Volume estimation of small scale debris flows based on observations of topographic changes using airborne LiDAR DEMs

This paper describes a geographic information system(GIS)-based method for observing changes in topography caused by the initiation, transport, and deposition of debris flows using highresolution light detection and ranging(LiDAR) digital elevation models(DEMs) obtained before and after the debris flow events. The paper also describes a method for estimating the volume of debris flows using the differences between the LiDAR DEMs. The relative and absolute positioning accuracies of the LiDAR DEMs were evaluated using a real-time precise global navigation satellite system(GNSS) positioning method. In addition, longitudinal and cross-sectional profiles of the study area were constructed to determine the topographic changes caused by the debris flows. The volume of the debris flows was estimated based on the difference between the LiDAR DEMs. The accuracies of the relative and absolute positioning of the two LiDAR DEMs were determined to be ±10 cm and ±11 cm RMSE, respectively, which demonstrates the efficiency of the method for determining topographic changes at an scale equivalent to that of field investigations. Based on the topographic changes, the volume of the debris flows in the study area was estimated to be 3747 m3, which is comparable with the volume estimated based on the data from field investigations.     

Historical Changes and Characteristics of Rehabilitation, Management and Utilization of Forest Resources in South Korea

This study analyzed the causes of forest devastation, the characteristics of forest rehabilitation process, and the success factors of reforestation. And it reviewed the management of rehabilitated forest resources and identified the income sources of mountain villages in South Korea. The devastation of forest starting from the early twentieth century was continued to the 1950＇s. The main causes of deforestation were the illegal cutting of trees for fuel and the slash-and-burning agriculture in forest. The success factors of reforestation were the decrease in the dependence on forest of fuel source, strict administration system and national participation. Sustainable forest management could be made possible through the practical use of social issues like public work project for prevention of landslide damages caused by the thinned logs left in the forest. Also it could be possible by making people realize that the public benefit was obtained from forest and the income sources of mountain villages were supplemented by non-timber forest products and tourism. Food and Agriculture Organization indicated Korea as the country that forestation was succeeded in a very short period. Korea seems to be not ordinary because economic growth was accomplished with rehabilitating natural environment. Korean forestation can become a good prototype of combining environmental rehabilitation and economic development.     

Korea’s approach to overcoming difficulties in adopting the emission trading scheme

In this study, we aim to describe the background for design characteristics of emissions trading schemes (ETS) in developing and emerging economies, with a particular focus on the case of Korea. These countries may face unique hardships such as fierce opposition from industry sectors, the presence of a power imbalance between the Ministry of Environment (MOE) and ministries that are in charge of supporting output growth, and the absence or incomplete development of financial markets and auctioning mechanisms. To overcome these hardships, the Korean government legislated laws that defined timelines for every stage of ETS development, established a strategic governance architecture to make up the weak position of the MOE, offered strong market-stabilizing measures focused on maintaining the allowance price below a certain level, and provided support packages to make the low-carbon transition easy by compensating for losses caused by the Korea Emissions Trading Scheme (KETS). Such policy instruments that made adoption of KETS easier could be obstacles to making it efficient.

Policy relevance

In the process of adopting a cap-and-trade system, both a developing economy and an emerging economy may face unique hardships, such as strong opposition from industry sectors, the presence of a power imbalance between the Ministry of Environment (MOE) and ministries that are in charge of supporting output growth, and the absence or incomplete development of financial markets and auctioning mechanisms. To make up for the weak base of Korea’s ETS, the government legislated laws that defined timelines for every stage of the ETS development, established a strategic governance architecture to make up for the weak position of the MOE, offered strong market-stabilizing measures focused on maintaining the allowance price below a certain level, and provided support packages to make the low-carbon transition easy by compensating for losses caused by the Korea’s ETS. Korea’s experiences can be shared with other developing economies that are considering adoption of a cap-and-trade scheme.     

A steepness index unit volume flood hydrograph approach for sub‐daily flow disaggregation

The estimation of sub‐daily flows from daily flood flows is important for many hydrological and hydraulic applications. Flows during flood events often vary significantly within sub‐daily time‐scales, and failure to capture the sub‐daily flood characteristic can result in an underestimation of the instantaneous flood peaks, with possible risk of design failure. It is more common to find a longer record of daily flow series (observed or modelled using daily rainfall series) than sub‐daily flow data. This paper describes a novel approach, known as the steepness index unit volume flood hydrograph approach, for disaggregating daily flood flows into sub‐daily flows that takes advantage of the strong relationship between the standardized instantaneous flood peak and the standardized daily flood hydrograph rising‐limb steepness index. The strength of this relationship, which is considerably stronger than the relationship between the standardized flood peak and the event flood volume, is shown using data from six rivers flowing into the Gippsland Lakes in southeast Australia. The results indicate that the steepness index unit volume flood hydrograph approach can be used to disaggregate modelled daily flood flows satisfactorily, but its reliability is dependent on a model's ability to simulate the standardized daily flood hydrograph rising‐limb steepness index and the event flood volume. Copyright © 2007 John Wiley & Sons, Ltd.     

Nature and Properties of sub-DLAs (absorbers with 1019 ≤ N(HI) ≤ 2 * 1020 cm-2)

Quasar absorbers provide an alternative approach to the study of galaxies. In particular, the detection of high-column density systems allow to measure the cosmological evolution of the neutral gas mass and metals in the Universe. At z <3.5, 90% of the HI mass is in damped Lyα systems (DLAs). But it has been suggested that atz > 3.5, 45% of the HI lies in systems below the traditional DLA definition (2 x 10²⁰ cm^-2), in ‘sub-DLAs’ with 10¹⁹ < N(HI) < 2 x 10²⁰ cm^-2. Here we present a sample of sub-DLAs issued from UVES archive quasar spectra. We have measured the sub-DLA number density redshift evolution and directly establish their column density distribution function. We have also undertaken a detailed metal abundance analysis of this class of absorbers to compare with the characteristics of the well studied DLAs. This revised version was published online in September 2006 with corrections to the Cover Date.     

Ionomeric electroactive polymer artificial muscle for naval applications

Specialized propulsors for naval applications have numerous opportunities in terms of research, design, and fabrication of an appropriate propulsor. One of the most important components of any propulsor is the actuator that provides the mode of locomotion. ionomeric electroactive polymer may offer an attractive solution for locomotion of small propulsors. A common ionomeric electroactive polymer, ionic polymer-metal composites (IPMCs) give large true bending deformations under low driving voltages, operate in aqueous environments, are capable of transduction, and are relatively well understood. IPMC fabrication and operation are presented to further elucidate the use of the material for a propulsor. Various materials, including IPMCs, are investigated and a simplified propulsor model is explored.     

Diurnal variation of simulated 2007 summertime precipitation over South Korea in a real-time forecast model system

A real-time forecast (RTF) system using Weather Research and Forecast (WRF) model version 2.2 is used to evaluate the diurnal variation of precipitation over South Korea in the summer (June to August) of 2007. The characteristics of the observed precipitation are also analyzed. The analysis and simulation period is divided into two sub-periods following the end of the changma, or East Asian monsoon, in 2007: Period_1 is from 1 June to 21 July, and Period_2 is from 22 July to 31 August. A 24-h precipitation cycle is observed over the entire period. The diurnal variation of precipitation over the South Korea shows that the nighttime maximum precipitation in Period_1 is affected by a largescale system; in contrast, the daytime maximum precipitation in Period_2 resulted from mesoscale convections is induced by thermal instability and moisture advection. The phases of the diurnal variation of simulated precipitation are consistent with those of the observed precipitation. The daytime rainfall amount of simulated precipitation in Period_2 is overestimated, and the convective rain process significantly affects the simulated total precipitation. The daytime overestimated precipitation is associated with overestimations of low-level temperature and moisture during the daytime in the model simulations as compared with the observations.     

2D Fokker–Planck models of rotating clusters

Globular clusters rotate significantly, and with the increasing amount of detailed morphological and kinematical data obtained in recent years on galactic globular clusters many interesting features show up. We show how our theoretical evolutionary models of rotating clusters can be used to obtain fits, which at least properly model the overall rotation and its implied kinematics in full 2D detail (dispersions, rotation velocities). Our simplified equal mass axisymmetric rotating model provides detailed two-dimensional kinematical and morphological data for star clusters. The degree of rotation is not dominant in energy, but also non-negligible for the phase-space distribution function, shape and kinematics of clusters. Therefore, the models are well applicable for galactic globular clusters. Since previously published papers on that matter by us made it difficult to do detailed comparisons with observations, we provide a much more comprehensive and easy-to-use set of data here, which uses as entries dynamical age and flattening of observed cluster and then offers a limited range of applicable models in full detail. The method, data structure and some exemplary comparison with observations are presented. Future work will improve modelling and data base to take a central black hole, a mass spectrum and stellar evolution into account.