The feeding habits of Austrolethops wardi, a gobiid fish inhabiting burrows of the thalassinidean shrimp Neaxius acanthus

The feeding habit of Austrolethops wardi (Gobiidae) in the seagrass beds of Barrang Lompo and Bone Batang Island in the Spermonde Archipelago, South West Sulawesi, Indonesia, was investigated through gut content analysis. The feeding preferences of this species are very similar on both islands: A. wardi, a burrow associate of Neaxius acanthus, was found to feed almost exclusively on seagrass (which was found in 100% of the investigated stomachs and made up >94% of food items). However, seagrass epiphytes (<5% of food items) and animal food (<1% of food items) occurred in the guts as well, the latter predominantly in terms of copepods and to a lesser degree in other small invertebrates. These results indicate that animal food is of little importance for A. wardi. Some specimens even contained no parts of animal food.     

晚震旦世至早寒武世扬子地台北缘碳同位素研究

震旦-寒武交变期是地史上一个重大转折期,亦是一个具有特殊意义的过渡时期。运用碳同位素地球化学方法,探讨扬子地台北缘四川南江地区晚震旦世-早寒武世交变期,碳同位素地球化学异常与环境变化和生物演化的相互联系。南江剖面沉积岩有机碳同位素组成在-35．8‰～-30．1‰间变化;碳酸盐碳同位素组成从-3．5‰～ 0．5‰。在灯影组顶部、牛蹄塘组下部和上部,变化的碳、硫同位素组成和不同的黄铁矿与有机碳含量反映了有机碳埋藏量和环境的变化。下寒武统富有机碳和黄铁矿的黑色页岩沉积,暗示了早寒武世早期缺氧环境的存在。     

Validation of official erosion modelling based on high‐resolution radar rain data by aerial photo erosion classification

The universal soil loss equation (USLE) is the most frequently applied erosion prediction model and it is also implemented as an official decision‐making instrument for agricultural regulations. The USLE itself has been already validated using different approaches. Additional errors, however, arise from input data and interpolation procedures that become necessary for field‐specific predictions on a national scale for administrative purposes. In this study, predicted event soil loss using the official prediction system in Bavaria (Germany) was validated by comparison with aerial photo erosion classifications of 8100 fields. Values for the USLE factors were mainly taken from the official Bavarian high‐resolution (5 × 5 m²) erosion cadastre. As series of erosion events were examined, the cover and management factor was replaced by the soil loss ratio. The event erosivity factor was calculated from high‐resolution (1 × 1 km², 5 min), rain gauge‐adjusted radar rain data (RADOLAN). Aerial photo erosion interpretation worked sufficiently well and average erosion predictions and visual classifications correlated closely. This was also true for data broken down to individual factors and different crops. There was no reason to assume a general invalidity of the USLE and the official parametrization procedures. Event predictions mainly suffered from errors in the assumed crop stage period and tillage practices, which do not reflect interannual and farm‐specific variation. In addition, the resolution of radar data (1 km²) did not seem to be sufficient to predict short‐term erosion on individual fields given the strong spatial gradients within individual rains. The quality of the input data clearly determined prediction quality. Differences between USLE predictions and observations are most likely caused by parametrization weaknesses but not by a failure of the model itself. Copyright © 2017 John Wiley & Sons, Ltd.     

Future high- and low-flow estimations for Central Vietnam: a hydro-meteorological modelling chain approach

We apply a complex hydro-meteorological modelling chain for investigating the impact of climate change on future hydrological extremes in Central Vietnam, a region characterized by limited data availability. The modelling chain consists of six General Circulation Models (GCMs), six Regional Climate Models (RCMs), six bias correction (BC) approaches, the fully distributed Water Flow and Balance Simulation Model (WaSiM), and extreme values analysis. Bias corrected and raw climate data are used as input for WaSiM. To derive hydrological extremes, the generalized extreme value distribution is fitted to the annual maxima/minima discharge. We identify limitations according to the fitting procedure and the BC methods, and suggest the usage of the delta change approach for hydrological decision support. Tendencies towards increased high- and decreased low flows are concluded. Our study stresses the challenges in using current GCMs/RCMs in combination with state-of-the-art BC methods and extreme value statistics for local impact studies.     

贵州瓮安陡山沱组剖面碳同位素生物地球化学研究

在对扬子地台贵州瓮安陡山沱组剖面干酪根碳同住素组成进行分析后发现其变化显示了一定的规律性。碳同住素规律变化反映了最初的沉积信息,特别是有机质埋藏量的变化。获得的陡山沱期沉积岩中碳同位素组成研究结果初步反映了震旦一寒武交变期沉积环境的面貌;碳同位素组成变化规律可以用于反映扬子地台沉积层序和世界同期地层全球碳循环的对比和参考。为扬子区陡山沱期环境变化和生物演化提供了证据。δ^13Cker值在-32．3‰和-24．5‰(PDB)间漂移与δ^13Ccarb值在-4．9‰和3．6‰(PDB)间的变化,反映了当时海水的碳同位素组成。无机和有机碳同位素组成之差的△δorg-carb值沿剖面不断变化,是由于沉积有机质中有促进发酵功能的细菌数量比例变化所致。     

Scenario-based seismic hazard analysis using spectral element method in northeastern Pakistan

Natural Hazards - Seismic hazard analysis is carried out in this study by estimating ground motion for hypothetical earthquakes in the area of Muzaffarabad, Pakistan, with the MT solution of the...     

贵州台江下、中寒武统界线层型候选剖面碳同位素研究

在扬子地台贵州台江八郎下、中寒武统界线剖面界线附近,碳酸盐岩和干酪根碳同位素组成有规律变化。1δ3Cker(PDB)值在-33.4‰和-26.5‰间漂移与1δ3Ccarb(PDB)值在-2.7‰和 3.1‰间变化,反映了当时海水的碳同位素组成。无机和有机碳同位素组成之差的Δδ值,沿剖面不断变小,指示剖面上部样品可能受到热扰动和成岩后期作用影响。碳同位素规律的变化,反映了最初的沉积信息,特别是有机质埋藏量的变化,这些变化与早-中寒武世环境变化和生物组合差异有关。     

Landslide inventory and susceptibility modelling using geospatial tools,in Hunza-Nagar valley,northern Pakistan

A comprehensive landslide inventory and susceptibility maps are prerequisite for developing and implementing landslide mitigation strategies. Landslide susceptibility maps for the landslides prone regions in northern Pakistan are rarely available. The Hunza-Nagar valley in northern Pakistan is known for its frequent and devastating landslides. In this paper, we have developed a landslide inventory map for Hunza-Nagar valley by using the visual interpretation of the SPOT-5 satellite imagery and mapped a total of 172 landslides. The landslide inventory was subsequently divided into modelling and validation data sets. For the development of landslide susceptibility map seven discrete landslide causative factors were correlated with the landslide inventory map using weight of evidence and frequency ratio statistical models. Four different models of conditional independence were used for the selection of landslide causative factors. The produced landslides susceptibility maps were validated by the success rate and area under curves criteria. The prediction power of the models was also validated with the prediction rate curve. The validation results shows that the success rate curves of the weight of evidence and the frequency models are 82% and 79%, respectively. The prediction accuracy results obtained from this study are 84% for weight of evidence model and 80% for the frequency ratio model. Finally, the landslide susceptibility index maps were classified into five different varying susceptibility zones. The validation and prediction result indicates that the weight of evidence and frequency ratio model are reliable to produce an accurate landslide susceptibility map, which may be helpful for landslides management strategies.     

Probability distributions for maximum wave and crest heights

The paper discusses short- and long-term probability models of ocean waves. The Gaussian theory is reviewed, and nonlinear short-term probability distributions are derived from a narrow band second-order model. The nonlinearity has different impact on different measurement techniques, and this is further demonstrated for wave data from the WAVEMOD Crete measurement campaign and laser data from the North Sea. Finally, we give some examples on how the short-term statistics may be used to estimate the probability distributions for the maximum waves during individual storms as well as in a wave climate described by long-term distributions.     

Organic Carbon Isotope Geochemistry of the Neoproterozoic Doushantuo Formation, South China

The Neoproterozoic Doushantuo Formation on the Yangtze Platform, South China, documents a sedimentary succession with different sedimentary facies from carbonate platform to slope and to deep sea basin, and hosts one of the world-class phosphorite deposits. In these strata, exquisitely preserved fossils have been discovered： the Weng＇an biota. This study presents carbon isotope geochemistry which is associated paired carbonate and organic matter from the Weng＇an section of a carbonate platform （shelf of the Yangtze Platform, Guizhou Province） from the Songtao section and Nanming section of a transition belt （slope of the Yangtze Platform, Guizhou Province） and from the Yanwutan section （basin area of the Yangtze Platform, Hunan Province）. Environmental variations and bio-events on the Yangtze Platform during the Late Neoproterozoic and their causal relationship are discussed. Negative carbon isotope values for carbonate and organic carbon （mean δ^13Corg = -35.0‰） from the uppermost Nantuo Formation are followed by an overall increase in δ^13C up-section. Carbon isotope values vary between -9.9‰ and 3.6‰ for carbonate and between -35.6‰ and -21.5‰ for organic carbon, respectively. Heavier δ^13Ccarb values suggest an increase in organic carbon burial, possibly related to increasing productivity （such as the Weng＇an biota）. The δ^13C values of the sediments from the Doushantuo Formation decreased from the platform via the slope to basin, reflecting a reduced environment with minor dissolved inorganic carbon possibly due to a lower primary productivity. It is deduced that the classical upwelling process, the stratification structure and the hydrothermal eruption are principally important mechanisms to interpret the carbon isotopic compositions of the sediments from the Doushantuo Formation.