of my own work, and that any ideas or work of other people are fully referenced in accordance with standard reference practices. The work has not been submitted previously for any other degree, nor is it presently under consideration by any other degree awarding body.

Vienna 30. December 2008 Abbildung in dieser Leseprobe nicht enthalten

Location Date Signature

Abstract

The EU Water Framework Directive (EU-WFD) currently represents the main driving force of river restoration across Europe. The focus of the WFD is on whole river catchments, the natural hydrologic unit of rivers, a scale that has never been tackled during past river restoration efforts in Austria. The central target is the restoration of the ecological status of rivers measured by four organism groups (algae, fish, macrozoobenthos and macrophytes) till 2015, latest till 2027 under certain circumstances. Besides ensuring the ecological efficiency of restoration measures, the WFD requires the integration of the public and an economically commensurable restoration. Sound ecological knowledge and strategic instruments and decision support for a timely, ecologically successful and economically optimized implementation of the WFD are therefore strongly needed to support politicians, decision makers and planners within the complex process of river restoration at catchment scales. Up to now existing tools that could be accessed via the web by the public (Water Information System Austria – WISA or Water Information System Europe – WISE) only allow to select and view data, but do not allow any further interaction with the existing GIS data. Within this thesis therefore a framework for a Web based Spatial Decision Support System (WSDSS) allowing to model and share the results of different river restoration strategies to enhance the ecological status of rivers for fish created by multiple users is being developed. The proposed WSDSS allows for removing single and multiple pressures from 500 m river segments and the calculation and aggregation of the ecological effects and costs on different spatial scales relevant for the EU-WFD (water bodies, catchments, national planning areas). Different scenarios can be created by multiple users via the WWW using an HTML interface, and the results are stored within a server-side database and can be shared with other users. Due to their free availability, the presented WSDSS framework is based on available open source technology under free license. The integration of latest multi-scale river ecological knowledge is assured by the strong relatedness of this thesis to the MIRR project (“Model based Instrument for River Restoration), a project that has been run at the University of Natural Resources and Applied Life Sciences (BOKU) in Vienna between 2005 and 2008 aiming at the development of a strategic instrument to identify hydro-morphological restoration measures for rivers based on comprehensive multivariate analyses of fish/pressure relationships. Finally future steps needed to implement such a system based on the results of the MIRR project for the whole Austrian river network are described, and the advantages and limitations of the presented approach are discussed.

List of figures

Figure 1: General structure of the development of a Management Support System in relation to this thesis, redrawn from TURBAN et al. (2004).

Figure 2: Principle of the DPSIR method with different options of restoration responses: driver=relevant activity, pressure=type of pressure, state=actual ecological integrity, impact=effect on ecological status, response=measure, changed after BMLFUW (2005).

Figure 3: Spatial scales relevant for the implementation of the EU-WFD in Austria: 1. River Basin Districts (RBD), 2. The Danube catchment as the most important RDB, 3. Eight national planning areas, 4. Basic water bodies and 5. Differentiated water bodies, both for the river network > 100 km² catchment area (figure compiled from BLMFUW 2005).

Figure 4: Generalised time frame of the implementation of the EU-WFD (ZITEK et al. 2007) and the need for decision support.

Figure 5: Main human pressures and their interactions within Austrian rivers (ZITEK 2006).

Figure 6: Location of the 400 fish sampling sites within different fish ecological river regions in Lower Austria (SCHMUTZ et al. 2008).

Figure 7: General structure of the MIRR project (POPPE et al. 2008).

Figure 8: Comparison of the CORINE, SINUS hemeroby datasets around St. Pölten, mind the different spatial resolution of the CORINE and SINUS data set.

Figure 9: Local scale buffer analysis.

Figure 10: Example of the analysis of connected land use (without any lateral buffer), by extracting raster elements by an overlay with river segments at various longitudinal scales.

Figure 11: Buffer circles around fishing sites with 1 km, 5 km and 10 km diameter.

Figure 12: Land use analyses of GIS data on different spatial scales for 1 km, 5 km and 10 km buffers and the potential floodplain area.

Figure 13: Example of land use analyses on different longitudinal scales (total catchment, sub-catchment) together with lateral buffers (potential flood plain width and 100 m buffer).

Figure 14: Estimation of the potential floodplain width based on the topography using AMap 3D (BEV) in relation to existing information on the areas flooded by a HQ100 flood (a flood with a 100 year annularity).

Figure 15: Selection of the catchment area above a fishing site (red dot).

Figure 16: Calculation of river slope for the Nattersbach.

Figure 17: Estimation of the number of connectivity interruptions within a 5 km buffer.

Figure 18: Residual flow stretches (in red) and fishing sites at the river Pielach.

Figure 19: Relationship of impounded sections (red) and free flowing sections between two connectivity interruptions (black triangles).

Figure 20: Analysis of the morphological condition of the left shoreline within a 5 km buffer with results for each parameter.

Figure 21: General structure of the MIRR database (SCHMUTZ et al. 2007).

Figure 22: Final regression tree yielded by a validation of the original model based on a case study, redrawn from HOHENSINNER et al. (2008).

Figure 23: Flow chart for identifying measures fort he pressure types “land use“ and channelization (POPPE et al. 2008).

Figure 24: General scheme for restoring rivers in Austria (SCHMUTZ et al. 2008), without hydropeaking as a pressure type, that was not treated within the MIRR project.

Figure 25: Conceptual approach of the MIRR project, where restoration is treated as a reciprocal action to degradation processes; in this simplified approach restoration is seen as a reduction of the pressures (SCHMUTZ et al. 2008).

Figure 26: Knowledge as a procession of states, adopted from HOLSAPPLE (2008) and TURBAN et al. (2004).

Figure 27: Representation of major parts of a decision support system redrawn from REGMI (2002).

Figure 28: The MIRR project translated into a DSS framework containing the typical phases (intelligence, design, choice, implementation, monitoring); changed after TURBAN et al. (2004).

Figure 29: Schematic representation of pre-processing needed to translate the results of the MIRR project into the proposed WSDSS.

Figure 30: Entity-relationship model of the SDSS database.

Figure 31: Concept of the HTML interface implemented in Mapbender, containing the functionality to create users and view the pressure values and the ecological status for each 500 m segment.

Figure 32: General structure of the Web Based Spatial Decision Support System based on open source software.

Figure 33: Concept of the HTML interface implemented in Mapbender, showing two selected water bodies (left side) and the information on the magnitude of different pressures for each 500 m segment, the ecological status of each 500 m segment and the overall ecological status of water body 2 returned by a HTML spreadsheet; the ecological status per 500 m segment is NOT the mean value, but is calculated by a defined algorithm, that might be driven by the worst ecological status in a row, but has to be specified as one of the most important components of the WSDSS.

Figure 34: Concept of the HTML interface implemented in Mapbender, showing the changed values of the magnitude of different pressures (in blue) and the recalculated ecological status for each 500 m and the overall ecological status of water body 2 returned by a HTML spreadsheet; the ecological status is still 2,6 (moderate), as 40 % (two 500 m segments) are still impounded, although some restoration measures enhanced the ecological status of the impoundments, and the forest in catchment is still less than 54 %.

Figure 35: Components needed to establish a communication between the user and the database; the newly created user is added to the SQL statement of the Map-file with his user number. This will only select the content that was newly created and added to the existing table with the user ID. Another, separate OGC WMS only queries for the data of the user root. This map service shows the original, unaltered data. It cannot be changed.

Figure 36: Roles of the components within the Web based Spatial Decision Support System.

List of tables

Table 1: Definitions of the high, good and moderate status in rivers defined by fish (WFD 2000).

Table 2: Summary of the scales used for analysis.

Table 3: Instruments relevant for the implementation of the WFD at surface water bodies with main responsibilities and activities.

Table 4: Entity relationship diagram information.

Glossary & Abbreviations

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1 Introduction

1.1 Goal and background of - and need for - this thesis

The main goal of this thesis is to develop a framework for a Web based Spatial Decision Support System (WSDSS) for supporting the development of river restoration strategies. Due to their free availability, open source/free GIS tools and technology are used to develop this decision support framework supporting a multi-user decision support platform via the web. The integration of latest multi-scale river ecological knowledge is assured by the strong relatedness of this thesis to a project that has been run at the University of Natural Resources and Applied Life Sciences (BOKU) in Vienna between 2005 and 2008 – the MIRR project (“Model based Instrument for River Restoration, http://mirr.boku.ac.at, 26.12.1008). By order of the Austrian Ministry of Life, being responsible for the implementation of the EU-Water Framework Directive (WFD 2000), a strategic instrument to identify hydro-morphological restoration measures for running waters to enhance the ecological status of rivers in Austria measured by fish was developed at the Institute of Hydrobiology and Aquatic Ecosystem Management (IHG) at the BOKU based on comprehensive multivariate analyses of fish/pressure relationships using data from Lower Austria (SCHMUTZ et al. 2008). The identification and quantification of the effects of the main relevant pressure types allowed the development of flow charts for guiding restoration activities at multiple scales. Up to now no tool exists allowing an automated evaluation of the effects of different restoration strategies on the ecological status of the so called water bodies, the relevant scale for action and reporting with regard to the EU-WFD. Furthermore existing web based GIS tools related to rivers and the implementation of the EU WFD in Austria and on an EU level do not allow any interaction with the data, and are therefore not well suited for decision support (for example the Water Information system of Austria “WISA”[1], or the Water Information System of Europe “WISE”[2] ). The following parts of the MIRR project conducted under the supervision of the author of this thesis as work package leader (WP 1, SCHMUTZ et al., 2007), and can be seen as part of this thesis, although mainly content relevant for the development of the WSDSS framework is reproduced here.

- Literature research and definition of relevant parameters to model fish/pressure relationships on multiple spatial and temporal scales (ZITEK 2006)
- Investigation and collection of the available GIS datasets in Austria, that might be of relevance for the MIRR project, and matching of criteria per pressures type with the availability of pressure data, a full list of the criteria finally assessed within the MIRR project can be found in SCHMUTZ et al. (2007)
- Development of geographical data analysis strategies, geographical data analysis and guidance and supervision of the whole (abiotic) data gathering process of the project (POPPE und ZITEK 2006).

Although the analysis results of the MIRR study were evaluated within a case study, within that spatial explicit recommendations for restoration measures together with a prioritization scheme were developed, there is no tool available to simulate the outcome of different restoration strategies on the level of surface water bodies (detailed and basic), catchments or national planning areas, which represent the most important spatial scales for the implementation of the EU-WFD. Although the MIRR project delivered a strategic scheme for river restoration based on quantitative criteria, it did not directly relate this scheme to water bodies or catchments. The DSS developed within this thesis will be based on the ecologically relevant criteria that were identified within the MIRR project, and will allow for a spatially explicit analysis of the outcome of different restoration strategies on spatial scales relevant for the EU-WFD (surface water bodies, catchments and national planning areas). The web based decision support framework presented here was not part of the MIRR project, but centrally builds up on the results of the MIRR project and represents a first innovative step towards a decision support system supporting a collective decision support via the www. Following the structure of the development of general Management Support Systems (MSS) described by TURBAN et al. (2004) this master thesis contains the planning, analysis and design phases of the development of a MSS, but not the implementation of a prototype (Fig. 1). The general need for decision support was the reason, why the Ministry of Life charged the IHG with the development of a model based instrument for river restoration. The development of the presented WDSS can be seen as consequent continuation of the MIRR project, making added value of the valuable results by making them available for a collaborative spatial explicit decision support via the www.

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Figure 1: General structure of the development of a Management Support System in relation to this thesis, redrawn from TURBAN et al. (2004).

1.2 The EU Water Framework Directive

In 2000 the European Union launched the Water Framework Directive (WFD, http://www.euwfd.com) (WFD, 2000). The main focus of the WFD is the management of river basins, the natural geographical and hydrological unit following modern river restoration principles by developing and implementing actions ameliorating impacts at entire catchments of large rivers, expressly to enhance natural attributes that have been measurably degraded (STANFORD und WARD 2001). One of the key objectives of the WFD is to achieve “good ecological status” of running waters by 2015 being measured by fish, macrozoobenthos, algae or macrophytes. The good ecological status thereby allows only “slight changes in species composition and abundance from the type-specific communities attributable to anthropogenic impacts on physicochemical and hydro-morphological quality elements” (WFD 2000). Generally, for a successful restoration of the ecological status multiple spatial and temporal scales (GEORGE und ZACH 2001; FEIST et al. 2003; ALLAN 2004; ZIEMER 1997) together with social and natural science integration (MACLEOD et al. 2007) have to be considered. Furthermore the WFD requires the assessment of restoration measures with regard to their economic commensurability, they must not be “disproportionately expensive” (WFD 2000). The use of spatial data in reporting and public participation at various stages in the planning cycle is explicitly required by the WFD, and GIS has become a key technology for the implementation of the WFD (EC 2003). Especially web based client/server are offering a variety of opportunities that might significantly help to fulfil the requirements of the WFD and to support a successful implementation of the WFD (DIETRICH und SCHUMANN 2006). Generally the required focus on integrated management of river catchments and, in particular, on ecological quality, raises major scientific and technical questions (WHEATER und PEACH 2004).

Table 1: Definitions of the high, good and moderate status in rivers defined by fish (WFD 2000).

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1.3 The implementation of the EU-WFD in Austria

As a basic step for the implementation of the WFD the current state of Austrian rivers had to be assessed following a special scheme, the DPSIR-method (Driver-Pressure-State-Impact-Response) (Fig. 2) and reported to the EU (BMLFUW 2005). An important point is, that the response (definition and implementation of measures) could apply to drivers, pressures, states and impacts, and a integrated approach can be seen as basis for a sustainable restoration of rivers. The main pressures on Austrian rivers identified were mainly of hydro-morphological character (channelization, water abstraction, hydro-peaking, connectivity interruptions) (BMLFUW 2005), as water quality problems have been solved during the last two decades.

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Figure 2: Principle of the DPSIR method with different options of restoration responses: driver=relevant activity, pressure=type of pressure, state=actual ecological integrity, impact=effect on ecological status, response=measure, changed after BMLFUW (2005).

The rivers of Austria drain into the three main river basin districts (RBD) Elbe, Rhine and Danube, with the RBD Danube being most relevant for Austria (Fig. 3). Furthermore for management purposes, Austria was divided into eight national planning areas. As a next step river types were identified following the „CIS Horizontal Guidance on establishing reference conditions and ecological status class boundaries for inland surface waters”. Furthermore for the strategic implementation of the EU-WFD so called “Surface water bodies”, the spatial main units for management, have been displayed following the „Horizontal Guidance on the Identification of Water Bodies“ (BMLFUW 2005). The basic principle for the national preparation of “Surface water bodies” consisted of two essential components: the classification of basic water bodies and their division into differentiated water bodies. The basic classification of the water bodies followed the geographical classification of natural landscapes; a change in typology resulted in a change of water body. In a next step, a differentiated classification of the water bodies has been done based on (1) the status of river stretches with regard to their combinations of significant pressures and (2) on the classification as “Heavily modified water bodies” (when the ecological status and criteria identified them). Within heavily modified water bodies only the “good ecological potential” (GEP) has to be achieved, which is the combination of all possible measures that have no adverse effect on the actual use. All water bodies have been classified with regard of a potential risk having an ecological status worse than “good” and were displayed in a map. All those water bodies at risk are candidates for the monitoring programme. The number of basic water bodies for rivers with > 100 km² catchment area in Austria is 568 (mean length of 20 km with a maximum length of 288 km) and 2596 for rivers with > 10 km² catchment area (mean length of 12 km) (BMLFUW 2005). The number of differentiated water bodies characterised by different combinations of pressures for Austria`s rivers >100 km² catchment area is 940 (mean length of 12,2 km with a maximum length of 135 km), and about 5000 for the river network > 10 km catchment area.

Generally, the aim of the restoration actions is, to reduce the multiple pressures from the individual differentiated water bodies in a way, that a good ecological status of each water boy (with exception of those, that have been classified as heavily modified) is achieved. The environmental objective, to achieve a "good ecological status" or “good ecological potential” for all water bodies has to be met until 2015, with the possibility to extend the management cycle until 2027[3]. From that perspective it becomes clear, that it represents a relatively complex task, to reduce the existing combinations of pressures in a way that the good ecological status of the basic water bodies is achieved in an economically commensurate way decision support, especially from ecological disciplines, is strongly required (Fig. 4).

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Figure 3: Spatial scales relevant for the implementation of the EU-WFD in Austria: 1. River Basin Districts (RBD), 2. The Danube catchment as the most important RDB, 3. Eight national planning areas, 4. Basic water bodies and 5. Differentiated water bodies, both for the river network > 100 km² catchment area (figure compiled from BLMFUW 2005).

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Figure 4: Generalised time frame of the implementation of the EU-WFD (ZITEK et al. 2007) and the need for decision support.

2 Development of a strategy for river restoration in Austria – the MIRR project

As described above, the so called MIRR project, to which this thesis is strongly related to, aimed at the development of a strategic instrument to identify hydro-morphological restoration measures for running waters (SCHMUTZ et al. 2008). Because of their sensitivity for hydro-morphological pressures, especially for connectivity interruptions, fish were considered as indicators within the MIRR project. At the beginning of the MIRR project the following pressures were considered as relevant for probably influencing the ecological status of rivers in Austria (Fig. 5):

- loss of lateral, longitudinal and vertical connectivity
- alteration of the natural morphological character (channelization)
- alteration of the natural flow regime (hydro-peaking, water abstraction)
- impoundment
- land use (indirectly related to many kinds of impacts)
- reservoir flushing (critical short term impact altering water quality and natural morphological character)
- alteration of water quality (pollution)
- shipping
- river bed degradation
- fish eaters, stocking, fishing pressure and alien fish species
- multiple/cumulative impacts.

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Figure 5: Main human pressures and their interactions within Austrian rivers (ZITEK 2006).

A large set of potentially ecologically relevant abiotic criteria for the pressure types above, mainly focusing on water abstraction, impoundment, land use, channelization, continuum interruptions (lateral, longitudinal) and water quality changes on multiple scales was determined from an extensive literature review (ZITEK 2006).

Based on this list of criteria and the available information and datasets on pressure data in Austria, a comprehensive set of criteria for about 400 fish sampling points in Lower Austria (Fig. 6) was assessed within an extensive GIS analysis matching the results of the literature review with the existence of datasets. Besides the analysis of pressure data, additionally natural environmental parameters that also could influence the fish communities at the fish sampling sites were also assessed (POPPE und ZITEK 2006).

Multivariate analyses of the relationships between different fish metrics and pressure variables on different spatial and temporal scales were conducted, allowing for a quantification of these relationships and an assessment of cumulative effects of pressures (SCHMUTZ et al. 2007).

Finally these modelling results were evaluated within a case study (HOHENSINNER et al. 2008) proving the determined criteria for ecological relevance different spatial scales which led to an adaptation of the initial quantitative fish/pressure relationships. The general structure of the MIRR project is shown in Fig. 7.

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Figure 6: Location of the 400 fish sampling sites within different fish ecological river regions in Lower Austria (SCHMUTZ et al. 2008).

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Figure 7: General structure of the MIRR project (POPPE et al. 2008).

2.1 Data research and analysis

Central target of the data research was the assessment of each criterion of the parameter list for each fishing occasion (POPPE und ZITEK 2006). In the following sections the relevant datasets and selected GIS analyses conducted within the MIRR project are described in more detail to demonstrate the complexity of the data collection process under supervision of the author of this thesis.

2.1.1 Relevant datasets

Within the MIRR project both, vector and raster data were processed using ArcGIS 9.0. Vector data were fishing sites (points), rivers (lines), buffer zones around rivers (polygons), whereas land use data (CORINE, SINUS) were processed as raster data.

The dominating type of analyses were spatial requests („spatial join“) and the calculation of attributes (area, length, height, slope) for each fish sampling point on different spatial scales. As a uniform projection Lambert-Conformal-Conic was used, and as geographic coordinate system MGI.

The main underlying datasets analyzed were:

- Digital Terrain Model (DTM) of Austria with a 10 m * 10 m in ESRI GRID format (provided by the Umweltbundesamt – UBA[4] )
- Digital ÖK50 maps (provided by the Ministry of Life[5] )
- Digital river network used for EU-WFD reporting (provided by the Umweltbundesamt – UBA[6] )
- Digital results of a comprehensive river morphological mapping project in Lower Austria – NÖMORPH (provided by the Government of Lower Austria[7] ) containing various parameters describing in sum the naturalness of river sinuosity, condition of the river bottom, condition of land-water ecotone, shoreline condition and vegetation of the shoreline and the surrounding landscape; these data were originally mapped in a 7-tiered scheme, and had to be translated in a WFD compliant 5-tiered scheme.
- Digital data of the ANF/KLF project (MUHAR 1996; MUHAR 1998)
- Potential morphological river type
- Actual river course
- Potential width of the floodplain
- Fish ecological river regions
- Additional data on hydropower plants based on a online documentation („Wasserbuch Niederösterreich“[8] ) and ESRI shape files (provided by the Government of Lower Austria[9] )
- Discharge data (MAF, MALF, HQ1, HQ1,5 und HQ2,33) at relevant gauges at rivers in Lower Austria (provided by the Government of Lower Austria[10] )
- Land use data (see also Fig. 8)
- CORINE Landcover Projekt 2000 (CLC2000) with (provided by the Umweltbundesamt – UBA[11] )

Based on: Landsat 7 ETM+ data of the year 2000

Vector based

Scale 1:100.000

Spatial resolution: +/- 25 m

Manually on-screen digitizing by visual interpretation of landscape structures

Minimum size of polygons 25 ha

Minimum width of line elements 100 m

Nomenclature: 3 levels with hierarchical structure (for displaying different spatial scales)

1. Level: 5 classes
2. Level: 15 classes(M 1:500.000 bis 1:1.000.000)
3. Level: 44 classes for Europe

27 classes for Austria (M 1:100.000)

- SINUS dataset containing in formation on hemeroby in nine classes describing the degree of human influences on land ecosystems , WRBKA, 2003; provided by the Institute of Surveying, Remote Sensing and Land Information (IVFL) at the BOKU, Vienna[12] )

Based on: Landsat 5-TM of the years1993 – 96 (WRBKA, 2003)

Raster based

Spatial resolution: 30m

Automated segmentation and classification of satellite pictures

Minimum size of spatial elements 0,5 ha

Nomenclature: 2 levels with hierarchical structure allowing the visualisation of information on different aggregation levels

1. Level: 7 classes

2. Level: 18 classes

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Figure 8: Comparison of the CORINE, SINUS hemeroby datasets around St. Pölten, mind the different spatial resolution of the CORINE and SINUS data set.

- Data on catchment area and water quality (from 1966, 88, 98 und 2001) were taken from the digHAÖ („Digitaler hydrologischer Atlas Österreich, available on CD)
- Population density based on the SINUS data provided by the Institute of Surveying, Remote Sensing and Land Information (IVFL) at the BOKU, Vienna[13] )
- Digital data from the Austrian report on the current situation of water bodies and rivers (BMLFUW 2005) (provided by the Umweltbundesamt – UBA[14] ) containing information on
- Connectivity interruptions
- To evaluate and update this dataset additional field mapping was needed and conducted within the frame of the MIRR project
- Water abstraction
- To complete this dataset
- Integration of information from the „Wasserbuch Niederösterreich“[15] and ESRI shape files provided by the Government of Lower Austria[16]
- and additional investigations by personally contacting power plant owners were needed
- Hydro-peaking
- In Lower Austria there were no data available on hydropeaking, why this pressure type was not further analysed
- Impoundment
- To complete this dataset, information on the dimensions of impoundments was derived from
- Calculations, using the height of connectivity interruptions and the local slope to calculate the length of an impoundment and
- from the „Wasserbuch Niederösterreich“
- River morphology
- Digital information on point sources and sewage treatment plans (provided by the Umweltbundesamt – UBA[17] )
- Existing River Managament Plans (“Gewässerbetreuungskonzepte”)
- Due to the inhomogeneity of these data, only selected information could be selected from those studies
- Fishing sites characterized by biological and environmental data (provided by the Institute of Hydrobiology and Aquatic Ecosystem Management – IHG[18] and by the BAW in Scharfling[19]

2.1.2 GIS analyses

Spatial scales

Spatial analyses with regard to river connectivity, morphology and land use were conducted at different spatial scales. Generally buffer circles around the fishing sites with 1 km, 5 km and 10 km were created and spatial information extracted per river; that means that the river length considered was not 1, 5 or 10 km, but resulted in that river segment with the same river name that as cut by the buffer. Furthermore the fish ecological river regions (MUHAR 1996; MUHAR 1998; HAUNSCHMID et al. 2006), the local scale (250 m) (Fig. 10) full and partial catchment areas also represented important longitudinal scales for analysis (Tab. 2). Buffer widths used in the analyses were 30 m, 50 m and 100 m, as well as the so called directly “connected” information. Furthermore the potential floodplain width was used as a lateral buffer; this information was available from MUHAR (1996, 1998) or was estimated by the topography using the digital Austrian Map 3D (1:50 000, available on CD). Although this methodology delivered reliable results at steeper topographies, at lowland rivers no useful results could be achieved with this methodology due to the very flat topography. Most of the buffer dimensions used were determined by the comprehensive literature review (ZITEK 2006).

Table 2: Summary of the scales used for analysis.

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Figure 9: Local scale buffer analysis.

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Figure 10: Example of the analysis of connected land use (without any lateral buffer), by extracting raster elements by an overlay with river segments at various longitudinal scales.

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Figure 11: Buffer circles around fishing sites with 1 km, 5 km and 10 km diameter.

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Figure 12: Land use analyses of GIS data on different spatial scales for 1 km, 5 km and 10 km buffers and the potential floodplain area.

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Figure 13: Example of land use analyses on different longitudinal scales (total catchment, sub-catchment) together with lateral buffers (potential flood plain width and 100 m buffer).

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Figure 14: Estimation of the potential floodplain width based on the topography using AMap 3D (BEV) in relation to existing information on the areas flooded by a HQ100 flood (a flood with a 100 year annularity).

Calculation of catchment areas

For each point of interest (fishing site, water gauge, and connectivity interruption) full and partial catchment areas were calculated based on a technology developed within the digHAÖ project allowing selecting the catchment area above each point (Fig. 15).

Calculation of river discharge at point s of interest

For each fishing site, and for each connectivity interruption different statistical discharge values (MAF; MALF, HQ1; HQ1,5; HQ2,33) were calculated starting at the water gauges by linear interpolation based on the catchment area. The values calculated, were compared to information that was already available from another project that has been run in Lower Austria (ILF und LIMNOLOGIE 2004). The difference between the two approaches was that ILF and LIMNOLOGIE (2004) interpolated the discharge for river sections and not for specific locations. Generally the values from the site specific approach applied within the MIRR project were used.

Abbildung in dieser Leseprobe nicht enthalten

Figure 15: Selection of the catchment area above a fishing site (red dot).

Calculation of slope for river segments

For each river segment the slope was calculated based on the segment length (3dlenght) by overlaying the river network with the DTM (Fig. 16) resulting in height values at the beginning and the end of the line. Together with the segment length it was possible to calculate the slope in %. This value was then assigned to fishing sites and connectivity interruptions within that specific segment. This information was mainly used to calculate the missing lengths of impoundments by relating the height of a connectivity interruption to the slope of the related river segment.

Abbildung in dieser Leseprobe nicht enthalten

Figure 16 : Calculation of river slope for the Nattersbach.

Extraction of the number of connectivity interruptions at different scales

The number of connectivity interruptions was estimated for certain buffers including 1 km, 5 km, 10 km, fish ecological river region as longitudinal buffers. The following parameters were thereby considered:

- Absolute number
- Type of connectivity interruption
- Functionality of existing fish ladders

An automated analysis of the number of connectivity interruptions per buffer within one step was complicated by the excessive overlapping of the circles (Fig. 17). The number of connectivity interruptions per fish region of a river (often containing several fishing sites) was visually counted from the screen.

Abbildung in dieser Leseprobe nicht enthalten Figure 17 : Estimation of the number of connectivity interruptions within a 5 km buffer .

Pressure type water abstraction

As no detailed data spatial on water abstraction were digitally available, these data were assessed within the MIRR project (Fig. 18) taking advantage of another project that was conducted at the IHG at the same time (ZEIRINGER 2006-2008). The following parameters were assessed:

- Residual flow
- by integrating information from the „Wasserbuch Niederösterreich“[20] and ESRI shape files provided by the Government of Lower Austria[21]
- and additional investigations by personally contacting power plant owners
- Dimension of the hydropower turbines to estimate the maximum amount of water that could be abstracted
- by integrating information from the „Wasserbuch Niederösterreich“
- River length subjected to water abstraction was measured
- by integrating information from the „Wasserbuch Niederösterreich“
- measuring the length of residual flow stretches existing within AMap 3D (available on CD, BEV)

Abbildung in dieser Leseprobe nicht enthalten

Figure 18: Residual flow stretches (in red) and fishing sites at the river Pielach.

Pressure type impoundment

The following parameters were assessed with regard to the pressure type “impoundment” (Fig. 19):

- Impoundment dimensions
- calculations, using the height of connectivity interruptions and the local slope to calculate the length of an impoundment
- the „Wasserbuch Niederösterreich“ and NÖMORPH data being used to determine width and length of impoundments
- Relationship of impoundment and free flowing river sections between two connectivity interruptions
- Water exchange rate of impoundments
- Length and depth of impoundments (calculated form the height of the connectivity interruptions) were divided by MAF and MALF

Figure 19 : Relationship of impounded sections (red) and free flowing sections between two connectivity interruptions (black triangles).

Pressure type channelization

The analysis of the pressures type “channelization” was mainly based on the NÖMORPH dataset. These data consist of several separate parameters mapped that were finally integrated into a composite parameter to judge the degree of the effect of this pressure type. Originally these data were mapped in a 7-tiered scheme, and had to be translated in a WFD compliant 5-tiered scheme. This analysis had to be run for the left and right shoreline separately. The following parameters were assessed with regard to the pressure type on the defined different spatial scales using (Fig. 20):

- Composite pressure degree
- naturalness of river sinuosity
- condition of the river bottom
- condition of land-water ecotone
- shoreline condition
- vegetation of the shoreline and the surrounding landscape

Additionally data like the

- Potential morphological river type
- Actual river course
- Potential width of the floodplain

were used from ANF/KLF project (MUHAR 1996; MUHAR 1998).

Abbildung in dieser Leseprobe nicht enthalten

Figure 20: Analysis of the morphological condition of the left shoreline within a 5 km buffer with results for each parameter.

Pressure type land use

Land use data on different spatial scales were derived from the SINUS dataset due to its better spatial resolution (WRBKA 2003) (see the Spatial scales” section at the beginning of this chapter). Results of this analysis were the percentage of each land use type and each hemeroby class in the selected buffers.

Pressure type water quality

Criteria derived from that dataset provided by the UBA were

- Distance of a fishing site to point sources and sewage treatment plants
- Upstream number of point sources and sewage treatment plants
- Capacity of the sewage treatment pant upstream(expressed in number of inhabitants connected to this sewage treatment plant)
- Summed capacity of the upstream sewage treatment plants (expressed in number of inhabitants connected to this sewage treatment plant)

Pressure type population density

The population density analyses were based on the SINUS data provided by the Institute of Surveying, Remote Sensing and Land Information (IVFL) at the BOKU, Vienna and were calculated as “number of inhabitants per pixel”.

Natural characteristics

Finally natural characteristics describing the fishing sites that were integrated into the analyses incorporate:

- Meters above sea levels
- Catchment area
- Slope
- Distance to source
- Distance to river mouth
- Mean monthly air temperature
- Discharge
- Geology
- Potential floodplain width
- Natural river type

2.1.3 Relevant spatial (pressure) criteria and their quantitative relationship to fish

Out of about 550 pressure criteria (summarized in a table in the appendix of SCHMUTZ et al., 2007), most of them assessed using GIS technology (POPPE und ZITEK 2006), and managed in a large relational ACCESS database (Fig. 21), only a few were identified to be significantly related to fish variables (SCHMUTZ et al. 2007; HOHENSINNER et al. 2008).

Abbildung in dieser Leseprobe nicht enthalten

Figure 21: General structure of the MIRR database (SCHMUTZ et al. 2007).

The most important criteria, also forming the basic input for developing the WSDSS framework, that were identified by multivariate analysis (SCHMUTZ et al. 2007) and adapted within a case study (HOHENSINNER et al. 2008) were (Fig. 22):

- Proportion of forest in the catchment (> 54 % yielded a significant better fish ecological situation)
- Proportion of forest in 100 m x 10 km buffer (if the proportion of forest in a catchment is below 54 %, the proportion of forest in the described buffer becomes an important criterion; more than 24 % leads to a significant better fish ecological situation).
- Number of connectivity interruptions within the ecological fish region (less than 10 connectivity interruptions yield a significant better fish ecological situation)
- Morphology index of the river bottom (within a five-tiered scheme, the morphological status of the river bottom within a 10 km buffer was found to significantly influence the fish ecological situation negatively when it was above 2,1).
- Additionally the number of tributaries within the fish region positively influenced the fish ecological status (this could not be tested with regression tree).

Abbildung in dieser Leseprobe nicht enthalten

Figure 22: Final regression tree yielded by a validation of the original model based on a case study, redrawn from HOHENSINNER et al. (2008).

[...]


[1] http://wisa.lebensministerium.at/, 26.12.2008

[2] http://water.europa.eu/, 26.12.2008

[3] http://ec.europa.eu/environment/water/water-framework/info/timetable_en.htm, 29.12.2008

[4] http://www.umweltbundesamt.at, 27.12.2008

[5] http://www.lebensministerium.at, 27.12.2008

[6] http://www.umweltbundesamt.at/umweltschutz/wasser/berichtsgewaessernetz, 27.12.2008

[7] http://www.noe.gv.at/Umwelt/Wasser/Fliessgewaesser/Fliessgewaesser_Situation_in_Niederoesterreich.html, 27.12.2008

[8] http://www.noe.gv.at/Umwelt/Wasser/Wasserdatenverbund-NOe/wdv_wasserbuch.wai.html, 27.12.2008.

[9] http://www.noe.gv.at/Umwelt/Wasser/Fliessgewaesser/Fliessgewaesser_Situation_in_Niederoesterreich.html, 27.12.2008

[10] http://www.noe.gv.at, 27.12.2008

[11] http://www.umweltbundesamt.at/umwelt/raumordnung/flaechennutzung/corine/, 27.12.2008

[12] http://www.rali.boku.ac.at/ivfl.html, 27.12.2008

[13] http://www.rali.boku.ac.at/ivfl.html, 27.12.2008

[14] http://www.umweltbundesamt.at/umwelt/raumordnung/flaechennutzung/corine/, 27.12.2008

[15] http://www.noe.gv.at/Umwelt/Wasser/Wasserdatenverbund-NOe/wdv_wasserbuch.wai.html, 27.12.2008.

[16] http://www.noe.gv.at/Umwelt/Wasser/Fliessgewaesser/Fliessgewaesser_Situation_in_Niederoesterreich.html, 27.12.2008

[17] http://www.umweltbundesamt.at/, 27.12.2008

[18] http://www.boku.ac.at/hfa/, 27.12.2008

[19] http://www.baw-igf.at/, 27.12.2008

[20] http://www.noe.gv.at/Umwelt/Wasser/Wasserdatenverbund-NOe/wdv_wasserbuch.wai.html, 27.12.2008.

[21] http://www.noe.gv.at/Umwelt/Wasser/Fliessgewaesser/Fliessgewaesser_Situation_in_Niederoesterreich.html, 27.12.2008

Details

Seiten
66
Erscheinungsform
Originalausgabe
Jahr
2008
ISBN (eBook)
9783836640473
Dateigröße
3.6 MB
Sprache
Englisch
Katalognummer
v227487
Institution / Hochschule
Universität Salzburg – Computerwissenschaften, Geographie und und angewandte Geoinformatik
Note
1,0
Schlagworte
wasserrahmenrichtlinie water decision river

Autor

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Titel: Development of a web-based spatial decision support system (WSDSS) for river restoration