Structural changes in macrozoobenthic communities due to summer hypoxia in Gamak Bay,Korea

The purpose of this study was to examine the structural changes that macrozoobenthic communities underwent as a result of the annual summer hypoxia at the northern part of Gamak Bay, Korea. During this study period, summer hypoxia occurred at the northern part of Gamak Bay in July. Under hypoxic conditions, both the number of species and population density decreased rapidly. Species diversity also manifested lower values during this hypoxic period. Faunal composition changed seasonally with Capitella capitata dominant at the hypoxic sites in spring but disappearing in summer. The health condition of the benthic faunal community assessed by the composition of functional groups within community also changed due to the summer hypoxia from a slightly polluted condition to a highly polluted condition. From these results it has been shown that the recent macrozoobenthic community structure in Gamak Bay has returned to a state similar to what it was before dredging works commenced.     

Estimation of non-CO2 GHGs emissions by analyzing burn severity in the Samcheok fire, South Korea

This study was performed to estimate the emission of non-CO 2 greenhouse gases(GHGs) from biomass burning at a large fire area.The extended methodology adopted the IPCC Guidelines(2003) equation for use on data from the Samcheok forest fire gathered using 30 m resolution Landsat TM satellite imagery,digital forest type maps,and growing stock information per hectare by forest type in 1999.Normalized burn ratio(NBR) technique was employed to analyze the area and severity of the Samcheok forest fire that occurred in 2000.The differences between NBR from pre-and post-fire datasets are examined to determine the extent and degree of change detected from burning.The results of burn severity analysis by dNBR of the Samcheok forest fire area revealed that a total of 16,200 ha of forest were burned.The proportion of the area characterized by a ’Low’ burn severity(dNBR below 152) was 35%,with ’Moderate’(dNBR 153-190) and ’High’(dNBR 191-255) areas were at 33% and 32%,respectively.The combustion efficiency for burn severity was calculated as 0.43 for crown fire where burn severity was ’High’,as 0.40 for ’Moderate’ severity,and 0.15 for ’Low’ severity surface fire.The emission factors for estimating non-CO 2 GHGs were separately applied to CO 130,CH 4 9,NO x 0.7 and N 2 O 0.11.Non-CO 2 GHGs emissions from biomass burning in the Samcheok forest fire area were estimated to be CO 44.100,CH 4 3.053,NO x 0.238 and N 2 O 0.038 Gg.     

Critical literacy and the geography classroom: Including gender and feminist perspectives

Abstract: Teaching secondary school geography students about different perspectives on the way knowledge is produced can be challenging. The forms of critical thinking that are prompted by interrogating the ways in which knowledge are produced equips students with intellectual tools for independent learning; an attribute which is a key feature of successful learners. This article provides an overview of the ways in which gender/feminist perspectives have been generated over time; how the teaching of these perspectives has been included in one New Zealand school, as well as suggesting useful resources.     

New seismogenic source and deep structures revealed by the 1999 Chia-yi earthquake sequence in southwestern Taiwan

In a tectonically active setting large earthquakes are always threats; however, they may also be useful in elucidating the subsurface geology. Instrumentally recorded seismicity is, therefore, widely utilized to extend our knowledge into the deeper crust, especially where basement is involved. It is because the earthquakes are triggered by underground stress changes that usually corresponding to the framework of geological structures. Hidden faults, therefore, can be recognized and their extension as well as orientation can be estimated. Both above are of relevance for assessment on seismic hazard of a region, since the active faults are supposed to be re-activated and cause large earthquakes. In this study, we analysed the 1999 October 22 earthquake sequence that occurred in southwestern Taiwan. Two major seismicity clusters were identified with spatial distribution between depths of 10 and 16 km. One cluster is nearly vertical and striking 032°, corresponding to the strike-slip Meishan fault (MSF) that generated the 1906 surface rupture. Another cluster strikes 190° and dips 64° to the west, which is interpreted as west-vergent reverse fault, in contrast to previous expectation of east vergence. Our analysis of the focal solutions of all the larger earthquakes in the 1999 sequence with the 3-D distribution of all the earthquakes over the period 1990–2004 allows us reinterpret the structural framework and suggest previously unreognized seismogenic sources in this area. We accordingly suggest: (1) multiple detachment faults are present in southwestern Taiwan coastal plain and (2) additional seismogenic sources consist of tear faults and backthrust faults in addition to sources associated with west-vergent fold-and-thrust belt.     

How does resilience matter? An empirical verification of the relationships between resilience and vulnerability

Natural Hazards - The theoretical relationships between resilience and vulnerability have long been debated, but limited research has been done to test their relationships from an empirical...     

A structural relationship between place attachment and intention to conserve landscapes–a case study of Harz National Park in Germany

Place attachment is an important motivation for people to spend more time outdoors and to protect landscapes. This study explores visitors’ intention to conserve natural landscapes based on the relationship with their place attachment to National Park landscape. Structural equation modelling (SEM) was used to determine the relationship between landscape conservation and place attachment. A survey with a structured questionnaire was administered to visitors to the seven designated hiking courses of Harz National Park in Germany. The path coefficient of 0.77 revealed that place dependence positively and significantly affected place attachment, whereas place identity did not. Place attachment had a significant effect on both affective appraisals and visiting satisfaction. Higher place attachment led to higher emotional reaction to landscapes on site and higher satisfaction of visiting the park. Among the variables, visiting satisfaction, but not affective appraisals, played a statistically significant mediating role between place attachment and conservation intention. With a path coefficient of 0.86, conservation intention was highly affected by visiting satisfaction. These results suggest that the managers of National Parks should focus on increasing visiting satisfaction based on how visitors are emotionally bonded with their visiting places, in order to enhance the intentions to conserve the landscape of the visitors to National Parks.     

Investigation of OMA formation and the effect of minerals

Oil-mineral-aggregates (OMA) have been shown to be effective in oil spills cleanup. Experimental work was carried out to study the effects of physical-chemical properties of natural minerals and chemically modified minerals on OMA formation and oil removal. The results showed that the hydrophobicity, particle sizes and specific surface of minerals played an important role in OMA formation. Appropriate hydrophobicity of minerals can enhance the formation of OMA. The surface property of minerals can also influence the shape of OMA. Spherical mineral-oil aggregates were frequently formed with hydrophilic minerals while irregular shaped OMA were observed with hydrophobic minerals. The sizes of OMA also increased when the minerals changed from hydrophilic to hydrophobic. The effects of dispersant and mixing energy were also carefully studied. The results showed that dispersant were a dominant factor. When dispersant was applied, effects of other factors became minimal.     

Component correlations in structure‐specific seismic loss estimation

This paper addresses correlations between multiple components in structure‐specific seismic loss estimation. To date, the consideration of such correlations has been limited by methodological tractability, increased computational demand, and a paucity of data for their computation. The effect of component correlations, which arises in various forms, is however a significant factor affecting the results of structure‐specific seismic loss estimation and therefore it is prudent that adequate consideration be given to their effect. This paper provides the details of a tractable and computationally efficient seismic loss estimation methodology in which correlations can be considered. Methods to determine the necessary correlations are discussed, particularly those that can be used in the absence of sufficient empirical data, for which values are suggested based on the judgement. The effects of various assumptions regarding correlations are illustrated via application to a case‐study office structure. It is observed that certain correlation assumptions can lead to errors in excess of 50% in the lognormal standard deviation in the loss given intensity and loss hazard relationships, while full consideration of partial correlations is 50 times more computationally expensive than other assumptions. Copyright © 2009 John Wiley & Sons, Ltd.     

Flood-tide Delta Morphological Change at the Gippsland Lakes Artificial Entrance,Australia (1889–2009)

Analysis of historical survey and navigation charts, aerial imagery, and digital hydro-data (representing a time-series of 1889–2009) allows the morphological evolution of a flood-tide delta at the artificial entrance to the Gippsland Lakes (Victoria, Australia) to be visualised and quantified. Analysis shows that flood-tide delta growth has imposed progressively greater demands upon port managers for publicly funded maintenance dredging. This flood-tide delta growth corresponds with a progressive diminution of Gippsland Lakes catchment river discharge volumes, and dampening of flow variability, due to both regional precipitation pattern changes and changes in catchment water resource allocation. Future climate change predictions for the Gippsland Lakes catchment and coastal area suggest both further decreases in catchment river discharge, and changing sediment flux along this sector of the Ninety Mile Beach. Thus, scope for flood-tide delta nourishment will probably increase, as will the demand for mitigation of the inevitable effects upon entrance channel navigability. Information derived from the analysis of time-series bathymetry used for this study offers baseline information in support of stakeholder consensus building regarding options for maintaining navigability. Analysis points to the merit of considering (and testing via morphological modelling) alternative options for navigation channel maintenance than those in present practice. We argue that the circumstances prevailing at the artificial entrance call for consideration of engineered configuration changes practised elsewhere by entrance managers faced with similar issues.