Hinweis zum Urheberrecht
Monographie zugänglich unter
URL: https://epub.sub.uni-hamburg.de/epub/volltexte/campus/2015/38976/
Hydromorphologic survey and assessment of the lakeshore of Lake Scharmützelsee as a prerequisite for the development of a lakeshore utilization strategy
Fernando, Ranjin
| pdf-Format:
|
|
| Dokument 1.pdf (17.868 KB)
|
|
| Zugriffsbeschränkung: |
| nur innerhalb des Universitäts-Campus |
| BK - Klassifikation: |
| 38.87 |
| DDC-Sachgruppe: |
| Biowissenschaften, Biologie |
| Dokumentart: |
| Monographie |
| ISBN: |
| 978-3-8428-1576-6 |
| Sprache: |
| Englisch |
| Erstellungsjahr: |
| 2011 |
| Publikationsdatum: |
| 16.03.2015 |
| Bemerkung: |
| Impressum falsch |
| Kurzfassung auf Englisch: |
| Abstract: Lakeshores are ecotones between aquatic and terrestrial habitats with a high economic and socio-economic significance. For many years, lake conservation focused on biological and chemical conditions and while improvements on these fields have been achieved, the anthropogenic pressures on European lakeshores have rather increased in recent years. Against this background, the development of utilization and protection strategies for lakeshores is urgently needed. A precondition for this is a standardized survey and assessment of the hydromorphological status which is also required by the European Water Framework Directive under certain circumstances. For this thesis, the lakeshore of Lake Scharmützelsee, the largest lake in the German state of Brandenburg, was classified according to the GIS-based Hydromorphology Lake (HML) protocol of Ostendorp (2008). Since the HML protocol was at the time still in a testing phase, methodical modifications were applied and recommendations for an improvement of the protocol are given. Deviating from the HML protocol, the eulittoral zone was delineated with a constant width of five meters and the sublittoral zone according to the potential maximum water depth where the available light permits the growth of submerged macrophytes. A detailed on-site mapping and a separate assessment of linear and planar objects in the eulittoral zone enhanced the quality of the data further. For Lake Scharmützelsee, the assessment showed an expected increase in anthropogenic structural modifications from sublittoral (impact = 1.3) to eulittoral (impact = 1.7) to epilittoral (2.5). A correlation analysis between the impacts in different zones and the mapped objects was carried out and showed inter alia that the main reasons for structural deficits in the eulittoral zone are shore stabilizations and that in the presence of large piers and marinas a reinforced shore is more likely than in the presence of small piers and marinas. Further analysis showed that small marinas and piers can impair approximately 25% of the emergent reed belt area. The results qualify to designate conservation zones for continuous natural or near-natural lakeshore sections and to identify sections with a potential for restoration. The results of this thesis were already used by local authorities to design a blueprint for a lakeshore utilization strategy.Inhaltsverzeichnis:Table of Contents: List of Figuresv List of Tablesix 1.Introduction1 1.1Importance and deterioration of lakeshores1 1.2Lakeshores and hydromorphology in the WFD2 1.3Hydromorphology Lake (HML) protocol4 1.4Motives and objectives6 1.4.1Motives6 1.4.2Objectives7 1.5Structure of thesis7 2.Methods8 2.1Characterization of Lake Scharmützelsee and main anthropogenic pressures8 2.2Acquisition of primary data10 2.3Setting up of GIS-project10 2.4Delineation of subzones and segments11 2.4.1Generalization of shoreline12 2.4.2Delineation of subzones12 2.4.3Modifications of subzones and exclusion of islands13 2.4.4Delineation of segments14 2.5On-site mapping of shoreline stabilizations15 2.5.1Prearrangements and execution16 2.5.2Documentation by photographs16 2.6Digitalization of a submerged macrophytes map17 2.7Adaptation of catalog of objects18 2.8Mapping and classification of objects19 2.8.1Mapping of objects20 2.8.2Classification of objects21 2.9Computation of impacts22 2.9.1Formulas for the calculation22 2.9.2Implementation of a database for the calculation of impacts23 3.Results25 3.1Zoning, segmentation and numbering25 3.2Mapped objects and derived impacts26 3.2.1Sublittoral zone26 3.2.2Eulittoral zone27 3.2.3Epilittoral zone30 3.3Outline of classification32 3.3.1Lakeshore section 133 3.3.2Lakeshore section 234 3.3.3Lakeshore section 335 3.3.4Lakeshore section 436 3.3.5Lakeshore section 537 3.3.6Lakeshore section 638 3.3.7Lakeshore section 739 3.3.8Outline of the distribution of selected objects40 3.4Graphical illustration of classification41 3.5Statistical analysis44 3.5.1Overview of the classification by subzone44 3.5.2Correlation between impacts in subzones and presence of objects44 3.6Further analysis48 3.6.1Estimation of reed bed area impeded by small piers and marinas48 3.6.2Occurrence of objects depending on reed bed area49 4.Discussion and conclusion50 4.1Discussion of applied methods50 4.1.1Limitations50 4.1.2Methodical modifications of the HML-protocol51 4.1.3Suggestions for modifications and improvements of the HML-protocol52 4.2Discussion of results53 4.2.1Main hydromorphological pressures53 4.2.2Lakeshore hydromorphological status55 4.3.3Implications for lakeshore conservation and utilization concepts57 5.References59 Appendix I - Catalog of objects63 Appendix II - Object profiles67Textprobe:Text Sample: Chapter 2.8, Mapping and classification of objects: Objects in the sublittoral, eulittoral and epilittoral were mapped by analyzing the DOP40 images as well as the other primary data provided. Additionally shore stabilizations in the eulittoral were mapped based on the data of the on-site mapping. Deviant from Ostendorp et al., linear and planar objects in the eulittoral zone were mapped and assessed separately. The mapping of areas was realized by creating polygons that enclosed objects seen on the DOP40 images. For the mapping of shore stabilizations as linear objects, the shoreline was divided into sections with a length corresponding to the shore stabilizations. Following the creation of polygons and polylines, they were classified as one of the objects defined in the catalog of objects by ascription of the corresponding ID. An example how objects in the sublittoral and epilittoral were mapped and classified is shown in Figure 17 and Figure 18. The proceeding regarding the classification of linear and planar objects in the eulittoral is illustrated by Figure 19 and Figure 20. 2.8.1, Mapping of objects: Sublittoral zone: The polylines displaying the piers and marinas served as an orientation of the objects’ location, and the polylines of the lakeward boarder of the reed belt were used to generate polygons. Additionally, the generated map of submerged macrophytes was used to identify areas with submersed macrophytes and areas without. In accordance to recommendations by Ostendorp (pers. Communication) not the actual area of marinas and piers was delineated but rather a broader area that also included potential areas of landing boats. Eulittoral zone (planar mapping): Since the eulittoral zone was extremely narrow, an approach not defined by Ostendorp et al. was applied. First, the eulittoral zone was divided into two halves, a lakeward part and a landward part. Secondly, each half was cut into subparts so that polygons enclosing the objects were created. Hereby, in the lakeward part the same objects that occurred in the sublittoral zone were mapped, more precisely if an object was mapped in the sublittoral zone it was also mapped in the eulittoral zone. Eulittoral zone (linear mapping): The trackpoints set in Fugawi Global Navigator during the on-site mapping were exported to an ESRI shapefile and imported to the ArcMap project. Based on the trackpoints and the notes on the aerial images, the beginnings and endings of shoreline stabilizations were identified. Since many trackpoints that were recorded form the boat were not directly located at the shoreline but parallel to it, they had to be projected to the shoreline by dropping perpendiculars. Next, each section of the shoreline-polyline was cut into subsections so that for each mapped object in each segment a polyline was created. Additionally to the recorded shore stabilizations of the on-site mapping at each marina and pier seen on the DOP40 images a shore stabilization of approximately 2.5 m was mapped. Epilittoral zone: The biotope and habitat map was used as orientation for identifying objects in the Epilittoral. Additionally, maps available at Google Maps were used to identify roads and in some cases to get a colored view of objects. After objects were identified, polygons enclosing them were created. |
