Application of Remote Sensing in Flood Management with Special Reference to Monsoon Asia: A Review

The conventional means to record hydrological parameters of aflood often fail to record an extreme event. Remote sensingtechnology along with geographic information system (GIS)has become the key tool for flood monitoring in recent years.Development in this field has evolved from optical to radarremote sensing, which has provided all weather capabilitycompared to the optical sensors for the purpose of flood mapping.The central focus in this field revolves around delineation of floodzones and preparation of flood hazard maps for the vulnerable areas.In this exercise flood depth is considered crucial for flood hazardmapping and a digital elevation model (DEM) is considered to bethe most effective means to estimate flood depth from remotelysensed or hydrological data. In a flat terrain accuracy of floodestimation depends primarily on the resolution of the DEM. Riverflooding in the developing countries of monsoon Asia is very acutebecause of their heavy dependence on agriculture but any floodestimation or hazard mapping attempt in this region is handicappedby poor availability of high resolution DEMs. This paper presents areview of application of remote sensing and GIS in flood managementwith particular focus on the developing countries of Asia.     

Fitting the Linear Model of Coregionalization by Generalized Least Squares

In geostatistical studies, the fitting of the linear model of coregionalization (LMC) to direct and cross experimental semivariograms is usually performed with a weighted least-squares (WLS) procedure based on the number of pairs of observations at each lag. So far, no study has investigated the efficiency of other least-squares procedures, such as ordinary least squares (OLS), generalized least squares (GLS), and WLS with other weighing functions, in the context of the LMC. In this article, we compare the statistical properties of the sill estimators obtained with eight least-squares procedures for fitting the LMC: OLS, four WLS, and three GLS. The WLS procedures are based on approximations of the variance of semivariogram estimates at each distance lag. The GLS procedures use a variance–covariance matrix of semivariogram estimates that is (i) estimated using the fourth-order moments with sill estimates (GLS₁), (ii) calculated using the fourth-order moments with the theoretical sills (GLS₂), and (iii) based on an approximation using the correlation between semivariogram estimates in the case of spatial independence of the observations (GLS₃). The current algorithm for fitting the LMC by WLS while ensuring the positive semidefiniteness of sill matrix estimates is modified to include any least-squares procedure. A Monte Carlo study is performed for 16 scenarios corresponding to different combinations of the number of variables, number of spatial structures, values of ranges, and scale dependence of the correlations among variables. Simulation results show that the mean square error is accounted for mostly by the variance of the sill estimators instead of their squared bias. Overall, the estimated GLS₁ and theoretical GLS₂ are the most efficient, followed by the WLS procedure that is based on the number of pairs of observations and the average distance at each lag. On that basis, GLS₁ can be recommended for future studies using the LMC.     

Simulation of Orissa Super Cyclone (1999) using PSU/NCAR Mesoscale Model

In this study a non-hydrostatic version of Penn State University (PSU) -- NationalCenter for Atmospheric Research (NCAR) mesoscale model is used to simulate thesuper cyclonic storm that crossed Orissa coast on 29 October 1999. The model isintegrated up to 123 h for producing 5-day forecast of the storm. Several importantfields including sea level pressure, horizontal wind and rainfall are compared with theverification analysis/observation to examine the performance of the model. The modelsimulated track of the cyclone is compared with the best-fit track obtained from IndiaMeteorological Department (IMD) and the track obtained from NCEP/NCAR reanalysis. The model is found to perform reasonably well in simulating the track and in particular, the intensity of the storm.     

Tectonic and hydrodynamic control of landslides in the northern area of the Central Rif, Morocco

The northern edge of the Central Rif (Morocco) is subject to numerous landslides where mechanisms do not correspond to the classical models used by geomechanics specialists. It is necessary to adopt a multidisciplinary approach that combines geomorphology, geology, hydrogeology, and geotechnics in order to understand how such slope failures are generated, especially in a region with a heterogeneous structure characterised by significant lithological differences, severe fracturing, and thrust sheets where tectonic contacts play a major role in groundwater circulation. This report shows that these failures are essentially controlled by the tectonic contact separating the Tisirene and Chouamat thrust sheets and by subsurface hydrodynamic conditions. A model of spatial and temporal variations in the factor of safety is proposed.     

Sorption Characteristics of Rare Earth Element Eu^3＋ onto Silica-Water Interfaces Studied by Fluorescence Spectroscopy

The sorption of Eu species onto nano-size silica-water interfaces was investigated using fluorescence spectroscopy for Ph ranges of 1-8.5 and an initial Eu concentration (Ceu) of 2×10-4 M. The sorption rate of Eu was initially low, but significantly increased at Ph>4. The sorption density of Eu species on a silica surface was ～1.58×10-7 mol/m2 when the dissolved Eu species were completely sorbed onto silica-water interfaces at Ph=～5.8. The sorbed Eu species at Ph<6 is aquo Eu3 , which is sorbed onto silica-water interfaces as an outer-sphere complex at Ph<5, but may be sorbed as an inner-sphere bidentate complex at 5相似文献   

Modélisation morphodynamique cross-shore d'un estran vaseux

Numerical experiments were performed to simulate the profile evolution of an intertidal mudflat with a 1D cross-shore morphodynamical model. First, the hydrodynamical forcing is a cross-shore tidal current due to semi-diurnal variations of the free surface elevation at the open boundary. Further, considering the conservation of the action density of surface gravity waves, a wave height (and resulting bottom shear stress) calculation is added to the morphodynamical model. Results of the numerical experiments show that the shape of the profile reaches equilibrium. The mudflat progrades continually when the forcing is tide only, whereas it can be steady under the simultaneous action of tide and waves. To cite this article: B. Waeles et al., C. R. Geoscience 336 (2004).     

Crustal thickening in an extensional regime: application to the mid-Norwegian Vøring margin

The structure of the mid-Norwegian volcanic Vøring margin at the onset of the Maastrichtian–Paleocene extension phase reflects the cumulative effect of earlier consecutive rifting events. Lateral structural differences present on the margin at that time are a consequence of migration of the location of maximum extension in time between Norway and Greenland. The most important imprints (Moho depth, thermal structure) of these events on the lithosphere are incorporated in a numerical simulation of the final extension phase. We focus on a possible mechanism of formation of the Vøring Marginal High and address the relationship between spatial and temporal evolution of crustal thinning and thickening, uplift of the surface and strength of the lithosphere.It is found that the Vøring Basin formed the strongest part of the margin which explains why the Maastrichtian–Paleocene rift axis was not located here but instead jumped westward with respect to the earlier rift axes locations. The modeling study predicts that local crustal thickening during extension can be expected when large lateral thermal variations are present in the lithosphere at the onset of extension. Negative buoyancy induced by lateral temperature differences increases downwelling adjacent to the rifting zone; convergence of material at the particular part of the margin is mainly taken up by the lower crust. The model shows that during the final phase of extension, the crust in the Vøring Marginal High area was thickened and the surface uplifted. It is likely that this dynamic process and the effects of magmatic intrusions both acted in concert to form the Marginal High.     

东吴小筑园林植物应用评价

园林植物配置是园林植物应用的重要内容，对充分发挥园林功能和观赏特性具有重要作用。通过对东吴小筑入口、前庭小院、主景区、山林区、园路、出口等6个功能区园林植物水平配置的现状调查，分析了本景区园林植物的物种多样性、水平结构、垂直结构、色彩变化等特征。结果表明：东吴小筑园林景观营造中．植物配置显示出较高水准。在树种选择、树丛组合、层次搭配、空间组织、色彩表现、季相变化等方面的设计布局十分精细，对今后园林设计及园林绿化水平的提高具有较好的指导作用。     

我国农村合作医疗的地区模式

农村合作医疗是我国农村主要的医疗保障形式。但是由于我国各地社会经济发展水平不平衡，中央政府的扶持政策也有所不同，合作医疗出现了多种不同的地区模式。高收入地区、中等收入地区及低收入地区的合作医疗在筹资方式、管理方式和补偿方式上都各有特点。