Studienlandschaft Schwingbachtal: an out-door full-scale learning tool newly equipped with augmented reality

This paper addresses education and communication in hydrology and geosciences. Many approaches can be used, such as the well-known seminars, modelling exercises and practical field work but out-door learning in our discipline is a must, and this paper focuses on the recent development of a new out-door learning tool at the landscape scale. To facilitate improved teaching and hands-on experience, we designed the Studienlandschaft Schwingbachtal. Equipped with field instrumentation, education trails, and geocache, we now implemented an augmented reality App, adding virtual teaching objects on the real landscape. The App development is detailed, to serve as methodology for people wishing to implement such a tool. The resulting application, namely the Schwingbachtal App, is described as an example. We conclude that such an App is useful for communication and education purposes, making learning pleasant, and offering personalized options

Constraining a complex biogeochemical model for CO₂ and N₂O emission simulations from various land uses by model-data fusion

This study presents the results of a combined measurement and modelling strategy to analyse N₂O and CO₂ emissions from adjacent arable land, forest and grassland sites in Hesse, Germany. The measured emissions reveal seasonal patterns and management effects, including fertilizer application, tillage, harvest and grazing. The measured annual N₂O fluxes are 4.5, 0.4 and 0.1 kg N ha$^{-1}$ a$^{-1}$, and the CO₂ fluxes are 20.0, 12.2 and 3.0 t C ha$^{-1}$ a$^{-1}$ for the arable land, grassland and forest sites, respectively. An innovative model–data fusion concept based on a multicriteria evaluation (soil moisture at different depths, yield, CO₂ and N₂O emissions) is used to rigorously test the LandscapeDNDC biogeochemical model. The model is run in a Latin-hypercube-based uncertainty analysis framework to constrain model parameter uncertainty and derive behavioural model runs. The results indicate that the model is generally capable of predicting trace gas emissions, as evaluated with RMSE as the objective function. The model shows a reasonable performance in simulating the ecosystem C and N balances. The model–data fusion concept helps to detect remaining model errors, such as missing (e.g. freeze–thaw cycling) or incomplete model processes (e.g. respiration rates after harvest). This concept further elucidates the identification of missing model input sources (e.g. the uptake of N through shallow groundwater on grassland during the vegetation period) and uncertainty in the measured validation data (e.g. forest N₂O emissions in winter months). Guidance is provided to improve the model structure and field measurements to further advance landscape-scale model predictions

Nonequilibrium entropy production for open quantum systems

We consider open quantum systems weakly coupled to a heat reservoir and driven by arbitrary time-dependent parameters. We derive exact microscopic expressions for the nonequilibrium entropy production and entropy production rate, valid arbitrarily far from equilibrium. By using the two-point energy measurement statistics for system and reservoir, we further obtain a quantum generalization of the integrated fluctuation theorem put forward by Seifert [PRL 95, 040602 (2005)].Comment: 4 pages, 1 figur

Lasst Gras darüber wachsen : Zur Überweidung der Grassteppe in der Inneren Mongolei

Die Lebensbedingungen der Nomaden in Zentralasien haben sich im letzten Jahrhundert grundlegend verändert. So wurden z.B. in der Inneren Mongolei, einer Autonomen Region im Nordosten von China, die Nomaden in der zweiten Hälfte des 20. Jahrhunderts sesshaft gemacht. In einem engen Zusammenhang mit diesen Veränderungen stehen die Überweidung der Grassteppe, Bodenerosion und Sandstürme in diesen Gebieten. Im Rahmen eines interdisziplinären Forschungsprojektes, das in Zusammenarbeit mit der Chinese Academy of Science durchgeführt und von der Deutschen Forschungsgemeinschaft gefördert wird, befasst sich eine Arbeitsgruppe des Instituts für Landschaftsökologie und Ressourcenmanagement der Universität Gießen mit Fragen zum Wasserhaushalt, mit der Wassererosion und mit dem Austrag von Kohlenstoff und Stickstoff über die Gewässer in der Inneren Mongolei

Sensitivity analysis of a climate vulnerability index - a case study from Indian watershed development programmes

Background: This paper presents a detailed analysis of a composite Climate Vulnerability Index (CVI) to examine and compare climate change vulnerability and its dimensions adaptive capacity, sensitivity and exposure. Thereby, we are mainly interested on climate change vulnerability at community-level watershed development programmes and how the different implementing agencies could help to address the problems associated with climate change in future planning and implementation. Method: The primary data used for this study was obtained from household surveys (n=215) in three watershed communities of Kerala, India. We use bootstrap sampling and a leave-one-out sensitivity analysis to compare the climate vulnerability of the three examined watersheds in detail. By introducing the bootstrapping method and sensitivity analysis into the research field of climate vulnerability, the paper describes significant differences in CVI values and the influencing indicators to the overall vulnerability at the watershed community level. Results The results show that there are significant differences in the exposure and sensitivity dimensions of vulnerability even if the overall CVI shows less variability and no significant differences among the three watersheds. The sensitivity analysis emphasizes that Livelihood Strategies and SSocial Network are the most influencing major components of vulnerability. This suggests that implementing agencies should focus on these two major components in order to improve the watershed development programmes. Conclusion The bootstrapping approach is transferable to evaluate the degree of influence of indicators on a composite index like the CVI. Moreover, it allows us to evaluate the potential effectiveness of various other climate change programmes where the evaluation is commonly done by field surveys. This thereby helps to increase the credibility in the examination of the impacts of climate change at different scales in order to find key areas for better policy planning

a resonant Raman study

We report resonant Raman scattering (RRS) by the TO, LO, and 2 LO modes of single wurtzite and zinc-blende GaAs nanowires. The optical band gap of wurtzite GaAs is 1.460eV ± 3meV at room temperature, and 35 ± 3meV larger than the GaAs zinc-blende band gap. Raman measurements using incoming light polarized parallel and perpendicular to the wire c axis allowed us to investigate the splitting of heavy Γ9 and light-hole Γ7 band at the Γ point of 65 ± 6meV

Improving irrigation efficiency will be insufficient to meet future water demand in the Nile Basin

The Nile River Basin covers an area of approximately 3.2 million km2 and is shared by 11 countries. Rapid population growth is expected in the region. The irrigation requirements of Nile riparian countries of existing (6.4 million ha) and additional planned (3.8 million ha, 2050) irrigation schemes were calculated, and the likely water savings through improved irrigation efficiency were evaluated. We applied SPARE:WATER to calculate irrigation demands on the basis of the well-known FAO56 Crop Irrigation Guidelines. Egypt (67 km3 yr-1) and Sudan (19 km3 yr-1) consume the highest share of the 84 km3 yr-1 total (2011). Assuming today’s poor irrigation infrastructure, the total consumption was predicted to increase to 123 km3 yr-1 (2050), an amount far exceeding the total annual yield of the Nile Basin. Therefore, a key challenge for water resources management in the Nile Basin is balancing the increasing irrigation water demand basin-wide with the available water supply. We found that water savings from improved irrigation technology will not be able to meet the additional needs of planned areas. Under a theoretical scenario of maximum possible efficiency, the deficit would still be 5 km3 yr-1. For more likely efficiency improvement scenarios, the deficit ranged between 23 and 29 km3 yr-1. Our results suggest that that improving irrigation efficiency may substantially contribute to decreasing water stress on the Nile system but would not completely meet the demand. Study Region: The Nile River Basin covers an area of approximately 3.2 million km2 and is shared by 11 countries. Rapid population growth is expected in the region. Study Focus: Record population growth is expected for the study region. Therefore, the irrigation requirements of Nile riparian countries of existing (6.4 million ha) and additional planned (3.8 million ha, 2050) irrigation schemes were calculated, and likely water savings through improved irrigation efficiency were evaluated. We applied a spatial decision support system (SPARE:WATER) to calculate the irrigation demands on the basis of the well-known FAO56 Crop Irrigation Guidelines. New Hydrological Insights for the Region: Egypt (67 km3yr-1) and Sudan (19 km3yr-1) consume the highest share of 84 km3yr-1 (2011). Assuming today’s poor irrigation infrastructure, the total demand were predicted to increase to 123 km3yr-1 (2050), an amount far exceeding the total annual yield of the Nile Basin. Therefore, a key challenge for water resources management in the Nile Basin is balancing the increasing irrigation water demand and available water supply. We found that water savings from improved irrigation technology will not be able to meet the additional needs of planned areas. Under a theoretical scenario of maximum possible efficiency, the deficit would still be 5 km3yr-1. For more likely efficiency improvement scenarios, the deficit ranges between 23 and 29 km3yr-1. Our results suggest that improving irrigation efficiency may substantially contribute to decreasing water stress on the Nile system but would not completely meet the demand