GEOCHEMICAL EXPLORATION

正20141058 Chen Ling(Key Laboratory of Mathematical Geology of Sichuan Province,Chengdu University of Technology,Chengdu610059,China);Guo Ke Study of Geochemical Ore-Forming Anomaly Identification Based on the Theory of Blind Source Separation(Geosci-     

SEISMIC GEOLOGY

正20141334 Chen Kun(Institute of Geophysics,China Earthquake Administration,Beijing100081,China);Yu Yanxiang Shakemap of Peak Ground Acceleration with Bias Correction for the Lushan,Sichuan Earthquake on April20,2013(Seismology and Geology,ISSN0253-4967,CN11-2192/P,35(3),2013,p.627-633,2 illus.,1 table,9 refs.)Key words:great earthquakes,Sichuan Province     

MATHEMATICAL GEOLOGY

正20142560Hu Hongxia(Regional Geological and Mineral Resources Survey of Jilin Province,Changchun 130022,China);Dai Lixia Application of GIS Map Projection Transformation in Geological Work(Jilin Geology,ISSN1001-2427,CN22-1099/P,32(4),2013,p.160-163,4illus.,2refs.)     

ChinaExcel在地质勘查软件研发中的应用

地质勘查行业用到大量的原始和综合报表,为提高报表的制作和设计效率,需要开发必要的应用软件。本文介绍ChinaExcel软件的主要功能、报表类型和应用流程,以实例分析展示了该软件在地质勘查软件研发中的应用过程。武警黄金部队自主研发的勘探工程数字地质编录系统和地质勘查项目经费预算系统,首次将 ChinaExcel 报表软件引入地质勘查行业,它能够简化地勘经费预算过程,提高经费预算的效率和准确性,推进地质勘查数字化和信息化建设进程。     

Adaptive management of declining fisheries: When is it worth trying to rebuild stocks through fishery regulation?

Declining catches are typically taken to be a warning sign of overfishing. But in fact, many such declines have been driven by recruitment changes unrelated to stock size, as evidenced by the failure of stocks to recover after reduction in fishing or recovery despite the failure to reduce fishing. Given a declining pattern, supposedly precautionary decisions to reduce fishing should be treated as experimental management options with a high probability of not resulting in the desired recovery to more productive stock sizes. Simple decision tables can be used to compare such experimental options to “wait and see” options that do not involve fishing reductions. A case example with a grouper fishery in Kuwait demonstrates that experimental effort reduction may not be the best policy from a decision analysis perspective, at least when there are substantial reasons to expect recruitment changes unrelated to stock size. In this case, virtual population analysis and stock reduction analysis models indicate either unusually weak recruitment compensation (steepness h < 0.4) or progressive decline in recruitment carrying capacity, possibly caused by decreases in estuarine rearing habitat associated with declining flows of the Tigris and Euphrates Rivers.     

Distributed and integrated response of a geographic information system‐based hydrologic model in the eastern Palouse region,Idaho

Verification of distributed hydrologic models is rare owing to the lack of spatially detailed field measurements and a common mismatch between the scale at which soil hydraulic properties are measured and the scale of a single modelling unit. In this study, two of the most commonly calibrated parameters, i.e. soil depth and the vertical distribution of lateral saturated hydraulic conductivity K_s, were eliminated by a spatially detailed soil characterization and results of a hillslope‐scale field experiment. The soil moisture routing (SMR) model, a geographic information system‐based hydrologic model, was modified to represent the dominant hydrologic processes for the Palouse region of northern Idaho. Modifications included K_s as a double exponential function of depth in a single soil layer, a snow accumulation and melt algorithm, and a simple relationship between storage and perched water depth (PWD) using the drainable porosity. The model was applied to a 2 ha catchment without calibration to measured data. Distributed responses were compared with observed PWD over a 3‐year period on a 10 m × 15 m grid. Integrated responses were compared with observed surface runoff at the catchment outlet. The modified SMR model simulated the PWD fluctuations remarkably well, especially considering the shallow soils in this catchment: a 0·20 m error in PWD is equivalent to only a 1·6% error in predicted soil moisture content. Simulations also captured PWD fluctuations during a year with high spatial variability of snow accumulation and snowmelt rates at upslope, mid‐slope, and toe slope positions with errors as low as 0·09 m, 0·12 m, and 0·12 m respectively. Errors in distributed and integrated model simulations were attributed mostly to misrepresentation of rain events and snowmelt timing problems. In one location in the catchment, simulated PWD was consistently greater than observed PWD, indicating a localized recharge zone, which was not identified by the soil morphological survey. Copyright © 2006 John Wiley & Sons, Ltd.     

A numerical test of two approximate solutions to the radiative transfer equation using the Elsasser scheme

In a recent paperCharlock, Herman andZdunkowski (1976) disagree on how best to apply the Radiative Transfer Equation (RTE) in the construction of Elsasser type radiation tables. The two proposed approximation solutions are analyzed and compared against a quasiexact solution. Infrared fluxes and cooling rates are calculated for part of the 6.3 m water vapor band for two model atmospheres. It is found that the Zdunkowski (Z) approximation yields more accurate downward fluxes, while the Charlock-Herman (CH) approximation, in general, results in more accurate upward fluxes. For the two model atmospheres studied the cooling rates for theZ approximation are usually of better quality than those due to the CH solution, unless the divergence of the net flux is extremely small.     

Jason-1 Altimeter Ground Processing Look-Up Correction Tables

Poseidon-2 is the dual frequency radar altimeter embarked on the CNES/NASA oceanographic satellite Jason-1 that was launched on 7 December 2001. The primary objective of the Jason-1 mission is to continue the high accuracy time series of altimeter measurements that began with TOPEX in 1992. To achieve this goal, it is necessary to improve each component of the ground processing continually. Among these components are the look-up correction tables that are used to correct the estimations (range, significant waveheight, and sigma naught) issued from the retracking algorithms (on-board and ground). Look-up tables were first computed taking into account the prelaunch characteristics of the altimeter. They have to be updated to take into account better all the in-flight characteristics of the altimeter and all the updated ground algorithms that can impact the estimation process. The aim of this article is to describe the radar altimeter simulator of performances that has been used to compute look-up tables, to display the freshly computed look-up tables, and to discuss the consequences of these new corrections on the products provided to the users. The updated look-up correction tables allow improvement of SWH estimation, in particular with respect to TOPEX SWH data. It is also shown that no range dependency on SWH has to be looked for in these tables, and that the on-board TOPEX and Poseidon-2 tracking systems may contain the differences explaining the relative sea state bias between both altimeters.     

A probabilistic description of the wind over Liverpool Bay with application to oil spill simulations

Surface winds from the UK Meteorological Office mesoscale (12 km grid) atmospheric model have been used to define the wind at a location in Liverpool Bay during 1997–2001. Winds from the SW (centred on 240°) with a speed of about 10 m/s (20 knots) were the most frequent, although weaker winds from the SE were also common. The wind spectra were red in character and showed no evidence for a peak at the synoptic (2–5 day) time scale; however, a zero-up-crossing analysis suggested a dominant periodicity at 3.1 days, and at this time scale the winds were spatially coherent over a distance of 300 km. A wind direction transition matrix was derived to quantify the probability with which the wind changed between two specified directions. This information was then used with an estimate of the mean duration of a wind event to compute a stochastic wind time series that contained a similar energy level, periodicity, and direction variability to the archived wind data. The archived and stochastic winds were then used in 1000 oil spill contingency simulations during which estimates of the mean and minimum times taken for oil to reach the coastline, and the percentage of the oil impacting selected sites were computed. The stochastic winds provided more realistic results, when compared against those derived using the wind archive, than those obtained using a wind rose representation of the winds. The derivation and use of a stochastic wind time series has application to a range of modelling studies.     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),