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991.
为研究有关潮汐通道浅水槽建港问题,以辐射沙脊群黄沙洋水道末端的条渔港为例,首先,进行了自然条件分析;其次,构建二维水动力数学模型,根据实测资料对水动力模型进行验证,并对工程前后整体海区的潮流流态、特征点横流大小进行了分析;最后,应用泥沙经验公式计算条渔港区港池及航道的年回淤量。以上数据可为港区方案设计提供科学依据。  相似文献   
992.
Site selection is a key factor in any aquaculture operation, affecting both success and sustainability. Moreover, it can solve conflicts between different coastal activities, making a rational use of the coastal space. Geographical information systems (GIS) have become of increased significance for environmental planning and assessment mainly because of the need to compare a great number of spatially related data, and because it can be used to couple these spatial data with their attributes and overlay them. This study used GIS and related technology to build a spatial database using those criteria which were considered to have any influence in integrating marine fish-cage culture within the tourism industry in Tenerife. Criteria were grouped in three submodels (distance to beaches, nautical sports, and viewshed), which were combined to generate a final output showing the most suitable areas for cage culture development in coexistence with tourism. Most areas of the coastline of Tenerife were identified as being suitable (56%) or very suitable (46%), suggesting that marine cage aquaculture could be developed on the island in coexistence with the well-established tourism industry.  相似文献   
993.
Raja Ampat, Indonesia, possesses the greatest diversity of corals and reef fishes on the planet. The area is a priority for marine conservation for the provincial government, local communities, and major international nongovernmental organizations such as The Nature Conservancy and Conservation International. Traditional marine resource management practices in the region, referred to as sasi, have the potential to support conservation objectives. This article contends that while traditional marine resource management systems may support conservation, they must be reinforced by a supportive social structure and governance system to remain relevant in a rapidly changing world. Two villages in Raja Ampat were studied to gain a better understanding of sasi and how this practice has been affected by cultural, political, and economic change. These villages illustrate how the role of religious authorities, access to alternative livelihoods, proximity to urban centers, and capacity for monitoring and enforcement may influence the effectiveness of marine resource management systems. Our research suggests that the continued relevance of sasi in marine resource management relies on the support of influential local leaders and businesses and government regulations that reinforce traditional resource use practices.  相似文献   
994.
This article presents the results of the Thematic Study on "the role of information in delivering Integrated Coastal Zone Management (ICZM) in Europe." It provides a definition of information and discusses the need for, and nature of, information as it influences and supports ICZM. The conclusions from the study are summarized, highlighting the importance of viewing information provision as part of the process of developing effective ICZM. The results of InfoCoast '99, a symposium held in February 1999 on knowledge and information for coastal management, are discussed and some of the practical steps that have and can be taken to meet the information need for ICZM in Europe are considered.  相似文献   
995.
Estuaries are last in line as a recipient of river water and for this reason they are particularly vulnerable to negative environmental impacts due to water scarcity and pollution. They only receive the runoff that has not been abstracted or prevented from reaching rivers. When this runoff is substantially reduced their functionality is undermined and they often become less attractive for recreational use. This article explores some aspects entailed in efficiently managing the allocation of water to estuaries problem and some associated problems. It is shown that efficient management requires the marginal social costs of the inflows to be brought into equivalence with the marginal social values of the inflows, and these values may be estimated, but that there are the challenges in this estimation and in linking these estimates to the welfare of the people in whom the managers of river systems are (presumed to be) interested.  相似文献   
996.
为增进对长江下游通州沙河段暗沙、浅滩滩面水沙特性及近底泥沙运移现状的认识,首次在该河段引入坐底式 综合观测系统,通过各型自动水沙观测仪器获取通州沙河段洲滩及主槽的洪枯季近底层水沙运动过程并展开分析。实测数 据表明:该河段落潮水动力>涨潮;涨潮动力深槽≥高滩>低滩,落潮动力深槽≥低滩>高滩,大潮>中潮>小潮;水流 旋转性则表现为低滩>高滩>深槽;且水动力与潮差间有较好的线性相关关系,相关系数基本均大于0.9;近底悬沙含沙量 表现为落潮>涨潮,大潮>中潮>小潮,深槽>低滩>高滩,洪季为枯季的1.5~2倍,该河段枯季期间近底悬沙含沙量与 水动力因子v2/(gh)的线性相关系数为0.5左右,洪季在0.6~0.7,据此建立的输沙能力公式可用于该河段浅滩及深槽的近底层 悬沙输沙能力推算。  相似文献   
997.
介绍了依据JTS 147-1—2010《港口工程地基规范》研发的“易工水运工程地基CAD软件 V1.0”的主要功能、界 面、开发原理和主要模块的算例。软件主要针对水运工程的边坡稳定问题,考虑了港口工程中常用的地基处理方法,可模 拟软基条件下边坡的分级加载工况,并具备渗流场计算分析功能。  相似文献   
998.
针对万州晒网坝滑坡地质勘查与长期监测滑移趋势不一致的现状,进行滑移机理跟踪,并通过物探验证跟踪结论。研究了135~175 m范围变化库水位及24 h强降水对该滑坡稳定性的影响,揭示了真实滑移面地质状况,纠正了地勘存在的不足,同时分析了滑移破坏机理。结果表明:该滑坡整体稳定、局部缓慢滑移;并提出了埋入式抗滑桩、裂隙封闭及地表排水的维护方案。  相似文献   
999.
基于有限体积方法,建立平面二维水流数学模型,对北江白石窑枢纽坝下19km航道整治工程进行数值研究.运用实测水文资料对模型进行验证.验证结果表明:该模型精度符合规范要求.计算了整治工程实施前、后白石窑坝下游河段通航水流特性,分析了各级恒定流和非恒定流作用下整治工程对坝下游河段通航水流条件的影响.研究结果表明:实施整治工程后,整治河段水流条件得到了明显的改善,水流条件可以满足千吨级船舶的通航要求.  相似文献   
1000.
采用级配不合格的机制砂与河砂按一定比例混合后得到了合格的混合砂,研究了不同比例组成的混合砂对混凝土耐久性的影响,并采用化学结合水法、热重分析法以及SEM等测试方法分析了混合砂对混凝土耐久性的影响机理。结果表明:混合砂混凝土试件的氯离子扩散系数要低于纯河砂混凝土试件,且混凝土氯离子扩散系数的变化趋势随机制砂比例的提高而降低;混凝土的抗硫酸盐耐蚀系数随机制砂比例的提高而降低,原因是提高机制砂的比例会提高混凝土的密实度,导致抗压强度比变化不大;不同比例组成的混合砂的级配不同,同时混合砂中的石粉可参与胶凝材料的水化进程,混合砂对混凝土耐久性的影响是这两因素的综合体现。  相似文献   
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