Monitoring River Basin Development and Variation in Water Resources in Transboundary Imjin River in North and South Korea Using Remote Sensing

This paper presents methods of monitoring river basin development and water variability for the transboundary river in North and South Korea. River basin development, such as dams and water infrastructure in transboundary rivers, can be a potential factor of tensions between upstream and downstream countries since dams constructed upstream can adversely affect downstream riparians. However, because most of the information related to North Korea has been limited to the public, the information about dams constructed and their locations were inaccurate in many previous studies. In addition, water resources in transboundary rivers can be exploited as a political tool. Specifically, due to the unexpected water release from the Hwanggang Dam, upstream of the transboundary Imjin River in North and South Korea, six South Koreans died on 6 September 2009. The Imjin River can be used as a political tool by North Korea, and seven events were reported as water conflicts in the Imjin River from 2001 to 2016. In this paper, firstly, we have updated the information about the dams constructed over the Imjin River in North Korea using multi-temporal images with a high spatial resolution (15-30 cm) obtained from Google Earth. Secondly, we analyzed inter- and intra-water variability over the Hwanggang Reservoir using open-source images obtained from the Global Surface Water Explorer. We found a considerable change in water surface variability before and after 2008, which might result from the construction of the Hwanggang Dam. Thirdly, in order to further investigate intra-annual water variability, we present a method monitoring water storage changes of the Hwanggang Reservoir using the area-elevation curve (AEC), which was derived from multi-sensor Synthetic Aperture Radar (SAR) images (Sentinel-1A and -1B) and the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM). Since many previous studies for estimating water storage change have depended on satellite altimetry dataset and optical images for deriving AEC, the method adopted in this study is the only application for such inaccessible areas since no altimetry ground track exists for the Hwanggang Reservoir and because clouds can block the study area for wet seasons. Moreover, this study has newly proven that unexpected water release can occur in dry seasons because the water storage in the Hwanggang Reservoir can be high enough to conduct a release that can be used as a geopolitical tool. Using our method, potential risks can be mitigated, not in response to a water release, but based on pre-event water storage changes in the Hwanggang Reservoir

On the Changing Contribution of Snow to the Hydrology of the Fraser River Basin, Canada

This paper presents an application of the Variable Infiltration Capacity (VIC) model to the Fraser River basin (FRB) of British Columbia (BC), Canada, over the latter half of the twentieth century. The Fraser River is the longest waterway in BC and supports the world’s most abundant Pacific Ocean salmon populations. Previous modeling and observational studies have demonstrated that the FRB is a snow-dominated system, but with climate change, it may evolve to a pluvial regime. Thus, the goal of this study is to evaluate the changing contribution of snow to the hydrology of the FRB over the latter half of the twentieth century. To this end, a 0.25° atmospheric forcing dataset is used to drive the VIC model from 1949 to 2006 (water years) at a daily time step over a domain covering the entire FRB. A model evaluation is first conducted over 11 major subwatersheds of the FRB to quantitatively assess the spatial variations of snow water equivalent (SWE) and runoff (R). The ratio of the spatially averaged maximum SWE to R (RSR) is used to quantify the contribution of snow to the runoff in the 11 subwatersheds of interest. From 1949 to 2006, RSR exhibits a significant decline in 9 of the 11 subwatersheds (with p < 0.05 according to the Mann–Kendall test statistics). To determine the sensitivity of RSR, the air temperature and precipitation in the forcing dataset are then perturbed. The ratio RSR decreases more significantly, especially during the 1990s and 2000s, when air temperatures have warmed considerably compared to the 1950s. On the other hand, increasing precipitation by a multiplicative factor of 1.1 causes RSR to decrease. As the climate continues to warm, ecological processes and human usage of natural resources in the FRB may be substantially affected by its transition from a snow to a hybrid (nival/pluvial) and even a rain-dominated system

NASA's SnowEx Campaign and Measuring Global Snow from Space

Snow blankets 30% of Earth's land surface (60% of northern hemisphere land) in midwinter, dramatically changing our planet's land surface and affecting our weather for months. Seasonal snow is critically important to society for the management of water resources, natural hazards, water security, and in many economic sectors. The only practical way to estimate the quantity of snow on a global scale is through satellites. Despite 4 decades of satellite observations, the highly variable nature of snow still presents significant challenges toward achieving this goal. For example, current space-based techniques underestimate snow water equivalent (SWE) by as much as 50%, and model-based estimates can differ greatly versus estimates based on remotely-sensed observations. Snow community consensus is that a multi-sensor approach is needed to adequately address global snow, combined with modeling and data assimilation to fill the gaps in space and time. What remains, then, is how best to combine and use the various sensors under different types of snow conditions and confounding factors. NASA's multi-year SnowEx airborne campaign is designed to collect measurements needed to enable algorithm development and to guide those mission trade studies. Year 1 (2017) focused on the distribution of snow-water equivalent (SWE) and the snow energy balance in a forested environment. This paper will discuss the various remote sensing options for snow, the challenging factors, and describe the recently-completed first year of SnowEx in Colorado, USA. Ground-based remote sensing and in situ data collection involved nearly 100 participants over three weeks. The airborne campaign included nine sensors on five aircraft. We will conclude by discussing options for a future snow satellite mission

Overview of SnowEx Year 1 Activities

SnowEx is a multi-year airborne snow campaign with the primary goal of addressing the question: How much water is stored in Earths terrestrial snow-covered regions? Year 1 (2016-17) focused on the distribution of snow-water equivalent (SWE) and the snow energy balance in a forested environment. The year 1 primary site was Grand Mesa and the secondary site was the Senator Beck Basin, both in western, Colorado, USA. Nine sensors on five aircraft made observations using a broad range of sensing techniques, active and passive microwave, and active and passive optical infrared to determine the sensitivity and accuracy of these potential satellite remote sensing techniques, along with models, to measure snow under a range of forest conditions. SnowEx also included an extensive range of ground truth measurements in-situ manual samples, snow pits, ground based remote sensing measurements, and sophisticated new techniques. A detailed description of the data collected will be given and some preliminary results will be presented

NASA's SnowEx Campaign: Observing Seasonal Snow in a Forested Environment

SnowEx is a multi-year airborne snow campaign with the primary goal of addressing the question: How much water is stored in Earth's terrestrial snow-covered regions? Year 1(2016-17) focused on the distribution of snow-water equivalent (SWE) and the snow energy balance in a forested environment. The year 1 primary site was Grand Mesa and the secondary site was the Senator Beck Basin, both in western Colorado, USA. Nine sensors on five aircraft made observations using a broad range of sensing techniques - active and passive microwave, and active and passive optical/infrared - to determine the sensitivity and accuracy of these potential satellite remote sensing techniques, along with models, to measure snow under a range of forest conditions. SnowEx also included an extensive range of ground truth measurements - in-situ manual samples, snow pits, ground based remote sensing measurements, and sophisticated new techniques. A detailed description of the data collected will be given and some preliminary results will be presented

A Case of Hepatocellular Carcinoma Within Hepatocellular Adenoma in a Non-Cirrhotic Male

Hepatocellular adenoma (HA) is a benign hepatic lesion that predominantly occurs in young women. Most hepatocellular carcinomas (HCC) arise in a cirrhotic liver during the fifth or sixth decades. There have been several reported cases of HCC developing from HA in female patients. However, there are rare cases about HCC arising in HA in a non-cirrhotic male patient. We have recently encountered a 53-year-old man who had a liver mass in a non-cirrhotic liver, and the liver mass was compatible with HA on the pre-operative computed tomography. The mass was completely resected and the histopathology revealed a focus of HCC arising in HA. We report here on this case along with a brief review of the relevant literature

Korean Version of Mini Mental Status Examination for Dementia Screening and Its' Short Form

Objective We developed a Korean version of Mini-Mental Status Examination (MMSE) optimized for screening dementia (MMSE-DS) and its short form (SMMSE-DS). Methods We constructed the MMSE-DS using the items of the two current Korean versions of MMSE and then construct the SMMSE-DS consisted of 13 items from the MMSE-DS based on the diagnostic accuracy of individual items for dementia. We investigated reliability and validity of MMSE-DS and SMMSE-DS on 1,555 subjects (1,222 nondemented controls, 333 dementia patients). We compared the diagnostic accuracy of the SMMSE-DS with that of the three full Korean versions of MMSE, and examined its age- and education-specific optimal cutoff scores for dementia. Results The internal consistency obtained by Cronbach`s coefficient alpha was 0.826. The inter-rater reliability and test-retest reliability were 0.968 (p<0.001) and 0.825 (p<0.001), respectively. It showed significant correlation with the Clinical Dementia Rating (CDR) (r=-0.698, p<0.05) and the three full Korean versions of MMSE (r=0.839-0.938, p<0.001). The area under the receiver operator curve for dementia of the SMMSE-DS was larger than those of the three full Korean versions of MMSE (p<0.001). Age, education and gender explained 19.4% of the total variance of SMMSE-DS scores. The optimal cutoff scores for dementia of the SMMSE-DS were estimated differently by age and educational attainment of the subjects. Conclusion The SMMSE-DS was found to be accurate, brief and portable instrument for screening dementia in Korean elders, and may be particularly useful for screening dementia in elderly populations with wide variation in educational levels. Psychiatry Investig 2010;7:102-108This study was supported by a research grant from the Ministry of Health and Welfare, Korea (Grant NO. 08-2009-014).Han C, 2008, ARCH GERONTOL GERIAT, V47, P302, DOI 10.1016/j.archger.2007.08.012PARK JH, 2007, PSYCHIAT INVEST, V4, P84Kim KW, 2005, DEMENT GERIATR COGN, V19, P324, DOI 10.1159/000084558JHOO JH, 2005, J KOREAN NEUROPSYCHI, V44, P98KIM HS, 2005, HYEONDAE GUGEO SAYON, V2Boustani M, 2003, ANN INTERN MED, V138, P927KANG Y, 2003, NEUROPSYCHOLOGICAL SLee JH, 2002, J GERONTOL B-PSYCHOL, V57, pP47LEE DY, 2002, J KOREAN NEUROPSYCHI, V41, P508PARK J, 1999, J KOREAN NEUROPSYCHI, V38, P173Malloy PF, 1997, J NEUROPSYCH CLIN N, V9, P189KANG Y, 1997, J KOREAN NEUROL ASS, V15, P300WOO JL, 1996, J KOREAN NEUROPSYCHI, V35, P122LINN RT, 1995, ARCH NEUROL-CHICAGO, V52, P485MASUR DM, 1994, NEUROLOGY, V44, P1427*AM PSYCH ASS, 1994, DIAGN STAT MAN MENTIMAI Y, 1994, J HONG KONG COLL PSY, V4, P20MORRIS JC, 1993, NEUROLOGY, V43, P2412CRUM RM, 1993, JAMA-J AM MED ASSOC, V269, P2386TOMBAUGH TN, 1992, J AM GERIATR SOC, V40, P922FEHER EP, 1992, ARCH NEUROL-CHICAGO, V49, P87HODGES JR, 1990, J NEUROL NEUROSUR PS, V53, P1089GALASKO D, 1990, ARCH NEUROL-CHICAGO, V47, P49OCONNOR DW, 1989, PSYCHOL MED, V19, P771PARK JH, 1989, J KOREAN NEUROPSYCHI, V28, P508OCONNOR DW, 1989, J PSYCHIAT RES, V23, P87HANLEY JA, 1983, RADIOLOGY, V148, P839HUGHES CP, 1982, BRIT J PSYCHIAT, V140, P566ANTHONY JC, 1982, PSYCHOL MED, V12, P397FOLSTEIN MF, 1975, J PSYCHIATR RES, V12, P198