黄海西部沿岸流系特征分析及其对物质输运的影响   总被引：10，自引：0，他引：10  

韦钦胜  于志刚  冉祥滨  臧家业 《地球科学进展》2011,26(2):145-156

黄海西部沿岸是我国人类活动和海洋经济开发较为集中的地带,陆地和海洋相互作用较为强烈,其特殊的地形和所处的独特地理位置,使得该海域的环流复杂多变,沿岸海域各水团与陆架锋以及长江口东北部的锋面一起构成了黄海西部特有的环流体系和背景场,对该海域的物质输运和扩散、海水运动以及海洋生物地球化学过程产生影响,并制约着沿岸海域对污染...  相似文献   

海岸带水文地质学研究中的几个热点问题   总被引：2，自引：0，他引：2  

李海龙  万力  焦赳赳 《地球科学进展》2011,26(7):685-694

对海岸带水文地质学中几个热点问题的研究现状和待解决的主要问题做了综述.主要包括如下几个方面:①海潮波动引起的滨海含水层系统地下水位波动的定量解析及其应用;②潮间带海水一地下水相互作用的定量模拟及其在海滩漏油污染治理中的应用;③滨海近岸包气带中海潮波动引起的地下水气两相流及其生态和工程效应;④海底地下水排泄量的定量估计.  相似文献   

汶川震区映秀镇"8·14"特大泥石流灾害调查   总被引：2，自引：0，他引：2  

唐川  李为乐  丁军  黄翔超 《地球科学》2011,36(1):172-180

2010年8月14日强降雨过程导致汶川震区映秀镇红椿沟泥石流暴发,泥石流堰塞堆积体堵断岷江主河道,导致河水改道冲入映秀新镇,引发洪水泛滥;造成映秀镇13人死亡、59人失踪,受灾群众8 000余人被迫避险转移.由于这场泥石流灾害发生在汶川地震震中区,是地震与降雨共同作用下的结果,研究其形成与成灾过程对于进一步认识强震区泥...  相似文献   

暴雨洪涝淹没模型在洪灾损失评估中的应用     

史瑞琴  刘宁  李兰  叶丽梅  刘旭东  郭广芬 《湖北气象》2013,(4):379-384

为了开展客观定量的暴雨洪涝灾害评估,探讨了基于暴雨洪涝淹没模型的暴雨洪涝灾害损失评估业务流程,其核心环节有两部分：估算因降水造成的淹没范围和建立适用的经济损失评估模型。其中暴雨洪涝淹没模型以最大坡降算法和曼宁公式计算暴雨洪涝汇流过程,通过给定汇流时间得到研究区域的淹没面积和水深;经济损失评估模型由直接经济损失和间接经济损失构成,直接经济损失由淹没范围内各类财产的价值乘以其相应的损失率得到。以武汉市江夏区2010年7月一次暴雨洪涝灾害过程为例给出了整个评估流程的实现过程,结果表明基于暴雨洪涝淹没模型的洪涝灾害损失评估业务流程物理意义清楚,表达了暴雨-径流-洪涝灾害全过程,可用以提高洪涝灾害影响评估的定量化程度,同时也为暴雨洪涝风险管理提供一定的依据。  相似文献   

Variation of diffuse attenuation coefficient of downwelling irradiance in the Arctic Ocean     

WANG Weibo  ZHAO Jinping 《海洋学报(英文版)》2014,33(6):53-62

The diffuse attenuation coefficient(Kd) for downwelling irradiance is calculated from solar irradiance data measured in the Arctic Ocean during 3rd and 4th Chinese National Arctic Research Expedition(CHINARE), including 18 stations and nine stations selected for irradiance profiles in sea water respectively. In this study, the variation of attenuation coefficient in the Arctic Ocean was studied, and the following results were obtained. First, the relationship between attenuation coefficient and chlorophyll concentration in the Arctic Ocean has the form of a power function. The best fit is at 443 nm, and its determination coefficient is more than 0.7. With increasing wavelength, the determination coefficient decreases abruptly. At 550 nm, it even reaches a value lower than 0.2. However, the exponent fitted is only half of that adapted in low-latitude ocean because of the lower chlorophyll-specific absorption in the Arctic Ocean. The upshot was that, in the case of the same chlorophyll concentration, the attenuation caused by phytoplankton chlorophyll in the Arctic Ocean is lower than in low-latitude ocean. Second, the spectral model, which exhibits the relationship of attenuation coefficients between 490 nm and other wavelength, was built and provided a new method to estimate the attenuation coefficient at other wavelength, if the attenuation coefficient at 490 nm was known. Third, the impact factors on attenuation coefficient, including sea ice and sea water mass, were discussed. The influence of sea ice on attenuation coefficient is indirect and is determined through the control of entering solar radiation. The linear relationship between averaging sea ice concentration(ASIC, from 158 Julian day to observation day) and the depth of maximum chlorophyll is fitted by a simple linear equation. In addition, the sea water mass, such as the ACW(Alaskan Coastal Water), directly affects the amount of chlorophyll through taking more nutrient, and results in the higher attenuation coefficient in the layer of 30–60 m. Consequently, the spectral model of diffuse attenuation coefficient, the relationship between attenuation coefficient and chlorophyll and the linear relationship between the ASIC and the depth of maximum chlorophyll, together provide probability for simulating the process of diffuse attenuation coefficient during summer in the Arctic Ocean.  相似文献   

A global synthesis of the economic multiplier effects of marine sectors     

《Marine Policy》2014

As competition for use of the ocean increases, coastal managers must consider the economic impacts of competing marine sectors in decision-making processes. To capture the full extent of the economic impacts of marine industries, multiplier values can be used to estimate the sum of direct, indirect, and induced effects on associated industries. This study provides a global synthesis of multiplier effects on four economic indicators of eight marine sectors in regions of varying size and development status. The average multiplier was 1.82, indicating that every dollar generated by a direct marine industry leads to an additional 82 cents generated by associated industries. The industry of offshore energy and the economic indicator of revenue had the largest multiplier effects. No significant difference was found between multiplier values in developed and developing regions, and weak correlations were found between multiplier value and region size. This synthesis offers the first global view of the economic multiplier effects of marine industries and can serve as a tool to support city- to country-level marine industry development decisions throughout the world, especially where similar data are not available.  相似文献   

Spatial and temporal seasonal trends in coastal upwelling off Northwest Africa, 1981–2012     

《Deep Sea Research Part I: Oceanographic Research Papers》2014

Seasonal coastal upwelling was analyzed along the NW African coastline (11–35°N) from 1981 to 2012. Upwelling magnitudes are calculated by wind speed indices, sea-surface temperature indices and inferred from meteorological station, sea-surface height and vertical water column transport data. A permanent annual upwelling regime is documented across 21–35°N and a seasonal regime across 12–19°N, in accordance with the climatology of previous studies. Upwelling regions were split into three zones: (1) the Mauritania–Senegalese upwelling zone (12–19°N), (2) the strong permanent annual upwelling zone (21–26°N) and (3) the weak permanent upwelling zone (26–35°N). We find compelling evidence in our various indices for the Bakun upwelling intensification hypothesis due to a significant coastal summer wind speed increase, resulting in an increase in upwelling-favorable wind speeds north of 20°N and an increase in downwelling-favorable winds south of 20°N. The North Atlantic Oscillation plays a leading role in modifying interannual variability during the other seasons (autumn–spring), with its influence dominating in winter. The East Atlantic pattern shows a strong correlation with upwelling during spring, while El Niño Southern Oscillation and Atlantic Multi-decadal Oscillation teleconnections were not found. A disagreement between observationally-based wind speed products and reanalysis-derived data is explored. A modification to the Bakun upwelling intensification hypothesis for NW Africa is presented, which accounts for the latitudinal divide in summer wind regimes.  相似文献   

渤海南部Lz908孔海陆交互沉积的粒度特征及其对沉积环境的指示     

李琰 《海洋科学》2014,(4)

文章对采自莱州湾南岸的钻孔沉积物样品进行了粒度测试和分析。样品平均粒径介于3.3-6.8?,以极细砂和粗粉砂为主,含有少量的粘土质;分选较差;偏度表现为正偏和极正偏;沉积物粒度表现为正态、正态—尖锐和尖锐,少数表现为平坦和极尖锐。粒度象指示了历史时期持续高的初始沉积水动能和多种沉积环境的变化,粒度参数散点图反映了多种动能影响了沉积物的沉积改造,综合判别分析对沉积环境的限定,得到了莱州湾南岸沉积物受到河水径流、潮流、波浪等共同作用形成。沉积物总体反映了莱州湾南岸长时期处于河流相和三角洲相的沉积环境,少数较细的粒度表现可能与研究区的多期海侵过程相对应。  相似文献   

Societal phosphorus metabolism in future coastal environments: Insights from recent trends in Louisiana,USA     

《Global Environmental Change》2014

Successful adaptation to global environmental change will require confronting multiple unfolding challenges in concert. Coastal regions vulnerable to sea level rise and tropical storms will likely also be influenced by resource limitation in an uncertain future. In this paper, we explore the interrelated dynamics of coastal population migration, economic instability, and anthropogenic phosphorus (P) flows. Accounting for P flows and improving human P use efficiency are critical tasks given the finite global supply of phosphate rock and widespread eutrophication. We use material flow analysis to examine societal P metabolism in the Upper Pontchartrain Basin in coastal Louisiana, USA for two 5-y time periods (2001–2005 and 2006–2010) to capture the effects of fertilizer economics and population growth partially driven by the impact of Hurricane Katrina in the lower basin in 2005. Mass balances encompass human-mediated P fluxes in food production and consumption subsystems across agricultural, developed, and forested landscapes. Drastic reductions in locally purchased inorganic P fertilizer (78% decline between periods) were correlated to increases in fertilizer prices. Total P input to the study region decreased from 5452 to 3268 Mg P y⁻¹ between periods. Changes in P flows were primarily driven by fertilizer economics, declining dairy production, and the influx of new residents, which has been characterized by decentralized settlement that limits P recycling. Societal P metabolic efficiency increased from 22% to 32% due largely to reduced fertilizer inputs. Leakage to the Pontchartrain Estuary and the Mississippi River represented 17–23% of total system P input, while the vast majority of P accumulated within soils, wastewater systems, and landfills. We discuss basin trends and management implications. A historic opportunity exists to encourage future coastal development characterized by synergies between local agriculture and human habitation to promote energy efficient nutrient recycling. The effect would be a decreased vulnerability to future fertilizer price spikes, along with the mitigation of current and future eutrophication.  相似文献   

Storm extreme levels and coastal flood hazards: A parametric approach on the French coast of Languedoc (district of Leucate)   总被引：1，自引：0，他引：1  

Brice Anselme  Paul Durand  Yves-François Thomas  Alexandre Nicolae-Lerma 《Comptes Rendus Geoscience》2011,343(10):677-690

Coastal flooding is a significant risk on the shores of Languedoc-Roussillon. The storms that periodically hit the coast can generate strong swells and storm surges. Most beach resorts, built on a low elevation dune ridge, are periodically flooded during major storms. Although risks zoning regulations take into consideration coastal flood hazards, the delineation of vulnerable areas is still insufficient and the commonly accepted threshold is regularly exceeded during most severe storms. This paper presents a method to improve the assessment of extreme storm-related water levels. It relies on fieldwork carried out in the Leucate commune (Aude), which is particularly exposed to the risk of sea level rise. It considers both storm surges and wave phenomena that occur within the surf zone (set-up and swash), calculated from the Simulating WAves Nearshore (SWAN^®) numerical wave model and the Stockdon formula. Water levels reached during several recent storm events have been reconstructed and simulations of submerged areas were carried out by numerical modelling.  相似文献