北盘江坝油滩河床演变分析及整治措施研究

通过对北盘江坝油滩河段水沙特性、河床组成的深入分析,重点研究了该河段的河床演变规律。从而,提出了该河段的整治措施。     

Coastal Management Using Public Judgments,Importance Scales,and Predetermined Schedule

A predetermined schedule of sanctions and regulations that reflect both scientific knowledge of resources and the preference and judgments of resource users in the community may provide a useful guide for management decisions involving complex coastal resource systems. Such a schedule can be implemented by constructing scales reflecting public judgments of the relative importance of adverse impacts on resources, or of activities causing such impacts. The importance scales can then be used to assess existing regulations and current management priorities and to serve as a guide for revisions and changes to current practice, for the design of new policy, for rationalizing regulatory controls, and for determining damage awards and other deterrence sanctions. The resulting evolution of a schedule can improve the consistency of resource use with community preferences by, for example, prescribing more severe restrictions on what are widely agreed to be more serious harms and lesser controls on less important ones. The application of this approach is demonstrated using Ban Don Bay, Thailand.     

Book review

Coastal Resource Use: Decisions on Puget Sound by Robert L. Bish, Robert Warren, Louis F. Weschler, James A. Crutchfield, and Peter Harrison.

Published by University of Washington Press in cooperation with Washington Sea Grant Program, 1975. 206 pp., 15 figs.     

Coastal Crisis: The Failure of Coastal Management in the Spanish Mediterranean Region

It is a fact that coastal zones in the Mediterranean are becoming progressively more seriously degraded. Instrumental to the phenomenon in Spain is the evident failure of the coastal management that the institutions have pursued for over three decades, both under the old, state-centralized model, and the new organizational model with the political division of land into autonomous regions. This failure can in part be explained not only by the inadequate tools the administration possesses to address the dynamism and complexity of the new economic activities that have sprung up along the coast, but also by incoherent sectoral policies. Finally, there has been no all-encompassing political strategy capable of dealing with coastal communities' demands for development and the need for the protection of ecosystems and their natural resources. All this has resulted not only in a deterioration of the area, but also in the discrediting of actions implemented by the institutions, and their plans and programs being perceived as an obstacle to economic development.     

Integrated Coastal Management in the Philippines: Testing New Paradigms

With fisheries declining, coral reefs battered, mangrove forests under threat, pollution levels rising, and coastal communities experiencing increased poverty, the Philippines faces severe challenges in managing its coastal resources. Coastal management efforts began in the Philippines more than 20 years ago through various community-based projects. Now, integrated coastal management is expanding in the country and holds the potential to reverse the trends. This article analyzes the situation in relation to new approaches for coastal management being undertaken through the Coastal Resource Management Project supported by the United States Agency for International Development implemented by the Department of Environment and Natural Resources. This project, drawing on the lessons generated by past and ongoing coastal management initiatives, is emphasizing integrated approaches to management over narrowly focused fisheries management and habitat protection efforts. It highlights the increasingly important role of local governments and the changing roles of national government to effectively support integrated coastal management. Multisectoral collaboration is explained as standard procedure to achieve outcomes that are broad based and sustainable. Local and national level activities are contrasted and shown as essential complements in building institutionalization of resources management within all levels of government. A practical result framework is explained for measuring relative success at the local government level of implementing best practices for coastal management. Finally, lessons being learned related to collaboration, level of focus, education, and communication; who is responsible; and expansion of the project are highlighted.     

Effect of mixing on microbial communities in the Rhone River plume

The biological processes involved during mixing of a river plume with the marine underlying water were studied off the Rhone River outlet. Samples of suspended and dissolved matter were collected while tracking a drifting buoy. Three trajectories were performed, at 2-day intervals, under different hydrological and meteorological situations. A biological uptake was evidenced from ammonium (NH₄) and phosphate (PO₄) shortage, indicating an early “NH₄-dependent” functioning occurring before the well-known “NO₃-based” cycle. The different ratios between NH₄, NO₃ and PO₄, as a function of salinity, were discussed to detail the preferential use in PO₄ and NH₄. Salinity zones with enhanced bacterial production, high chlorophyll a concentration, as well as DOC, NH₄ and PO₄ consumption were evidenced from 20 to 35 in salinity. It was shown that the successive abundance of bacteria and phytoplankton during transfer reflected the competition for PO₄ of both communities. On the Rhone River plume, the role played by temperature, light conditions and suspended matter upon biological activity seems relatively minor compared to salinity distribution and its related parameter: nutrient availability. It can be concluded that biological uptake in the Rhone River plume was closely related to the dilution mechanism, controlled itself by the dynamics of the plume. In windless conditions and close to the river mouth, the density gradient between marine and river water induced limited exchanges between the nutrient-rich freshwater and the potential consumers in the underlying marine water. Consequently, little biological activity is observed close to the river mouth. Offshore, mixing is enhanced and a balance is reached between salinity tolerance and nutrient availability to form a favourable zone for marine phytoplankton development. This can be quite far from the river mouth in case of a widely spread plume, corresponding to high river discharge. Under windy and wavy conditions, the plume freshwater is early and rapidly mixed, so that the extension of the “enhanced production zone” is drastically reduced and even bacteria could not benefit from the fast mixing regime induced.     

抛石挤淤在处理滨海公路软土地基中的应用

简述了软土地基加固处理的方法,指出了抛石挤淤加固软土地基的优点,分析了抛石挤淤地基处理原理,通过工程实例,详细介绍了抛石挤淤地基处理的施工方法和处理效果,以推广该方法。     

高斯过程回归短时交通流预测方法

已有的短时交通流预测方法均属于确定性预测,无法对预测的不确定性进行定量分析.针对上述问题,提出了一种基于高斯过程回归的短时交通流预测方法.通过该方法在对短时交通流进行预测的同时还可以得到预测的方差估计值,并依此可以确定预测值的95%置信区间.在仿真实例中,在相同条件下对所提方法与支持向量机预测方法进行比较.仿真结果表明,高斯过程回归短时交通流预测方法不仅与支持向量机预测方法具有相近的预测精度,其中均方根误差为12.09,绝对值误差为118.42,相对误差为17.32%,而且能够获得预测结果的方差估计值,从而有效实现短时交通流概率意义上的预测.     

基于Markov决策过程的驾驶员行为模型

将驾驶员-汽车看作统一的人机系统,利用驾驶员驾驶过程的本质是决策过程的性质,通过确定系统的决策时刻、决策报酬、状态转移速率和概率、抽象驾驶员的行为集合等建立了基于Markov决策过程的驾驶员行为模型,最后对所建模型进行了计算机仿真.     

小缸径增压中冷柴油机燃烧特性及放热规律分析

通过实测小缸径增压中冷柴油机气缸压力,分析其燃烧过程及放热规律。结果表明,负荷增加,放热率增大,燃烧始点提前;采用较小的供油提前角,可降低最大压力升高率和最大燃烧压力;采用增压中冷技术,可降低峰值温度,因而对降低NOx 有利。