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11.
Nga Thi Thanh Pham Quang Hong Nguyen Anh Duc Ngo Hang Thi Thu Le Cong Tien Nguyen 《Natural Hazards》2018,92(1):189-204
Flooding associated with landing tropical cyclones (TCs) is one of the major natural hazards in the coastal region of Vietnam. Annually, approximately 5 or 6 TCs make landfall in Vietnam, bringing heavy rains and inducing flooding, particularly to the central coastal region because of its topography and geographic configuration. This study focuses on the modelling of typhoon-induced floods that have resulted in widespread damage to agriculture over the central Thua Thien Hue Province of Vietnam by coupling two well-known hydrological models, KINEROS2 and HEC-RAS (Daniel et al. in Open Hydrol J 5(1), 2011), and using GSMaP (Global Satellite Mapping of Precipitation) data as the satellite rainfall input. Landsat imagery and GIS are also used for mapping and analysing the inundated areas. The discharge and water level from the KINEROS2 and HEC-RAS models displayed acceptable results for the floods modelled from three selected typhoons; both the Nash–Sutcliffe simulation efficiency coefficient (NSE) and the coefficient of determination (R2) were greater than 0.6. The simulated inundation maps of these typhoon-induced floods were compared with those extracted from the Landsat imagery to assess consistency. The result revealed a similar spatial extension of the inundated agricultural areas. This information, together with the forecasted TC movements and associated rainfalls, will be helpful to plan methods for mitigating potential typhoon-induced flooding and damage, particularly damage to agricultural regions. 相似文献
12.
Behzad Fatahi Thu Minh Le Behnam Fatahi Hadi Khabbaz 《Geotechnical and Geological Engineering》2013,31(5):1421-1435
In this study, effects of two types of geofibers, namely polypropylene and recycled carpet, on three dimensional shrinkage properties of cement treated kaolinite and bentonite clays are investigated. Cement treated clay specimens were prepared with cement contents of 5, 10, and 15 % by weight of dry soil for kaolinite samples, and 30, 40 and 50 % for bentonite samples. To investigate and understand the influence of different fiber types and contents, three different percentages of fiber content (i.e. 0.1, 0.2 and 0.5 % polypropylene fibers; and 0.5, 0.75 and 1 % carpet fibers) were adopted. The results of shrinkage tests on 126 cylindrical samples of cement treated clay with various cement and fiber contents were analysed to understand the relationships between these parameters and the shrinkage percentage of treated soil. Results of this study indicate that combination of cement and fiber is effective in reducing the volume change of clayey soils undergoing drying process. In the applied ranges of cement and fiber contents, the influence of cement addition on the shrinkage reduction is more significant than the addition of fibers for the treated kaolinite. However, addition of fibers in curtailing the shrinkage of bentonite clay is more significant than the cement addition. 相似文献
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锆石U-Pb年代学方法已经成为地质学研究必不可少的方法。本文收集整理了二十世纪八十年代以来分散在期刊论文、学位论文等多种出版载体中的锆石U-Pb年代学数据,建成中国大陆单颗粒锆石数据库中文子库。该数据子库涉及截至到2017年底的文献2331篇,有效数据154768条目,数据总量已经能够用来进行数据的初步分析和相关地球科学研究。数据子库中年龄-年龄绝对误差关系的分析表明,Age(~(206)Pb/~(238)U)、Age(~(207)Pb/~(235)U)、Age(~(207)Pb/~(206)Pb)在不同的地质年代区间误差表现有所不同。在小于1684.4Ma、1684.4~2855.2Ma、大于2855.2Ma年龄区Age(~(206)Pb/~(238)U)、Age(~(207)Pb/~(235)U)、Age(~(207)Pb/~(206)Pb)的误差最小、置信度最好,除了Age(~(207)Pb/~(235)U)测试方法的原因外,Age(~(206)Pb/~(238)U)和Age(~(207)Pb/~(206)Pb)可分别作为不同年龄段的推荐年龄。将选用的推荐年龄运用于LA-ICP-MS、SHRIMP、SIMS三种方法的比较,得出其适用于不同地质年代的范围。推荐年龄运用于年龄-频数图中并使用高斯多峰拟合,则可发现中国大陆锆石存在6个生长峰期,分别为131.71Ma、255.17Ma、442.42Ma、811.56Ma、1868.36Ma和2505.31Ma等;更小尺度下的新生代则存在七个峰期,分别为16.99Ma、27.64Ma、35.26Ma、43.44Ma、48.27Ma、52.74Ma和62.07Ma等,峰期及其对应测试点的位置可与中国大陆地壳演化重大历史事件对应。 相似文献
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Summary A shallow water single level primitive equation model is ideally suited for studying the motion of a tropical cyclone. Three factors seem to be important in the initialization, i.e. the size, intensity and the initial speed and direction of motion of the storm. This study presents the results of sensitivity studies on the above parameters in the definition of a synthetic idealized vortex. The sensitivity studies include results of experimental forecasts for typhoons Betty of 1987 and Dan of 1989. The results of these studies show that the initial size, intensity and direction and speed of motion show considerable sensitivity to the predicted track. Finally a summary of the track forecast errors through 72 hours are presented for these storms.With 8 Figures 相似文献
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Land tenure rights reflect the deeper structures of society, particularly gender distinctions in relation to land. Considering
the structural differences between patrilineal and matrilineal customary tenure systems in East Timor are understudied, this
paper explores men and women’s experiences in accessing land under such arrangements. The comparative analysis of two patrilineal
with one matrilineal land tenure systems in Ainaro and Manufahi districts suggests a significant degree of flexibility within
both systems with respect to the norms of gendered inheritance. Therefore, the binary constructs of ‘patrilineal’ and ‘matrilineal’
societies are limiting. Both men and women in these communities may acquire land rights under different circumstances, mainly
through negotiations with their parents or hamlet chief. Daughters in the patrilineal communities could inherit family land
upon their parents’ death and sons in the matrilineal community could gain land by cultivating and maintaining unclaimed customary
land. Empirical evidence show that inheritance principally determines usufruct rights to land, but marriage exchange practices
complicates a deeper understanding of traditional East Timorese land rights.
相似文献
| Pyone Myat ThuEmail: |
17.
Evolution of metamorphic fluid recorded in granulite facies metacarbonate rocks from the middle segment of the Mogok metamorphic belt in central Myanmar 总被引：1，自引：0，他引：1 
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下载免费PDF全文 The Mogok metamorphic belt of Palaeogene age, which records subduction‐ and collision‐related events between the Indian and Eurasian plates, lies along the western margin of the Shan plateau in central Myanmar and continues northwards to the eastern Himalayan syntaxis. Reaction textures of clinohumite‐ and scapolite‐bearing assemblages in Mogok granulite facies metacarbonate rocks provide insights into the drastic change in fluid composition during exhumation of the collision zone. Characteristic high‐grade assemblages of marble and calcsilicate rock are clinohumite+forsterite+spinel+phlogopite+pargasite/edenite+calcite+dolomite, and scapolite+diopside+anorthite+quartz+calcite respectively. Calculated petrogenetic grids in CaO–MgO–Al2O3–SiO2–H2O–CO2 and subsets of this system were employed to deduce the pressure–temperature–fluid evolution of the clinohumite‐ and scapolite‐bearing assemblages. These assemblages suggest higher temperature (>780–810°C) and [=CO2/(CO2+H2O) >0.17–0.60] values in the metamorphic fluid for the peak granulite facies stage, assuming a pressure of 0.8 GPa. Calcite grains commonly show exsolution textures with dolomite particles, and their reintegrated compositions yield temperatures of 720–880°C. Retrograde reactions are mainly characterized by a reaction zone consisting of a dolomite layer and a symplectitic aggregate of tremolite and dolomite grown between clinohumite and calcite in marble, and a replacement texture of scapolite by clinozoisite in calcsilicate rock. These textures indicate that the retrograde reactions developed under lower temperature (<620°C) and (<0.08–0.16) conditions, assuming a pressure of 0.5 GPa. The metacarbonate rocks share metamorphic temperatures similar to the Mogok paragneiss at the peak granulite facies stage. The values of the metacarbonate rock at peak metamorphic stage are, however, distinctly higher than those previously deduced from carbonate mineral‐free paragneiss. Primary clinohumite, phlogopite and pargasite/edenite in marble have F‐rich compositions, and scapolite in calcsilicate rock contains Cl, suggesting a contrast in the halogen compositions of the metamorphic fluids between these two lithologies. The metamorphic fluid compositions were probably buffered within each lithology, and the effective migration of metamorphic fluid, which would have extensively changed the fluid compositions, did not occur during the prograde granulite facies stage throughout the Mogok metamorphic belt. The lower conditions of the Mogok metacarbonate rocks during the retrograde stage distinctly contrast with higher conditions recorded in metacarbonate rocks from other metamorphic belts of granulite facies. The characteristic low conditions were probably due to far‐ranging infiltration of H2O‐dominant fluid throughout the middle segment of the Mogok metamorphic belt under low‐amphibolite facies conditions during the exhumation and hydration stage. 相似文献
18.
Literature on common-interest development (CID) in housing, most common in the form of gated communities, has been based largely on the US’s experience, where the interpretation has centered on the interaction between three actors (local government, private developer, and homeowner association) and barely focused on the privatization of neighborhood governance in transition economies. This paper, through a case study of gated community in Phu My Hung new town shows that Ho Chi Minh City, Vietnam—in the context of transition from centrally-planned to market-based economy—has been witnessing this privatized phenomenon of neighborhood governance. It employs both primary data, collected through observation and key informant interview, and secondary data to explain the contextual factors for the rise of gated communities in the city and find out the mechanism of neighborhood governance. In the city, housing privatization reforms, influx of foreign direct investment, and the formation of urban middle class have constituted the supply- and demand-side factors for the rise of gated communities. In addition, the reforms towards grassroots participation created a favorable environment for a privatization of neighborhood governance in which the private developer plays a dominant role in partnership with local government and homeowner association. To a certain extent, this privatization is similar to the case of US’s gated communities, however, it does not threaten the public authority and instead maintains a good collaboration between these three actors. This is an indigenous innovation of gated communities in Vietnam due to its socio-economic conditions and political context. 相似文献
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Grace Yee Wong Cecilia Luttrell Lasse Loft Anastasia Yang Thuy Thu Pham Daisuke Naito 《Climate Policy》2019,19(8):1038-1051
REDD+ was designed globally as a results-based instrument to incentivize emissions reduction from deforestation and forest degradation. Over 50 countries have developed strategies for REDD+, implemented pilot activities and/or set up forest monitoring and reporting structures, safeguard systems and benefit sharing mechanisms (BSMs), offering lessons on how particular ideas guide policy design. The implementation of REDD+ at national, sub-national and local levels required payments to filter through multiple governance structures and priorities. REDD+ was variously interpreted by different actors in different contexts to create legitimacy for certain policy agendas. Using an adapted 3E (effectiveness, efficiency, equity and legitimacy) lens, we examine four common narratives underlying REDD+ BSMs: (1) that results-based payment (RBP) is an effective and transparent approach to reducing deforestation and forest degradation; (2) that emphasis on co-benefits risks diluting carbon outcomes; (3) that directing REDD+ benefits predominantly to poor smallholders, forest communities and marginalized groups helps address equity; and (4) that social equity and gender concerns can be addressed by well-designed safeguards. This paper presents a structured examination of eleven BSMs from within and beyond the forest sector and analyses the evidence to variably support and challenge these narratives and their underlying assumptions to provide lessons for REDD+ BSM design. Our findings suggest that contextualizing the design of BSMs, and a reflexive approach to examining the underlying narratives justifying particular design features, is critical for achieving effectiveness, equity and legitimacy.
Key policy insights
A results-based payment approach does not guarantee an effective REDD+; the contexts in which results are defined and agreed, along with conditions enabling social and political acceptance, are critical.
A flexible and reflexive approach to designing a benefit-sharing mechanism that delivers emissions reductions at the same time as co-benefits can increase perceptions of equity and participation.
Targeting REDD+ to smallholder communities is not by default equitable, if wider rights and responsibilities are not taken into account
Safeguards cannot protect communities or society without addressing underlying power and gendered relations.
The narratives and their underlying generic assumptions, if not critically examined, can lead to repeated failure of REDD+ policies and practices.
20.
Jia He Soon Keat Tan Thu Trang Vu Kok Pang Lam 《Marine Georesources & Geotechnology》2017,35(5):593-602
Soil slurry dredged from seabed is becoming more widely used in land reclamation projects. A major problem encountered is that soil slurry is very high in water content and the dewatering process is difficult and time consuming. In this paper, the use of chemical flocculant for the dewatering of soil slurry is proposed and experimentally tested. Polyacrylamide (PAM) with different charge types/charge densities was tested in preliminary slurry dewatering tests. The results showed that the most effective flocculant, cationic PAM (CPAM) with +15 charge density, can reduce the volume of soil slurry (500% water content) by around 60% in 10 minutes. In contrast, the volume of pure soil slurry was almost unchanged. Slurry sedimentation tests on slurries with different flocculant contents and water contents were conducted. It is shown that, by adding flocculant into soil slurry, the rate of settlement under self-weight can be considerably increased in the tested range of water contents (100.7–879.5%). But the water content at the final state increases with flocculant additions. Slurry sedimentation curves displayed different characteristics with different flocculant contents as well as water contents. It is evidenced by particle size analysis that the addition of flocculant into soil slurry can attract soil particles and form large flocs (assemblage of particles), which explains the faster settlement rate in flocculant-treated soil slurry as compared with pure soil slurry. Scanning electron microscopic analysis revealed that flocculant-treated soil particles are more randomly oriented, while soil particles with no flocculant addition deposit in a more paralleled manner. This could explain the higher water content of flocculant-treated soil slurry at the final state. 相似文献