More than 2,600 relict rock glaciers are known in the Austrian Alps but the knowledge of their hydraulic properties is severely limited. The relict Schöneben Rock Glacier (Niedere Tauern Range, Austria), with an extension of 0.17 km2, was investigated based on spring data (2006–2014) and seismic refraction survey. Spring-discharge hydrographs and natural and artificial tracer data suggest a heterogeneous aquifer with a layered internal structure for the relict rock glacier. The discharge behavior exhibits a fast and a delayed flow component. The spring discharge responds to recharge events within a few hours but a mean residence time of several months can also be observed. The internal structure of the rock glacier (up to several tens of meters thick) consists of: an upper blocky layer with a few meters of thickness, which lacks fine-grained sediments; a main middle layer with coarse and finer-grained sediments, allowing for fast flow; and an approximately 10-m-thick basal till layer as the main aquifer body responsible for the base flow. The base-flow component is controlled by (fine) sandy to silty sediments with low hydraulic conductivity and high storage capacity, exhibiting a difference in hydraulic conductivity to the upper layer of about three orders of magnitude. The high storage capacity of relict rock glaciers has an impact on water resources management in alpine catchments and potentially regulates the risk of natural hazards such as floods and related debris flows. Thus, the results highlight the importance of such aquifer systems in alpine catchments. 相似文献
The Central West Bank aquifer (CWB) is one of the most important resources of fresh groundwater of Palestine. The geology of the area consists mainly of karstic and permeable limestones and dolomites interbedded with argillaceous beds of late Albian–Turonian age. Exploitation of the CWB aquifer, combined with lack of information required to understand the groundwater pattern, represents a challenge for reservoir management. The present work reports hydrogeochemistry, microbiology and environmental isotope data from spring water samples, which were utilized to understand recharge mechanisms, geochemical evolution and renewability of groundwater in CWB aquifer. Besides the major chemical compositions, ionic ratios were used to delineate mineral-solution reactions and weathering processes. Interpretation of chemical data suggests that the chemical evolution of groundwater is primarily controlled by (1) water–rock interactions, involving dissolution of carbonate minerals (calcite and dolomite), and (2) cation exchange processes. The measured equation of the local meteoric water line is δD?=?5.8 δ18O?+?9.9. Stable isotopes show that precipitation is the source of recharge to the groundwater system. The evaporation line has a linear increasing trend from south to north direction in the study area. All analyzed spring waters are suitable for irrigation, but not for drinking purposes. The results from this study can serve as a basis for decision-makers and stakeholders, with the intention to increase the understanding of sustainable management of the CWBs. 相似文献
The overexploitation of groundwater in coastal aquifers is often accompanied by seawater intrusion, intensified by climate change and sea level rise. Heading long-term water quality safety and thus the determination of vulnerable zones to seawater intrusion becomes a significant hydrogeological task for many coastal areas. Due to this background, the present study focussed the established methodology of the GIS-based GALDIT model to assess the aquifer vulnerability to seawater intrusion for the Algerian example of the Quaternary coastal Collo aquifer. According to the result analysis overall, more than half of the total surface of the northern study area can be classified as highly vulnerable. Besides the coastline, the areas nearby the local wadis of Guebli and Cherka occur to be the most vulnerable in the region. In view of further map removal performance as well as single-parameter sensitivity analyses from a coupled perspective respectively the GALDIT parameters, distance from the shore (D) and aquifer hydraulic conductivity (A) have been found to be of key significance regarding the model results (mean effective weightings ~?18–19%). Overall, the study results provide a good approximation basis for future management decisions of the Collo aquifer region, including various perspectives such as identification of suitable settings for prospective groundwater pumping wells. 相似文献
The Manitou Mine sulphidic-tailings storage facility No. 2, near Val D’Or, Canada, was reclaimed in 2009 by elevating the water table and applying a monolayer cover made of tailings from nearby Goldex Mine. Previous studies showed that production of acid mine drainage can be controlled by lowering the oxygen flux through Manitou tailings with a water table maintained at the interface between the cover and reactive tailings. Simulations of different scenarios were performed using numerical hydrogeological modeling to evaluate the capacity of the reclamation works to maintain the phreatic surface at this interface. A large-scale numerical model was constructed and calibrated using 3 years of field measurements. This model reproduced the field measurements, including the existence of a western zone on the site where the phreatic level targeted is not always met during the summer. A sensitivity analysis was performed to assess the response of the model to varying saturated hydraulic conductivities, porosities, and grain-size distributions. Higher variations of the hydraulic heads, with respect to the calibrated scenario results, were observed when simulating a looser or coarser cover material. Long-term responses were simulated using: the normal climatic data, data for a normal climate with a 2-month dry spell, and a simplified climate-change case. Environmental quality targets were reached less frequently during summer for the dry spell simulation as well as for the simplified climate-change scenario. This study illustrates how numerical simulations can be used as a key tool to assess the eventual performance of various mine-site reclamation scenarios.
ABSTRACTReal-time geospatial information is used in various applications such as risk management or alerting services. Especially, the rise of new sensing technologies also increases the demand for processing the data in real time. Today’s spatial data infrastructures, however, do not meet the requirements for real-time geoprocessing. The OpenGIS® Web Processing Service (WPS) is not designed to process real-time workflows. It has some major drawbacks in asynchronous processing and cannot handle (geo) data streams out of the box. In previous papers, we introduced the GeoPipes approach to share spatiotemporal data in real time. We implemented the concept extending the Message Queue and Telemetry Transport (MQTT) protocol by a spatial and temporal dimension, which we call GeoMQTT. In this paper, we demonstrate the integration of the GeoPipes idea in the WPS interface to expose standardized real-time geoprocessing services. The proof of the concept is illustrated in some exemplary real-time geo processes. 相似文献
Natural Hazards - The scarcity of model input and calibration data has limited efforts in reconstructing scenarios of past floods in many regions globally. Recently, the number of studies that use... 相似文献
Climate adaptation is uniquely linked to location, making it predominantly a local government and community responsibility. Despite the obligation to act, local governments are hindered by the absence of applicable guides to adaptation decision-making, especially adaptation to extreme events. In this paper, we describe a framework for prioritising adaptation options that could be locally implemented and illustrate it with a study of flooding in Kochi: a city in southern India. Unlike many demand driven, economics based studies, our new framework also incorporates non-economic dimensions of the extremes and potential adaptation options. Local knowledge is used to tackle data gaps and uncertainty related to extreme events: local experts select adaptation options that offer additional benefits besides those related to climate change. These co-benefits aid decision making under uncertainty by giving weight to community priorities. The Indian case study reveals that, risk evaluation and reduction need to be locally contextualised based on resources available, immediate community requirements, planning periods and local expert knowledge. Although there will be residual damage even after implementing selected options, we argue that, climate response will be most likely to be accepted when it also supports pressing needs. 相似文献