Distribution of suspended sediment in the coastal sea off the Ganges–Brahmaputra River mouth: observation from TM data

Remote sensing technique was applied to estimate suspended sediment concentration (SSC) and to understand transportation, distribution and deposition of suspended sediment in the estuary and throughout the coastal sea, off the Ganges–Brahmaputra River mouth. During low river discharge period, zone of turbidity maximum is inferred in the estuary near the shore. SSC map shows that maximum SSC reaches 1050 mg/l in this period. Magnitude of SSC is mainly owing to resuspension of the bottom surface sediments induced by tidal currents flowing over shallow water depths. The influence of depth on resuspension is farther revealed from the distribution and magnitude of SSC along the head of Swatch of No Ground (SNG) submarine canyon. During high river discharge period, huge river outflow pushed the salt wedge and flashes away the suspended sediments in the coastal sea off the river mouth. Zone of turbidity maximum is inferred in the coastal water approximately within 5–10 m depth of water, where the maximum SSC reaches 1700 mg/l. In this period, huge fluvial input of the suspended sediments including the resuspended bottom sediments and the particles remaining in suspension for longer period of time since their initial entry control mainly the magnitude of SSC. In the estuary near the shore, seasonal variation in the magnitude of SSC is not evident. In the coastal sea (>5 m water depth), seasonal influence in the magnitude of SSC could be concluded from the discrepancy between SSC values of two different seasons. Transportation and deposition of suspended sediments also experiences seasonal variations. At present, suspended sediments are being accumulated on the shallow shelf (between 5 and 10 m water depth) in low discharge period and on the mid-shelf (between 10 and 75 m water depth) during high discharge period. An empirical (exponential) relationship was found between gradual settle down of suspended sediments in the coastal sea and its lateral distance from the turbidity maximum.     

相依性条件下滨海软土隧道盾构施工渗漏水风险评价

滨海地区多为海相和湖相沉积的软土,施工难度大,渗漏水病害多发,因此,应对盾构施工过程的渗漏水风险进行评价来保证隧道安全施工。构建渗漏水风险评价三级指标体系,将云模型与Copula函数结合,基于Copula函数对于风险指标中相关风险因素的相依性处理,云理论对于定性与定量概念的处理与转换优势,构建相依性条件下的二维和三维云-Copula模型。以宁波市轨道交通1号线为例,利用云-Copula模型计算二级指标对于各个风险等级的隶属度,确定危险性较大的二级指标为注浆质量、止水条、衬砌混凝土自防水。利用D-S证据理论进行证据融合确定该检测区段渗漏水病害的风险状态为安全,但有向基本安全状态发展的趋势。通过对危险性较大的指标加强监控,使渗漏水得到有效控制,为软土盾构隧道施工过程中渗漏水病害的风险评价与管理提供了一种新的方法。     

Shaping the Coast with Permits: Making the State Regulatory Permitting Process Transparent with Text Mining

This paper examines the California Coastal Commission's permitting process. Using several text mining techniques, including web scraping, information extraction, and supervised classification, I demonstrate how to retrieve empirical data from unstructured texts, namely public meeting agendas and staff reports. Contrary to the concern that the Commission routinely delays or rejects permitting requests, the data reveal that outright rejection of permit applications is rare. On average, eight of ten applications were approved. Single-family homes and commercial development projects were approved about 80% of the time; the rates were about 70% for seawalls and retaining walls, and 60% for land-use changes. Most applications were processed swiftly, with a median application length of 3 months. The agency's influence comes primarily from negotiating each application. Qualitative study of 50 cases pertaining to single-family home construction reveals that the agency adopts a “managed development” approach, that is, allowing development but scrupulously managing various aspects of development. These case studies illustrate how the agency interprets the broad, abstract state laws and translates the mandates into enforceable actions as permitting conditions. In areas where the state mandates conflict, particularly over development in receding shorelines, the agency has the largest leverage in creating and implementing its preferred policies. The text mining techniques demonstrated in this paper can be applied to study any governmental agency. These techniques help to extract information from a massive volume of papers and organize them into a database for analyses. The empirical data extracted from texts can significantly increase bureaucratic transparency.     

模拟海洋环境条件下碳纤维复合材料力学性能试验研究

本文主要进行了CFRP材料浸渍于碱溶液、浸渍于盐溶液及经人工老化后的力学性能试验。试验证实,上述几种长期环境条件作用对CFRP的极限强度影响不大,但能显著降低CFRP的极限延伸率,碱溶液浸渍、盐溶液浸渍显著降低了CFRP的弹性模量,而人工老化则几乎没什么影响。试验结果分析证明,应用于加固结构分析的CFRP的应力-应变关系,可应用线弹性关系。     

Why is the southwest the most productive region of the East Sea/Sea of Japan?

The East Sea/Sea of Japan is a moderately productive sea that supports a wealth of living marine resources. Of the East Sea subregions, the southwest has the highest productivity. Various authors have proposed coastal upwelling, the Tsushima Current, the Changjiang Dilute Water, eddies, or discharge from the Nagdong River as potential sources of additional nutrients. In this paper, we propose, using satellite data from 1998 to 2006, that the biological productivity of the southwestern region is enhanced mainly by wind-driven upwelling along the Korean coast. Firstly, the climatology of seasonal patterns suggests that the enhanced chlorophyll a along the Korean coast is of local origin. Secondly, coastal upwelling is frequent in all seasons except winter. For example, along the coast of the Ulgi region, enhanced chlorophyll a due to coastal upwelling was observed for 25–92% of the time between Jun and Sep in the period 1998–2006. Thirdly, the advection of upwelled water through various pathways to the deeper basin was observed. Fourthly, there appeared to be a strong correlation between the interannual chlorophyll a variations of the coastal upwelling regions and the Ulleung Basin. The chlorophyll a patterns of both regions were closely related to the wind pattern in the upwelling regions, but not to that in the Ulleung Basin. Finally, changes in advection pathways also appeared to affect the productivity of the Ulleung Basin. Since 2004, there has been a shift in the pathways of upwelled water, and consequent increases in chlorophyll a in the Ulleung Basin were observed. This last observation requires further investigation.     

An algorithm for oceanic front detection in chlorophyll and SST satellite imagery

An algorithm is described for oceanic front detection in chlorophyll (Chl) and sea surface temperature (SST) satellite imagery. The algorithm is based on a gradient approach: the main novelty is a shape-preserving, scale-sensitive, contextual median filter applied selectively and iteratively until convergence. This filter has been developed specifically for Chl since these fields have spatial patterns such as chlorophyll enhancement at thermohaline fronts and small- and meso-scale chlorophyll blooms that are not present in SST fields. Linear Chl enhancements and localized (point-wise) blooms are modeled as ridges and peaks respectively, whereas conventional fronts in Chl and SST fields are modeled as steps or ramps. Examples are presented of the algorithm performance using modeled (synthetic) images as well as synoptic Chl and SST imagery. After testing, the algorithm was used on > 6000 synoptic images, 1999–2007, to produce climatologies of Chl and SST fronts off the U.S. Northeast.     

The visual impact of development in coastal zone areas

Abstract

The focus of this paper is theoretical, as well as methodological. It reviews previous studies of visual impact and reports research by the author on people's evaluation of the appropriateness of different man‐made facilities in different coastal‐area contexts and other environments. In this study, subjects were asked to react to slides developed through the use of landscape models and experimental facilities to simulate the appearance of a building in the landscape, while systematically varying the visual relatedness between the two. Specific interest centered on the variable of congruity vs. contrast between the appearance of the building and its landscape context, manipulated by co‐varying the attributes of color and size to create a five‐point scale of contrast/obtrusiveness. The hypothesis was that judgments of appropriateness, and to a lesser extent judgments of liking, would vary inversely with level of contrast. The role of two further variables, the functional significance of the building in its setting, and the character of the setting itself, was also investigated. The author reviews methodological issues involved where subjects respond to visual stimuli for purposes of judging change in visual quality. These methodological issues include: stimulus‐selection and problems of simulation, choice of response measures, and choice of respondents, and the treatment of individual differences. The author calls for development of standardized scales and indices such as “perceptually‐relevant environmental quality indicators.”     

Building Philippine Local Government Capacity for Coastal Resource Management

The responsibility for managing coral reefs and other coastal resources was largely devolved to coastal municipalities and cities in the Philippines in 1991 with the passage of the Local Government Code. Devolution of powers and responsibilities to local government has paved the way for mainstreaming coastal resource management at the local level. However, the capacity to carry out this mandate has only recently begun to mature as municipalities and cities gain an increased awareness of the importance of coastal resources to communities and economic development. Approaches and strategies to increase local government capacity for coastal resource management are described based on the experiences of the Coastal Resource Management Project of the United States Agency for International Development. Qualitative and quantitative data are used to illustrate the possible impact of these capacity building efforts and to describe the current capacity of local government to undertake coastal resource management. After five years of project implementation, coastal municipalities have increased technical capacity, have allotted financial resources, and have achieved key performance benchmarks in the delivery of coastal resource management as a basic service.     

Support for Oregon land‐use planning: A multi‐level analysis

Abstract

This article analyzes support for and opposition to state land‐use planning in Oregon, using voting records from the 1976 referendum to repeal Oregon's regulatory legislation and survey data. Support for controlled growth legislation is found to be a product of both individual‐level characteristics and characteristics of the larger community where one resides. The most influential contextual variables are the county's economy and the class composition of the city. The authors conclude that coastal zone managers must exercise caution when interpreting individual survey data which indicate support for various environmental concerns. Contextual differences must be taken into consideration because sources of support for coastal zone management may vary among individuals, depending on the nature of the communities in which they live.     

The California Coastal Act and Ports: The Unintended Environmental Justice Implications of Preserving California's Coastline

Consistent with the policies set forth in the Coastal Zone Management Act, the California Coastal Act seeks to balance the utilization and conservation of coastal resources, taking into account the social and economic needs of the citizens of California. One way the statute pursues this balance is through its provisions for ports. These provisions have functioned as a type of smart growth planning for ports, encouraging densification of existing port districts and possibly averting maritime commercial and industrial sprawl along the California coast. One unintended consequence of the encouraged consolidation of port activities, when combined with the rapid growth in international trade over the last four decades, has been disproportionally large environmental and health impacts on low-income and minority communities surrounding ports. This article examines how the Port of Long Beach's conformance with the California Coastal Act has resulted in ongoing environmental justice concerns. It discusses approaches employed by the Port of Long Beach to reduce environmental justice concerns resulting from significant and unavoidable environmental impacts and offers suggestions for how to address this issue.