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161.
Analyses have been undertaken to examine shoreline positions established from remote sensing data along the northwestern part
of the Nile delta from the Abu Qir Bay to Gamasa embayment (∼143 km length). The image data used (MSS, TM and ETM+ sensors)
are acquired at unequal intervals between 1972 and 2006, i.e., covering a time span of 34 years. Automated waterline positions
extracted from Landsat satellite images during this period of time were computer generated. A digital shoreline analysis software
was used to calculate the annual rate of beach changes at 1,432 cross-shore transects prior to (1972–1990) and after protection
(1993–2006). On comparison, rates estimated from three statistical approaches (the end point rate, the Jackknife and a weighted
linear regression) at corresponding positions are successfully validated with those measured from ground survey. Before protection,
results reveal longshore patterns wherein erosion along a coastal stretch gives way to accretion in an adjacent stretch, refining
the sub-cells previously identified within the littoral system of the delta. Maximum shoreline retreat occurs along the Rosetta
promontory (−138.52 m/year) and along the central bulge of the delta at Burullus headland (−6.07 m/year). In contrast areas
of shoreline accretion exist within saddles or embayments between the promontories at west Abu Qir Bay (20.04 m/year), Abu
Khashaba saddle (16.17 m/year) and Gamasa embayment (20.68 m/year). These rates of changes have been significantly altered
by the construction of intensive shoreline protective structures built from 1990 to combat areas of rapid erosion at both
the Rosetta promontory and Burullus–Baltim headland, ∼15-km length in total. 相似文献
162.
Brian Baily Alastair Pearson Peter Collier Dominic Fontana 《Journal of Coastal Conservation》2002,8(1):77-86
This paper discusses a research project dealing with the mapping of the intertidal vegetation of several harbours along the
southern coastline of England. It describes in detail the methods used to map the vegetation and gives examples of the results
from these studies. This paper then goes on to explain how these results are applied by the Environment Agency of England
and Wales to improve water quality in the harbours. This type of vegetation mapping is useful in monitoring the development
of the intertidal species includingSpartina, Zostera and of particular importance to this study the green algaeUlva andEnteromorpha. The work was undertaken with funding from the Environment Agency and at present has taken place over a four year period.
The data collected will be used by the Environment Agency to assess macro-algae covervalues for the intertidal area of the
harbours concerned. This forms part of the Agency's commitment to the EU Nitrates Directive and the Urban Waste Water Treatment
Directive. Some of the species mapped act as suitable indicators of water quality and are symptoms of entrophication. Other
species are of interest for nature conservation and were recorded to provide a record for longer-term trends in vegetation
patterns within the harbour. This paper aims to provide readers with an understanding of the techniques involved as well as
an evaluation of the methodology. 相似文献
163.
S. D. Chaudhuri 《环境科学学报(英文版)》1990,2(2):115-120
The paper deals with the characteristics of Bangladesh basin including river morphology, rain fall pattern, cyclonic storms, forests and coastal area environment and ecosystem. It deals with factors which contribute to floods both natural and man-induced. The paper does with pollution problems including land and water use and indicates briefly policy measures and strategy adopted by government to combat problems of environment and ecology in Bangladesh. 相似文献
164.
Kitto ME 《Environmental monitoring and assessment》2003,83(2):163-175
The New York State Department of Health has estimated and mappedradon concentrations for every town and city in the State. Sincefor many towns there are few indoor radon measurements, the radonestimates for these towns were determined using correlations to surficial geology. A project was conducted to target towns for additional measurements that currently have few data but, based on the surficial geology of the town, are estimated to have elevated levels of indoor radon. The objective of the project wasto obtain at least 30 additional measurements for the targeted towns and to compare the measurement results with the estimates based on geology. The study completed 1606 radon measurements from 9080 detector applications mailed to home owners in 94 underserved towns spread throughout the State. Of the 1115 basement measurements, 43% exceeded 148 Bq m-3, with a maximum of 6900 Bq m-3. Three homes measured in one town hadradon concentrations above 2900 Bq m-3. Of the 491 living-area measurements, 19% exceeded 148 Bq m-3, with a maximum of 2700 Bq m-3. About 60% and 86% of measurementresults were within one standard deviation and a factor of two,respectively, of estimated concentrations. Results indicate thatregardless of the magnitude of radon potential, the estimates arein good agreement with measured concentrations. 相似文献
165.
Preliminary investigation of submerged aquatic vegetation mapping using hyperspectral remote sensing 总被引:5,自引:0,他引:5
William DJ Rybicki NB Lombana AV O'Brien TM Gomez RB 《Environmental monitoring and assessment》2003,81(1-3):383-392
The use of airborne hyperspectral remote sensing imagery for automated mapping of submerged aquatic vegetation (SAV) in the tidal Potomac River was investigated for near to real-time resource assessment and monitoring. Airborne hyperspectral imagery and field spectrometer measurements were obtained in October of 2000. A spectral library database containing selected ground-based and airborne sensor spectra was developed for use in image processing. The spectral library is used to automate the processing of hyperspectral imagery for potential real-time material identification and mapping. Field based spectra were compared to the airborne imagery using the database to identify and map two species of SAV (Myriophyllum spicatum and Vallisneria americana). Overall accuracy of the vegetation maps derived from hyperspectral imagery was determined by comparison to a product that combined aerial photography and field based sampling at the end of the SAV growing season. The algorithms and databases developed in this study will be useful with the current and forthcoming space-based hyperspectral remote sensing systems. 相似文献
166.
Simone Sehnem 《环境质量管理》2019,28(3):83-96
This research aims to map Brazilian companies that have business models aligned with the concept of the circular economy. Data were collected for this study through use of a survey and additional research based on the survey results. Within these businesses’ models, an emphasis on the second use of materials as well as the marketing of the product as a service has been highlighted. 相似文献
167.
Sarah Sax 《Journal of Land Use Science》2020,15(2-3):290-305
ABSTRACT This paper follows the evolution of the discourse of agricultural productivity, from its inception in colonial land-use mapping to current land-use changes, using a case study of the expansion of an oil palm company onto the territory of an indigenous community in the Peruvian Amazon that caused large-scale deforestation. Drawing on analytical tools of political ecology and insights from historical geographythis paper shows how current soil and land classification, forest usufruct rules, and forest designations under the 2011 Forest and Wildlife law stem from a colonial discourse of agricultural productivity. This discourse excludes other forms of land-use, such as indigenous forest management, and the identities and relationships bound up in those. This research contributes to an understanding of how the processes that seek to quantify and determine land-use change are historically embedded in western ideas of agricultural productivity. 相似文献
168.
Emission of metals in the urbanenvironment is a growing concern throughout theworld. In order to identify metal emissionssources in the Stockholm metropolitan region, amethod for detailed mapping of roof coatings andother urban land covers has been developedconducted. High accuracy area calculation ofcopper roof coatings based on scanned aerialphotography was used. The geometric resolution ofthe digital photographs was 0.4 metre. Imagelayers with identified copper roof objects weremerged with a digital elevation model of 1 metregeometric resolution. The slope gradient for eachroof was calculated in order to account for slopein the calculation of roof areas. In total,622,590 m2 of copper roofs were accounted,of which 176,845 m2 and 447,745 m2represent new and patinated copper respectively.The number of copper roofs larger than 1,000m2 was 142. Applying corrosion and runoffrates on these figures, a yearly Cu flux ofapproximately 1,200 kg in Stockholm may bederived from copper coated building. 相似文献
169.
Expanding the opportunities for public participation in environmental planning is not always the best option. Starting from an institutional public choice analysis of public participation in terms of the collective action problem, this paper emphasises the roots of participatory activities in the incentive structures facing potential participants. It then goes on to consider the strategies that may be adopted for encouraging greater public involvement and looks particularly to the social capital literature for suggestions of how institutional redesign may alter these incentive structures. The paper concludes by distinguishing three different modes of environmental planning, in terms of the rationale for participation, the severity of the collective action problem and the associated participatory strategy that can be adopted. 相似文献
170.
Emilie Nolet 《Disasters》2016,40(4):720-739
The islands of Fiji, in the Western Pacific, are exposed to a wide range of natural hazards. Tropical storms and associated floods are recurring natural phenomena, but it has been regularly alleged that Fijians lack preparation, over‐rely on state assistance in post‐disaster situations or engage in risky behaviours that aggravate the negative impact of floods. Risk reduction strategies, which are now implemented by government authorities and international organisations, heavily promote the principle of ‘community preparedness’. Both community awareness programmes and capacity‐building programmes are conducted throughout the country in the most vulnerable communities. This paper analyses how the inhabitants of Lomanikoro village, in the low areas of the Rewa Delta, perceive and manage existing flood risks. It examines social and cultural factors that contribute to shape risk response locally—in particular, why villagers may be reluctant to adopt some recommended preparedness measures and resettle in higher, safer zones. 相似文献