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Pohang, South Korea

Kang S.,Gyeonggi Research Institute | Kim J.-O.,Kyung Hee University
Landscape and Ecological Engineering | Year: 2015

The purpose of this study is to understand changes in green infrastructure (GI) in the Seoul metropolitan area, South Korea, focusing on the critical GI components of hubs and links. We applied a morphological analysis tool, morphological spatial pattern analysis (MSPA), to explore GI in the Seoul metropolitan area. For input data to run MSPA, we used 30-m pixel-sized land cover data of 2000 and 2009 provided by the Ministry of Environment of Korea. Land cover data are used as foundational information for GI network mapping. Using MSPA, we examined morphological changes in hubs and links from 2000 to 2009 in the metropolitan area as well as in 32 municipalities in Gyeonggi-do, a major part of the metropolitan area. Our analysis showed that the area of hubs in the Seoul metropolis has decreased, while the number of links has dramatically increased, over this 10-year period. This implies that hubs have largely been fragmented into smaller ones with a rapid increase in links in a way that does not conserve and enhance GI. We also compared analysis of network area changes in the Seoul metropolitan area with the environmental conservation value assessment map (ECVAM) currently in use by the government to assess conservation value, and found that the network areas of 2009 mapped by MSPA corresponded to a 87.8 % level to the Grade I areas of the ECVAM, with variation by municipality. From these analyses, we conclude that MSPA is helpful in establishing conservation planning strategies optimized for local and regional contexts. The MSPA also provides a useful tool to complement the ECVAM for improving GI functions. © 2015, International Consortium of Landscape and Ecological Engineering and Springer Japan.

Kang S.,Gyeonggi Research Institute | Choi W.,University of Wisconsin - Milwaukee
Regional Environmental Change | Year: 2014

North Korea used to have abundant forest stocks but underwent substantial deforestation and degradation of forest in recent decades. This study examined morphological changes of forest cover in North Korea between the 1980s and 2000s. Land cover data based on Landsat TM imagery were obtained as images from the Republic of Korea's Ministry of Environment. The images were processed and used for the morphological spatial pattern analysis (MSPA) and network analysis. MSPA classified the forest cover into morphological classes such as core, islet, bridge, perforation, edge, loop, and branch. The network analysis identified individual networks of forest, each of which represents a patch of connected forest. The results are summarized as follows: (1) forest cover sharply decreased between the 1990s and 2000s, particularly in western provinces; (2) morphological classes indicating forest fragmentation such as islet, branch, and edge consistently increased in their fraction to the total area between the 1980s and 2000s; (3) islet, branch, and edge also increased in number during the same period; (4) forest networks shrank in size and increased in number. Overall, the results demonstrate that deforestation and fragmentation of forest occurred simultaneously in North Korea during the time. © 2013 Springer-Verlag Berlin Heidelberg.

Baek K.O.,Gyeonggi Research Institute | Seo I.W.,Seoul National University
Advances in Water Resources | Year: 2010

Routing procedures have been used for determining the observed values of the dispersion coefficient in river mixing studies. In order to overcome the shortcomings of the existing routing procedures, we developed a new routing procedure capable of being applied under a transient concentration situation while accounting for river irregularities. The proposed routing procedure is based on the exact solution of the depth-averaged, two-dimensional, mass transport equation combined with the stream-tube concept and was verified through the tracer data acquired from field tests conducted in natural rivers located in Korea. The observed dispersion coefficients evaluated by the routing procedure exhibited a stream-wise variation along the rivers, in that a minimum value was seen in the straight region and a maximum value downstream of the apex of the bend. This variation was attributed to the flow dynamics of secondary currents induced by the meandering of the rivers. The dispersion coefficients obtained by the new method over the reach were in the same range of those calculated by other methods. © 2010 Elsevier Ltd.

Hwang S.-A.,Gyeonggi Research Institute | Hwang S.-J.,Konkuk University | Park S.-R.,Konkuk University | Lee S.-W.,Konkuk University
Water (Switzerland) | Year: 2016

Although close relationships between the water quality of streams and the types of land use within their watersheds have been well-documented in previous studies, many aspects of these relationships remain unclear. We examined the relationships between urban land use and water quality using data collected from 527 sample points in five major rivers in Korea-the Han, Geum, Nakdong, Younsan, and Seomjin Rivers. Water quality data were derived from samples collected and analyzed under the guidelines of the Korean National Aquatic Ecological Monitoring Program, and land use was quantified using products provided by the Korean Ministry of the Environment, which were used to create a Geographic Information System. Linear models (LMs) and generalized additive models were developed to describe the relationships between urban land use and stream water quality, including biological oxygen demand (BOD), total nitrogen (TN), and total phosphorous (TP). A comparison between LMs and non-linear models (in terms of R2 and Akaike's information criterion values) indicated that the general additive models had a better fit and suggested a non-linear relationship between urban land use and water quality. Non-linear models for BOD, TN, and TP showed that each parameter had a similar relationship with urban land use, which had two breakpoints. The non-linear models suggested that the relationships between urban land use and water quality could be categorized into three regions, based on the proportion of urban land use. In moderate urban land use conditions, negative impacts of urban land use on water quality were observed, which confirmed the findings of previous studies. However, the relationships were different in very low urbanization or very high urbanization conditions. Our results could be used to develop strategies for more efficient stream restoration and management, which would enhance water quality based on the degree of urbanization in watersheds. In particular, land use management for enhancing stream water quality might be more effective when urban land use is in the range of 1.1%-31.5% of a watershed. If urban land use exceeds 31.5% in a watershed, a more comprehensive approach would be required because water quality would not respond as rapidly as expected. © 2016 by the authors.

Kang S.,Gyeonggi Research Institute | Choi W.,University of Wisconsin - Milwaukee | Schierenbeck T.M.,University of Wisconsin - Milwaukee
Disaster Advances | Year: 2012

We investigated the spatial pattern of storm damage in residential and rice paddy areas in Gyeonggi-do (province), Korea in the aftermath of two heavy rainfall events in July and August of 2009. We counted the number of damage locations in each catchment or administrative unit of the province and calculated global and local Moran's I values. We also calculated the distance from nearest streams to the damage locations. As a result, we identified clusters of several catchments or administrative units that have high z-scores of local Moran's I for damage count. Such areas did not always have the highest level of damage, but they should be considered altogether for storm damage management. We also found that the damage in rice paddy areas was more strongly related to the distance from streams than the damage in residential areas.

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