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Measuring penetration resistance (PR) is a common technique for evaluating the effects of field management on soils. This study focuses on the effects of long-term tillage on the spatial distribution of PR, comparing reduced and conventional tillage (CT) practices. The study site, located in Lower Saxony (Germany), has been subdivided into three plots, with one plot having been managed conventionally, whereas reduced tillage (RT) practices have been applied to the other two. In total, PR was measured at 63 randomly selected points. The PR data were stepwise interpolated using kriging with external drift. Core samples have been taken at 20 additional sites. The results show significant differences in PR between the different tillage practices. Within the conventionally managed plot, PR ranges to 2.3 MPa less in the topsoil than under RT. However, measured saturated hydraulic conductivity and amount of biopores at the depth of 30-35 cm are significantly greater under RT, indicating improved soil properties under RT. Comparisons between the headlands (HL) and the inner field point out the effects of intense field traffic in the HL, where maximum PR values of about 6 MPa have been measured. The spatial prediction of PR values show that long-term effects of different tillage practices result in clearly structured patterns between CT and RT and the HL. Combining extensive PR measurements and point measurements of additional soil properties supports an adequate interpretation of PR data and can lead to fieldwide derivation of soil functions influenced by field management.

The increasing use of biogas, produced from energy crops like silage maize, is supposed to noticeably change the structures and patterns of agricultural landscapes in Europe. The main objective of our study is to quantify this assumed impact of intensive biogas production with the example of an agrarian landscape in Northern Germany. Therefore, we used three different datasets; Corine Land Cover (CLC), local agricultural statistics (Agrar-Struktur-Erhebung, ASE), and data on biogas power plants. Via kernel density analysis, we delineated impact zones which represent different levels of bioenergy-generated transformations of agrarian landscapes. We cross-checked the results by the analyses of the land cover and landscape pattern changes from 2000 to 2012 inside the impact zones. We found significant correlations between the installed electrical capacity (IC) and land cover changes. According to our findings, the landscape pattern of cropland—expressed via landscape metrics (mean patch size (MPS), total edge (TE), mean shape index (MSI), mean fractal dimension index (MFRACT)—increased and that of pastures decreased since the beginning of biogas production. Moreover, our study indicates that the increasing number of biogas power plants in certain areas is accompanied with a continuous reduction in crop diversity and a homogenization of land use in the same areas. We found maximum degrees of land use homogenisation in areas with highest IC. Our results show that a Kernel density map of the IC of biogas power plants might offer a suitable first indicator for monitoring and quantifying landscape change induced by biogas production.

“The Anthropocene” currently serves as a framework to acknowledge global human influences on the earth systems. Different prominent authors call for geographers and especially physical geographers to intensify their involvement in the discussions on the theme. A bibliometric analysis shows that geographers are already one of the leading contributors to the keyword Anthropocene in journal articles. While we generally support the standpoint of increased engagement with the topic, we want to emphasize that we need to do more than only attaching the “Anthropocene” label to our daily research practice. A critical engagement with and reflection of the research questions and contexts is needed to play a vital role as discussant in the debate. We should take advantage of the diverse themes, topics and viewpoints of our subject by actively following a more critical approach to our research practices in order to find those geographic ties that join us and our discipline and that enable us to contribute more substantially to the Anthropocene debate.

Heat demand of buildings and related CO2 emissions caused by energy supply contribute to global climate change. Spatial data-based heat planning enables municipalities to reorganize local heating sectors towards efficient use of regional renewable energy resources. Here, annual heat demand of residential buildings is modeled and mapped for a German federal state to provide regional basic data. Using a 3D building stock model and standard values of building-type-specific heat demand from a regional building typology in a Geographic Information Systems (GIS)-based bottom-up approach, a first base reference is modeled. Two spatial data sets with information on the construction period of residential buildings, aggregated on municipality sections and hectare grid cells, are used to show how census-based spatial data sets can enhance the approach. Partial results from all three models are validated against reported regional data on heat demand as well as against gas consumption of a municipality. All three models overestimate reported heat demand on regional levels by 16 to 19%, but underestimate demand by up to 8% on city levels. Using the hectare grid cells data set leads to best prediction accuracy values at municipality section level, showing the benefit of integrating this high detailed spatial data set on building age.

The transition to renewable energy sources requires extensive changes to the energy system infrastructure, ranging from individual households to the national scale. During this transition, stakeholders must be able to make informed decisions, researchers need to investigate possible options and analyse scenarios, and the public should be informed about developments and options for future infrastructure. The data and parameters required for this are manifold and it is often difficult to create an overview of the current situation for a region of interest. We propose an environmental information system for the visualisation and exploration of large collections of heterogeneous data in the scope of energy system infrastructure and subsurface geological energy storage technologies. Based on the study area of Schleswig-Holstein, a federal state in Germany, we have set up a virtual geographic environment integrating GIS data, topographical models, subsurface information, and simulation results. The resulting application allows users to explore data collection within a unified context in 3D space, interact with datasets, and watch animations of selected simulation scenarios to gain a better understanding of the complex interactions of processes and datasets. Based on the cross-platform game engine Unity, our framework can be used on regular PCs, head-mounted displays, and virtual reality environments and can support domain scientists during assessment and exploration of the data, encourages discussions and is an effective means for outreach activities and presentations for stakeholders or the interested public.

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<p>High temperature aquifer thermal energy storage (HT-ATES) is a promising technology for mitigating the temporal disparity between availability and demand for heating energy supply. By applying seasonal storage, renewable or alternative sources like waste heat can be used, reducing the dependency on fossil fuels and avoiding CO<sub>2</sub>-emissions.</p> <p>HT-ATES uses external heat sources and stores heat in suitable formations in the geological underground by injecting hot water at temperatures of up to 90°C. Balanced energy injection and extraction however, is usually not feasible due to energy losses, leading to residual heat in the subsurface and maybe changing groundwater composition and quality. This study shows that numerical simulations can be used to quantify the thermal impact of heat storage on the geological storage formations as well as the subsurface space demand of such storage sites.</p> <p>In a hypothetical scenario, a HT-ATES system is designed to store about 35 GWh/a of excess heat from solar thermal installations and a waste incineration plant, which would cover about 20 % of the heat energy needs of a typical city district. For this purpose, a three-dimensional numerical model of the HT-ATES is set up, which consists of six well doublets placed at 100 m depth in a typical northern German Pleistocene formation, a sand aquifer bounded by till layers at the top and bottom. The screen lengths of all wells cover the entire storage formation thickness of 20 m. The daily excess heat storage demand is derived from the estimated daily heat demand for space heating and hot water production for the city district, based on an available 3D building stock model and daily outside temperature data for 2018, combined with a supply curve for solar thermal heat production, which is based on available roof and open space area in the district and daily global radiation data for the location of the district from 2018.</p> <p>Injection flow rates vary between 0 and 45 m³/h, while the injection temperature is assumed constant at 70°C. The extraction flow rates are controlled by a well doublet control module, which iteratively adapts the extraction flow rates according to the heat demand curve.</p> <p>Results show that during the heating period from October to May, at least 21 GWh and up to 26 GWh after 30 years of operation or 12 - 15 % of total district heat demand can be supplied each year by the HT-ATES. Supply temperatures range from 70 to 39 °C at the start and at the end of the heating period, respectively. The storage efficiency increases from 65 to 74 to 78 % after 5, 15 and 30 years of operation, respectively. After 30 years, the HT-ATES operation affects an ellipsoid shaped volume of 28 Mio m³ with temperature increases of > 1 °C, which corresponds to the volume of a cube of approximately 300 m side length.</p>