Der Aufsatz befasst sich mit der Wasserversorgung im Schlosspark Großsedlitz. Ein weitläufiger Terrassengarten erforderte im frühen 18. Jahrhundert reichhaltige Wasserspiele. Nach bisherigen Erkenntnissen war dies in Großsedlitz aufgrund der topografischen Lage auf dem Bergrücken kaum zu gewährleisten. Die jüngste Betrachtung zeigt allerdings, dass der frühe Garten unter Wackerbarth nicht nur auf Größe, sondern auch auf einen sehr nachhaltigen Umgang mit den Wasserressourcen ausgerichtet war. Nach Berechnungen war durch das vorhandene Reservoir nur eine Betriebsdauer der Wasserspiele von dreieinhalb bis vier Stunden möglich. / The article deals with the water supply to the Baroque gardens at Großsedlitz. In the early 18th century such extensive terraced gardens demanded the inclusion of an elaborate set of water features. It has been known for some time that the location of Großsedlitz on the crest of a hill made it very difficult to satisfy this requirement. Recent research shows, that in the early Wackerbarth days the gardens were not served by a large and sustainable water supply, and calculations show that the available water reserves were only sufficient to enable the water features to operate for three and a half to four hours at a time.

Die Chronik der Landestalsperrenverwaltung reicht von den Anfängen der sächsischen Wasserwirtschaft im 15. Jahrhundert bis zur Gegenwart. Redaktionsschluss: 19.10.2017

Die Landestalsperrenverwaltung wurde 1992 als erster Staatsbetrieb des Freistaates Sachsen gegründet. Sie gehört zum Geschäftsbereich des Sächsischen Staatsministeriums für Umwelt und Landwirtschaft und führt eine Vielzahl an hoheitlichen Aufgaben aus. Diese sind im Sächsischen Wassergesetz festgelegt. Verantwortlich ist die Landestalsperrenverwaltung unter anderem für den Bau und die Wartung der landeseigenen Stauanlagen. Im Jahr 1994 wurde ihr außerdem die Zuständigkeit für die Unterhaltung und den Ausbau der Gewässer I. Ordnung und der Grenzgewässer in Sachsen übertragen. Auch die Umsetzung der Europäischen Wasserrahmenrichtlinie ist ein fester Bestandteil der Arbeit der Landestalsperrenverwaltung. Nach dem Hochwasser 2002 wurden Hochwasserschadensbeseitigung und präventiver Hochwasserschutz zu weiteren Schwerpunktaufgaben. Um diese Generationenaufgaben bewältigen zu können, stellt die sächsische Staatsregierung der Landestalsperrenverwaltung die notwendigen finanziellen Mittel zur Verfügung. Im Bereich Rohwasserbereitstellung decken die Einnahmen von den regionalen Wasserversorgern die entstehenden Kosten. Der Hauptsitz der Landestalsperrenverwaltung ist in Pirna. Hier befindet sich die Geschäftsführung sowie die drei Fachbereiche Verwaltung/Finanzen, Wasserwirtschaft und Betrieb, die vor allem betriebsübergreifende Aufgaben bearbeiten. Die Stauanlagen und Fließgewässer in den Regionen werden von den fünf Betrieben der Landestalsperrenverwaltung betreut. Redaktionsschluss: 30.11.2018

Coleanthus subtilis ist eine durch die FFH-Richtlinie geschützte, weltweit sehr seltene Art, welche periodisch trockenfallende Standorte in Flussauen (Primärhabitate) bzw. durch den Menschen geschaffene Staugewässer (Sekundärhabitate) besiedelt. Die Erarbeitung der aktuellen Verbreitungsbilder der Art in Sachsen und ihrer Besiedlungshistorie waren Ausgangspunkt für die Analysen zur Ökologie dieser Art. Anhand von Analysen zu den Ausbreitungsmechanismen, Standortansprüchen und Reaktionsmöglichkeiten von C. subtilis wurden grundlegende Beiträge zum besseren Verständnis der Strategien dieser Art erbracht. Die Arbeit gibt Hinweise für eine artenschutzgerechte Bewirtschaftung der Staugewässer insbesondere für die Regulierung von Zeitpunkt, Dauer, Intensität und Häufigkeit von Wasserstandsabsenkungen sowie hinsichtlich einzelner Praktiken im Zusammenhang mit einer fischereilichen Nutzung. Weiterhin zeigt die Arbeit auf, wie C. subtilis auf bestimmte, von den durchschnittlichen Wasserstandsschwankungen abweichende, Bedingungen reagieren kann. Damit sind nun wichtige Grundlagen zum nachhaltigen Schutz und zur Förderung von C. subtilis, insbesondere in Sekundärhabitaten, vorhanden. / Coleanthus subtilis is a globally rare species protected by the European Union Habitats Directive. This grass establishes on periodically drying sites in river floodplains (primary habitats) but also in man made ponds and reservoirs (secondary habitats). The identification of the present distribution patterns as well as the reconstruction of the colonisation history of C. subtilis in Saxony were the basis for analyses about the ecology of this species. By analysing dispersal mechanisms, habitat demands and response traits of C. subtilis fundamental contributions to a better understanding of the strategies of this species are given. The thesis provides information about optimum time, duration, intensity and frequency of water level reductions and about the consequences of different management practices particularly with respect to fishery in ponds and reservoirs inhabiting C. subtilis. Further the thesis shows how C. subtilis can cope with deviations from mean water level fluctuations. In summary important fundamental knowledge for the sustainable conservation and promotion of C. subtilis, particularly in secondary habitats, has been established.

No description available.

Driven by many factors, the water supply services (streamflow and groundwater) of many rivers in the dryland area of China have declined significantly. This aggravates the inherent severe water shortages and results in increased severity in the water use conflicts that are threatening sustainable development in the region. Innovative strategies towards more water-efficient land management are vital for enhancing water quantity to ensure water supply security. A key step in the successful development and implementation of such measures is to understand the response of hydrological processes and related services to changes in land management and climate. To this end, it was decided to investigate these processes and responses in the upper reaches of the Jing River (Jinghe), an important meso-scale watershed in the middle reaches of the Yellow River on the Loess Plateau (NW China). It has been shown that vegetation restoration efforts (planting trees and grass) are effective in controlling soil erosion on the Loess Plateau. Shifts in land cover/use lead to modifications of soil physical properties. Yet, it remains unclear if the hydraulic properties have also been improved by vegetation restoration. A better understanding of how vegetation restoration alters soil structure and related soil hydraulic properties, such as water conductivity and soil water storage capacity, is necessary. Three adjacent sites, with comparable soil texture, soil type, and topography but contrasting land cover (Black locust forest, grassland, and cropland), were investigated in a small catchment in the upstream Jinghe watershed (near Jingchuan, Gansu province). Seasonal variations of soil hydraulic properties in topsoil and subsoil were examined. Results revealed that the type of land use had a significant impact on field-saturated, near-saturated hydraulic conductivity, and soil water characteristics. Specifically, conversion from cropland to grass or forests promotes infiltration capacity as a result of increased saturated hydraulic conductivity, air capacity, and macroporosity. Moreover, conversion from cropland to forest tends to promote the formation of mesopores that increase soil water storage capacity. Tillage in cropland temporarily created well-structured topsoil, but also compacted subsoil, as indicated by low subsoil saturated hydraulic conductivity, air capacity, and plant available water capacity. An impact of land cover conversion on unsaturated hydraulic conductivities was not identified, indicating that changes in land cover do not affect functional meso- and microporosity. Changes in soil hydraulic properties and associated hydrological processes and services due to soil conservation efforts need to be considered, should soil conservation measures be implemented in water-limited regions for sustaining adequate water supply. To differentiate between the impacts of land management and climate change on streamflow, the variation of annual streamflow, precipitation, potential evapotranspiration, and climatic water balance in a small catchment of the upstream Jinghe watershed (near Pingliang, Gansu province) was examined during the period of 1955 – 2004. During this time the relative contributions of changes in land management and climate to the reduction of streamflow were estimated. A statistically significant decreasing trend of -1.14 mm y-1 in annual streamflow was detected. Furthermore, an abrupt streamflow reduction due to afforestation and construction of terraces and check-dams was identified around 1980. Remarkably, 74% of the total reduction in mean annual streamflow can be attributed to the soil conservation measures. Among various conservation measures, streamflow could be considerably reduced by afforestation and terracing (including damland creation), due to their low contribution to water yield. In contrast, slope farmland and grassland can maintain a certain level of water supply services due to higher runoff coefficients. According to a meta-analysis of the published studies on the Loess Plateau, the impact of changes in land management on annual streamflow appears to diminish with increasing catchment size while the impact of climate change appears uniform across space. This means that there is a dependency between the catchment size and the response of hydrological processes to environmental change. At least at the local scale, it appears that well-considered land management may help to ensure the water supply services. Due to limited surface water availability, groundwater is an essential water source for supporting ecosystem and socio-economic development in the dryland region. However, the groundwater process is susceptible and vulnerable to changes in climate and landscape (i.e., land cover and form) that in turn can result in profound adverse consequences on water supply services in water-limited regions. In addition, an improved understanding of the response of groundwater related processes to natural and artificial disturbances is likely to ensure more secure and more sustainable governance and management of such regions, as well as better options for adapting to climate change. Yet, this topic has seldom been researched, especially in areas that have already experienced large-scale alteration in landscape and are located in dryland regions, such as the Loess Plateau. Therefore, an investigation of the baseflow variation along the landscape change was conducted. The average annual baseflow has significantly decreased at catchment scale during the period of 1962 – 2002 without any obvious significant change in climate. At decadal scale, the reduction accounts for approximately 9% in the 1970s, 48% in the 1980s, and 92% in the 1990s, while the baseflow index declines averaging 5%, 16% and 67%, respectively. All of the monthly baseflow levels dropped at varying rates except in January, among which July was the most severe in terms of both magnitude (-4.17) and slope (-0.09 mm y-1). In perspective of landscape change, landform change (terrace and check-dam) tends to reduce baseflow by reallocation of surface fluxes and retention for crop growth causing limited deep drainage in other areas. Land cover change (i.e., afforestation) reduced the baseflow to a larger extent by enhanced evapotranspiration and thus hampered deep drainage as suggested by the soil moisture measurement underneath. The study indicates that knowledge about baseflow formation on catchment scale needs further improvement. Integrated soil conservation and water management for optimizing landscape structure and function in order to balance soil (erosion) and water (supply) related hydrological ecosystem services is vital. The governing processes to the changes of water-supply-services-related hydrological process (e.g., streamflow) are assumed to be different across space. To this end, the factors controlling streamflow were investigated on both a small and large scale. Streamflow in small catchments was found to be mainly controlled by precipitation and land cover type. On a larger scale, evaporative demand was found to be another additional major driving force. Hydrological modeling is a frequently used tool for the assessment of impacts of land use and climate change on water balance and water fluxes. However, application of the Soil and Water Assessment Tool (SWAT) model in the upstream Jinghe watershed was unsuccessful due to difficulties in calibration. The inability of the SWAT model to take the influence of terraces on steep slopes into consideration and the method how to calculate lateral flow were the main reasons for unsatisfactory calibration, at least for the current version of SWAT used in this study. Alternatively, Budyko’s frameworks were applied to predict the annual and long-term streamflow. However, the effect of changes in land management (e.g., afforestation) on streamflow could not be assessed due to a lack of vegetation factors. Therefore, an empirical analysis tool was derived based on an existing relationship for estimation. This method was found to be the most effective in reproducing the annual and long-term streamflow. The incorporation of temporal changes in land cover and form in the approach enables the estimation of the possible impact of soil conservation measures (e.g., afforestation or terracing). The importance of adaptive land management strategies for mitigating water shortage and securing the water supply services on the Loess Plateau was highlighted. A cross-sectoral view of the multiple services offered by managed ecosystems at different spatial scales under changing environments needs to be integrated to improve adaptive land management policy. In a water limited environment, such as the Loess Plateau, multiple ecosystem services including hydrological services need to be balanced with minimum trade-offs. This can only be achieved when management is based on a holistic understanding of the interdependencies among various ecosystem services and how they might change under alternative land management.

Viele Menschen arbeiten daran, dass immer ausreichend Trinkwasser in der bestmöglichen Qualität und zu sozialverträglichen Preisen zur Verfügung steht. Die Landestalsperrenverwaltung steht ganz am Anfang der Kette. Der Staatsbetrieb speichert Oberflächenwasser und gibt es als Rohwasser an Wasserwerke ab. Redaktionsschluss: 31.05.2016

Dieses Dissertationsprojekt befasst sich mit der Bedeutung von urbaner Infrastruktur für syrische Stadtbewohner:innen vor Beginn des Krieges, der auf die friedlichen Proteste im Jahre 2011 folgte. Fokus der Arbeit liegt auf den Infrastrukturnetzwerken Wasserversorgung und Müllentsorgung in der Stadt Aleppo im Nordwesten Syriens. In den Interviews, die für die Forschungsarbeit mit aleppinischen Exilant:innen geführt wurden, zeigte sich, dass die beiden Netzwerke auch über ihren Zusammenbruch im Kontext kriegerischer Auseinandersetzungen in Aleppo (insbesondere zwischen 2012 und 2016) hinaus Funktionen im Leben der Befragten erfüllten – nun mehr weit weg von Aleppo im westeuropäischen Exil. Beispielsweise diente die Beschreibung von privaten Praktiken und institutionalisierten Abläufen der Müllentsorgung auch im Exil der Einteilung der aleppinischen Bevölkerung in bestimmte soziale Gruppen. Auch die politische Bedeutung der Wasserversorgung überdauerte den infrastrukturellen Kollaps. Vor diesem Hintergrund diskutiert diese Dissertation mit Hinblick auf insbesondere Literatur inspiriert durch die actor-network theory die zeitliche Verortung und Entstehung von Infrastrukturen. Insbesondere wird hinterfragt, ob die sozialen und materiellen Komponenten, die gemeinsam ein Infrastrukturnetzwerk bilden, notwendigerweise in Raum und Zeit koexistieren müssen. Hier schlägt die Arbeit ein Konzept von Infrastruktur vor, die zu verschiedenen Zeitpunkten (dispersed in time) und, im Migrationskontext, auch an verschiedenen Orten entsteht. / This dissertation project focuses on the meaning of urban infrastructure for Syrian city dwellers before the beginning of the war that followed the peaceful protests in 2011. The project thereby focuses on the infrastructural networks of water supply and waste disposal in the city of Aleppo in northwestern Syria. Interviews conducted with Aleppans in exile showed how the two networks continued to play role in the interlocutors’ lives in Western Europe also beyond the infrastructural breakdown in the context of armed conflict in Aleppo (especially between 2012 and 2016). For example, the description of private practices and institutionalized processes of garbage disposal still served to divide the Aleppan population into specific social groups in exile. Likewise, the political meaning of water supply in Aleppo survived the infrastructural collapse of the provision of water in the city. Against this background, this dissertation discusses the temporality of the emergence of infrastructures with regard to literature inspired by actor-network theory. In particular, it questions whether the social and material components that in their interactions form an infrastructural network necessarily need to coexist in time and space. Here, the work proposes a concept of infrastructure that emerges at different points in time (infrastructure as dispersed in time), and, in the context of migration, also in different places.

Coleanthus subtilis ist eine durch die FFH-Richtlinie geschützte, weltweit sehr seltene Art, welche periodisch trockenfallende Standorte in Flussauen (Primärhabitate) bzw. durch den Menschen geschaffene Staugewässer (Sekundärhabitate) besiedelt. Die Erarbeitung der aktuellen Verbreitungsbilder der Art in Sachsen und ihrer Besiedlungshistorie waren Ausgangspunkt für die Analysen zur Ökologie dieser Art. Anhand von Analysen zu den Ausbreitungsmechanismen, Standortansprüchen und Reaktionsmöglichkeiten von C. subtilis wurden grundlegende Beiträge zum besseren Verständnis der Strategien dieser Art erbracht. Die Arbeit gibt Hinweise für eine artenschutzgerechte Bewirtschaftung der Staugewässer insbesondere für die Regulierung von Zeitpunkt, Dauer, Intensität und Häufigkeit von Wasserstandsabsenkungen sowie hinsichtlich einzelner Praktiken im Zusammenhang mit einer fischereilichen Nutzung. Weiterhin zeigt die Arbeit auf, wie C. subtilis auf bestimmte, von den durchschnittlichen Wasserstandsschwankungen abweichende, Bedingungen reagieren kann. Damit sind nun wichtige Grundlagen zum nachhaltigen Schutz und zur Förderung von C. subtilis, insbesondere in Sekundärhabitaten, vorhanden. / Coleanthus subtilis is a globally rare species protected by the European Union Habitats Directive. This grass establishes on periodically drying sites in river floodplains (primary habitats) but also in man made ponds and reservoirs (secondary habitats). The identification of the present distribution patterns as well as the reconstruction of the colonisation history of C. subtilis in Saxony were the basis for analyses about the ecology of this species. By analysing dispersal mechanisms, habitat demands and response traits of C. subtilis fundamental contributions to a better understanding of the strategies of this species are given. The thesis provides information about optimum time, duration, intensity and frequency of water level reductions and about the consequences of different management practices particularly with respect to fishery in ponds and reservoirs inhabiting C. subtilis. Further the thesis shows how C. subtilis can cope with deviations from mean water level fluctuations. In summary important fundamental knowledge for the sustainable conservation and promotion of C. subtilis, particularly in secondary habitats, has been established.