地下水科学调控与增效利用     

吕红  张静  刘萍 《地下水》2005,27(4):263-265

地下水参与自然界的水分循环,同时又独立参与自身的补给、径流、排泄小循环,具有再生性.只要把握地下水资源的客观规律,充分利用地下含水空间和多年调节功能,准确调控地下水资源开发利用的尺度,地下水将会发挥更大的效益.从地下水循环机理的层面上,阐明地下水超采区是动态的,是某一时期的产物,阐述地下水科学调控的合理水位标限,提出了增效利用的措施.  相似文献   

发挥区域资源优势　调整江西农业产业结构     

陈双溪  魏丽  王保生 《气象与减灾研究》2002,25(3):1-4

根据江西省农业自然资源特点,结合全省土地利用遥感调查结果,对江西省部分种植业的优势区域布局进行了分析和规划,并指出了江西在农业产业结构调整中应注意的问题.  相似文献   

Revisiting the red light district: Still neglected, immoral and marginal?     

Phil Hubbard  Mary Whowell 《Geoforum》2008,39(5):1743-1755

Twenty years ago, Ashworth et al. (1988) offered a distinctive and innovative interpretation of a neglected aspect of the urban scene: the red light district. Focusing on the location of female prostitution in a series of Western European cities, their paper suggested that the geographies of sex work are revealing of some of the ‘less obvious’ social and political processes that shape urban space. Here, we revisit Ashworth et al’s paper in the light of subsequent developments in the organisation of commercial sex as well as the study of sexuality and space. Noting important continuities as well as major shifts in the location of sex work, with a significant shift to off-street forms of sex working having occurred, this paper argues that some of the ideas in Ashworth et al’s paper remain highly pertinent, but others appear in need of updating. In particular, we stress the importance of focusing on men as both clients and workers within the sex industry, and flag up a number of connections that might be made with the emerging literatures on the geographies of sex itself. We hence conclude by considering Ashworth et al’s paper as an important early intervention in debates surrounding the relations of sexuality and space, albeit one in which questions of gender, embodiment, and sexual desire remained largely unexplored.  相似文献   

康熙帝对气候和天气的调查和处理     

王鹏飞 《南京气象学院学报》1998,21(3):446-454

介绍康熙帝关心气候和天气变化,多方调查了解其特点,常亲自课晴问雨,积累气象经验,其目的在于保障农业生产,他所订的“报雨泽”制度,比历代更为精密,他还对预估的灾害作出预防措施。  相似文献   

Interplay between top-down, bottom-up, and wasp-waist control in marine ecosystems   总被引：1，自引：1，他引：1  

George L. Hunt  Jr.  Skip McKinnell 《Progress in Oceanography》2006,68(2-4):115

In October 2004, the North Pacific Marine Science Organization (PICES) sponsored a symposium to consider “Mechanisms that regulate North Pacific ecosystems: Bottom up, top down, or something else?” It sought to examine how marine populations, particularly the upper-trophic-level species, are regulated and to understand how energy flows through marine ecosystems. This introductory essay examines aspects of control mechanisms in pelagic marine ecosystems and some of the issues discussed during the symposium and in the 11 papers that were selected for this special issue. At global scales, the greatest biomass of fishes, seabirds and marine mammals tends to occur in regions of the world ocean with high primary production, e.g., the sub-arctic seas and up-welling regions of continental shelves. These large-scale animal distribution patterns are driven by food availability, not the absence of predators. At regional scales however, it is likely that current predation or past predation events have shaped local distributions, at least in marine birds and pinnipeds. Wasp-waist control occurs when one of the intermediate trophic levels is dominated by a single species, as occurs with small pelagic fishes of the world’s up-welling zones. Processes in these ecosystems may have features that result in a switch from bottom-up to top-down control.  相似文献   

论中国经济区的类型与组织   总被引：20，自引：5，他引：20  

胡序威 《地理学报》1993,48(3):193-203

根据作者对经济区概念和性质的理解,对我国现实存在的名目繁多的经济区进行了系统的归纳和类型的划分,指出了组织经济区的重要实践意义,并重点论述了如何从组织上加强对不同层次的综合经济区的规划协调和调控管理。  相似文献   

区域PRED的系统分析与决策制定方法   总被引：16，自引：0，他引：16  

张志强 《地理研究》1995,14(4):62-68

人口问题、资源问题、环境问题和发展问题是当今世界人地关系的四大焦点问题,它们相互联系、相互影响,因而解决它们的关键在于实现PRED四者的协调发展.从定义“区域PRED系统”这一概念入手,进而运用系统科学的分析方法,可以较为深入地探讨区域PRED协调发展的相互作用与内部信息联系机制.在此基础上,通过数学分析、模型仿真和多目标决策评判等方法的逐步深入,可以构筑起区域PRED协调发展的辅助决策支持系统的运行框架.  相似文献   

A coming boom in commercial shipping? The potential for rapid growth of noise from commercial ships by 2030     

《Marine Policy》2016

Ocean noise levels are thought to be increasing as a result of major growth in global shipping activity, but data quantifying those changes are limited in space and time. As an alternative approach, this study examines the current and future maximum noise capacity of three segments of the global commercial shipping fleet: container ships, oil tankers, and bulk carriers. It shows that continued growth in the number of ships, the quantity of goods carried and the distances traveled could increase the maximum noise capacity of the global shipping fleet by up to a factor of 1.9 by 2030, with major growth in particular in the container and bulk carrier segments. Thus, in the absence of operational or manufacturing changes to such ships, the contribution of commercial shipping to ambient ocean noise levels can be expected to dramatically increase.  相似文献   

Explaining Growing Glyphosate Use: The Political Economy of Herbicide-Dependent Agriculture     

《Global Environmental Change》2021

The growing use of chemical herbicides for weed control has become a dominant feature of modern industrial agriculture and a major environmental and health concern in agricultural systems worldwide. This paper seeks to explain how and why glyphosate-based agricultural herbicides have become so entrenched in modern agriculture. It shows that a complex interplay among technological, market, and regulatory developments have encouraged a lock-in of glyphosate linked technologies in agricultural systems. These are: (1) the repurposing of glyphosate for use with genetically modified crops; (2) the rise of the generic glyphosate market, which globalized the chemical’s use and encouraged new agricultural uses; (3) new technologies such as digital agriculture and genome editing that interface with glyphosate use; and (4) growing corporate market power and declining public investment in agricultural research programs that constrained innovation in non-herbicide weed control technologies.  相似文献   

Fisheries regulation: A survey of the literature on uncertainty,compliance behavior and asymmetric information     

《Marine Policy》2017

Economists normally claim that a stock externality arises within fisheries because each individual fisherman does not take the effect on stock size into account when making harvest decisions. Due to the stock externality, it is commonly argued that fisheries regulation is necessary, but regulatory decisions are complicated by a tremendous amount of uncertainty and asymmetric information. This paper provides an overview of selected parts of the literature on the regulation of fisheries under uncertainty and asymmetric information, and possible areas for future research are identified. Specifically, three main topics are covered. First, the issue of choosing regulatory instruments under uncertainty is discussed. Second, compliance and enforcement problems caused by fisheries regulation are investigated. Third, alternatives to a traditional enforcement policy are presented.  相似文献