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51.
Groundwater is crucial for the livelihoods and food security of millions of people, and yet, knowledge formation in the field of groundwater has remained asymmetrical. While, scientific knowledge in the discipline (hydrology and hydrogeology) has advanced remarkably, relatively little is known about the socio-economic impacts and institutions that govern groundwater use. This paper therefore has two objectives. The first is to provide a balanced view of the plus and the down side of groundwater use, especially in agriculture. In doing so, examples are drawn from countries such as India, Pakistan, Bangladesh, China, Spain and Mexico—all of which make very intensive use of groundwater. Second, institutions and policies that influence groundwater use are analyzed in order to understand how groundwater is governed in these countries and whether successful models of governance could be replicated elsewhere. Finally, the authors argue that there is a need for a paradigm shift in the way groundwater is presently perceived and managed—from management to governance mode. In this attempt, a number of instruments such as direct regulation, indirect policy levers, livelihood adaptation and peoples participation will have to be deployed simultaneously in a quest for better governance.
Tushaar ShahEmail:
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52.
塔河油田盐体覆盖区奥陶系储层发育特征及主控因素研究   总被引:2,自引:0,他引:2  
塔河盐下地区储层分布特征为奥陶系裂缝发育程度较高,溶蚀孔洞和半-未充填的高角度构造缝、溶蚀缝是本区最主要的储集空间类型.大型洞穴发育程度低于土体区,最主要的储集层类型为孔洞。裂缝型或裂缝-孔洞型储层.该区西部储层发育程度优于东部,本区有利储层多呈近NS条带状(或指状)展布;中下奥陶统上部储层发育程度高于下部;中下奥陶统储层发育程度高于上奥陶统良里塔格纽.控制盐下奥陶系储层发育与展布的主要因素是构造变形作用、加里东中期岩溶和沉积相.  相似文献   
53.
1. IntroductionObservations of surface air temperature indicatethat a significant global average warming has occurredduring the 20th century. The Intergovernmental Panelon Climate Change (IPCC, 2001) concludes that thereis new and stronger evidence that man has influencedthe climate. International negotiations have led to afirst step in combating climate change with the UnitedNations Framework Convention on Climate Change(UNFCCC) and the Kyoto Protocol, but further stepsare needed in …  相似文献   
54.
Heat waves associated with global warming are a significant hazard to human health, and they particularly endanger low-income households. In this study, we systematically analyze how the different components of heat vulnerability are related to household income, and present empirical evidence on the determinants of heat adaptation, focusing on the role of income. We contribute the first empirical analysis of heat vulnerability using household-level data at the national level, based on a longitudinal survey, including data points for 10,226 households in Germany in the period 2012–2020. Our results indicate that low income households are significantly more heat sensitive and have lower adaptive capacity than high income households, measured inter alia by health status, household composition, and economic and psychological resources to implement adaptation measures. However, heat hazard and exposure levels are comparable between income groups, hence there is no sorting of richer households into less hazardous or exposed locations on a national scale. We also contribute robust empirical evidence on the factors influencing household decisions to implement technical adaptation measures (e.g. installation of air conditioning), ultimately showing that the adaptation behavior of the most vulnerable households (e.g. people with poor health conditions or the elderly) is not limited by financial constraints.  相似文献   
55.
The Tam Duong karst area in NW Vietnam is among the poorest and remotest regions in the country. The local population largely depends on water from two main karst springs. Due to agricultural activity and untreated domestic wastewaters, the spring water is often microbiologically contaminated. In order to provide a scientific basis for groundwater protection in the area, different field methods have been applied including hydrogeological framework investigations, tracer tests, and hydrochemical and microbiological sampling and analyses. All methods had to be adapted to the conditions of a poor and remote area. These adaptations included, amongst other measures, the use of a portable microbiological water_testing kit and the involvement of the local population in the sampling campaign. The tracer tests showed simple and direct connections between two important swallow holes and the two main springs, and made it possible to determine the linear groundwater flow velocities, which are extremely high (up to 875 m/h). The hydrochemical and microbiological data confirmed the strong impact of the streams sinking into the swallow holes on the spring water quality. Future groundwater source protection strategies should consequently focus on the reduction of polluting activities near the sinking streams and within their catchment areas.  相似文献   
56.
越来越多的地震滑坡相对于地震断层的不对称分布震例让人们意识到断层上盘效应的存在。 然而,目前有关断裂运动方式与滑坡空间分布关系的研究还不够充分和深入。在收集大量地震滑坡震例资料并获得其分布规律的基础上,建立了一个简化的断层模型,以地震波在地表与断层面之间反射传播特性为基础,探讨断层倾角改变对地表地震动强度的影响。进而,以汶川地震触发的大型滑坡为例,研究了断层的几何特征和运动方式对诱发滑坡空间分布的影响。结果表明,断层的倾角对滑坡空间分布范围具有控制作用,随着倾角的增加,垂直断层走向的滑坡分布范围逐渐减小;并且,大型滑坡的初始坡面受到断裂运动方向的影响,与断裂运动方向一致的坡面更容易发生滑坡。所获结果不仅有助于提高区域性地震滑坡危险区域的预测精度,而且对认识大型滑坡的滑动机制、主控因素以及可能的滑动规模、滑距等也起到促进作用。通过对滑坡崩塌的认识来辅助提高对地质构造、地震断层等的认识,应是地震诱发滑坡崩塌研究的新的意义所在。  相似文献   
57.
Selected volatile organic compounds (VOCs) emitted from commercial activities and industrial processes have been classified as hazardous air pollutants, posing a potential health risk in the urban environment. In this respect, perchloroethylene (PCE), a suspected human carcinogen, is the most noticeable compound because it is widely used in laundries and hotels as a dry‐cleaning solvent. The objective of this paper was to quantify the emissions of PCE and other petroleum‐based solvents from dry cleaning business in illustration of the regulatory infrastructure of reducing PCE exposure in the environment of Taiwan. Based on the Emission Factors (AP‐42) method, the emissions of the non‐methane hydrocarbons (NMHCs) from dry cleaning business had decreased from 5100 metric tons in 1997 to 2800 metric tons in 2007. The success of significant reduction of NMHCs in Taiwan has been ascribed to the fact that Taiwan established the relevant regulations at the end of the 1990s. From the data on the industrial/commercial demand for PCE and the emission inventories of NMHCs from dry cleaning business, the reduction of PCE emissions will show a declining trend in the near future.  相似文献   
58.
余天堂 《岩土力学》2007,28(Z1):305-310
扩展有限元法是一种在常规有限元框架内求解强和弱不连续问题的新型数值方法,其原理是在裂尖附近用一些奇异函数和沿裂纹面用阶跃函数加强传统有限元的基,以考虑跨过裂纹的位移场的不连续,该加强策略允许计算网格独立于不连续体几何。讨论了扩展有限元法的一些数值方面,主要包括:水平集法确定界面和加强节点与加强方式、裂尖加强范围的选择、J积分区域的确定和积分方案等。  相似文献   
59.
福建长乐海岸沙丘形成发育及其区域分布特征   总被引:8,自引:0,他引:8  
福建长乐东部海岸沙丘较为发育, 沙丘的形成发育受风力、沙源、植被、地形等影响。根据沙丘类型、沙丘组合和现代风沙活动差异, 将长乐东部风沙区分为三段, 五个不同风沙地貌区。  相似文献   
60.
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