Scaling issues in multi-criteria evaluation of combinations of measures for integrated river basin management

In integrated river basin management, measures for reaching the environmental objectives can be evaluated at different scales, and according to multiple criteria of different nature (e.g. ecological, economic, social). Decision makers, including responsible authorities and stakeholders, follow different interests regarding criteria and scales. With a bottom up approach, the multi criteria assessment could produce a different outcome than with a top down approach. The first assigns more power to the local community, which is a common principle of IWRM. On the other hand, the development of an overall catchment strategy could potentially make use of synergetic effects of the measures, which fulfils the cost efficiency requirement at the basin scale but compromises local interests. Within a joint research project for the 5500 km2 Werra river basin in central Germany, measures have been planned to reach environmental objectives of the European Water Framework directive (WFD) regarding ecological continuity and nutrient loads. The main criteria for the evaluation of the measures were costs of implementation, reduction of nutrients, ecological benefit and social acceptance. The multi-criteria evaluation of the catchment strategies showed compensation between positive and negative performance of criteria within the catchment, which in the end reduced the discriminative power of the different strategies. Furthermore, benefit criteria are partially computed for the whole basin only. Both ecological continuity and nutrient load show upstream-downstream effects in opposite direction. The principles of "polluter pays" and "overall cost efficiency" can be followed for the reduction of nutrient losses when financial compensations between upstream and downstream users are made, similar to concepts of emission trading.BMBF/FKZ/033021

Simulation of Irrigation Demand and Control in Catchments – A Review of Methods and Case Studies

The world's water resources are continuously facing challenges in fulfilling the needs of increasing agricultural water demand with finite or diminishing resources. Therefore, it is important to quantify the amount of irrigation water required to attain sustainable yield at a local, regional, and global level, especially in arid and semi-arid regions. This is mostly quantified by using agro-hydrological or agricultural models. The advances in simulation models and several options incorporated in them allow catchment/site-specific application of irrigation water to depict the field management practices undertaken by farmers. The objective of the present study is to provide a review of the simulation of irrigation water demand at catchment scale by agro-hydrological and agricultural models. This study discusses the different types of models, their dimensions, and the hydrological and agricultural process models incorporated into them. Additionally, this review provides an overview of how irrigation can be scheduled, how water is applied, and from which sources irrigation water can be extracted by the considered models, taking horizontal hydrological connectivity into consideration. Adding to the model review, seven different fields of innovative case studies are covered. Many agricultural models have been applied in a regional context without simulating horizontal hydrological fluxes, but only a few hydrological catchment models provide full support of both irrigation and plant growth simulation, which are important for the simulation of future crop yield under different climatic and agricultural management scenarios

Combined Weak Lensing and X-Ray Search for Galaxy Clusters and the Filaments Connecting Them

The work presented here has four main parts. (1) A newly developed, almost fully automated data reduction pipeline for optical single- and multi-chip CCD cameras is described. Its image products are compared to those against reduced images produced from an independently developed pipeline. The comparison shows very good agreement between both pipelines. (2) The theory of cosmic structure formation predicts a filamentary large-scale structure of the Universe. These filaments have been observed in large scale redshift surveys for some time. Here we present an attempt to map such a filament between the close pair of massive galaxy clusters A 222/223 using weak gravitational lensing. A mass bridge connecting both clusters is seen in a mass reconstruction making this system only the third known candidate for such a filamentary structure observed with weak lensing. (3) A public imaging survey following-up on deep XMM-Newton exposures was carried out as collaboration between ESO, the XMM-Newton Survey Science Centre, and the University of Bonn. We present the reduced and calibrated data released from this survey in July 2005. (4) A combined X-ray, optical matched filter, and X-ray search for clusters of galaxies is carried out on the XMM-Newton Follow-Up Survey. We develop and test our selection criteria for the weak lensing search using ray-tracing simulations through N-body simulations. With the adopted selection criteria we find 28 significant weak lensing peaks that positionally coincide with either X-ray or optical matched filter selected cluster candidates, or correspond to previously known clusters

Partonic scattering cross sections in the QCD medium

A medium modified gluon propagator is used to evaluate the scattering cross section for the process gg - gg in the QCD medium by performing an ex- plicit sum over the polarizations of the gluons. We incorporate a magnetic sreening mass from a non - perturbative study. It is shown that the medium modified cross section is finite, divergence free, and is independent of any ad-hoc momentum transfer cut-off parameters. The medium modified finite cross sections are necessary for a realistic investigation of the production and equilibration of the minijet plasma expected at RHIC and LHC PACS: 12.38.Mh; 14.70.Dj; 12.38.Bx; 11.10.W

Hochwasservorhersage und effektive Warnung : Die Überschwemmungen im Erzgebirge (2002) und in der Eifel (2021)

Am 14. Juli 2021 ereignete sich in der Eifel eine Hochwasserkatastrophe, deren Auswirkungen selbst die Fachwelt überrascht und erschüttert haben. In Anbetracht der zahlreichen Todesopfer und der enormen Sachschäden stellt sich die Frage, ob das Hochwasser vorhersehbar war und warum nicht angemessen gewarnt wurde. Jörg Dietrich, Wissenschaftler am Institut für Hydrologie und Wasserwirtschaft erläutert die Zusammenhänge

Einfluss bauchemisch relevanter Schadstoffe auf Mineralphasen und mechanisch-hydraulische Eigenschaften werksfertiger Einphasen-Dichtwandmassen

Bisher existieren keine Richtlinien, nach denen der Einfluss gelöster Schadstoffe auf die mechanisch-hydraulischen Eigenschaften von Dichtwandmassen beurteilt werden kann. In der Baupraxis wird daher behelfsweise DIN EN 206, Teil 1 (2001) herangezogen, die die Entfestigungswirkung von Wasserinhaltsstoffen auf Betone einstuft. Dichtwandmassen unterscheiden sich jedoch sowohl im Mineralbestand als auch hinsichtlich des Feststoffgehaltes deutlich von Betonen. Im Rahmen dieser Arbeit wurde überprüft, ob die in DI N 206, Teil 1 (2001) angegebenen Kriterien zur Beurteilung der Schadstoffbeständigkeit von Betonen auf Dichtwandmassen übertragbar sind. Hierzu wurden neun unterschiedlich zusammengesetzte werksfertige Einphasen-Dichtwandmassen über bis zu 270 Tage in Lösungen der betonaggressiven Schadstoffe Magnesium, Sulfat und Kohlensäure gelagert. Zur Bestimmung des schadstoffspe-zifischen Einflusses auf die hydraulisch-mechanischen Eigenschaften und den Mineralbestand der Dichtwandmassen wurden insgesamt 1850 Einzelversuche durchgeführt. Neben der einaxialen Druckfestigkeit wurde die Oberflächenaufweichung, die Durchlässigkeit sowie die Expansion und Massenänderung der eingelagerten Dicht-wandmassen bestimmt. Die in magnesiumhaltigen Lösungen eingelagerte feststoffarme Dichtwandmasse zeigte bereits bei Magnesiumkonzentrationen, die von DIN EN 206, Teil 1 (2001) als unkritisch eingestuft werden, eine zunehmende Oberflächenaufweichung. Die Magnesiumbeständigkeit der untersuchten Dichtwandmasse wird demnach durch die Normvorgaben überschätzt. Die Aufweichungsgeschwindigkeit nahm mit steigender Magnesiumkonzentration näherungsweise linear zu, die aufgeweichte Zone erfuhr einen totalen Festigkeitsverfall und wies eine signifikant erhöhte Durchlässigkeit auf. Ursache des Aufweichungsprozesses ist die Herabsetzung des pH-Wertes der Porenlösung durch die Bildung hydroxidhaltiger Verbindungen wie Manasseit. Eine Lagerung der Dichtwandmassen in hochkonzentrierten Sulfatlösungen, die nach DIN EN 206, Teil 1 (2001) als „sehr stark angreifend“ eingestuft werden, führte trotz einer sekundären Ettringit- und Gipsbildung weder zu einer Expansion noch zu einer Beeinflussung der Festigkeits- und Durchlässigkeitseigenschaften der Prüfkörper. Die Sulfatbeständigkeit der eingelagerten Dichtwandmassen ist demnach größer, als nach den Normvorgaben zu erwarten wäre. In kombinierten Lösungen, die sowohl Magnesium- als auch Sulfationen enthalten, wird die Geschwindigkeit des Aufweichungsfortschrittes durch die Magnesiumkonzentration bestimmt. Die Kohlensäurebeständigkeit der untersuchten Dichtwandmassen nimmt mit zunehmendem Feststoffgehalt linear zu und mit zunehmendem Kalkanteil ab

In situ monitoring of the influence of water on DNA radiation damage by near-ambient pressure X-ray photoelectron spectroscopy

Ionizing radiation damage to DNA plays a fundamental role in cancer therapy. X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS xperiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. The results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further

New techniques for deeper insights

To gain deeper insights into the old questions about the influence of water on radiation interaction with DNA, new spectroscopic techniques had to be applied

Scientific modeling of Optical 3D Measuring Devices based on GPU-accelerated Ray Tracing using the NVIDIA OptiX Engine

Scientific optical 3D modeling requires the possibility to implement highly flexible and customizable mathematical models as well as high computing power. However, established ray tracing software for optical design and modeling purposes often has limitations in terms of access to underlying mathematical models and the possibility of accelerating the mostly CPU-based computation. To address these limitations, we propose the use of NVIDIA's OptiX Ray Tracing Engine as a highly flexible and high-performing alternative. OptiX offers a highly customizable ray tracing framework with onboard GPU support for parallel computing, as well as access to optimized ray tracing algorithms for accelerated computation. To demonstrate the capabilities of our approach, a realistic focus variation instrument is modeled, describing optical instrument components (light sources, lenses, detector, etc.) as well as the measuring sample surface mathematically or as meshed files. Using this focus variation instrument model, exemplary virtual measurements of arbitrary and standardized sample surfaces are carried out, generating image stacks of more than 100 images and tracing more than 1E9 light rays per image. The performance and accuracy of the simulations are qualitatively evaluated, and virtually generated detector images are compared with images acquired by a respective physical measuring device.Comment: conferenc