Acoustic monitoring using bamboo set net in the Southern Sea of Korea     

Hyungbeen Lee  Kyounghoon Lee  Hyoung Sul La  Yongsu Yang  Pyungkwan Kim 《Ocean Science Journal》2017,52(1):67-74

High-temporal resolution profiles of acoustic backscatter were collected from a traditional bamboo set net along the coast of the Southern Sea, Korea, using sideward-looking multi-beam imaging sonar. These data were used to examine the impact of variations in tidal cycles and current speeds on the bamboo set net. The relatively high influx of fish during the nighttime compared to the low influx and high outflux of fish during the daytime suggests visual avoidance of the net by the fish during the daytime. The observed diel variation in the captured fish flux was significantly correlated with the current speed (day: r = 0.35, p = 0.002, night: r = 0.60, p < 0.001). The ratio of influx and outflux of fish, and current speed were correlated in a linear relationship (day: r = 0.45, p < 0.001; night: r = 0.56, p < 0.001). The fish activity of those inhabiting the bamboo set nets appears to be greatly influenced by day-night differences and current speed. The present study enhances understanding of fish behavior via utilization of a bamboo set net in the coastal zone.  相似文献   

Metals in tidal flats colonized by microbial mats within a South-American estuary (Argentina)     

Analía V. Serra  Sandra E. Botté  Diana G. Cuadrado  Noelia S. La Colla  Vanesa L. Negrin 《Environmental Earth Sciences》2017,76(6):254

In this study, we measured the concentrations of metals (Cd, Cu, Pb, Ni, Cr, Zn, Hg, Mn, and Fe) and assessed the characteristics of tidal flats (grain size and organic matter content) in sediments and their overlying microbial mats fractions to evaluate the anthropogenic impact within the Bahía Blanca Estuary (BBE). Puerto Rosales (PR) and Almirante Brown (AB), located in the middle and inner zone of the estuary, respectively, were used as sampling sites. Sediments were composed mainly of silt–clay in AB, whereas first fine-grained particles were coarser in depth in PR. Regarding the concentration of metals in both fractions, we found differences between sites: There were higher concentrations of overall metals in AB relative to PR. In addition, higher concentrations of Cu were recorded in the first centimeters of AB tidal flats, whereas higher concentration of Cd were recorded in microbial mats of PR. Considering that the grain size was similar between sites, these results are consistent with the high concentration of organic matter found in AB, probably because this site is close to a former municipal dump and sewage discharges. Also, the higher Cd content found in PR site would highlight both the influence of untreated urban discharges and port anthropogenic activities. In conclusion, this study allowed identifying high values of some metals in the presence of microbial mats in the BBE, thus suggesting a possible interaction between both, at least for metals like Cu or Cd.  相似文献   

基于水准剖面的山西断陷带现今活动性研究     

陈阜超  塔拉  陈聚忠 《大地测量与地球动力学》2015,35(4):576-580

根据跨山西断陷带的水准剖面观测资料,计算其垂直形变量和垂直形变速率,研究其现今垂直活动性。2006年以来的垂直形变揭示,山西断陷带东北段延怀盆地和蔚县盆地呈掀斜上升活动,北段阳原盆地和大同盆地以下降活动为主,晋中盆地为上下波动,临汾盆地呈现上升活动。2013年山西断陷带活动出现转折性变化,蔚县盆地大幅度下降,大同盆地、代县-定襄盆地、晋中盆地和临汾盆地均呈现不同程度的上升。  相似文献   

北京地区主要活断层活动参数的重力反演     

董运洪  刘峡  韩月萍  杜雪松  塔拉 《地震研究》2014,37(3)

采用1991~1999年首都圈重力测网的重力测量资料,根据地质调查结果确定断层初始运动模型,利用稳健—贝叶斯最小二乘方法反演北京地区4条活断层的活动参数(走滑、倾滑、引张)。反演结果表明:在1991~1999年间,北京地区活断层的运动性质均以走滑和垂直升降为主,兼有伸展特征,但运动速率都不大,约为2 mm/a。北京地区北西走向断层反演的运动特征为左旋走滑正断层,北东走向断层反演的运动特征为右旋走滑正断层。  相似文献   

Morphometric and molecular data on two mitochondrial genes of a newly discovered chimaeran fish (Hydrolagus melanophasma, Chondrichthyes)     

José De La Cruz-Agüero  Francisco Javier García-Rodríguez  Víctor Manuel Cota-Gómez  Felipe Neri Melo-Barrera  Rogelio González-Armas 《Ocean Science Journal》2012,47(2):147-153

Fresh and preserved (type material) specimens of the black ghost chimaera Hydrolagus melanophasma were compared for morphometric characteristics. A molecular comparison was also performed on two mitochondrial gene sequences (12S rRNA and 16S rRNA gene sequences). While significant differences in measurements were found, the differences were not attributable to sexual dimorphism or the quality of the specimens, but to the sample size and the type of statistical tests. The result of the genetic characterization showed that 12S rRNA and 16S rRNA genes represented robust molecular markers that characterized the species.  相似文献   

Seismic assessment of a real RC asymmetric hospital building according to NTC 2008 analysis methods     

A. La Brusco  V. Mariani  M. Tanganelli  S. Viti  M. De Stefano 《Bulletin of Earthquake Engineering》2015,13(10):2973-2994

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Exploration of deep sedimentary layers in Tacna city,southern Peru,using microtremors and earthquake data for estimation of local amplification   总被引：1，自引：1，他引：0  

Hiroaki Yamanaka  Mileyvi Selene Quispe Gamero  Kosuke Chimoto  Kouichiro Saguchi  Diana Calderon  Fernándo Lázares La Rosa  Zenón Aguilar Bardales 《Journal of Seismology》2016,20(1):107-116

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Parameter and rating curve uncertainty propagation analysis of the SWAT model for two small Mediterranean catchments     

Haykel Sellami  Isabelle La Jeunesse  Sihem Benabdallah  Marnik Vanclooster 《水文科学杂志》2013,58(8):1635-1657

Abstract

The SWAT model was tested to simulate the streamflow of two small Mediterranean catchments (the Vène and the Pallas) in southern France. Model calibration and prediction uncertainty were assessed simultaneously by using three different techniques (SUFI-2, GLUE and ParaSol). Initially, a sensitivity analysis was conducted using the LH-OAT method. Subsequent sensitive parameter calibration and SWAT prediction uncertainty were analysed by considering, firstly, deterministic discharge data (assuming no uncertainty in discharge data) and secondly, uncertainty in discharge data through the development of a methodology that accounts explicitly for error in the rating curve (the stage?discharge relationship). To efficiently compare the different uncertainty methods and the effect of the uncertainty of the rating curve on model prediction uncertainty, common criteria were set for the likelihood function, the threshold value and the number of simulations. The results show that model prediction uncertainty is not only case-study specific, but also depends on the selected uncertainty analysis technique. It was also found that the 95% model prediction uncertainty interval is wider and more successful at encompassing the observations when uncertainty in the discharge data is considered explicitly. The latter source of uncertainty adds additional uncertainty to the total model prediction uncertainty.