Niedersachsischer Landesbetrieb fur Wasserwirtschaft

Bahnhof Löhne, Germany

Niedersachsischer Landesbetrieb fur Wasserwirtschaft

Bahnhof Löhne, Germany
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Kreibich H.,German Research Center for Geosciences | Meyer S.,Niedersachsischer Landesbetrieb fur Wasserwirtschaft | Diekkruger B.,University of Bonn
Hydrologie und Wasserbewirtschaftung | Year: 2011

Severe damage due to high groundwater levels occurred during and after the 2002 flood in the city of Dresden, Germany. So far, damage caused by high groundwater levels has rarely been considered in flood risk analysis. However, reliable damage models are necessary to evaluate the cost-effectiveness of mitigation measures and to support a comprehensive risk management. Therefore, the "Flood Loss Estimation Model for the private sector" FLEMOps was further developed for modelling damage due to high groundwater levels. FLEMOps is empirically based and considers several damage influencing factors. In addition to the water depth, information on the building type as well as the level of precaution and contamination are also taken into account. FLEMOps for groundwater flooding has been successfully validated at the micro- and meso-scale and a sensitivity analysis has been implemented in Dresden.

Schmiedel I.,University of Gottingen | Schacherer A.,Niedersachsischer Landesbetrieb fur Wasserwirtschaft | Hauck M.,Niedersachsischer Landesbetrieb fur Wasserwirtschaft | Schmidt M.,Nordwestdeutsche Forstliche Versuchsanstalt | Culmsee H.,University of Gottingen
Tuexenia | Year: 2011

Detailed knowledge about the spatial distribution of richness centres is a prerequisite for the development of national strategies for the conservation of vascular plant species. However, different groups of plant taxa may have different relevance depending on their naturalisation and threat status. In this study we investigate the spatial distribution of plant species richness centres in the area of the federal states of Lower Saxony and Bremen, based on data from the plant survey of Lower Saxony (Niedersächsisches Pflanzenarten-Erfassungsprogramm). Our analyses include: 1.) The complete floristic list (1819 taxa) 2.) Three groups of taxa defined by their naturalisation status (1509 indigenous taxa, 160 archaeophytes, 145 established neophytes), 3.) Two groups of taxa defined by their threat situation (unthreatened versus threatened taxa, including 643 taxa which have been Red Listed with status 1, 2, 3, G or R). Based on the complete floristic list, a clumped distribution pattern was observed. Site conditions in the Quaternary coastal and lowland areas are relatively homogeneous and, with exception of the major stream valleys of the Weser, Aller, and Elbe, relatively species-poor. The upland area with its heterogeneous site conditions shows the overall highest taxonomic richness. The large group of indigenous taxa shows a distribution very similar to that of the complete floristic list. Archaeophytes are concentrated in the coastal area of Bremen, the Weser and Aller plains, the old moraine loess landscapes, and in smaller cities. High diversity of established neophytes is mainly found in congested urban areas and several other small-scale centres of diversity. Red List species are mainly indigenous (91 %), 8 % are archaeophytes and only 1 % are neophytes. Their diversity centres are spatially highly differentiated: at the coast only the islands in the North Sea are small hotspots, while in the lowlands relatively large hotspots are situated in the Wendland, the Luneburg Heath, and the Elbe-Weser triangle north of Bremen. In the uplands, the area around Göttingen, the uplands of the Weser and Leine valleys, and the Harz mountain margins are well-defined hotspots of Red List taxa. Many of these endangered species are presumably specialists adapted and limited to natural and semi-natural habitats.

Schmiedel I.,University of Gottingen | Schmidt M.,Nordwestdeutsche Forstliche Versuchsanstalt | Schacherer A.,Niedersachsischer Landesbetrieb fur Wasserwirtschaft | Culmsee H.,University of Gottingen | Culmsee H.,DBU Naturerbe GmbH
Naturschutz und Landschaftsplanung | Year: 2013

Effectiveness of Protection Areas for the Conservation of Rare and Endangered Vascular Plant Species - Investigation in the Lowlands of Lower Saxony, Germany The establishment of protected areas is a central tool in species conservation. Using the 41 geographical regions of the lowlands of Lower Saxony as a model region, the study introduces a method to test the effectiveness of nature protection areas and Natura 2000 sites for the conservation of rare and endangered vascular plant species (RL, Red List species). The results show that RL species are effectively protected by nature protection areas in 85% of the geographical regions; for RL species depending on forest habitats this is the case in only 61% of the geographical regions. The extension of the protection area system to include Natura 2000 sites considerably improves the situation. The approach allows the identification of regions with high species richness of endangered plants (hotspots) that should be particularly considered for conservation and management actions.

Folmer E.O.,Netherlands Institute for Sea Research | Drent J.,Netherlands Institute for Sea Research | Troost K.,Institute for Marine Resources and Ecosystem Studies | Buttger H.,BioConsult SH | And 6 more authors.
Ecosystems | Year: 2014

Intertidal blue mussel beds are important for the functioning and community composition of coastal ecosystems. Modeling spatial dynamics of intertidal mussel beds is complicated because suitable habitat is spatially heterogeneously distributed and recruitment and loss are hard to predict. To get insight into the main determinants of dispersion, growth and loss of intertidal mussel beds, we analyzed spatial distributions and growth patterns in the German and Dutch Wadden Sea. We considered yearly distributions of adult intertidal mussel beds from 36 connected tidal basins between 1999 and 2010 and for the period 1968-1976. We found that in both periods the highest coverage of tidal flats by mussel beds occurs in the sheltered basins in the southern Wadden Sea. We used a stochastic growth model to investigate the effects of density dependence, winter temperature and storminess on changes in mussel bed coverage between 1999 and 2010. In contrast to expectation, we found no evidence that cold winters consistently induced events of synchronous population growth, nor did we find strong evidence for increased removal of adult mussel beds after stormy winter seasons. However, we did find synchronic growth within groups of proximate tidal basins and that synchrony between distant groups is mainly low or negative. Because the boundaries between synchronic groups are located near river mouths and in areas lacking suitable mussel bed habitat, we suggest that the metapopulation is under the control of larval dispersal conditions. Our study demonstrates the importance of moving from simple habitat suitability models to models that incorporate metapopulation processes to understand spatial dynamics of mussel beds. The spatio-dynamic structure revealed in this paper will be instrumental for that purpose. © 2014 The Author(s).

Rathing F.,Niedersachsischer Landesbetrieb fur Wasserwirtschaft | Melzer O.,Niedersachsischer Landesbetrieb fur Wasserwirtschaft
Wasser und Abfall | Year: 2014

Since 2010, the state of Lower Saxony offers a groundwater protection consultation for agricultural enterprises. The consultation is one of the measures in order to achieve the good chemical state with regard to nitrate. In 2014, this offer was enhanced by surface water consultation in three pilot consulting areas. The different requirements of the Water Framework Directive on the protection of groundwater and flowing waters in terms of nutrients, the experiences in groundwater protection and also the starting position in the consultation for surface waters will be presented.

Biotope Types as Mapping and Evaluation Units in Nature Conservation and Landscape Planning - Proposals for a Standardisation The mapping of biotope types has become the standard technique of site related inventories for nature conservation and landscape planning. Still a drawback is the lacking compatibility of classifications on regional, national and European level. Therefore it needs standardization, beginning with the biotope term. A biotope type is a comprehensive category consisting of up to four components influencing and depending on each other: obligatory components are location type and (spatial) structure type, facultative aspects are the vegetation type and land use type. Compared to ecotopes the term biotope particularly focusses on the existing biocenosis; as opposed to plant communities site-ecological and structural aspects are stressed; in contrast to habitats it focusses on synecology and on a certain dimension of sites. Regarding their major evaluation aspects biotope types should be homogeneous, i.e. the biotopes associated should be of nearly equal value.

The European Flood Risk Management Directive (FRMD) came into force on October 23, 2007. The results of the initial working steps in the implementation of the directive and the Lower Saxon approach to the development of the FRM plans will be presented.

Haberlandt U.,Leibniz University of Hanover | Belli A.,Leibniz University of Hanover | Holscher J.,Niedersachsischer Landesbetrieb fur Wasserwirtschaft
Hydrologie und Wasserbewirtschaftung | Year: 2010

Trend analyses have been carried out with observed time series of temperature and precipitation in Lower Saxony. The investigations are based on daily data from 18 temperature stations and 263 precipitation stations in the time period from 1951 until 2005. The trends were studied separately for the winter, spring, summer and autumn seasons as well as for the whole year. Specific indices like maximum 5-day rainfall sum, maximum number of consecutive dry days etc. were used here to address especially the behaviour of extreme values. The Mann-Kendall-Test was applied to detect trends and the linear regression to assess its magnitude. Temperature showed significant positive trends in all seasons without spatial differences. In winter significant positive trends were found in precipitation, especially in the northern and southern parts of Lower Saxony. In the summer season, significant positive trends were detected in the duration of dry spell especially in the central region of Lower Saxony. The correction of precipitation regarding systematic undercatch led to a certain reduction in the number of significant positive winter trends, but did not change the overall picture.

'Favourable conservation status' is a key concept in Habitats Directive implementation. In Germany it is assessed according to the Pinneberg Scheme using three criteria: 'Structures', 'Species' and 'Adverse effects'. Based on theoretical principles of assessment and on fictitious examples of habitats the paper discusses whether these criteria and assessment.

From the beginnings of water preservation to today's waters development strategies and implementation of the WFD, much was done in the field of preservation of watercourses. Efforts to enhance water purification and measures of waters development implemented in years past have made for a sizeable decrease in contamination and a discernible overall ecological enhancement. A short historical outline by example of Lower Saxony depicts' stations along the way'. Also, insights gained from implementation experience and new challenges posed by the WFD, are discussed.

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