基于ArcGIS平台的渔业信息化管理平台

本文介绍了基于ArcGIS平台的渔业信息化管理平台的建设目标,阐述了系统的设计架构与建设内容,并简要分析了系统的关键技术及应用实践。     

Application of logistic regression model for slope instability prediction in Cuyahoga River Watershed,Ohio, USA

High incidences of slope movement are observed throughout Cuyahoga River watershed in northeast Ohio, USA. The major type of slope failure involves rotational movement in steep stream walls where erosion of the banks creates over-steepened slopes. The occurrence of landslides in the area depends on a complex interaction of natural as well as human induced factors, including: rock and soil strength, slope geometry, permeability, precipitation, presence of old landslides, proximity to streams and flood-prone areas, land use patterns, excavation of lower slopes and/or increasing the load on upper slopes, alteration of surface and subsurface drainage. These factors were used to evaluate the landslide-induced hazard in Cuyahoga River watershed using logistic regression analysis, and a landslide susceptibility map was produced in ArcGIS. The map classified land into four categories of landslide susceptibility: low, moderate, high, and very high. The susceptibility map was validated using known landslide locations within the watershed area. The landslide susceptibility map produced by the logistic regression model can be efficiently used to monitor potential landslide-related problems, and, in turn, can help to reduce hazards associated with landslides.     

南极磷虾渔业反馈式管理探析

随着近几年南极磷虾渔业的快速发展,南极海洋生物资源养护委员会(CCAMLR)正在抓紧建立反馈式管理(FBM)机制,以预防和控制磷虾渔业对南大洋局部生态系统可能产生的负面影响,介绍了CCAMLR南极磷虾渔业反馈式管理的基本概念和理论框架,梳理了反馈式管理工作开展的具体进程;侧重阐述了近期反馈式管理的两类模式策略,分析了反馈式管理关注的科学问题和基础理论、方法;提出我国渔业相关机构应积极储备科学数据和理论,参与反馈式管理建设,以适应未来南极磷虾渔业新的管理模式,促进我国南极磷虾渔业的可持续发展。     

Enhancing the performance of quota managed fisheries using seasonality information: The case of the Portuguese artisanal dredge fleet

Several fisheries across the world are managed by a quota regime. These quotas can be set yearly, monthly, weekly or daily. However, for some fish species demand seasonality may occur, which should be taken into consideration in the establishment of the quota (especially in those fisheries managed by daily or monthly quotas). This would allow fishermen to catch more fish at times of the year with higher demand in detriment of periods when demand is low. The present work investigates the existence of demand seasonality for bivalves from the artisanal dredge fleet. This fleet operates along the entire coast of the Portugal mainland. The analysis of fleets' revenue efficiency is assessed with Data Envelopment Analysis models, and the monthly seasonality effects on the revenue efficiency were tested using a Tobit regression. The results revealed that on the South coast there is a strong demand in the summer whereas on the western coast (northwest and southwest fishing areas) demand increases during Christmas and New Year festivities. Since this fishery is managed by weekly/daily quotas, it is proposed that these quotas should be redistributed in order to adjust them to periods of higher demand, thereby increasing the profitability of the vessels. The approach followed could be applied to similar fisheries worldwide.     

Market integration and its relation to income distribution and inequality among fishers and traders: The case of two small-scale Kenyan reef fisheries

This study, carried out in five fishing communities along the Kenyan coast, examined fisheries-derived income of fishers and traders in two different invertebrate fisheries (octopus and sea cucumber) and tested if differences in global market integration of these two products could explain differences in income inequalities among actors involved in the two fisheries. The structure of the value chains was mapped, differences in income between fishers and traders tested, and income inequalities among actors in each fishery examined. Although the octopus fishery included a greater diversity of actors and thereby provides income to a larger group of people, income inequality in this fishery was higher among fishers and traders than in the sea cucumber fishery. Thus, the often cited relationship between increasing market integration and income inequality may require a re-evaluation and a more nuanced treatment.     

On coherent ice drift features in the southern Beaufort sea

Previous studies have highlighted reversals in the Beaufort Gyre on regional scales during summer months, and more recently, throughout the annual cycle. In this study we investigate coherent ice drift features associated with individual ice beacons during winter 2008 that may be a signature of ice–coast interactions, atmospheric and/or oceanic forcing. Examined in particular are three case studies associated with reversals in ice beacon trajectories in January and April of 2008; case I corresponds to a meander reversal event in January, case II to a loop reversal event in April, and case III to a meander reversal event located to the northeast of the Mackenzie Canyon in April. An assessment of atmospheric and oceanic conditions during these reversal events shows enhanced ocean–sea-ice–atmosphere dynamical coupling during the Case I meander reversal event in January and comparatively weak coupling during the Case II loop and Case III meander reversal event in April. Absolute (single-particle/beacon) and relative (two-particle/beacon) dispersion results demonstrate dominant meridional ice drift displacement and inter-beacon separation for Case I relative to Cases II and III indicative of ice–ice and ice–coast interactions in January. The results from this investigation provide an ice drift case study analysis relevant to, and template for, high-resolution sea ice dynamic modeling studies essential for safety and hazard assessments of transportation routes and shipping lanes, ice forecasting, and nutrient and contaminant transport by sea ice in the Arctic.     

基于神经网络的规则提取及其渔业应用研究

为了解决远洋渔业中过度依赖经验而产生的盲目捕捞问题,结合海洋环境数据和历史产量数据对渔场进行有效分析,提出了一种基于径向基函数神经网络(Radial basis function neural network,RBFNN)的栖息地指数(HSI)预测方法,并将其应用于印度洋海域大眼金枪鱼(Thunnus obesus)栖息地指数的预测。在RBFNN训练过程中使用模糊C均值(Fuzzy c-means,FCM)聚类算法,在基于神经网络的规则提取过程中首次采用了和声搜索(Harmony search,HS)算法。实验研究表明,利用FCM改进后的RBFNN,均方误差(Mean square error,MSE)达到0.021 6。和声搜索由于算法简单,易于实现,能够应用于训练后的FCM-RBFNN提取分类规则,提取出的规则能够反映该渔业现状。     

POSSIBLE RELATIONSHIPS AMONG SOUTH CHINA SEA SSTA, SOIL MOISTURE ANOMALIES IN SOUTHWEST CHINA AND SUMMER PRECIPITATION IN EASTERN CHINA

By using 1958-2001 NOAA extended reconstructed sea surface temperature(SST) data, ERA40 reanalysis soil moisture data and precipitation data of 444 stations in China(east of 100°E), the possible relationships among South China Sea(SCS) SST anomaly(SSTA), soil moisture anomalies(SMA) and summer precipitation in eastern China as well as their possible physical processes are investigated. Results show that the SSTA of SCS bears an evidently negative correlation with spring soil moisture in the east part of Southwest China. More(less) precipitation happens in the Yangtze River basin and less(more) in the Southeast China in summer when the SSTA of SCS is higher(lower) than normal and the soil in the east part of Southwest China is dry(wet) in spring. Further analysis shows that when the SSTA of SCS is high(low), the southwesterly wind at low level is weak(strong), decreasing(increasing) the water vapor transport in South China, resulting in reduced(increased) spring precipitation in the east part of Southwest China and more(less) soil moisture in spring. Through the evaporation feedback mechanism, the dry(wet) soil makes the surface temperature higher(lower) in summer, causing the westward extension(eastward retreat) of the West Pacific Subtropical High, eventually leading to the summer precipitation anomalies.     

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国土资源科技管理统计指标体系的设计

科技统计指标体系是对科技活动进行统计的重要工具。本文从国土资源科技管理的角度对科技统计指标体系进行分析和补充,细化了科技投入与研发、科技人才培养、科技产出、国际科技合作的量化值,进一步丰富和完善了科技统计的指标体系。