Morphological Change in the Northern Red River Delta,Vietnam

Coastal erosion has become a worldwide concern, typically in the densely populated Asian mega-river deltas. Severe coastal erosion in the southern Red River Delta(RRD) has been intensively studied. Coastal morphological change in the northern RRD was examined in detail through DEM(Digital Elevation Model) analysis based on time series of bathymetrical maps(1965–2004) and Landsat images(1975–2015) in this study. The results show that the northern RRD is featured by rapid coastal accretion in the past few decades, although suspended sediment flux has dropped by roughly 60% after the completeness of Hoa Binh Dam(HBD) in 1988 and relative sea level rose at 1.9 mm yr^(-1). However, accretion at the outer part of subtidal shoals and platforms was observed to slow down quickly or even turned into erosion in the last two decades. The resuspended sediments from the erosion zone can be transported landward to replenish the inner coastal zone, keeping the latter accretion in the near future to compensate for the sediment discharge decrease from the river. However, this lag effect should be terminated soon if other adverse effects go worse, e.g., damming rivers, sea-level rising, strengthening storms, land reclamation and other poor-designed coastal engineering. Coastal planners and managers should pay full attention to these changes.

Analysis of Storm Pattern for Design Urban Drainage System in the Monsoon Areas of Vietnam

In Vietnam,rainfall data usually received using daily rainfall at all hydrology stations with higher time resolution are scarce.However,its analyses to achieve IDF(Intensity-Duration-Frequency)curves are often required at a finer scale such as hourly.Therefore,it needs to develop and apply methods to derive the IDF characteristics of short-duration events from daily rainfall statistics in Vietnam.In recent years,the need for new insights into the rainfall process leading to new approaches to model the distribution of rainfall intensities in time and space was recognized.This research aims to establish IDF curves for monsoon climate area in Vietnam based on scaling method.Scaling properties of extreme rainfall are examined in the Red River Delta of Vietnam in order to establish scaling behavior of statistical moments over different durations.Such scaling or scale-invariant models enable us to scale data from one temporal resolution to another,and thus,help to overcome the lack of the extreme rainfall data of sub-daily durations.The disaggregation or downscaling techniques are used to obtain sub-daily rainfall data from daily rainfall data for the derivation of scaled IDF curves.Research results show that most of rainfall amount(approximately 70%)received from rains occurring between 6:0 pm to 6:0 am of the day after that,the daytime usually less rainfall occurrence with only 30%.The peak rainfall is usually occurred during 0:0 am to 4:0 am having approximately 42.98%of rainfall amount over a day.The peak rainfall likely happen earlier in the recent year(36%rainfall amount over a day occurrence from 6:00 pm to 10:00 pm in 2008).The analysis also illustrated that approximately 40%of rainfall events have duration less than 60 minutes.In contrast,only approximately 9%of rainfall events have duration more than 6 hours but total rainfall depths of these events is approximately.

越南鞋业配套产业发展的现状和方向

越南在世界主要鞋类出口国中排名第四,在世界上十大鞋类生产国中排名第一,在该国,鞋业也排名第三。大量出口,仅次于纺织品、石油和天然气。但是,根据许多经济专家以及皮革行业的说法他说,在世界市场上,除了阿迪达斯(Adidas),Converve,艾伦-埃德蒙兹(Allen-Edmonds)(美国)等著名品牌外,没有越南品牌鞋的影子。越南的皮革和制鞋业目前主要是加工产品,并非以其品牌直接出口。从现在起的5年后的10年中,如果仍仅从中国内地,中国台湾或韩国的材料供应商处加工和进口原材料,越南的制鞋业就很难断言定位为经济的主要出口部门。因此,皮革和制鞋业的发展需要与许多辅助产业的发展相结合,例如发展规划,工厂的发展方向,生产皮革和鞋底的工厂。鞋类行业的辅助产品,例如缝纫线,缝纫针,拉链,胶水,漂白剂……以代替进口商品。