• 한국해양공학회지
• /
• 제21권6호
• /
• pp.59-63
• /
• 2007

This study discusses the spatiotemporal characteristics of the geomorphological changes in Gwangyang Bay. In this study, we analyzed four aerial photos and nautical charts. The geomorphological changes that have occurred over time were identified using an MGIS (Marine geographic information system) overlay analysis. As a result, we were able to identify the geomorphological changes that have resulted from the coastal development and fairway dredging of Gwangyang Bay. This paper demonstrates that the marine geographic information system can be effective in monitoring the geomorphological changes in coastal zones.

• 대한원격탐사학회지
• /
• 제11권2호
• /
• pp.59-73
• /
• 1995

The study is focused on the analysis of geomorphological environment changes of alluvial bar in lower Kum river using satellite-based multitemporal/multisensor data. Landsat datas for environment changes analysis consists of Landset MSS(2 scenes) and Landset TM(7 scenes) acquired from 1979 to 1994. This study is to develop the analysis techniques for the environment change detection of using ratio, classification, false color composite etc, of Landsat data especially useful to the geomorphological study of tidal flats and river channels. The results of this study can be summarized as follows : 1. The lower Kum River alluvial bar have had rapid geomorphological changes after the construction of the temporary dam to block the river flowing in 1983. The most alluvial bar located in the river has both bankway growth, especially the allurival bar in the Lower Kum River had grown between 1983 to 1990. 2. After construction of the estuarine barrage, no remarkable geomorphological changes have been found in Kum River area but the growth and formation of new underwater bar has continued. The enormous materials was needed for the growth and formations of new underwater barrier oslands and bar would be supplied from the sea bottom and river sediment to diminish of stream velocity after construction of the estuarine barrage.

• 한국지형학회지
• /
• 제26권3호
• /
• pp.31-42
• /
• 2019

The geomorphological changes of an unvegetated part of the Okjukdong coastal dune were analyzed between 2008 and 2018. Its natural landscape has been destroyed after artificial forestation, but there is no quantitative evidence on these changes. In this study, we measured the unvegetated area using a total station and a network RTK-GPS in 2008, 2014, and 2018. Using Krging method for the three point data sets, we constructed digital elevation models (DEMs) and analyzed topographic changes between the three years. The results showed that the sand of the study area decreased in volume from 2008 to 2014, because sand supply from the nearby beach was blocked by coastal forests. The sand volume temporarily increased from 2014 to 2018, because of the dune nourishment conducted in 2017. It seems that the upper part of the sand dune has shrunk, but the sand at the bottom has increased over the last decade.

• 한국지형학회지
• /
• 제24권4호
• /
• pp.27-41
• /
• 2017

In this study, geomorphological and geological research has been carried out to estimate the possibility of ancient port location near Hwaseong Dangseong. Geomorphological characteristics around Eunsupo were analyzed through comparison of past and present topographic maps and field survey. Grain size, age dating, and geochemical analysis on surface sediments and borehole sediments were performed. Through the geomorphological characteristics analysis, it was interpreted that Eunsupo area was submerged in seawater especially at high tide in the past, and that ships could approach to the inside of the area through the tidal channel which were developed in the area. It is also assumed that ships were anchored at a low elevation point in the area. The paleo-environmental change in the area was analyzed based on the classification of sedimentary environment using grain size distribution of surface and borehole sediments and geochemical analysis. It was confirmed that the geomorphological interpretation for the possibility of ancient port location coincided well with the paleo-environmental change interpreted through sediment analysis. This study is a basic study for estimating ancient port location, and it is expected that more accurate paleo-environmental changes will be restored through detailed geomorphological survey and additional borehole analysis in the future research.

• 한국지형학회지
• /
• 제23권1호
• /
• pp.129-140
• /
• 2016

Camera monitoring data for 5 years from January 2009 to January 2014 are analyzed to investigate changes in beach erosion on Sangju, Gujora and Haeundae beaches on the South sea and Jungmun beach on the south shore of Jeju Island. The data show the time series of beach area changes obtained from digital orthoimages rectified from oblique images taken near the beaches by cameras. Each beach has different sediment sizes and shapes, but faces the South and is eroded mainly during Typhoons. However, each beach often responds differently to the same Typhoon, and some beaches outside the influence of the Typhoon are also eroded. This study shows that high frequency data of beach area changes obtained from cameras can effectively analyze the seasonal changes in beach area.

• 한국지형학회지
• /
• 제24권2호
• /
• pp.1-13
• /
• 2017

Massive coastal sand dunes are distributed in Ui-island, Shinan-gun. The sand dunes in Ui-island is worth studying, in terms of preserving natural environment without anthropogenic impacts. In this study, we surveyed geomorphological processes of the sand dune based upon measuring of geometric properties, grain size analysis, and OSL(Optically Stimulated Luminescence) age dating. The sediments of the dune consist mainly of well sorted medium sand with about 250$\mu$m. Based on spatial distribution of sand dunes, we found that they are formed by northwest monsoon during winter, and sands are supplied from Seongchon area in northern UI-island. According to OSL age dating, the sand dunes were deposited from $0.07{\pm}0.01ka$ to $0.17{\pm}0.04ka$. This result shows that the transformation of the dune due to the sand movement by wind was active during the last 100-200 years. The aerial photograph indicates that the dimension of the largest sand dune has decreased since 1945. Further research is needed to get more detailed information on geomorphic changes of sand dunes in UI-island.

• 한국지형학회지
• /
• 제24권1호
• /
• pp.13-24
• /
• 2017

This study analyzes altitude changes of riverbed at 6 bridges in the upper and lower reaches of Yeongju Dam in Naeseong River, from 2009 to 2016 just before and after the dam construction. For 5 years from November 2010 to December 2015 when the dam was under construction, approximately 0.091m of the riverbed altitude in average more than twice before the dam construction was lowered, because of the effects of riverbed excavation for riverside maintenance in the upper reaches and transport limitation of flow and sediment by the dam in the lower reaches. Between November 2009 and December 2016 when the dam was in pre-construction and post-construction stages, respectively, the most sites in this study in the upper and lower reaches showed lowering in the riverbed altitudes. On the other hand, the riverbed around Hoeryongpo closed to the river mouth seems to be influenced by channel changes in Nakdong River rather than by the dam construction.

• 환경영향평가
• /
• 제11권1호
• /
• pp.51-66
• /
• 2002

The purpose of this study is to analyze the geomorphological environment changes of tidal flat in the Cheonsu Bay. Especially, it centers on the changes in the sedimentary environment using remote sensing data. Multi-temporal Landsat data and topographic maps were used in this study. The results are summarized as follows: the tidal flat of Cheonsu Bay changes in many ways depending on the direction of the tidal current. In the neighborhood of Ganwoldo, the scale of the tidal flat has continuously been expanded due to the superiority of sedimentation after a tide embankment was built. When we analyzed the grain size of sediments and implemented in-situ field survey, it was found that the innermost part of the bay consists of a mud flat, with the midway part mixed flat, and the nearest part to the sea sand flat. On the other hand, in the neighborhood of Seomot isle and its beach, sedimentation is superior in the eastern part whereas erosion is superior in the western part. In other words, the western coast of the beach is contacted with the open seas and under much influence of ocean wave. The eastern coast is placed at the entrance of the bay and has sand bar and tidal flat developed due to submarine deposits that are accumulated on the sea floor by the tidal current. In conclusions, remote sensing methods can be effectively applied for quantitative analysis of geomorphological changes in tidal flat, and it is expected that the proposed schemes can be applied to another geomorphological environments such as beach, sand dune, and sand wave.

• 한국지형학회지
• /
• 제18권3호
• /
• pp.83-92
• /
• 2011

본 연구는 경상북도 동해안에서 가장 규모가 큰 영덕군 고래불 모래해안을 대상으로, 사빈과 해안사구의 지형 기복 및 해안 퇴적물의 특성과 변화를 분석하였다. 모래의 입도를 분석한 결과, 고래불 해안은 강원도 동해안과는 달리, 여름을 제외한 대부분 계절에 파랑과 연안류가 북류하면서 사빈의 모래 이동과 퇴적을 유발하였고, 여름에는 남북간의 흐름이 둔화되거나 남류가 발생하는 것으로 나타났다. 사빈에서는 여름철에 태풍이나 폭풍으로 인한 침식작용이 발생하였고 상대적으로 조립의 모래가 퇴적되는 것으로 나타났으며, 가을철과 겨울철에는 모래의 퇴적이 활발하게 발생하는 것으로 분석되었다. 해안사구의 전면부에서는 모든 계절에 해풍에 의해 모래가 퇴적되었으며, 특히 겨울철에 퇴적작용이 가장 활발하였다.

• 한국지형학회지
• /
• 제18권3호
• /
• pp.21-36
• /
• 2011

암석의 풍화작용은 지형발달에 있어 물질의 준비과정으로서 역할을 한다. 이 중 동결-융해작용은 한대지역이나 주빙하 지역뿐만 아니라 심지어 온대지역에서도 암석을 파괴시키는데 효과적인 프로세스로 여겨져 왔다. 화강암(생암, 반풍화층), 편마암, 석회암, 돌로마이트의 슬랩시편 각각 10개를 -25℃~+30℃의 조건으로 동결-융해를 180회 반복하고 이들의 풍화양상과 물리적 특성변화를 검토한 결과, 파쇄는 대기와 토양조건보다는 침수조건에서 좀 더 활발히 진전되었으며 공극률이 높은 석회암과 돌로마이트가 가장 심하게 파쇄되었다. 편마암은 표면에 crack, joint, fissure들이 발달해 있고 암석강도(SHV)가 가장 낮았음에도, 어떠한 물리적 변화나 풍화산물들이 생성되지 않아 풍화에 저항력이 매우 높은 암석으로 나타나고 있다.