青藏公路多年冻土路段边坡植被种植试验研究

针对青藏公路多年冻土路段高、寒、旱、风,植物生长期短,植被种植难度大的特点,在青藏公路开心岭路段的边坡,采用垂穗披碱草(Elymus nutans)和老芒麦(E.sibiricus)等植物混播,采用普通喷播及客土喷播工艺,开展了植被种植试验.结果表明,由于添加了当地的表土,客土喷播工艺能够在该地区公路边坡快速建立比较优良的植被.喷播当年,植被覆盖率可达27.3%,地上生物量(鲜重)和地下生物量(干重)分别达到76.3 g·m-2和72.2g·m-2;第5年,边坡植被覆盖率约为10.0%,地上生物量(鲜重)和地下生物量(干重)分别达到189.3 g·m-2和721.5 g·m-2.客土喷播工艺的植被建植效果明显优于普通喷播工艺.对于普通喷播,增加保水刺和凝结剂的用量,可提高植被建植效果.而添加纤维则作用不明显.     

客土喷播技术在泌桐高速公路的应用

随着我国高速公路的发展,高速公路边坡防护的形式已由以往惯用的圬工防护向植被防护等生态防护形式发展。边坡植被防护不仅能消除和缓解高速公路对客观环境造成的不良影响,减小区域性水土流失,而且实现公路与自然景观的可持续协调发展。针对泌桐高速公路上实施的植被防护技术之一的客土喷播技术,从原理、机械设备、材料、施工工艺等方面做了详尽的介绍。根据对泌桐高速公路沿线的自然环境概况（包括气候、土壤、植被、工程情况）的研究,提出了新型的客土喷播技术的适用条件、植物种类选择及配比方案、施工工艺等,并从设计、施工角度提出了改进意见。     

鲁中山区公路岩石路堑边坡植被自然恢复初步调查

为探讨公路岩石路堑边坡植被的自然恢复效果,为山区公路边坡防护设计和植被恢复设计提供参考,调查了鲁中山区的6条省道和2条国道,得到了边坡的岩石类别、风化程度,以及边坡的建设年限、坡度、坡高和边坡植被的覆盖度与优势物种,并简要分析了植被自然恢复的原因。初步结果显示:(1)花岗岩、闪长岩边坡的植被自然恢复效果远好于石灰岩边坡;(2)黄背草、荩草等为花岗岩和闪长岩边坡的优势物种,而荆条、酸枣等为石灰岩边坡的优势物种。建议:(1)对稳定的花岗岩和闪长岩边坡宜采用不妨碍植被生长的防护型式,实现植被的自然恢复;(2)对石灰岩边坡,宜采用岩石裸露处理,并穴栽灌木进行美化;(3)高速公路建设资金充裕不应成为随意扩大边坡工程防护的理由,将边坡植被自然恢复的理念应用到高速公路边坡设计中非常重要。     

Benthic megafauna communities under the influence of the South Atlantic Central Water intrusion onto the Brazilian SE shelf: A comparison between an upwelling and a non-upwelling ecosystem

The structure and dynamics of the benthic invertebrate megafauna of the Southeastern Brazilian shelf were studied over a 2-year period. Two regions presenting different oceanographic conditions, Ubatuba-SP and Cabo Frio-RJ were compared in terms of biomass, density of organisms and species richness. Two to three 30-min tows were undertaken at each of the stations, located at 40 and 100 m isobath, in a normal transect offshore of both regions. Faunal distributional patterns correlated with water mass dynamics, depth and sediment parameters. In the Cabo Frio region, subjected to a Ekman-driven seasonal coastal upwelling, the impact of the South Atlantic Central Water (SACW) on the inner shelf leads to a change in the benthic communities, with a high dominance of top carnivores such as the crab Portunus spinicarpus and the sea-star Astropecten brasiliensis, which accounted for the larger part of the total biomass. Distinct species associations were found in each of the two regions and the total biomass at Cabo Frio inner shelf was almost twice that of Ubatuba during the 2002 summer, when a marked upwelling was verified. The relationship between megabenthic biomass and input of organic matter to the sea floor during upwelling events is discussed.     

协同克立格和标化植被指数在广东省登革热分布特征研究中的应用

目的　探索用标化植被指数 (NDVI)预测登革热 (denguefever,DF)流行和媒介种群的空间分布的可行性。方法　收集广东省 1995年各市县DF发病资料、同期的伊蚊媒介监测资料及广东省县界数字化地图。用ERDAS8.5软件从卫星图像中提取各监测点NDVI。用ArcGIS8.1空间分析软件进行协同克立格 (Co Kriging)分析。 结果　DF流行、种群媒介及NDVI三者的空间分布呈现地域一致性 ;从Co Kriging可见 ,用NDVI对DF发病和BI进行局部估计作图时 ,也呈现了一致性。用NDVI对DF发病、BI同时替代进行三者协同时也取得了一致性的效果。分布图的交叉核验时 ,DF发病、媒介和NDVI的平均预测误差 (MPE)接近于 0 ,估计的方差 (RMSE)与平均标准误 (ASE)都较小 ,且极为接近 ,预测误差的变异程度 (RMSSE)接近于 1。结论　Co Kriging方法是描述DF空间分布特征的较好方法 ,NDVI可以用来作为DF发病和媒介的预测替代     

拟建新街--恩格阿娄铁路沿线的植被特征

通过植被群落调查,发现拟建新街一恩格阿娄铁路沿线两侧200m范围内有常见植物19种,分属8科和17属,主要是禾本科、豆科和菊科植物。沿线植被平均盖度为48％,平均高度58．2cm,平均生物量为588g／m^2。通过比较发现,沿线平原、丘陵干草原平均生物量值高于全市均值,低地盐化草甸平均生物量远低于全市均值,荒漠草原平均生物量与全市均值较为接近。油蒿和柠条是当地抗逆性强、适应性广的物种,在铁路建设的植被恢复过程中,可采用柠条＋油蒿的灌草搭配模式进行绿化,来达到防沙固土、恢复和改善铁路沿线生态环境的目的。     

三维网植草防护在公路工程中的应用

就三维网植草在路基防护工程中的应用，论述三维植被网防护边坡的作用机理，重点阐述三维网植草新技术的特点及施工工艺，并对经济效益进行了分析。     

Comparison of Beach Nourishment along the U.S. Atlantic,Great Lakes,Gulf of Mexico,and New England Shorelines

The U.S. national beach nourishment experience is summarized for the East Coast barrier islands, the Gulf of Mexico, New England, and the Great Lakes. A total of 1,305 nourishment episodes on 382 beaches are recorded at a total estimated cost of approximately $1.4 billion ($2.5 billion in 1996 dollars). In terms of both volume and costs, nourishment has been the most extensive by far on the East Coast barrier islands. Depending on the region, between 65% and 85% of all nourishment projects have a federal funding component. Annual expenditures and sand volumes for beach nourishment are increasing, especially on East Coast barriers. At present, total annual national beach nourishment costs (excluding the Pacific Coast) are on the order of $100 million per year. The cost per cubic yard of nourishment sand as expressed in 1996 dollars has remained more or less constant over time. Additionally, the volumes of sand needed for subsequent nourishment episodes on individual beaches do not decrease, despite contrary assumptions in the shoreface-profile-ofequilibrium concept that subsequent nourishment volumes should diminish. In light of the historical experience of beach nourishment identified in this study, individual state and local coastal communities should reevaluate their plans for future beach nourishment programs. The complete listing of all the data on nourished beaches from this survey is available at www.geo.duke.edu/Research/psds/psds.htm     

Suitability of Decision-Theoretic Models to Public Policy Issues Concerning the Provision of Shoreline Stabilization and Hazard Management

This article examines the suitability and potential advances of decision-theoretic models from finance regarding investment decisions in shoreline stabilization projects. A set of scenarios represents the dynamics of the decision-state facing the planner and identifies factors that should be incorporated into the decision-making process. It is shown that decision models from finance can account for the risk and uncertainty inherent in shoreline stabilization projects, potentially suggest improvements and refinements to presently used cost-benefit analysis procedures, and offer new tools that can aid in decisions concerning provision of shoreline stabilization. The outcomes of these scenarios justify better planning and control of existing and future building, and that of poststorm policies. Lastly, these models allow us to explore the range of our understanding of coastal processes and interactions with shoreline stabilization projects and can identify new and useful data needed in coastal management and hazard management decisions.     

Variability of the western Galician upwelling system (NW Spain) during an intensively sampled annual cycle. An EOF analysis approach

The key features of the western Galician shelf hydrography and dynamics are analyzed on a solid statistical and experimental basis. The results allowed us to gather together information dispersed in previous oceanographic works of the region. Empirical orthogonal functions analysis and a canonical correlation analysis were applied to a high-resolution dataset collected from 47 surveys done on a weekly frequency from May 2001 to May 2002. The main results of these analyses are summarized bellow. Salinity, temperature and the meridional component of the residual current are correlated with the relevant local forcings (the meridional coastal wind component and the continental run-off) and with a remote forcing (the meridional temperature gradient at latitude 37°N). About 80% of the salinity and temperature total variability over the shelf, and 37% of the residual meridional current total variability are explained by two EOFs for each variable. Up to 22% of the temperature total variability and 14% of the residual meridional current total variability is devoted to the set up of cross-shore gradients of the thermohaline properties caused by the wind-induced Ekman transport. Up to 11% and 10%, respectively, is related to the variability of the meridional temperature gradient at the Western Iberian Winter Front. About 30% of the temperature total variability can be explained by the development and erosion of the seasonal thermocline and by the seasonal variability of the thermohaline properties of the central waters. This thermocline presented unexpected low salinity values due to the trapping during spring and summer of the high continental inputs from the River Miño recorded in 2001. The low salinity plumes can be traced on the Galician shelf during almost all the annual cycle; they tend to be extended throughout the entire water column under downwelling conditions and concentrate in the surface layer when upwelling favourable winds blow. Our evidences point to the meridional temperature gradient acting as an important controlling factor of the central waters thermohaline properties and in the development and decay of the Iberian Poleward Current.