Detailed measurements of thickness and grain size of a widespread onshore tsunami deposit in Phang‐nga Province,southwestern Thailand     

Shigehiro Fujino  Hajime Naruse  Dan Matsumoto  Norihiko Sakakura  Apichart Suphawajruksakul  Thanawat Jarupongsakul 《Island Arc》2010,19(3):389-398

Measurements of thickness and grain size along flow‐parallel transects across onshore deposits of the 2004 Indian Ocean tsunami revealed macroscopic horizontal variations and provided new insights into tsunami sedimentation. The tsunami caused severe erosion of beaches, river mouths, and the shallow seafloor along the coast of southwestern Thailand and supplied sufficient sediment to deposit a kilometer‐wide blanket of sand on the land surface. The tsunami deposits generally fine landward with some fluctuations caused by local entrainment and settlement of sediments. Sediments of medium and fine sand are restricted to a few hundreds of meters inland from their source, whereas finer grained sediments were suspended longer and deposited 1 km or more inland. Although the thickness of the tsunami deposits is strongly influenced by local topography, they generally thin landward. In areas of low‐relief topography, the rate of landward thinning is exponential and reflects the dominance of sediment supply to nearshore areas over that to areas farther inland.  相似文献   

On the connection between the atmospheric electric field measured at the surface and the ionospheric electric field in the Central Antarctica     

A.V. Frank-Kamenetsky  L.N. Makarova  V.N. Morozov  A.V. Shirochkov  G.B. Burns 《Journal of Atmospheric and Solar》2010,72(5-6):419-424

Regular measurements of the atmospheric electric field made at Vostok Station (φ=78.45°S; λ=106.87°E, elevation 3500 m) in Antarctica demonstrate that extremely intense electric fields (1000–5000 V/m) can be observed during snow storms. Usually the measured value of the atmospheric electric field at Vostok is about 100–250 V/m during periods with “fair weather” conditions. Actual relation between near-surface electric fields and ionospheric electric fields remain to be a controversial problem. Some people claimed that these intense electric fields produced by snowstorms or appearing before strong earthquakes can re-distribute electric potential in the ionosphere at the heights up to 300 km. We investigated interrelation between the atmospheric and ionospheric electric fields by both experimental and theoretical methods. Our conclusion is that increased near-surface atmospheric electric fields do not contribute notably to distribution of ionospheric electric potential.  相似文献   

矢量地图空间信息度量及其变化分析方法   总被引：1，自引：0，他引：1  

陈杰  邓敏  陈晓勇  孙金礼  潘智虎 《地理信息世界》2010,8(1):78-83

如何计算地图的空间信息含量是评价制图质量、地图综合算法以及实现空间信息有效传输的重要基础。论文在详细分析现有的空间信息度量方法的基础上,提出了一种空间信息度量的新方法。该方法分别从几何、专题、拓扑以及专题拓扑4个方面来度量地图空间信息。然后,提出利用膨胀和序贯膨胀形态学算子分析几何信息熵、专题信息熵、拓扑信息熵以及专题拓扑信息熵随地图符号影响范围不同而引起的变化。通过算例分析发现,利用Voronoi图计算得到的结果是论文方法的一个极值结果(即特例),并且该方法便于定量分析地图空间信息熵度量随符号影响范围(或大小)的变化情况。  相似文献   

High urine hippuric acid level among police working close to traffic in an urban area,Thailand: a preliminary study     

Viroj Wiwanitkit  Jamsai Suwansaksri  Suphan Soogarun 《Stochastic Environmental Research and Risk Assessment (SERRA)》2008,22(2):281-283

Toluene is of particular concern because recent research indicating that toluene exposure can result in several toxicities. Hence, toluene exposure is of particular concern because of ongoing exposure to thousands of workers in the industrial plants. Determination of the urine hippuric acid level is accepted as a helpful for monitoring risk groups of workers. Apart from the industrial workers, there are other occupations with high risk for toluene exposure. In this study, we study another at-risk occupation, the police. In this study, 45 urine samples were obtained from 45 Thai police working close to traffic in an urban area for determination for urine hippuric acid level. The average urine hippuric acid level was 0.70 ± 0.70 mg/gCr, respectively. This average is significant higher than that of the control non-exposed Thais (P < 0.05). Working in the air pollution in the urban area can be health hazard for the police. Exposure to the toluene from automobile exhaust can be an important occupational problem for these police.  相似文献   

PM10 in the atmosphere and incidence of respiratory illness in Chiangmai during the smoggy pollution     

Viroj Wiwanitkit 《Stochastic Environmental Research and Risk Assessment (SERRA)》2008,22(3):437-440

Adverse health effects of atmospheric exposure to particles have been described in numerous epidemiological studies. In early of March 2007, there was a big environmental crisis in the northern area of Thailand. Smoggy pollution due to the fires covered many provinces in this area. Here, the author analyzes the correlation on incidence of respiratory illness and PM10 level in Chiangmai, a province in northern Thailand where the pollution occurred. The finding of emerging of the respiratory illness is similar to those previous reports on other smoggy pollutions due to fires. However, there is not a direct statistical significant relationship. It is proved that PM10 might be a risk for respiratory illness attack.  相似文献   

High blood lead level among the Mahayana Buddhist monk: a note for environmental implication     

Viroj Wiwanitkit  Jamsai Suwansaksri  Suphan Soogarun 《Stochastic Environmental Research and Risk Assessment (SERRA)》2008,22(6):805-807

Lead has no biological function and is one of the most toxic metals. Of several heavy metals, monitoring of lead is an important focus in occupational medicine. In exposure and risk evaluation, monitoring lead biologically has several advantages over technical exposure assessment. In this article, the authors report a very high blood lead level among the Mahayana Buddhist monks. This is a forgotten high-risk population. The environmental implication in the monitoring and controlling of this population is raised.  相似文献   

Seasonal variation in water column conditions in the upper Gulf of Thailand     

Anukul Buranapratheprat  Tetsuo Yanagi  Satsuki Matsumura   《Continental Shelf Research》2008,28(17):2509-2522

Seasonal variation in water column conditions in the upper Gulf of Thailand (UGoT) was analyzed by considering four major factors including surface heat flux, freshwater discharge, tidal and wind stirrings. The coincidence of surface heat loss, low river discharge and strong wind resulted in vertical well-mixing in December. Strong stratification developed in September and October due to large river discharge and moderate heat flux. Strong surface heating in April and May has a potential to generate strong stratification, although not as large as that in September and October due to low river discharge. Although no factors are prominent during January and March, and June and August, weak to moderate stratification results, because the influences of river discharge and surface heating are still larger than those of tidal and wind stirrings. The results of water column analysis based on monthly average data agree well with analyses derived from cruise data in the same months. Most analytical results correspond to the distributions of temperature and salinity from field observations. Disagreement, however, was found in December 2003 (cruise CU-2) when stratification in some small regions occurs in the distribution of water properties, but the water column analysis suggests vertical well-mixing. This phenomenon is triggered by non-uniform distribution of freshwater over UGoT, which is related to river discharge, monsoonal wind and current. Compared to a previous study regarding surface chlorophyll dynamics, water column conditions may be used to explain the occurrence of phytoplankton bloom in this region.  相似文献   

Modeling Mercury Flows in Thailand on the Basis of Mathematical Material Flow Analysis          下载免费PDF全文

Manaporn Wongsoonthornchai  Suphaphat Kwonpongsagoon  Ruth Scheidegger 《洁净——土壤、空气、水》2016,44(1):16-24

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Long time-series spatiotemporal variations of NPP and water use efficiency in the lower Heihe River Basin with serious water scarcity     

《Physics and Chemistry of the Earth》2016

It is of great significance to analyze the long time-series spatiotemporal dynamics of water use efficiency (WUE) to formulating appropriate management measures in response to the growing water scarcity in arid and semi-arid regions. This study analyzed the long time-series variations of WUE in the Lower Heihe River Basin, a typical arid and semi-arid region in China. The net primary productivity (NPP) was first estimated with the C-fix model, then WUE during 2001–2010 was calculated with the NPP and evapotranspiration (ET) data, and the accumulative WUE was further calculated. The results showed that the annual NPP and WUE in the study area ranged from zero to 448.70 gC/(m² a) and from zero to 2.20 gC kg⁻¹ H₂O, respectively, both of which showed an overall increasing trend during 2001–2010. Besides, the spatial pattern of WUE kept overall unchanged during 2001–2010, but with remarkable change in some part of the study area. In addition, the accumulative WUE of the whole study area showed a first sharply decreasing and then gradually increasing trend, but there was still some scope to improve the WUE, and it is necessary to carry out some more specific policies to further improve the water allocation and WUE within the Lower Heihe River Basin. Although with some uncertainties, these results still can provide valuable reference information for improving the water resource management and ecological conservation to guarantee provision of essential ecosystem services in arid and semi-arid regions.  相似文献   

Numerical simulation of water resources problems: Models,methods, and trends     

《Advances in water resources》2013

Mechanistic modeling of water resources systems is a broad field with abundant challenges. We consider classes of model formulations that are considered routine, the focus of current work, and the foundation of foreseeable work over the coming decade. These model formulations are used to assess the current and evolving state of solution algorithms, discretization methods, nonlinear and linear algebraic solution methods, computational environments, and hardware trends and implications. The goal of this work is to provide guidance to enable modelers of water resources systems to make sensible choices when developing solution methods based upon the current state of knowledge and to focus future collaborative work among water resources scientists, applied mathematicians, and computational scientists on productive areas.  相似文献