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Geographic Object-Based Image Analysis of Changes in Land Cover in the Coastal Zones of the Red River delta (Vietnam)

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Journal of Environmental Protection 2019年第3期10卷 413-430页

作者： Simona Niculescu Chi Nguyen Lam University of Western Brittany CNRS Brest France

The majority of the population and economic activity of the northern half of Vietnam is clustered in the Red River delta and about half of the country’s rice production takes place here. There are significant problems associated with its geographical position and the intensive exploitation of resources by an overabundant population (population density of 962 inhabitants/km2). Some thirty years after the economic liberalization and the opening of the country to international markets, agricultural land use patterns in the Red River delta, particularly in the coastal area, have undergone many changes. Remote sensing is a particularly powerful tool in processing and providing spatial information for monitoring land use changes. The main methodological objective is to find a solution to process the many heterogeneous coastal land use parameters, so as to describe it in all its complexity, specifically by making use of the latest European satellite data (Sentinel-2). This complexity is due to local variations in ecological conditions, but also to anthropogenic factors that directly and indirectly influence land use dynamics. The methodological objective was to develop a new Geographic Object-based Image Analysis (GEOBIA) approach for mapping coastal areas using Sentinel-2 data and Landsat 8. By developing a new segmentation, accuracy measure, in this study was determined that segmentation accuracies decrease with increasing segmentation scales and that the negative impact of under-segmentation errors significantly increases at a large scale. An Estimation of Scale Parameter (ESP) tool was then used to determine the optimal segmentation parameter values. A popular machine learning algorithms (Random Forests-RFs) is used. For all classifications algorithm, an increase in overall accuracy was observed with the full synergistic combination of available data sets.

关键词： Coastal Zones Red River delta Land Cover Changes Remote Sensing Geographic Object-Based Images Analysis

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Aboveground Biomass Estimation of <i>Avicennia marina</i>(Forssk) Vierh. and <i>Rhizophora mucronata</i>Lam. in the Mangoky delta, SW Madagascar

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American Journal of Plant Sciences 2018年第9期9卷 1894-1910页

作者： Andriamparany Rakotomavo Higher Institute of Sciences Environment and Sustainable Development (ISSEDD) University of Toamasina Toamasin Madagascar

Forty-three trees (23 Rhizophora mucronata and 20 Avicennia marina) were studied for the establishment of allometric relationships between the aboveground biomass “y” and the following dendrometric variables “x”: diameter at breast height DBH, (DBH)2 product Ht (where Ht is the total height), and the basal circumference Cb of the trees. The Log y = A Log [(DBH)2·Ht] + B equation gives a fairly satisfactory regression coefficient (R2 > 0.9) for the woody compartments. For A. marina, it is the equation Log y = A Log Cb + B that is the best correlated for the estimation of less woody compartments (R2 = 0.826 to 0.847). As for R. mucronata, these are much more related to DBH. For trees of 8 - 10 m height, the aboveground biomass of the delta is higher (171 t·ha-1 for R. mucronata) than that of Puerto Rico, but quite comparable to that of Australia (110 t·ha-1 for A. marina). The first tools for estimating aboveground biomass are given for these two characteristic species of the Indo-Pacific Region and East Africa. Because of the low values of the regression coefficients for some allometric relationships obtained, precautions should be taken in case of extrapolation.

关键词： Avicennia marina Aboveground Biomass Mangoky delta Mangrove Allometric Relationships Rhizophora mucronata

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Assessing the Effects of Upstream Dam Developments on Sediment Distribution in the Lower Mekong delta, Vietnam

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Journal of Water Resource and Protection 2017年第7期9卷 822-840页

作者： Trieu Anh Ngoc Faculty of Water Resources Engineering Thuyloi University Ho Chi Minh City Vietnam

The Lower Mekong delta in Vietnam experiences widespread flooding annually. About 17 million people live in the delta with agriculture as the major economic activity. The suspended sediment load in the Mekong River plays an important role in carrying contaminants and nutrients to the delta and changing the geomorphology of the delta river system. In recent decades, it is generally perceived that the flow and sediment transport in the Mekong River have changed due to climate change and development activities, but observed sediment data are lacking. Moreover, after natural floodplains, the sediment deposition has replaced by dense river systems as resulting in floodplain compartments protected by embankments. This study is aimed to investigate impacts of changing water flow on erosion/deposition in the Lower Mekong delta. We used Mike 11 hydrodynamic model and sediment transport model for simulating the flow and sediment transport. Various scenarios were simulated based on anticipated upstream discharges. Our findings provide the positive and negative impacts to the changes in sediment transport on agriculture cultivation in the Lower Mekong delta.

关键词： Dong Thap Muoi Sediment Transport Lower Mekong delta Mike Model

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Seismic Imaging and Reservoir Architecture of Sub-Marine Channel Systems Offshore West Nile delta of Egypt

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Open Journal of Geology 2014年第12期4卷 718-735页

作者： Essam Sharaf Ibrahim Korrat Hamdy Seisa Eslam Esmaiel Geology Department Faculty of Science Mansoura University Mansoura Egypt Department of Production Management PETRONAS (PICL) Egypt Helwan Egypt

Offshore Nile delta gas reservoirs are dominated by slope-channel systems of Plio-Pleistocene age. High-quality, three-dimensional seismic imaging has significantly helped in defining the geomorphology and architectures of these channels. Integrating seismic, logs and core data from four wells resulted in understanding of different stages of channel development and reservoir quality. The studied reservoirs that are largely controlled by episodes of transgressive-regressive events resulted in deposition of fine grained sediment and shale. Sienna channel complex consists of unconfined channel system with clearly defined development stages. The stages include amalgamated or stacked channels followed by channel abandonment phases and local flooding events. The depositional pattern continued through the Late Pliocene-Pleistocene. SimSat-P1 and SimSat-P2 reservoirs are characterized by isolated sand bodies, most probably relics of fan depositional setting. The depositional scenario that is largely controlled by successive transgression and flooding events resulted in deposition of interbedded, sheet-like, fine grained sediment and shale.

关键词： Offshore Nile delta Western Nile delta Seismic Reservoir Architecture Submarine Channel System

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New Synchronization Algorithm Based on delta Synchronization for Compressed Files in the Mobile Cloud Environment

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International Journal of Communications, Network and System Sciences 2017年第4期10卷 59-74页

作者： Rizik M. H. Al-Sayyed Feras F. Namous AlMonther H. Alkhalafat Bashar Al-Shboul Samar Al-Saqqa Department of Business Information Technology King Abdulla II School for Information Technology The University of Jordan Amman Jordan

The fast growing market of mobile device adoption and cloud computing has led to exploitation of mobile devices utilizing cloud services. One major chal-lenge facing the usage of mobile devices in the cloud environment is mobile synchronization to the cloud, e.g., synchronizing contacts, text messages, imag-es, and videos. Owing to the expected high volume of traffic and high time complexity required for synchronization, an appropriate synchronization algo-rithm needs to be developed. delta synchronization is one method of synchro-nizing compressed files that requires uploading the whole file, even when no changes were made or if it was only partially changed. In the present study, we proposed an algorithm, based on delta synchronization, to solve the problem of synchronizing compressed files under various forms of modification (e.g., not modified, partially modified, or completely modified). To measure the effi-ciency of our proposed algorithm, we compared it to the Dropbox application algorithm. The results demonstrated that our algorithm outperformed the regular Dropbox synchronization mechanism by reducing the synchronization time, cost, and traffic load between clients and the cloud service provider.

关键词： Mobile Cloud Computing delta Synchronization Compressed Files Dropbox

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Palynological Study of OSE 1 Well in Offshore Niger delta Basin: Implications for Age, Paleoclimate and Depositional Paleoenvironment

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International Journal of Geosciences 2019年第10期10卷 860-883页

作者： Osazuwa Abifade Ogbahon Department of Applied Geology The Federal University of Technology Akure Nigeria

Palynological study of 45 ditch samples from sedimentary successions penetrated by OSE 1 well located offshore western Niger delta Basin was undertaken to determine the age of the sediment and reconstruct the paleoclimate and depositional paleoenvironment. All the analyzed samples were composited at 30 ft from stratigraphic depth interval of 6330 to 9010 ft. The lithologic composition comprised mainly of brownish grey or light grey, fine-grained shales with a gypsiferous horizon near the bottom. Palynological slides were prepared following standard palynological preparation procedures of sample maceration with hydrochloric (HCl) and hydrofluoric (HF) acids. The samples yielded moderately well-preserved, low to high diversity palynomorph assemblages of 58 taxa comprising 29 pollen grains, 9 pteridophic spores, 17 dinoflagellates, one acritarch, one freshwater algae and a fungi spore. The stratigraphic distribution of microflora assemblages was highly variable. The assemblage abundance was dominated by pollen and spores. The retrieved pollen grains included Monoporites annulatus, Sapotaceoidaepollenites sp. Psilatricolporites crassus, Psilatricolporites sp., Zonocostites ramonae, Retitricolporites irregularis, Monocolpites marginatus, Monocolpites sp., Pachydermites diederixi, Proxapertites cursus, Verrutricolporites rotundiporus, Striatopollis catatumbus, Retistephanocolpites gracilis, Echiperiporites estalae, Echiperiporites sp. and Inaperturopollenites sp. The retrieved spores included Magnastriatites howardi, Acrostichum aureum, Laevigatosporites sp., Polypodiaceoisporites sp., Verrucatosporites sp., Crassoretitriletes vanraadshooveni and Stereisporites sp. The recorded dinoflagellates included Achomosphaera sp., Andalusiella sp., Polysphaeridium zoharyi, Selenopemphix nephroides and Spiniferites sp. Leiosphaeridia sp. was the only acritarch present in the assemblage. The freshwater algae was Botryococcus braunii. Fungi spore was present but not in significant amo

关键词： Niger delta Paleoclimate Paleoenvironment Miocene

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Contraceptive Trends and Preferred Methods among Users in Port Harcourt, Niger delta Region of Nigeria

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Journal of Biosciences and Medicines 2017年第8期5卷 97-107页

作者： John Dimkpa Ojule Dagogo Semenitari Abam Department of Obstetrics and Gynaecology University of Port Harcourt Teaching Hospital Port Harcourt Nigeria

Background: Family planning has clearly been a major public health success as evidenced by substantial fertility decline and reductions in maternal mortality in countries with high contraceptive prevalence rates. Nigerian governments have continued to expand the scope and improve accessibility and availability of contraceptive commodities to improve uptake, giving the numerous benefits. Objective: To determine the trends in contraceptive usage and the preferred method among clients visiting the family planning clinic of University of Port Harcourt Teaching Hospital (UPTH), Nigeria. Method: It was a cross sectional study of all clients who accepted contraceptive methods at the UPTH, between 1st January 2000 and 31st December, 2015. Results: During the period, a total of 9190 clients accepted contraceptive methods, and 40,334 women were delivered in the maternity unit giving an acceptance rate of 1 in 4 deliveries or 22.8%. The acceptors of modern contraceptives increased steadily from 491 clients in 2001 to a peak in 2008 with 1477 clients and sharply declined to 381 in 2009 before increasing gradually again to 519 clients in 2015. The most commonly used method was the male condom by 3194 clients (37.9%), followed by injectables, which was accepted by 2185 clients (23.8%) while 1752 clients (19.1%) used the IUD. Implant contraceptive was used by 915 clients (9.9%), followed by oral contraceptive pills used by 547 (6.0%). Female sterilization was the least commonly used method by 302 clients (3.3%). There was no vasectomy over the 15 years period. Conclusion: Contraceptive trend in Port Harcourt has an ambivalent acceptance pattern. Although male condom and injectable contraceptives are the most commonly used method over time, the subdermal implants are increasingly becoming very popular in recent time. Female sterilization remains the least common method with no record of vasectomy.

关键词： Contraceptive Methods Contraception Trends Port Harcourt Niger delta Nigeria

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Paleogeomorphic Influence on Facies Characteristics of Braided delta and Reservoir Prediction—An Example from L oilfield in Bohai Bay Basin

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Journal of Geoscience and Environment Protection 2019年第8期7卷 195-205页

作者： Longtao Cui Xinwu Liao Liye Zhou Cheng Guo Lan Zhang Tianjin Branch of CNOOC Ltd. Tianjin China

Five wells of L oilfield in Bohai bay basin have drilled 10 - 15 meters thick oil layer in the Paleogene delta. Due to the deep-buried reservoir and the poor seismic performance, it is difficult to identify the reservoir genesis, and predict reservoir distribution. By analyzing core, well logging and seismic data, a stable mudstone section is selected as the correlation marker to establish a stratigraphic framework. The paleogeomorphology is reconstructed after decompaction correction and paleobathymetric analysis. Based on the differences of paleotopography and sedimentary facies, the study area mainly develops two delta systems: low gradient coarse-grain delta system and steep gradient delta-turbidite system. The favorable reservoir of low gradient coarse-grain delta, which is thick and has good lateral connectivity, mainly locates in the delta front. The favorable reservoir of steep gradient delta-turbidite system locates in the delta front and turbidite facies, and the delta front deposits are thin and have poor lateral connectivity. The boundary of delta front is first depicted on the basis of paleotopography. In combination with reservoir architecture and forward modeling analysis, the seismic attribute is then optimized to predict the distribution of favorable reservoir. Using this method, several sets of oil-bearing sandbodies have been drilled in L oilfield, and the prediction accuracy of reservoir distribution is proved to be high. This study demonstrates that the paleogeomorphology plays an important role in controlling the genesis and distribution of the delta reservoir and provides reference for the reservoir prediction in similar oilfields.

关键词： Slope Zone Braided delta Reservoir Prediction Forward Modeling

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Web GIS Solution for Monitoring the Forest-Cover in the Mekong delta, Vietnam

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Journal of Geographic Information System 2018年第5期10卷 491-502页

作者： Le Van Trung Dao Minh Tam Geomatics Center Vietnam National University Ho Chi Minh City Vietnam Ho Chi Minh City University of Technology Vietnam National University Ho Chi Minh City Vietnam

In recent years, Web GIS has been widely applied in mapping and sharing spatial data. This paper introduces a Web GIS solution has been applied to establishing “The Mekong delta Geographic Information Systems—MGIS”. The development and implementation of a web-based MGIS are a suitable technology for monitoring and managing the natural resources and environment that aims to achieve sustainable development in the Mekong delta region. The proposed solution shows that Web GIS can be applied effective to for integrating and sharing data among administration agencies in order to provide fully integrated information of updated on the status of land cover changes and analyzing the trend of forest-cover changes in this region. Results of this study illustrate the MGIS’s applications in sharing of regional data that allows multiple users to use tools for displaying spatial distribution of forest-cover in the period from the year 1990 to 2015 and analyzing the trend of changes.

关键词： Geographic Information System Web-Based GIS Forest-Cover Change MGIS Mekong delta

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THE FLOOD DISASTER AND MITIGATION PROJECTION IN YANGTZE delta AREA

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Natural Disaster Reduction in China 1994年第3期 131-136页

作者：孙顺才黄新

ＴＨＥＦＬＯＯＤＤＩＳＡＳＴＥＲＡＮＤＭＩＴＩＧＡＴＩＯＮＰＲＯＪＥＣＴＩＯＮＩＮＹＡＮＧＴＺＥＤＥＬＴＡＡＲＥＡＳｕｎＳｈｕｎｃａｉ（孙顺才）ａｎｄＨｕａｎｇＸｉｎ（黄新）（ＮａｎｊｉｎｇＩｎｓｔｉｔｕｔｅｏｆＧｅ... 详细信息

ＴＨＥＦＬＯＯＤＤＩＳＡＳＴＥＲＡＮＤＭＩＴＩＧＡＴＩＯＮＰＲＯＪＥＣＴＩＯＮＩＮＹＡＮＧＴＺＥＤＥＬＴＡＡＲＥＡＳｕｎＳｈｕｎｃａｉ（孙顺才）ａｎｄＨｕａｎｇＸｉｎ（黄新）（ＮａｎｊｉｎｇＩｎｓｔｉｔｕｔｅｏｆＧｅｏｇｒａｐｈｙａｎｄＬｉｍｎｏｌｏ...

关键词： delta

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