• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.185-185
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• 2015

미계측 지역에서의 토양수분을 예측하기 위한 공간보간 기법으로 크리깅 방법과 조건부합성기법을 한반도에 적용하여 비교 분석하였다. 연구에 사용된 토양수분 자료는 2011년 5월 1일부터 2011년 9월 30일까지이며, Advanced Microwave Scanning Radiometer-Earth observing system(AMSR-E)의 위성관측 자료와 농촌진흥청에서 제공하는 지상관측 자료를 이용하였다. leave-one-out 교차검증 방법을 사용하여 공간보간 성능을 평가했고, 관측지점별 시계열 분석 결과 총 24개 관측지점 중 14개 관측지점에서 CM의 결과가 우세한 것으로 나타났다. 특정 관측일에 대해 예측 성능 분석 결과 총 113일 중 68일에 대해 CM의 결과가 우세한 것으로 나타났다. 각 관측지점의 예측 성능을 공간적으로 분석하기 위하여 관측소별 예측 성능 지도를 작성하여 공간적인 특성을 분석한 결과 관측소가 밀집되어있는 한반도의 서쪽지역에서 예측이 성능이 좋게 나왔다. 이러한 결과는 위성으로부터 관측된 토양수분 자료의 공간적인 특성을 고려하여 지상관측 자료와 합성하는 것이 토양수분의 공간적인 보간성능을 향상 시킬 수 있다는 것을 의미한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.473-473
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• 2015

토양수분은 수문학적 과정의 시공간적 변동과 수자원 관리 및 계획 그리고 기후변화에 따른 자연재해의 원인규명에 중요한 부분이다. 본 연구에서는 사면의 단면선에 따른 토양수분의 분포 및 변동을 파악하기 위해, 청미천 유역내의 사면에서 10개월 동안의 토양수분들을 측정하여, 토양깊이별, 계절별로 분석하였다. 토양수분특성은 간단한 통계적 방법을 이용하여, 평균, 표준편차 그리고 토양수분의 감쇄기울기 값으로 표현하였다. 추가적 연구로, 측정지점의 위치, 지형, 토성의 토양수분에 대한 반응분석을 하였다. 깊은 토양층에서의 토양수분의 공간적 분포는 지표층에서의 공간적 분포 경향과는 상이하게 나타났으며, 사면의 지형 및 위치 그리고 토성의 공간적 분포는 토양수분의 시 공간적 분포특징에 큰 영향을 주는 것으로 나타났다. 특히 상부흐름의 기여를 받는 측정지점에서는 토양수분 변동의 안정화가 진행이 되는 것으로 보이며, 수문학적 경계(Hydrologic Threshold)에 대한 추가연구가 진행되어야 할 것으로 판단된다. 상부사면에서의 높은 토양수분 변동성 및 뷸 균질적인 공간적 분포는 우선적 흐름발달의 영향과 관련이 있다고 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.170-170
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• 2021

본 연구에서는 토지이용변화 예측 모형으로 산출된 토지이용도를 사용하여 용담댐 소유역의 지표유출량을 비교 및 분석하였다. 토지이용예측모형은 DynaCLUE 모형을 사용하였으며, 토지이용 면적 시나리오는 2000년, 2007년 및 2013년 실제 중분류 토지이용도를 기반으로 회귀식을 산정하였다. 모의된 토지이용도는 실제 토지이용도와 공간적인 분포 및 면적 비교를 통해 변환 탄성계수와 변환 행렬을 수정하여 검·보정하였다. DynaCLUE 모형으로 모의된 토지이용도는 공간적인 분포에서 초지가 실제 토지이용도와 차이가 발생하였으나, 각 토지이용별 면적을 비교한 경우 모의 토지이용도와 실제 토지이용도가 매우 유사하게 나타났다. CLUE 모형으로 모의된 토지이용도에서 발생하는 공간적인 불확실성은 복잡한 용담댐 소유역의 토지이용을 반영할 Driving factor가 부족하여 발생하는 것으로 판단된다. 산출된 모의 토지이용도를 SWAT 모형의 입력 자료로 사용하여 2013년 용담댐의 소유역 지표유출량을 모의하였다. SWAT으로 산정된 유출량의 보정은 SWAT-CUP의 SUFI-2 알고리즘을 이용했으며, 보정된 모의 지표유출량과 실제 유량 측정값을 비교한 결과 유의미한 비교 결과가 나타났다. 향후 토지이용예측모형을 이용하여 토지이용 변화를 수문 분석에 반영하는 추가 연구가 필요할 것으로 판단된다.

• Journal of the Korean Geographical Society
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• v.43 no.3
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• pp.276-295
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• 2008

Recent disputes on mountain ranges in Korea have partially been derived from the discordance of the spatial distribution and the extent of mountain ranges presented by different researchers and school textbooks. The lack of consensus on the definition and genesis of mountain ranges adds further confusion. In order to overcome these problems, it is necessary to provide genetically classified mountain range maps for different usages, map scales and educational purposes. This paper first argues that mountain ranges and mountain ridges should separately be used as different conceptual frameworks to explain complex spatial distribution of mountains in Korea. The new mountain range map (sanmaekdo) proposed in this research puts strong emphasis on tectonic movement and denudational processes to explain the spatial distribution of mountains. The new mountain range map has 15 mountain ranges (sanmaek: in total, which are further divided into 7 primary and 8 secondary mountain ranges. The new mountain range map eliminates Jeogyuryeongsanmaek, Myohyangsanmaek, Myeoraksanmaek, and Masingnyeongsanmaek from the existing map, since these have a vague definition and obscure spatial distribution. On the contrary, few new primary mountain ranges (Gilju-Myeongcheonsanmaek, Yangsansanmaek, Jirisanmaek) and secondary mountain ranges (Wolchulsanmaek and Buksubaeksanmaek) are added to the new mountain range map. Other mountain ranges also show a large difference both in their spatial distribution and the extent of mountain ranges, compared with the previous map. This is especially the case for Nangnimsanmaek, Hamgyeongsanmaek, Taebaeksanmaek, and Sobaeksanmaek. A few new names are also assigned to Macheollyeongsanmaek (Baekdusanmaek), Gwangjusanmaek (Hwaaksanmaek), Charyeongsanmaek (Chiaksanmaek), and Horyeongsanmaek (Naejangsanmaek), even though they show similar spatial distribution patterns with the ones in the existing map.

• Journal of Korea Water Resources Association
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• v.49 no.9
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• pp.761-771
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• 2016

The GloSea5 (Global Seasonal forecasting system version 5) is provided and operated by the KMA (Korea Meteorological Administration). GloSea5 provides Forecast (FCST) and Hindcast (HCST) data and its horizontal resolution is about 60km ($0.83^{\circ}{\times}0.56^{\circ}$) in the mid-latitudes. In order to use this data in watershed-scale water management, GloSea5 needs spatial-temporal downscaling. As such, statistical downscaling was used to correct for systematic biases of variables and to improve data reliability. HCST data is provided in ensemble format, and the highest statistical correlation ($R^2=0.60$, RMSE = 88.92, NSE = 0.57) of ensemble precipitation was reported for the Yongdam Dam watershed on the #6 grid. Additionally, the original GloSea5 (600.1 mm) showed the greatest difference (-26.5%) compared to observations (816.1 mm) during the summer flood season. However, downscaled GloSea5 was shown to have only a -3.1% error rate. Most of the underestimated results corresponded to precipitation levels during the flood season and the downscaled GloSea5 showed important results of restoration in precipitation levels. Per the analysis results of spatial autocorrelation using seasonal Moran's I, the spatial distribution was shown to be statistically significant. These results can improve the uncertainty of original GloSea5 and substantiate its spatial-temporal accuracy and validity. The spatial-temporal reproducibility assessment will play a very important role as basic data for watershed-scale water management.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.3
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• pp.223-235
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• 2011

Although ordinary least squares (OLS) regression analysis can be used to examine the spatial relationships between environmental equity and urban quality of life, this global method may mask the local variations in the relationships between them. These geographical variations can not be captured without using local methods. In this context, this paper explores the spatially varying relationships between environmental equity and urban quality of life across the Atlanta metropolitan area by geographically weighted regression (GWR), a local method. Environmental equity and urban quality of life were quantified with an integrated approach of GIS and remote sensing. Results show that generally, there is a negatively significant relationship between them over the Atlanta metropolitan area. The results also suggest that the relationships between environmental equity and urban quality of life vary significantly over space and the GWR (local) model is a significant improvement on the OLS (global) model for the Atlanta metropolitan area.

• Journal of the Economic Geographical Society of Korea
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• v.14 no.3
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• pp.377-393
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• 2011

This study aims to indicate the spatial characteristics of the changes in the Korean farm land. In particular, we analyze the spatial diffusion patterns of organic farms increasing rapidly with the growth in the agricultural product markets as well as the demand for safe food and sustainable growth. For the purpose, we examine the changes in the distribution patterns of organic farms between year 2000 and 2005. We analyze the agglomeration pattern by Location Quotient (LQ) and Local indicator of spatial association (LISA). Organic farms have been spread out from the outscuirts of Seoul, the capital city, to the traditional agriculture spetilized area in the southern parts of the nation. In order to analyze the relationships between organic farm distribution and the geographical variables affecting the organic farming, we develop multivariate regression models. Our findings indicate that organic farming is related with the number of agriculture-based business and information technique adaptation as well as the level of education and farmers age.

• Journal of the Economic Geographical Society of Korea
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• v.14 no.1
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• pp.33-51
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• 2011

This study investigates the spatial characteristics of the provision of and demand for the private tutoring service industries and the consumer groups. For the purpose, we analyze the spatial characteristics of various types of tutoring institutes in the Seoul Metropolitan area. In particular, we exam the spatial distribution patterns of attendants of tutoring institutes by institution type as well as the resident population by attendant age group. By applying spatial autocorrelation analysis, we examine the spatial clustering patterns of tutoring institutes and attendants by type. The results show distinct differences in the spatial distribution patterns by tutoring institute type as well as by attendant age group. We found significant socio-economic variables which influence on the spatial distribution of tutoring institutes. Finally, we propose private tutoring service provision models constructed with these variables through multiple regression analysis.

• Journal of the Korean association of regional geographers
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• v.16 no.5
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• pp.610-622
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• 2010

The proportion of overweight and obese individuals in the United States has been continuously increasing up to recently. Many studies related to obesity have concentrated on jurisdictional levels of aggregation, making it very difficult to dearly illustrate at risk regions. In other words, little research has been conducted in relation to spatial patterns considering spatial dependency and heterogeneity by spatial autocorrelation models over space. In response, this research analyzes spatial patterns between overweight/obesity and risk factors, such as high blood pressure and diabetes, over space. Specifically, the Moran''s I and Geary''s C will be conducted for global and local measures. What is more, the Ordinary Least Square (OLS) linear regression and Geographically Weighted Regression methods will be applied to identify spatial dependency and spatial heterogeneity. Data provided by the Behavioral Risk Factor Surveillance System (BRFSS) have Body-Mass Index (BMI) rates, containing 4 rates of under, healthy, overweight, and obesity. In addition, high blood pressure and diabetes rates in the United States will be used as independent variables. Lastly, we are confident that this research will be beneficial for a decision maker to make a prevention plan for obesity.

• Journal of the Korean Geographical Society
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• v.46 no.6
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• pp.724-737
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• 2011

The goal of solving a contiguous land acquisition problem is to find an optimal cluster of land parcels so that one can move from an acquired parcel to another without leaving the cluster. In many urban and regional planning applications, criteria such as acquisition cost and compactness of acquired parcels are important. Recent research has demonstrated that spatial contiguity can be formulated in a mixed integer programming framework. Spatial compactness, however, is typically formulated in an approximate manner using parameters such as external border length or other shape indices of acquired land parcels. This paper first develops an alternative measure of spatial compactness utilizing the characteristics of the internal structure of a contiguous set of land parcels and then incorporates this new measure into a mixed integer program of contiguous land acquisition problems. A set of computational experiments are designed to demonstrate the use of our model in a land acquisition context.