Datenbearbeitung und 3D Modellierung des Schwerefeldes am Beispiel des Salzstocks Geesthacht-Hohenhorn

Die Nutzung des unterirdischen Raumes ist ein wesentlicher Aspekt bei der Untersuchung von Systemen für die Speicherung von Energie. Dabei ist es nicht nur notwendig hinreichende Kenntnisse über die geologische Struktur des Untergrundes zu haben sondern auch die geophysikalischen Eigenschaften und Verhaltensweisen des Untergrundes zu untersuchen. Die vorliegende Arbeit beschreibt den Aufbau eines gravimetrischen 3D Untergrundmodells unter Berücksichtigung von geologischen sowie geophysikalischen Randbedingungen. Die Anwendung eines geologischen 3D Geometriemodells (GOCAD), welches vom Landesamt für Landwirtschaft, Umwelt und ländliche Räume Schleswig-Holstein zur Verfügung gestellt wurde, bildet die geologische Grundlage für die Erstellung des 3D Dichtemodells. Die geophysikalischen Randbedingungen sind im Wesentlichen die gravimetrischen Messdaten, die vom Leibniz-Institut für Angewandte Geophysik, Hannover sowie vom Wirtschaftsverband Erdöl- und Erdgasgewinnung e. V. bereitgestellt wurden. Die untersuchte Region befindet sich im Norddeutschen Becken, im Südosten des Glückstadt Grabens. Im Zentrum der Untersuchung liegt der Salzstock Geesthacht-Hohenhorn und dessen Umgebung. In der Arbeit wird zunächst die tektonische Situation im Untersuchungsgebiet unter besonderer Beachtung der Salztektonik betrachtet. Dabei wird auch auf einzelne Konzepte der Salzbewegung eingegangen. Anschließend erfolgt eine ausführliche Beschreibung der Datengrundlagen sowie des verwendeten geophysikalischen Modellierprogramms IGMAS+ (Interactive Geophysical Modelling ASsistant). Des Weiteren wird der Aufbau sowie die einzelnen Entwicklungsschritte der Bearbeitung des gravimetrischen Modells genauer erläutert. Dabei wird sowohl auf die Verteilung der Dichtewerte als auch auf die geometrischen Änderungen eingegangen. Das aufgebaute gravimetrische 3D Modell besteht aus 12 geologischen Schichten und erreicht eine Tiefe von ca. 5500 Meter. Die Modellierung konzentriert sich vor allem auf die geologische Schichtabfolge sowie die vorkommenden Salzstrukturen. Anschließend erfolgt eine Betrachtung des Stresses im Untersuchungsgebiet, der besonders im Zusammenhang mit möglichen Bohraktivitäten im untersuchten Gebiet von Interesse ist. Es konnte festgestellt werden, dass der Stress mit den Mächtigkeiten der geologischen Schichten korreliert und besonders die Trogstrukturen im untersuchten Gebiet gut widerspiegelt. Insgesamt konnte in dieser Arbeit ein gravimetrisches Modell aufgebaut werden, welches sowohl mit den geologischen als auch mit den geophysikalischen Randbedinungen hinreichend übereinstimmt. Ebenso eine Verifizierung des geologischen 3D Untergrundmodells ist durch die Betrachtung der geometrischen Änderungen möglich. Allerdings konnte auch festgestellt werden, dass die Genauigkeit und der Detailgrad der gravimetrischen Modellierung sehr stark von der Auflösung der gravimetrischen Messdaten abhängig ist. Das vorliegende gravimetrische 3D Modell kann als Grundlage für weitergehende Untersuchungen, wie beispielsweise Simulationen der Ausbreitung sowie des Monitorings von energetischen Stoffen genutzt werden.The usage of the subsurface is a key aspect in the study of systems for the storage of energy. Thereby it is not only necessary to have sufficient knowledge of the geological structure of the underground but also to investigate the geophysical properties and behaviours of the subsurface. This work describes the construction of a gravimetric 3D subsurface model taking into account geological and geophysical constraints. The application of a geological 3D geometry model (GOCAD), which was provided by the State Agency for Agriculture, Environment and Rural Areas of Schleswig-Holstein, forms the geological basis for the generation of the 3D density model. The geophysical constraints are basically the gravimetric measurement data, which were provided by the Leibniz Institute for Applied Geophysics, Hannover, as well as by the Wirtschaftverband Erdöl- und Erdgasgewinnung e.V. The study area is located in the North German Basin, in the southeast of the Glueckstadt Graben. The focus of the investigation is the salt dome Geesthacht-Hohenhorn and its surroundings. In this work the tectonic situation in the study area is first considered particularly with regard to salt tectonics. Also single concepts of salt movement were illustrated. This is followed by a detailed description of the data and of the used geophysical modeling program IGMAS+ (Interactive Geophysical Modeling ASsistant). Furthermore, the structure and the single stages of the development of the gravimetric model is described in more detail. Thereby attention is payed to both the distribution of the density values and the geometric changes. The generated gravimetric 3D model consists of 12 geological layers and has a depth of approximately 5500 meters. The modeling focuses on the geological formations as well as the occurring salt structures. Subsequently, an examination of the stress in the study area is carried out, which is particularly of interest in the context of potential drilling activities in the studied area. It could be noticed that the stress correlates with the thickness of the geological layers and especially reflects the trough structures in the study area. Overall, a gravimetric model, which sufficiently agrees with both the geological and the geophysical constraints, could be developed in this work. Similarly, a verification of the 3D geological subsurface model is possible by considering the geometrical changes. However, it was also found that the accuracy and level of detail of the gravimetric modeling is highly dependent on the resolution of gravimetric measurement data. The present gravimetric 3D model can be used as a basis for further investigations, such as simulation of the propagation as well as the monitoring of energetic substances

Technische Dokumentation zum Modell ReWaLe (Regionalisierung des ökonomischen Wertes von Waldleistungen)

In the project "Quantification and regionalisation of the value of forest ecosystem services in Germany (ReWaLe)", the economic benefits of forest ecosystem services are analysed. In particular, the forest ecosystem services of raw wood production, climate protection, recreational services and various services for nature protection and landscape preservation are considered. The model developed within this framework combines valuation data with regional statistical information applying valuation functions implemented in a geographic information system (GIS) and visualises the results. The regional data are managed with the help of geodatabases and can thus be applied to the model calculation. The ReWaLe model consists of a toolbox in which the various valuation functions are implemented. The application is possible via input masks as well as scripts. Simulations of how changes in forest management affect economic forest values can be done by varying the input data into the model. This technical documentation for the ReWaLe model (regionalisation of the economic value of forest services) includes a brief introduction, information on the data basis used and available in the project, the data preparation and processing relevant for the model, and a description of the implementation of the valuation functions in the geographic information system. In addition, information on licensing rights, the coordinate system used and the definition of forest in the project are explained

Regionalisierte Bewertung der Waldleistungen in Deutschland

The study aims at determining the economic benefits of fundamental forest ecosystem services (FES) in Germany from a demand perspective, at identifying their regional distribution, and at merging the respective benefit estimates into a consistent model which provides for scenario analyses of alternative forest utilisation options. Specifically, we consider the monetary benefits of raw wood production as a FES, of global climate protection (via carbon sequestration), of everyday recreation for the population, and of services for nature protection and landscape amenity, which accrue in the course of regular forest management as well as due to the establishment of separate protection areas. For this purpose, we combine available valuation data, information from official regional statistics, and an additional primary study, to identify regional specific drivers of the FES’ monetary benefits and to derive generic valuation functions for each of the services. Using a Geographical Information System, these valuation functions are then applied to the conditions in the Local Administrative Units (municipalities), resulting in Benefit Function Transfer estimates for each service and each municipality. Afterwards, results are aggregated to NUTS-3 level (counties) and mapped. Subsequently we simulate the consequences of modified regional conditions (e.g., modified forest management) for FES values and their relations, by appropriately changing the input data

Spatial Distribution of Forest Ecosystem Service Benefits in Germany: A Multiple Benefit-Transfer Model

We investigate the economic benefits of fundamental forest ecosystem services (FES) for the population in Germany at national level in monetary terms and estimate the spatial distribution of these benefits at county level. Specifically, we consider the benefits of timber production, of global climate protection due to carbon sequestration, of recreation for local residents, and of services for nature protection and landscape amenity. Combining information from official statistics and data from valuation studies that are compatible with economic demand theory, we identify spatial drivers of FES benefits and derive generic valuation functions for each of the services. Using a Geographic Information System, these valuation functions are applied to the conditions in the Local Administrative Units (municipalities), resulting in Benefit Function Transfer estimates for each service and each municipality. Afterwards, results are aggregated to NUTS-3 level (counties) and mapped. Aggregate annual benefits of timber production to society as a whole, of climate protection and of recreation services together exceed the ten billion Euro mark—far more than what is reflected in market statistics. Scenarios illustrate the potential for enhancing nature protection benefits particularly by restoring forest biodiversity, as measured by an avifaunistic indicator. The spatial analysis reveals distinct distributional patterns for each of the services. We conclude that a spatially explicit valuation for an entire country is possible even with limited data, which can help policy makers improve the institutional setting in a way that the protection and use of the forests become more sustainable and efficient. After pointing at several caveats, we finally suggest various possibilities for further model development.BMEL, 22022614, Verbundvorhaben: Quantifizierung und Regionalisierung des Wertes von Waldökosystemleistungen in Deutschland; Teilvorhaben 1: Zentrale Modellentwicklung, Primärdatenanalysen und nationaler Benefit Transfe