bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-term volcano-tectonic earthquake forecasts based on a MRT algorithm: the El Hierro seismo-volcanic crisis experience
Authors: García A. , De La Cruz-Reyna S. , Marrero J. M. , Ortiz R.
Published: January 2016

Abstract. Under certain conditions volcano-tectonic (VT) earthquakes may pose signiﬁcant hazards to people living in or near active volcanic regions, especially on volcanic islands; however, hazard arising from VT activity caused by localized volcanic sources is rarely addressed in the literature. The evolution of VT earthquakes resulting from a magmatic intrusion shows some orderly behavior that may allow forecasting the occurrence and magnitude of major events. Thus govern-mental decision-makers can be supplied of warnings of the increased probability of larger-magnitude earthquakes in the short term time-scale. We present here a methodology for forecasting the occurrence of large-magnitude VT events during volcanic crises; it is based on a Mean Recurrence Time (MRT) algorithm that translates the Gutenberg-Richter distribution parameter ﬂuctuations into time windows of increased probability of a major VT earthquake. The MRT forecasting algorithm was developed after observing a repetitive pattern in the seismic swarm episodes occurring between July and November 2011 at El Hierro (Canary Islands). From then on, this methodology has been applied to the consecutive seismic crises registered at El Hierro, achieving a high success rate in the real-time forecasting, within 10 day time-windows, of volcano-tectonic earthquakes
Evaluating the Efficiency of Subsurface Drainages for Li-Shan Landslide in Taiwan
Authors: Lin Der-Guey , Hung Sheng-Hsiung , Ku Cheng-Yu , Chan Hsun-Chuan
Published: January 2016

Abstract. This study investigates the efficiency of subsurface drainage systems includes drainage wells (vertical shaft with drainage boreholes or horizontal drains) and drainage galleries (longitudinal tunnel with sub-vertical drainage boreholes) for the slope stabilization of Li-Shan landslide in central Taiwan. The efficiency of the subsurface drainages is verified through a series of two-dimensional (2-D) rainfall induced seepage and slope stability analyses without and with subsurface drainages remediation during two typhoon events. Numerical results and monitoring data both show that the groundwater level at B5 monitoring station with subsurface drainages remediation during Toraji Typhoon (2001) is about 40 m lower than that without remediation during Amber Typhoon (1997), and the factor of safety Fs of the first potential sliding surface (1st-PSS, the most critical potential sliding surface) is promoted simultaneously from 1.096 to 1.228 due to the function of subsurface drainage systems. In addition, the Fs values of the three potential sliding surfaces (1st- PSS, 2nd-PSS, and 3rd-PSS) stabilized by subsurface drainage systems are constantly maintained greater than unity (FS>1.0 or FS≥1.217) during rainfalls with return periods increases from 25 to 50 and 100 years. This demonstrates the subsurface drainage systems in Li-Shan landslide are functional and capable of accelerating the drainage of infiltration rainwater induced from high intensity and long duration rainfall and protect the slope of landslide from further deterioration.
Rainfall feature extraction using cluster analysis and its application on displacement prediction for a cleavage-parallel landslide in the Three-Gorges Reservoir area
Authors: Liu Y. , Liu L.
Published: January 2016

Abstract. Rainfall is one of the most important factors controlling landslide deformation and failure. State-of-art rainfall data collection is a common practice in modern landslide research world-wide. Nevertheless, in spite of the availability of high-accuracy rainfall data, it is not a trivial process to diligently incorporate rainfall data in predicting landslide stability due to large quantity, tremendous variety, and wealth multiplicity of rainfall data. Up to date, most of the pre-process procedure of rainfall data only use mean value, maxima and minima to characterize the rainfall feature. This practice significantly overlooks many important and intrinsic features contained in the rainfall data. In this paper, we employ cluster analysis (CA)-based feature analysis to rainfall data for rainfall feature extraction. This method effectively extracts the most significant features of a rainfall sequence and greatly reduced rainfall data quantities. Meanwhile it also improves rainfall data availability. For showing the efficiency of using the CA characterized rainfall data input, we present three schemes to input rainfall data in back propagation (BP) neural network to forecast landslide displacement. These three schemes are: the original daily rainfall, monthly rainfall, and CA extracted rainfall features. Based on the examination of the root mean square error (RMSE) of the landslide displacement prediction, it is clear that using the CA extracted rainfall features input significantly improve the ability of accurate landslide prediction.
The flood of June 2013 in Germany: how much do we know about its impacts?
Authors: Thieken A. H. , Bessel T. , Kienzler S. , Kreibich H. , Müller M. , Pisi S. , Schröter K.
Published: January 2016

Abstract. In June 2013, widespread flooding and consequent damage and losses occurred in Central Europe, especially in Germany. The paper explores what data is available to investigate the adverse impacts of the event, what kind of information can be retrieved from these data and how good data and information fulfil requirements that were recently proposed for disaster reporting on the European and international level. In accordance with the European Floods Directive, impacts on human health, economic activities (and assets), cultural heritage and the environment are described on the national and sub-national scale. Information from governmental reports is complemented by communications on traffic disruptions and surveys of flood-affected residents and companies. Overall, the impacts of the flood event in 2013 were manifold. The study reveals that flood-affected residents suffered from a large range of impacts, among which mental health and supply problems were perceived more seriously than financial losses. The most frequent damage type among affected companies was business interruption. This demonstrates that the current scientific focus on direct (financial) damage is insufficient to describe the overall impacts and severity of flood events. The case further demonstrates that procedures and standards for impact data collection in Germany are widely missing. Present impact data in Germany are fragmentary, heterogeneous, incomplete and difficult to access. In order to fulfil, for example, the monitoring and reporting requirements of the Sendai Framework for Disaster Risk Reduction 2015–2030 that was adopted in March 2015 in Sendai, Japan, more efforts on impact data collection are needed.
Assessment of rockfall hazard on the steep-high slopes: Ermenek (Karaman, Turkey)
Authors: Taga Hidayet , Zorlu Kıvanç
Published: January 2016

Abstract. Ermenek is one of the curious settlement areas because of its topographical features in Karaman (Turkey). The city is located in northern side of the very steep cliffs formed byjointed limestone which are suddenly increased from 1250 m to 1850 m. Moreover, these cliffs having almost 90° slope dip are the main rockfall source areas due to their lithologicalcharacteristics, climatic effects and engineering properties of rock units. Up to now, depending on rockfall events, almost 500 residences were damaged severely, and losses oflives were also recorded in Ermenek. The rockfall phonemon are initiated by discontinuities, lithological changes, weathering and freeze-thaw process in the study area. In this study,extensive fieldwork including determination of location and dimension of hanging, detached and already fallen blocks, a detailed discontinuity survey, description of geological,morphological and topographical characteristics was performed. Besides, rockfall hazard is evaluated by two-dimensional rockfall analyses along 10 profiles. During the rockfallanalyses; run out distance, bounce height, kinetic energy and velocity of various size of blocks for each profiles are determined by using RocFall v4.0 software. The results obtainedfrom rockfall analyses were used to map the areas possible rockfall hazard zones and rockfall source areas were interpreted. According to rockfall analysis, field study and laboratory testing, protective and preventiverecommendations can be suggested for the areas under rockfall threat. But, the most widely- known remedial measures in literature such as trenches, retaining walls (barrier), wiremeshes, cable/streching nets and rock bolting etc. are not sufficient in the study area, due to topographical, atmospheric and lithological features. For these reasons, firstly total evacuation of the danger zone should be applied and then hanging blocks in the reachablelocations can be removed taking safety measures in this area to make it safer for the living people.
A new web-based system to improve the monitoring of snow avalanche hazard in France
Authors: Bourova E. , Maldonado E. , Leroy J.-B. , Alouani R. , Eckert N. , Bonnefoy-Demongeot M. , Deschatres M.
Published: January 2016

Abstract. Snow avalanche data in the French Alps and Pyrenees have been recorded for more than 100 years in several databases. The increasing amount of observed data required a more integrative and automated service. Here we report the comprehensive web-based Snow Avalanche Information System newly developed to this end for three important datasets: an avalanche chronicle (Enquête Permanente sur les Avalanches, EPA), an avalanche map (Carte de Localisation des Phénomènes d'Avalanche, CLPA) and a compilation of hazard and vulnerability data recorded on selected paths endangering human settlements (Sites Habités Sensibles aux Avalanches, SSA). These datasets are now integrated into a common database, enabling full interoperability between all different types of snow avalanche records: digitized geographic data, avalanche descriptive parameters, eyewitness reports, photographs, hazard and risk levels, etc. The new information system is implemented through modular components using Java-based web technologies with Spring and Hibernate frameworks. It automates the manual data entry and improves the process of information collection and sharing, enhancing user experience, data quality, and offering new outlooks to explore and exploit the huge amount of snow avalanche data available for fundamental research and more applied risk assessment.
Modelling the socio-economic impact of river floods in Europe
Authors: Alfieri L. , Feyen L. , Salamon P. , Burek P. , Thielen J.
Published: January 2016

Abstract. River floods generate a large share of the socio-economic impact of weather-driven hazards worldwide. Accurate assessment of their impact is key priority for governments, international organizations, re-insurance companies and emergency responders. Yet, available databases of flood losses over large domains are often affected by gaps and inconsistencies on reported figures. In this work, a framework to reconstruct the economic damage and population affected by river floods at continental scale is applied. Pan-European river flow simulations are coupled with a high resolution impact assessment framework based on 2D inundation modelling. Two complementary methods are compared in their ability to estimate the climatological average flood impact and the impact of each flood event in Europe between 1990 and 2013. The event based method reveals key features, such as the ability to include changes in time of all three components of risk, namely hazard, exposure and vulnerability. Furthermore, it skilfully reproduces the socio-economic impact of major flood events in the past two decades, including the severe flooding hitting the Central Europe in June 2013.
First GPS TEC maps of ionospheric disturbances induced by reflected tsunami waves: The Tohoku case study
Authors: Tang L. , Zhao Y. , An J.
Published: January 2016

Abstract. The straight tsunami waves from epicenter can be reflected when they reach to coasts or underwater obstacles. In this study, we present the first ionospheric maps of reflected tsunami signature caused by the great 11 March 2011 Tohoku earthquake using the dense GPS network GEONET in Japan. We observed tsunami-like travelling ionospheric disturbances (TIDs) with similar propagation characteristics in terms of waveform, horizontal velocity, direction, period and arrival time compared to the reflected tsunami at the sea-level, indicating the TIDs are induced by the reflected tsunami. The results confirm the atmospheric internal gravity waves (IGWs) produced by reflected tsunami can also propagate upward to the atmosphere and interact with the plasma at the ionospheric height.
A Hydrologically Based Model for Delineating Hazard Zones in the Valleys of Debris Flow Basins
Authors: Hu Kaiheng , Li Pu , You Yong , Su Fenghuan
Published: January 2016

Abstract. A hydrologically based model is developed for delineating hazard zones in valleys of debris flow basins. The basic assumption of this model is that the ratio of peak discharges of any two cross sections in a debris-flow basin is a power function of the ratio of their flow accumulation areas. Combining the advantages of the empirical and flow routing models of debris-flow hazard zoning, this hydrological model with minimal data requirements has the ability to produce hazard intensity values at different event magnitudes. The algorithms used in this model are designed in the framework of grid- based geographic processing and implemented completely on ArcGIS platform and a Python scripting environment. Qipan basin in the Wenchuan county of Sichuan province, southwest China where a large-scale debris-flow event occurred on July 11, 2013 was chosen as the test case for the model. The hazard zone identified by the model showed good agreement with the real inundation area of the event. The proposed method can help identify small hazard areas in upstream tributaries and the developed model is promising in terms of its application in debris-flow hazard zoning.
Using video games for volcanic hazard education and communication
Authors: Mani L. , Cole P. D. , Stewart I.
Published: January 2016

Abstract. This paper aims to understand whether video games (or serious games) can be effective in enhancing volcanic hazard education and communication. Using the eastern Caribbean island of St. Vincent, we have developed a video game – St. Vincent’s Volcano – for use in volcano education and outreach sessions, aimed at improving resident’s knowledge of potential future eruptive hazards (ash fall, pyroclastic flows and lahars). Here, we discuss the process of game development including concept design, game development through to final implementation on St. Vincent. Preliminary results for game implementation (obtained through pre and post-test knowledge quizzes) for both student and adult participants suggest that a video game of this style can be effective in improving learner’s knowledge. Both groups of participants demonstrated an increase in score percentage (9.3 % for adults and 8.3 % for students) and when plotted as learning gains (0.11 for adults and 0.09 for students). This preliminary data could provide a sound foundation for the increased integration of emerging technologies within traditional education sessions.
Impact of Optimal Observational Time Window on Parameter Optimization and Climate Prediction: Simulation with a Simple Climate Model
Authors: Yuxin Zhao A. A. , Xiong Deng B. B. , Shuo Yang C. C.
Published: January 2016

Abstract. Usually, an optimal time window (OTW) centred at the assimilation time to collect measured data for an assimilation cycle, can greatly improve the CDA analysis skill. Here, with a simple coupled model, we study the impact of optimal OTWs on the quality of parameter optimization and climate prediction. Results show that the optimal OTWs of valid atmosphere or ocean observations exist for the parameter being estimated and incorporating the parameter optimization will do some impact on the optimal OTWs for the state estimation. And using the optimal OTWs can enhance the predictability both of the atmosphere and ocean.
Multiscale statistical analysis of coronal solar activity
Authors: Gamborino Diana , del-Castillo-Negrete Diego , Martinell Julio J.
Published: January 2016

Abstract. Multi-filter images from the solar corona are used to obtain temperature maps which are analyzed using techniques based on proper orthogonal decomposition (POD) in order to extract dynamical and structural information at various scales. Exploring active regions before and after a solar flare and comparing them with quiet regions we show that the multiscale behavior presents distinct statistical properties for each case that can be used to characterize the level of activity in a region. Information about the nature of heat transport is also be extracted from the analysis.
Spatial scales of temperature and salinity variability estimated from Argo observations
Authors: Ninove F. , Le Traon P.-Y. , Remy E. , Guinehut S.
Published: January 2016

Abstract. Argo observations from 2005 to 2013 are used to characterize spatial scales of temperature and salinity variations from the surface down to 1300 m. Simulations are first performed to analyze the sensitivity of results to Argo sampling; they show that several years of Argo observations are required to estimate spatial scales of ocean variability over 20°  ×  20° boxes. Spatial scales are then computed over several large-scale areas. Zonal and meridional spatial scales (Lx and Ly which are zero crossing of covariance functions) vary as expected with latitudes. Scales are of about 100 km at high latitudes and more of 700 km in the Indian and Pacific equatorial–tropical regions. Zonal and meridional scales are similar except in tropical–equatorial regions where zonal scales are much larger (by a factor of 2 to 3) than meridional scales. Spatial scales are the largest close to the surface and have a general tendency for temperature to increase in deeper layers. There are significant differences between temperature and salinity scales, in particular, in the deep ocean. Results are consistent with previous studies based on sparse in situ observations or satellite altimetry. They provide, however, for the first time a global description of temperature and salinity scales of variability and a characterization of their variations according to depths.
The flow field of the upper hypoxic eastern tropical North Atlantic oxygen minimum zone
Authors: Stramma L. , Czeschel R. , Tanhua T. , Brandt P. , Visbeck M. , Giese B. S.
Published: January 2016

Abstract. A subsurface low oxygen zone is located in the eastern tropical North Atlantic Ocean (ETNA) in the upper ocean with the core of the hypoxic (O2 ≦60 µmol kg−1) oxygen minimum zone (OMZ) at 400 to 500 m depth. The subsurface circulation in the OMZ region is derived from observations and data assimilation results. Measurements in the ETNA of velocity, oxygen and of a tracer (CF3SF5) that was released in April 2008 at  ∼  8° N, 23° W (at  ∼  330 m depth) in November–December 2008, in November–December 2009 and October–November 2010 show the circulation in the upper part of the OMZ with spreading to the east in the North Equatorial Countercurrent (NECC) region and northwestward around the Guinea Dome. Three floats equipped with oxygen sensors deployed at  ∼  8° N, 23° W with parking depths at 330, 350 and 400 m depths were used to estimate velocity along the float trajectory at the surface and at the parking depth. At the 350 m park depth north of 9° N a cyclonic northwestward flow across the OMZ was observed. The northward drift of a float into the upper OMZ and a stronger cyclonic flow around the Guinea Dome seem to be connected to a strong Atlantic Meridional Mode (AMM) event in 2009. A near-surface cyclonic circulation cell east of the Cape Verde Islands reaches down into the OMZ layer. The circulation of the upper OMZ mirrors the near-surface circulation. Oxygen measurements from the cruises used here, as well as from other recent cruises up to the year 2014, confirm the continuous deoxygenation trend in the upper OMZ since the 1960s near the Guinea Dome. The three floats deployed with the tracer show spreading paths consistent with the overall observed tracer spreading. Oxygen sensors on the floats remained well calibrated for more than 20 months, and so the oxygen profiles can be used to investigate mesoscale eddy signatures. Mesoscale eddies may modify the oxygen distribution in OMZs. However, in general eddies are less energetic in the ETNA south of the Cape Verde Islands compared to similar latitudes in the eastern tropical South Pacific.
The Barents Sea frontal zones and water masses variability (1980–2011)
Authors: Oziel L. , Sirven J. , Gascard J.-C.
Published: January 2016

Abstract. The polar front separates the warm and saline Atlantic Water entering the southern Barents Sea from the cold and fresh Arctic Water located in the north. These water masses can mix together (mainly in the center of the Barents Sea), be cooled by the atmosphere and receive salt because of brine release; these processes generate dense water in winter, which then cascades into the Arctic Ocean to form the Arctic Intermediate Water. To study the interannual variability and evolution of the frontal zones and the corresponding variations of the water masses, we have merged data from the International Council for the Exploration of the Sea and the Arctic and Antarctic Research Institute and have built a new database, which covers the 1980–2011 period. The summer data were interpolated on a regular grid. A probability density function is used to show that the polar front splits into two branches east of 32° E where the topographic constraint weakens. Two fronts can then be identified: the Northern Front is associated with strong salinity gradients and the Southern Front with temperature gradients. Both fronts enclose the denser Barents Sea Water. The interannual variability of the water masses is apparent in the observed data and is linked to that of the ice cover. The frontal zones variability is found by using data from a general circulation model. The link with the atmospheric variability, represented here by the Arctic Oscillation, is not clear. However, model results suggest that such a link could be validated if winter data were taken into account. A strong trend appears: the Atlantic Water (Arctic Water) occupies a larger (smaller) volume of the Barents Sea. This trend amplifies during the last decade and the model study suggests that this could be accompanied by a northwards displacement of the Southern Front in the eastern part of the Barents Sea. The results are less clear for the Northern Front. The observations show that the volume of the Barents Sea Water remains nearly unchanged, which suggests a northwards shift of the Northern Front to compensate for the northward shift of the Southern Front. Lastly, we noticed that the seasonal variability of the position of the front is small.
Modeling the ocean and atmosphere during an extreme bora event in northern Adriatic using one-way and two-way atmosphere–ocean coupling
Authors: Ličer M. , Smerkol P. , Fettich A. , Ravdas M. , Papapostolou A. , Mantziafou A. , Strajnar B. , Cedilnik J. , Jeromel M. , Jerman J. , Petan S. , Malačič V. , Sofianos S.
Published: January 2016

Abstract. We have studied the performances of (a) a two-way coupled atmosphere–ocean modeling system and (b) one-way coupled ocean model (forced by the atmosphere model), as compared to the available in situ measurements during and after a strong Adriatic bora wind event in February 2012, which led to extreme air–sea interactions. The simulations span the period between January and March 2012. The models used were ALADIN (Aire Limitée Adaptation dynamique Développement InterNational) (4.4 km resolution) on the atmosphere side and an Adriatic setup of Princeton ocean model (POM) (1°∕30 × 1°∕30 angular resolution) on the ocean side. The atmosphere–ocean coupling was implemented using the OASIS3-MCT model coupling toolkit. Two-way coupling ocean feedback to the atmosphere is limited to sea surface temperature. We have compared modeled atmosphere–ocean fluxes and sea temperatures from both setups to platform and CTD (conductivity, temperature, and depth) measurements from three locations in the northern Adriatic. We present objective verification of 2 m atmosphere temperature forecasts using mean bias and standard deviation of errors scores from 23 meteorological stations in the eastern part of Italy. We show that turbulent fluxes from both setups differ up to 20 % during the bora but not significantly before and after the event. When compared to observations, two-way coupling ocean temperatures exhibit a 4 times lower root mean square error (RMSE) than those from one-way coupled system. Two-way coupling improves sensible heat fluxes at all stations but does not improve latent heat loss. The spatial average of the two-way coupled atmosphere component is up to 0.3 °C colder than the one-way coupled setup, which is an improvement for prognostic lead times up to 20 h. Daily spatial average of the standard deviation of air temperature errors shows 0.15 °C improvement in the case of coupled system compared to the uncoupled. Coupled and uncoupled circulations in the northern Adriatic are predominantly wind-driven and show no significant mesoscale differences.
Developing European operational oceanography for Blue Growth, climate change adaptation and mitigation and ecosystem-based management
Authors: She J. , Allen I. , Buch E. , Crise A. , Johannessen J. A. , Le Traon P. Y. , Lips U. , Nolan G. , Pinardi N. , Reißmann J. H. , Siddorn J. , Stanev E. , Wehde H.
Published: January 2016

Abstract. “Operational Approaches” have been more and more widely developed and used for providing marine data and information service for different socio-economic sectors of the Blue Growth and to advance knowledge about the marine environment. The objective of operational oceanographic research is to develop and improve the efficiency, timeliness, robustness and product quality of this approach. This white paper aims to address key scientific challenges and research priorities for the development of operational oceanography in Europe for the next 5–10 years. Knowledge gaps and deficiencies are identified in relation to common scientific challenges in four EuroGOOS knowledge areas: European Ocean Observations, Modelling and Forecasting Technology, Coastal Operational Oceanography and Operational Ecology. The areas “European Ocean Observations” and “Modelling and Forecasting Technology” focus on the further advancement of the basic instruments and capacities for European operational oceanography, while “Coastal Operational Oceanography” and “Operational Ecology” aim at developing new operational approaches for the corresponding knowledge areas.
Seismic imaging in the eastern Scandinavian Caledonides: siting the 2.5 km deep COSC-2 borehole, central Sweden
Authors: Juhlin C. , Hedin P. , Gee D. G. , Lorenz H. , Kalscheuer T. , Yan P.
Published: January 2016

Abstract. The Collisional Orogeny in the Scandinavian Caledonides (COSC) project, a contribution to the International Continental Scientific Drilling Program (ICDP), aims to provide a deeper understanding of mountain belt dynamics. Scientific investigations include a range of topics, from subduction-related tectonics to the present-day hydrological cycle. COSC investigations and drilling activities are focused in central Scandinavia where rocks from the mid to lower crust of the orogen are exposed near the Swedish-Norwegian border. Here, rock units of particular interest occur in the Seve Nappe Complex (SNC) of the so-called Middle Allochthon and include granulite facies migmatites (locally with evidence of ultra-high pressures) and amphibolite facies gneisses and mafic rocks. This complex overlies greenschist facies metasedimentary rocks of the dolerite-intruded Särv Nappes and underlying, lower grade Jämtlandian Nappes (Lower Allochthon). Reflection seismic profiles have been an important component in the activities to image the sub-surface structure in the area. Sub-horizontal reflections in the upper 1–2 km are underlain and interlayered with strong west- to northwest-dipping reflections, suggesting significant east-vergent thrusting. Two 2.5 km deep fully cored boreholes are a major component of the project which will improve our understanding of the sub-surface structure and tectonic history of the area. Borehole COSC-1, drilled in the summer of 2014, targeted the subduction-related Seve Nappe Complex and the contact with the underlying allochthon. The COSC-2 borehole will be located further east and investigate the lower grade, mainly Cambro-Silurian rocks of the Lower Allochthon, the main Jämtlandian décollement and penetrate into the crystalline basement rocks to identify the source of some of the northwest-dipping reflections. A series of high resolution seismic profiles have been acquired along a composite ca. 55 km long profile to help locate the COSC drillholes. We present here the results from this COSC-related composite seismic profile (CSP), including new interpretations based on previously unpublished data acquired between 2011 and 2014. These seismic data, along with shallow drillholes in the Caledonian thrust front and previously acquired seismic, magnetotelluric, and magnetic data, are used to identify two potential drill sites for the COSC-2 borehole.
Pull-apart basin tectonic model is structurally impossible for Kashmir basin, NW Himalaya
Authors: Shah A. A.
Published: January 2016

Abstract. Kashmir Basin in NW Himalaya is considered a Neogene-Quatermary piggyback basin that was formed as result of the continent-continent collision of Indian and Eurasian plates. This model however is recently challenged by a pull-apart basin model, which argues that a major dextral strike-slip fault through Kashmir basin is responsible for its formation. And here it is demonstrated that the new tectonic model is structurally problematic, and conflicts with the geomorphology, geology, and tectonic setting of Kashmir basin. It also conflicts, and contradicts with the various structural features associated with a typical dextral strike-slip fault system where it shows that such a major structure cannot pass through the middle of the basin. It is demonstrated that such a structure is structurally, and kinematically impossible, and could not exist.
The effectiveness of jute and coir erosion control blankets in different field and laboratory conditions
Authors: Kalibová J. , Jačka L. , Petrů J.
Published: January 2016

Abstract. A vegetation cover is found to be an ideal solution to most problems with erosion on steep slopes. Biodegradable geotextiles (GTX) have been proved to provide a sufficient protection against soil loss in the period before the vegetation reaches maturity. In this study, 500 g.m−2 jute (J500), 400 g.m−2 (C400), and 700 g.m−2 coir (C700) GTX were installed firstly on 9° slope in “no-inf iltration” laboratory conditions, secondly on 27° slope in natural field conditions. The impact of GTX on runoff and soil loss was investigated to compare the performance of GTX in different conditions. Laboratory runoff ratio (percentage portion of control plot) equaled 78 %, 83 % and 91 % and peak discharge ratio equaled 83 %, 91 % and 97 % for J500, C700 and C400, respectively. In the field, a runoff ratio of 31 %, 62 % and 79 % and peak discharge ratio of 37 %, 74 % and 87 % were recorded for C700, J500 and C400, respectively. All tested GTX significantly decreased soil erosion. The highest soil loss reduction in the field was observed for J500 (by 99.4%) followed by C700 (by 97.9%) and C400 (by 93.8%). Irrespective of slope gradient or experiment condition, C400 provided lower runoff volume and peak discharge control than J500 and C700. The performance ranking of J500 and C700 in the laboratory differed from the field, which may be explained by different slope gradient and also by the role of soil, which was not included in the laboratory experiment.
Trail impact monitoring in Rocky Mountain National Park, USA
Authors: Svajda J. , Korony S. , Brighton I. , Esser S. , Ciapala S.
Published: January 2016

Abstract. This paper examines impacts of increased visitation leading to human trampling of vegetation and soil along several trails in Rocky Mountain National Park (RMNP) to understand how abiotic factors and level of use can influence trail conditions. RMNP is one of the most visited national parks in the USA, with 3.3 million visitors in 2012 across 1075 km2 and 571 km of hiking trails. 95 % of the park is designated wilderness, making the balance between preservation and visitor use challenging. This research involves the application of trail condition assessments to 56 km of trails to determine prevailing factors and what, if any, connection between them exist. The study looked at a variety of inventory and impact indicators and standards to determine their importance and to develop a baseline condition of trails. The data can be used for future comparison and evaluation of development trends. We found that trail widening (mean trail width 88.9 cm) and soil loss (cross-sectional area 172.7 cm2) are the most visible effects of trail degradation. Further statistical analyses of data identified the role and influence of various factors (e.g., use level and topography). Insights into the influence of these factors can lead to the selection of appropriate management measures to avoid or minimize negative consequences from increased visitation.
X-ray microtomography analysis of soil structure deformation caused by centrifugation
Authors: Schlüter S. , Leuther F. , Vogler S. , Vogel H.-J.
Published: January 2016

Abstract. Centrifugation provides a fast method to measure soil water retention curves over a wide moisture range. However, deformation of soil structure may occur at high angular velocities in the centrifuge. The objective of this study was to capture these changes in soil structure with X-ray microtomography and to measure local deformations via digital volume correlation. Two samples were investigated that differ in texture and rock content. A detailed analysis of the pore space reveals an interplay between shrinkage due to drying and soil compaction due to compression. Macroporosity increases at moderate angular velocity because of crack formation due to moisture release. At higher angular velocities, corresponding to capillary pressure of ψ < −100 kPa, macroporosity decreases again because of structure deformation due to compression. While volume changes due to swelling clay minerals are immanent in any drying process, the compaction of soil is a specific drawback of the centrifugation method. A new protocol for digital volume correlation was developed to analyze the spatial heterogeneity of deformation. In both samples the displacement of soil constituents is highest in the top part of the sample and exhibits high lateral variability explained by the spatial distribution of macropores in the sample. Centrifugation should therefore only be applied after the completion of all other hydraulic or thermal experiments, or any other analysis that depends on the integrity of soil structure.
Grazing effects on soil characteristics and vegetation of grassland in northern China
Authors: Wang Z. , Johnson D. A. , Rong Y. , Wang K.
Published: January 2016

Abstract. Large areas of grassland in the agro-pastoral region of northern China were converted into cropland for grain production, and the remaining grasslands are being overgrazed and seriously degraded. The objective of this study was to evaluate how reductions in grazing intensity affect the soil and vegetation characteristics in grasslands of northern China. Soil heterogeneity and vegetation characteristics were evaluated for ungrazed (UG), moderate grazing (MG), and heavy grazing (HG) sites. Grazing increased diversity, but heavy grazing decreased aboveground biomass and increased the non-grass component. The non-grass proportion of total biomass increased with grazing intensity, which was 8, 16 and 48 % for UG, MG and HG sites, respectively. Species richness at the MG and HG sites was significantly higher than at the UG site (P< 0.05) with 3.6, 5.5 and 5.7 for UG, MG and HG sites, respectively. Strong spatial dependence of the examined soil properties at 10 m scale for all grazed sites was revealed by the ratio of nugget to total variation (0–23 %). Overgrazing homogenized soil characteristics at a 10 m scale. The ranges of spatial autocorrelation for soil organic C (SOC) and total N were both > 120 m at the HG site, which was considerably larger than that at the MG and UG sites with corresponding distances of 17.3 and 20.8 m for the MG site and 8.6 and 15.0 m for the UG site, respectively. The sampling density and sampling space for the HG site could be decreased under this scale sampling interval (10 m). Therefore, MG was recommended as the preferred management alternative for grasslands in northern China because of increased plant diversity without negative consequences related to decreased forage quality, forage quantity and soil heterogeneity for the investigated soil properties in northern China's grasslands.
Quantifying the impact of land degradation on crop production: the case of Senegal
Authors: Sonneveld B. G. J. S. , Keyzer M. A. , Ndiaye D.
Published: January 2016

Abstract. Land degradation has been a persistent problem in Senegal for more than a century and by now has become a serious impediment to long-term development. In this paper, we quantify the impact of land degradation on crop yields using the results of a nationwide land degradation assessment. For this, the study needs to address two issues. First, the land degradation assessment comprises qualitative expert judgements that have to be converted into more objective, quantitative terms. We propose a land degradation index and assess its plausibility. Second, observational data on soils, land use, and rainfall do not provide sufficient information to isolate the impact of land degradation. We, therefore, design a pseudo-experiment that for sites with otherwise similar circumstances compares the yield of a site with and one without land degradation. This pairing exercise is conducted under a gradual refining of the classification of circumstances, until a more or less stable response to land degradation is obtained. In this way, we hope to have controlled sufficiently for confounding variables that will bias the estimation of the impact of land degradation on crop yields. A small number of shared characteristics reveal tendencies of "severe" land degradation levels being associated with declining yields as compared to similar sites with "low" degradation levels. However, as we zoom in at more detail some exceptions come to the fore, in particular in areas without fertilizer application. Yet, our overall conclusion is that yield reduction is associated with higher levels of land degradation, irrespective of whether fertilizer is being applied or not.
Tree species and functional traits but not species richness affect interrill erosion processes in young subtropical forests
Authors: Seitz S. , Goebes P. , Song Z. , Bruelheide H. , Härdtle W. , Kühn P. , Li Y. , Scholten T.
Published: January 2016

Abstract. Soil erosion is seriously threatening ecosystem functioning in many parts of the world. In this context, it is assumed that tree species richness and functional diversity of tree communities can play a critical role in improving ecosystem services such as erosion control. An experiment with 170 micro-scale run-off plots was conducted to investigate the influence of tree species and tree species richness as well as functional traits on interrill erosion in a young forest ecosystem. An interrill erosion rate of 47.5 Mg ha−1 a−1 was calculated. This study provided evidence that different tree species affect interrill erosion differently, while tree species richness did not affect interrill erosion in young forest stands. Thus, different tree morphologies have to be considered, when assessing soil erosion under forest. High crown cover and leaf area index reduced interrill erosion in initial forest ecosystems, whereas rising tree height increased it. Even if a leaf litter cover was not present, the remaining soil surface cover by stones and biological soil crusts was the most important driver for soil erosion control. Furthermore, soil organic matter had a decreasing influence on interrill erosion. Long-term monitoring of soil erosion under closing tree canopies is necessary, and a wide range of functional tree traits should be considered in future research.
Calculating the sediment budget of a tropical lake in the Blue Nile basin: Lake Tana
Authors: Zimale F. A. , Mogus M. A. , Alemu M. L. , Ayana E. K. , Demissie S. S. , Tilahun S. A. , Steenhuis T. S.
Published: January 2016

Abstract. Soil erosion decreases soil fertility of the uplands and causes siltation of lakes and reservoirs. However, very little data exists to quantify accurately the impact of sediment on lakes in tropical monsoonal areas in the African highlands. Lake Tana is one of these lakes in Ethiopia. The objective of this study is to quantify the sediment budget for Lake Tana watershed with limited observational data. To overcome these limitations we use the Parameter Efficient Distributed (PED) model that has shown to perform well in the Ethiopian highlands. PED model parameters are calibrated using daily discharge data and sediment concentration infrequently measured for establishing sediment rating curves for the major rivers. The calibrated model parameters are then used to predict the sediment budget for the period 1994–2009. Sediment retained in the lake is calculated from two bathymetric taken 15 years apart and the sediment leaving the lake is based on measured discharge and observed sediment concentrations. Results show that annually on average 34 Mg/ha/year of sediment is removed from the gauged part of the Lake Tana watersheds. Depending on the up scaling method, 14 to 32 Mg/ha/year is transported from the watershed of which 82% to 96% (with the upper estimate more likely) is trapped on the floodplains and in the lake.
Simulated high-latitude soil thermal dynamics during the past 4 decades
Authors: Peng S. , Ciais P. , Krinner G. , Wang T. , Gouttevin I. , McGuire A. D. , Lawrence D. , Burke E. , Chen X. , Decharme B. , Koven C. , MacDougall A. , Rinke A. , Saito K. , Zhang W. , Alkama R. , Bohn T. J. , Delire C. , Hajima T. , Ji D. , Lettenmaier D. P. , Miller P. A. , Moore J. C. , Smith B. , Sueyoshi T.
Published: January 2016

Abstract. Soil temperature (Ts) change is a key indicator of the dynamics of permafrost. On seasonal and interannual timescales, the variability of Ts determines the active-layer depth, which regulates hydrological soil properties and biogeochemical processes. On the multi-decadal scale, increasing Ts not only drives permafrost thaw/retreat but can also trigger and accelerate the decomposition of soil organic carbon. The magnitude of permafrost carbon feedbacks is thus closely linked to the rate of change of soil thermal regimes. In this study, we used nine process-based ecosystem models with permafrost processes, all forced by different observation-based climate forcing during the period 1960–2000, to characterize the warming rate of Ts in permafrost regions. There is a large spread of Ts trends at 20 cm depth across the models, with trend values ranging from 0.010 ± 0.003 to 0.031 ± 0.005 °C yr−1. Most models show smaller increase in Ts with increasing depth. Air temperature (Tsub>a) and longwave downward radiation (LWDR) are the main drivers of Ts trends, but their relative contributions differ amongst the models. Different trends of LWDR used in the forcing of models can explain 61 % of their differences in Ts trends, while trends of Ta only explain 5 % of the differences in Ts trends. Uncertain climate forcing contributes a larger uncertainty in Ts trends (0.021 ± 0.008 °C yr−1, mean ± standard deviation) than the uncertainty of model structure (0.012 ± 0.001 °C yr−1), diagnosed from the range of response between different models, normalized to the same forcing. In addition, the loss rate of near-surface permafrost area, defined as total area where the maximum seasonal active-layer thickness (ALT) is less than 3 m loss rate, is found to be significantly correlated with the magnitude of the trends of Ts at 1 m depth across the models (R = −0.85, P = 0.003), but not with the initial total near-surface permafrost area (R = −0.30, P = 0.438). The sensitivity of the total boreal near-surface permafrost area to Ts at 1 m is estimated to be of −2.80 ± 0.67 million km2 °C−1. Finally, by using two long-term LWDR data sets and relationships between trends of LWDR and Ts across models, we infer an observation-constrained total boreal near-surface permafrost area decrease comprising between 39 ± 14  ×  103 and 75 ± 14  ×  103 km2 yr−1 from 1960 to 2000. This corresponds to 9–18 % degradation of the current permafrost area.
Case study of spatial and temporal variability of snow cover, grain size, albedo and radiative forcing in the Sierra Nevada and Rocky Mountain snowpack derived from imaging spectroscopy
Authors: Seidel F. C. , Rittger K. , Skiles S. M. , Painter T. H.
Published: January 2016

Abstract. Quantifying the spatial distribution and temporal change in mountain snow cover, microphysical and optical properties is important to improve our understanding of the local energy balance and the related snowmelt and hydrological processes. In this paper, we analyze changes of snow cover, optical-equivalent snow grain size, snow albedo, and radiative forcing by Light Absorbing Impurities in Snow and Ice (LAISI) with respect to terrain elevation and aspect at multiple dates during the snowmelt period. These snow properties are derived from Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data from 2009 of the maritime snowpack in California’s Sierra Nevada and from 2011 of the continental snowpack in Colorado’s Rocky Mountains, USA. Our results show a linearly decreasing snow cover during the ablation season in the Rocky Mountains and a snowfall driven change in snow cover in the Sierra Nevada. At the same time, the snow grain size is increasing primarily at higher elevations and north facing slopes from 200 microns to 800 microns on average. We ﬁnd that intense snowmelt renders the mean grain size almost invariant with respect to elevation and aspect. Our results conﬁrm the inverse relationship between snow albedo and grain size, as well as between snow albedo and radiative forcing by LAISI. At both study sites, the mean snow albedo value decreases from approximately 0.7 to 0.5. The mean snow grain size increased from approximately 150 to 650 microns. The mean radiative forcing increases from 20 W m−2 up to 200 W m−2 during the ablation period. The variability of snow albedo and grain size decreases in general with the progression of the ablation period. The spatial variability of the snow albedo and grain size decreases through the melt season while the spatial variability of radiative forcing remains constant.