Estimation of Monthly Precipitation in North Korea Using PRISM and Digital Elevation Model

• Published in: Korean Journal of Agricultural and Forest Meteorology Vol. 13; no. 1
• Main Authors: Kim, D.J., National Center for Agro-Meteorology, Seoul National University, Seoul, Republic of Korea, Yun, J.I., Kyung Hee University, Yongin, Republic of Korea
• Format: Journal Article
• Language: Korean
• Published: 01.03.2011
• Subjects: DEMOCRATIC PEOPLE'S REPUBLIC OF KOREA; Geospatial information; PRECIPITACION ATMOSFERICA; PRECIPITATION; PRISM; REPUBLICA POPULAR DEMOCRATICA DE COREA; REPUBLIQUE POPULAIRE DEMOCRATIQUE DE COREE
• ISSN: 1229-5671

While high-definition precipitation maps with a 270 m spatial resolution are available for South Korea, there is little information on geospatial availability of precipitation water for the famine - plagued North Korea. The restricted data access and sparse observations prohibit application of the widely used PRISM (Parameter-elevation Regressions on Independent Slopes Model) to North Korea for fine-resolution mapping of precipitation. A hybrid method which complements the PRISM grid with a sub-grid scale elevation function is suggested to estimate precipitation for remote areas with little data such as North Korea. The fine scale elevation - precipitation regressions for four sloping aspects were derived from 546 observation points in South Korea. A 'virtual' elevation surface at a 270 m grid spacing was generated by inverse distance weighed averaging of the station elevations of 78 KMA (Korea Meteorological Administration) synoptic stations. A 'real' elevation surface made up from both 78 synoptic and 468 automated weather stations (AWS) was also generated and subtracted from the virtual surface to get elevation difference at each point. The same procedure was done for monthly precipitation to get the precipitation difference at each point. A regression analysis was applied to derive the aspect - specific coefficient of precipitation change with a unit increase in elevation. The elevation difference between 'virtual' and 'real' surface was calculated for each 270m grid points across North Korea and the regression coefficients were applied to obtain the precipitation corrections for the PRISM grid. The correction terms are now added to the PRISM generated low resolution (~2.4 km) precipitation map to produce the 270 m high resolution map compatible with those available for South Korea. According to the final product, the spatial average precipitation for entire territory of North Korea is 1,196 mm for a climatological normal year (1971-2000) with standard deviation of 298 mm.