• Title/Summary/Keyword: Geomorphological Change

Search Result 123, Processing Time 0.025 seconds

Improvement of the Method using the Coefficient of Variation for Automatic Multi-segmentation Method of a Rating Curve (수위-유량관계곡선의 자동구간분할을 위한 변동계수 활용기법의 개선)

  • Kim, Yeonsu;Kim, Jeongyup;An, Hyunuk;Jung, Kwansue
    • Journal of Korea Water Resources Association
    • /
    • v.48 no.10
    • /
    • pp.807-816
    • /
    • 2015
  • In general, the water stage-discharge relationship curve is established based on the assumptions of linearity and homoscedasticity. However, the relationship between the water stage and discharge is affected from geomorphological factors, which violates the basic assumptions of the water stage-discharge relationship curve. In order to reduce the error due to the violations, the curve is divided into several sections based on the manager's judgement considering change of cross-sectional shape. In this research, the objective-splitting criteria of the curve is proposed based on the measured data without the subjective decision. First, it is assumed that the coefficient of variation follows the normal distribution. Then, if the newly calculated coefficient of variation is outside of the 95% confidential interval, the curve is divided. Namely, the groups is divided by the characteristics of the coefficient of variation and the reasonable criteria is provided for establishing a multi-segmented rating curve. To validate the proposed method, it was applied to the data generated by three artificial power functions. In addition, to confirm the applicability of the proposed method, it is applied to the water stage and discharge data of the Muju water stage gauging station and Sangegyo water stage gauging station. As a result, it is found that the automatically divided rating curve improves the accuracy and extrapolation accuracy of the rating curve. Finally, through the residual analysis using Shapiro-Wilk normality test, it is confirmed that the residual of water stage-discharge relationship curve tends to follow the normal distribution.

한강하류지형면의 분류와 지형발달에 대한 연구 (양수리에서 능곡까지)

  • Park, No-Sik
    • Journal of the Speleological Society of Korea
    • /
    • no.68
    • /
    • pp.23-73
    • /
    • 2005
  • Purpose of study; The purpose of this study is specifically classified as two parts. The one is to attempt the chronological annals of Quaternary topographic surface through the study over the formation process of alluvial surfaces in our country, setting forth the alluvial surfaces lower-parts of Han River area, as the basic deposit, and comparing it to the marginal landform surfaces. The other is to attempt the classification of micro morphology based on the and condition premising the land use as a link for the regional development in the lower-parts of Han river area. Reasons why selected the Lower-parts of Han river area as study objects: 1. The change of river course in this area is very serve both in vertical and horizontal sides. With a situation it is very easy to know about the old geography related to the formation process of topography. 2. The component materials of gravel, sand, silt and clay are deposited in this area. Making it the available data, it is possible to consider about not oかy the formation process of topography but alsoon the development history to some extent. 3. The earthen vessel, a fossil shell fish, bone, cnarcoal and sea-weed are included in the alluvial deposition in this area. These can be also valuable data related to the chronological annals. 4. The bottom set conglometate beds is also included in the alluvial deposits. This can be also valuable data related to the research of geomorphological development. 5. Around of this area the medium landform surface, lower landform surface, pediment and basin, are existed, and these enable the comparison between the erosion surfaces and the alluvial surfaces. Approach : 1. Referring to the change of river beds, I have calculated the vertical and horizontal differences comparing the topographic map published in 1916 with that published in 1966 and through the field work 2. In classifying the landform, I have applied the method of micro morphological classification in accordance with the synthetic index based upon the land conditions, and furthermore used the classification method comparing the topographic map published in 1916 and in that of 1966. 3. I have accorded this classification with the classification by mapping through appliying the method of classification in the development history for the field work making the component materials as the available data. 4. I have used the component materials, which were picked up form the outcrop of 10 places and bored at 5 places, as the available data. 5. I have referred to Hydrological survey data of the ministry of Construction (since 1916) on the overflow of Han-river, and used geologic map of Seoul metropolitan area. Survey Data, and general map published in 1916 by the Japanese Army Survbey Dept., and map published in 1966 by the Construction Research Laboratory and ROK Army Survey Dept., respectively. Conclusion: 1. Classification of Morphology: I have added the historical consideration for development, making the component materials and fossil as the data, to the typical consideration in accordance with the map of summit level, reliefe and slope distribution. In connection with the erosion surface, I have divided into three classification such as high, medium and low-,level landform surfaces which were classified as high and low level landform surfaces in past. furthermore I have divided the low level landform surface two parts, namely upper-parts(200-300m) and bellow-parts(${\pm}100m$). Accordingly, we can recognize the three-parts of erosion surface including the medium level landform surface (500-600m) in this area. (see table 22). In condition with the alluvial surfaces I have classified as two landform surfaces (old and new) which was regarded as one face in past. Meamwhile, under the premise of land use, the synthetic, micro morphological classification based upon the land condition is as per the draw No. 19-1. This is the quite new method of classification which was at first attempted in this country. 2. I have learned that the change of river was most severe at seeing the river meandering rate from Dangjung-ni to Nanjido. As you seee the table and the vertical and horizontal change of river beds is justly proportionable to the river meandering rate. 3. It can be learned at seeing the analysis of component materials of alluvial deposits that the component from each other by areas, however, in the deposits relationship upper stream, and between upper parts and below parts I couldn't always find out the regular ones. 4. Having earthern vessel, shell bone, fossil charcoal and and seaweeds includen in the component materials such as gravel, clay, sand and silt in Dukso and Songpa deposits area. I have become to attempt the compilation of chronicle as yon see in the table 22. 5. In according to hearing of basemen excavation, the bottom set conglomerate beds of Dukso beds of Dukso-beds is 7m and Songpa-beds is 10m. In according to information of dredger it is approx. 20m in the down stream. 6. Making these two beds as the standard beds, I have compared it to other beds. 7 The coarse sand beds which is covering the clay-beds of Dukso-beds and Nanjidobeds is shown the existence of so-called erosion period which formed the gap among the alluvial deposits of stratum. The former has been proved by the sorting, bedding and roundness which was supplied by the main stream and later by the branch stream, respectively. 8. If the clay-beds of Dukeo-bed and Songpa-bed is called as being transgressive overlap, by the Eustatic movement after glacial age, the bottom set conglomerate beds shall be called as being regressive overlap at the holocene. This has the closest relationship with the basin formation movement of Seoul besides the Eustatic movement. 9. The silt-beds which is the main component of deposits of flood plain, is regarded as being deposited at the Holocene in the comb ceramic and plain pottery ages. This has the closest relationship with the change of river course and river beds.

A Landscape of Joseon Dynasty in Late 19th Century through Experience Record of Modern Westerners - Focused on Landscape Vocabulary and Content Analysis - (근대기 서양인들의 조선견문기를 통해 본 19세기 말 조선의 경관 - 경관 관련 어휘와 내용 분석을 중심으로 -)

  • Kim, Dong-Hyun;Shin, Hyun-Sil
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.36 no.1
    • /
    • pp.20-33
    • /
    • 2018
  • This study aims to illuminated landscape of Joseon Dynasty in the end of 19th century when Joseon dynasty began to modernize through the perspective of Westerners. Historical meaning to Western people's landscape records has been preceded. And landscape typology and their perception were analyzed. The results were as follows. First, the Westerners who visited Joseon dynasty at that time were involved in the historical and political situation of the Joseon Dynasty or understood their culture through traveling for so long. And record of Westerners is a significant data to analyze scenery at that time because common contents appear in various books. Second, the landscape of Joseon dynasty that appears in Western records was mainly recorded in small towns and villages, natural environments, scenic sites, historic sites, modern facilities, and cultivated areas. Small towns and villages are mainly mentioned with shabby alleys and dense houses. And natural landscape were identified to mountain landscapes and diverse geomorphological landscape that surrounding vegetation along the coast and rivers. The palaces, fortress and temples were recorded as main objects of scenic sites and historic site. And western-style buildings such as foreign legations and settlements, churches and schools were mentioned in the modernized facilities. A cultivated land was confirmed to be underdeveloped and neglected, but as range of view became wider, it was seen to a peaceful and prosperous rural landscape. Third, Westerners' landscape perception of Joseon dynasty at that time can be deduced from positive or negative perceptions. The residential environment was perceived as negative because it was unsanitary and backward. On the contrary, outstanding natural landscapes, scenic sites and historic sites, and upper class gardens were perceived as positive. For modernized landscapes, positive and negative perceptions were similarly mentioned. Positive perceptions were formed in improvement of civilized landscape, and appeared negative perception because damaged traditional landscapes and heterogeneity.