• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
• /
• pp.1289-1291
• /
• 2003

Climatic characteristic and changes of snow cover over the Northern Hemisphere, Eurasian, North America and the Tibet Plateau are studied based on data of the Northern Hemisphere snow cover area observed by Satellite remote sensing from 1966 to 2003. Meanwhile, the seasons' distribution charts of the Asian snow cover are made, they provide the climatic background of snow cover. In addition, the influences of snow cover on the climate, especially on the monsoon are analysed briefly, and some significance results are concluded.

• 한국관개배수논문집
• /
• 제14권2호
• /
• pp.225-235
• /
• 2007

The shape of streamflow hydrograph during the early period of spring is very much controlled by the area and depth of snow cover especially in mountainous area. When we simulate the streamfolw of a watershed snowmelt, we need some information for snow cover extent and depth distribution as parameters and input data in the hydrological models. The purpose of this study is to suggest an extraction method of snow cover area and snow depth distribution using Terra MODIS image. Snow cover extent for South Korea was extracted for the period of December 2000 and April 2006. For the snow cover area, the snow depth was interpolated using the snow depth data from 69 meteorological observation stations. With these data, it is necessary to run a hydrological model considering the snow-related data and compare the simulated streamflow with the observed data and check the applicability for the snowmelt simulation.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 2005년도 학술발표논문집
• /
• pp.254-259
• /
• 2005

The shape of a streamflow hydrograph is very much controlled by the area and depth of snow cover in mountain area. The purpose of this study is to suggest extraction methods for snow cover area and depth using NOAA/AVHRR images in Soyanggang watershed. Snow cover area maps ware derived form channel 1, 3, 4 images of NOAA/AVHRR based on threshold value. In order to extract snow cover depth, snow cover area maps were overlaid daily snow depth data form 7 meteorological observation stations. Snow cover area and depth was mapped for period of Dec. 2002 and Mar. 2003. For evaluating snowmelt changes, depletion curve was created using daily snow cover area in the same period. It is necessary to compare these results with observed data and check the applicability of the suggested method in snowmelt simulation.

• 대한원격탐사학회지
• /
• 제34권6_1호
• /
• pp.1025-1032
• /
• 2018

적설은 강수의 한 형태로 지표면에 쌓인 눈으로 정의되며 빙권의 가장 큰 단일 구성 요소로서 지구 표면과 대기 사이의 열 교환이나 전 지구 또는 지역적인 측면에서 지구의 에너지 수지 균형을 유지하는 중요한 역할을 하는 등 지구 표면 온도를 조절하는데 영향을 미친다. 그러나 적설은 인간의 접근이 어려운 지역에 주로 분포하기 때문에 위성을 활용한 적설 탐지가 활발히 수행되고 있으며 산림 지역의 적설 탐지는 구름과 적설의 구분 다음으로 중요한 과정이다. 따라서 본 연구는 기존 극 궤도 위성에서 산림 지역 적설 탐지에 활용하는 Normalized Difference Snow Index(NDSI) 및 Normalized Difference Vegetation Index(NDVI)를 정지궤도 위성에 적용하였으며, 산림 지역 외 영역은 적설의 분광 특징을 활용한 $R_{1.61{\mu}m}$ anomaly 기법 및 NDSI를 활용하여 적설 탐지를 수행하였다. 본 연구에서 산출한 Snow Cover 자료와 Visible Infrared Imaging Radiometer(VIIRS) Snow Cover 자료를 활용해 간접 검증을 수행한 결과, Probability of Detection(POD)는 99.95%, False Alarm Ratio(FAR)는 16.63 %로 나타났다. Himawari-8 Advanced Himawari Imager(AHI) RGB 영상을 추가로 활용해 정성적 검증 또한 수행하였으며 수행 결과, VIIRS Snow Cover가 미탐지한 영역과 본 연구가 오탐지한 영역이 혼합되어 나타났다.

• 대한원격탐사학회지
• /
• 제23권2호
• /
• pp.119-124
• /
• 2007

융설 모형의 중요 매개변수인 적설분포면적은 실제 우리나라에서 적설과 관련한 관측 자료의 부족으로 인해 매개변수 추정이 어렵다. 이러한 문제점 해결을 위해 원격탐사기법을 활용하여 적설분포면적을 추출하였다. 본 연구에서는 1997년부터 2006년까지의 겨울철 NOAA (National Oceanic and Atmospheric Administration)의 AVHRR(Advanced Very High Resolution Radiometer) 위성영상의 8 sets의 총 108개 영상을 이용하여 적설분포면적을 추출하였고, 기상청의 지상기상관측소의 최심적설심 자료를 이용하여 GIS 자료를 구축함으로써 적설심의 공간적 분포를 추출하였다. 이를 국내 5대유역인 한강, 낙동강, 금강, 영산강, 섬진강 유역에 대하여 융설모형의 주요 매개변수인 적설분포면적, 유역 평균, 최대 적설심과 적설분포감소비곡선을 구축하였다. 그 중 적설분포면적감소곡선 (SDC : Snow cover Depletion Curve)는 적설분포면적의 감소형태를 나타내주는 지표로써 융설의 가장 민감한 매개변수이다. 이를 국내 5대강 유역에 대해 구축하여 정량화하였다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
• /
• pp.1292-1294
• /
• 2003

This paper presents the results of research and analysis with the satellite-derived snow data. It provides the main climatic characteristics of snow cover in China and shows the variation and distribution of snow in regions of Xinjiang, Inter Mongolia and Tibet plateau. The study reveals the vicissitude periods of winter snow cover in Tibetan Plateau by using wavelet analysis with the data from 1980 to 2001. It has about 10 years large period and 3-5 years small period. The analysis shows that the extension of snow increased in recent years in Xinjiang. The results of analysis proves the relationship between winter snow cover in Tibetan Plateau and next summer precipitation in the middle and lower reaches of the Yangtze River. They have good correlation.

• 대한원격탐사학회지
• /
• 제30권3호
• /
• pp.341-350
• /
• 2014

Landsat images can monitor the snow-covered Earth surface variations with the ground resolution of 30m and the multi-spectral bands in the visible, NIR, SWIR and TIR spectral regions for the last 30 years. The Southern Volcanic Zone (SVZ) of Chile consists of many volcanoes, and all of the volcanoes are covered with snow at the top of mountain. Snow cover area in southern province of the SVZ of Chile (37 to $46^{\circ}S$) have been influenced by significant frontal retreats as well as eruptive activities. In this study, we have investigated the changes of the snow-cover area and snow-line elevation at Mt. Villarrica and Mt. Llaima, Chile from three Landsat images acquired on Feb. 1990, 2005 and 2011. The snow-cover areas are 13.42, 26.75 and $21.60km^2$ at Mt. Villarrica in 1990, 2005 and 2011, respectively, and 3.82, 25.12 and $8.89km^2$ at Mt. Llaima in 1990, 2005 and 2011, respectively. The snow-line elevations are 1871, 1738 and 1826m at Mt. Villarrica in 1990, 2005 and 2011, respectively, and 2007, 1822 and 1818m at Mt. Llaima in 1990, 2005 and 2011, respectively. The results indicate that both of the snow-cover and snow-line changes are strongly related with the volcanic activity change. The results demonstrate that the snow-cover area and snow-line elevation changes can be used as an indicator of the volcanic activity at Mt. Villarrica and Mt. Llaima, Chile.

• 대한원격탐사학회지
• /
• 제25권2호
• /
• pp.193-203
• /
• 2009

적설은 지표 에너지수지를 결정하는 중요한 변수중의 하나이다. 위성자료를 이용하여 지면 정보를 산출함에 있어서 적설과 구름을 구분하는 것은 매우 중요한 위성전처리 과정이다. 일반적으로 잘못된 적설과 구름의 분류는 위성자료를 이용한 지면 정보 산출에 있어서 직접적인 오차 요인이 된다. 따라서, 본 연구에서는 원격탐사 자료를 이용하여 적설 지역을 탐지하는 알고리즘에 대해서 연구하고자 한다. 적설역을 탐하지 하기 위해서, 가장 많이 사용되는 정규화 적설 지수(NDSI: Normalized Difference Snow Index)를 사용하지 않고 가시채널과 적외 채널을 이용한 방법을 제시하였다. COMS 기상영상기 (MI: Meteorological Imager) 채널에서는 정규적설 지수 산출 시 요구되는 근적외 채널을 탑재하지 않기 때문이다. 가시 채널을 이용한 적설 탐지는 구름이 혼재되어 있지 않은 지역에서는 잘 탐지하였으나 구름과 혼재되어 있는 지역에서는 어려움이 있다. 이러한 어려움을 보완하기 위해 적외채널 온도차 ($11{\mu}m\;-\;3.7{\mu}m$)를 이용하는 방법을 수행하였다. 온도차를 이용하는 방법은 가시채널만을 적용했을 때 보다는 향상된 탐지 능력을 보인다.

• 대한원격탐사학회지
• /
• 제29권3호
• /
• pp.315-324
• /
• 2013

Spatial information of snow cover and depth distribution is a key component for snowmelt runoff modeling. Wide snow cover areas can be extracted from NOAA AVHRR or Terra MODIS satellite images. In this study eight sets of annual snow cover data (1997-2006) in two mountainous watersheds (A: Chungju-Dam and B: Soyanggang-Dam) were extracted using NOAA AVHRR images. The distribution of snow depth within the Snow Cover Area (SCA) was generated using snowfall data from ground meteorological observation stations. Snow depletion characteristics for the two watersheds were analyzed snow distribution time series data. The decreased pattern of SCA can be expressed as a logarithmic function; the determination coefficients were 0.62 and 0.68 for the A and B watersheds, respectively. The SCA decreased over 70% within 10 days from the time of maximum SCA.

• 대기
• /
• 제27권1호
• /
• pp.55-65
• /
• 2017

This study investigates how Eurasian snow cover in spring (March and April) is associated with Korean temperature during summer (June-July-August). Two leading modes of Eurasian snow cover variability in spring for 1979~2015 are obtained by Empirical Orthogonal Function (EOF) analysis. The first EOF mode of Eurasian snow cover is characterized by a zonally elongated pattern over the whole Eurasian region and its principal component is more correlated with Korean temperature during June. On the other hand, the second EOF mode of Eurasian snow cover is characterized by an east-west dipole-like pattern, showing positive anomalies over eastern Eurasian region and negative anomalies over western Eurasian region. This dipole-like pattern is related with Korean temperature during August. The first leading mode of Eurasian snow cover is associated with anomalous high (low) pressure over Korea (Sea of Okhotsk) during June, which might be induced by much evaporation of soil moisture in Eurasia during March. On the other hand, the second mode of Eurasian snow cover is associated with a wave train resembling with Eurasian (EU)-like pattern in relation to the Atlantic sea surface temperature forcing, leading to the anomalous high pressure over Korea during August. Understanding these two leading modes of snow cover in Eurasian continent in spring may contribute to predict Korean summer temperature.