• 제목/요약/키워드: geographic parameter

검색결과 75건 처리시간 0.031초

Retrieval of Key Hydrological Parameters in the Yellow River Basin Using Remote Sensing Technique

  • Dong, Jiang;Jianhua, Wang;Xiaohuan, Yang;Naibin, Wang
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.721-727
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    • 2002
  • Precipitation evapotranspiration and runoff are three key parameters of regional water balance. Problems exist in the traditional methods for calculating such factors , such as explaining of the geographic rationality of spatial interpolating methods and lacking of enough observation stations in many important area for bad natural conditions. With the development of modern spatial info-techniques, new efficient shifts arose for traditional studies. Guided by theories on energy flow and materials exchange within Soil-Atmosphere-Plant Continuant (SPAC), retrieval models of key hydrological parameters were established in the Yellow River basin using CMS-5 and FengYun-2 meteorological satellite data. Precipitation and evapotranspiration were then estimated: (1) Estimating tile amount of solar energy that is absorbed by the ground with surface reflectivity, which is measured in the visible wavelength band (VIS): (2) Assessing the partitioning of the absorbed energy between sensible and latent heat with the surface temperature, which was measured in the thermal infrared band (TIR), the latent heat representing the evapotranspiration of water; (3) Clouds are identified and cloud top levels are classified using both VIS and TIR data. Hereafter precipitation will be calculated pixel by pixel with retrieval model. Daily results are first obtained, which are then processed to decade, monthly and yearly products. Precipitation model has been has been and tested with ground truth data; meanwhile, the evapotranspiration result has been verified with Large Aperture Scintillometry (LAS) presented by Wageningen University of the Netherlands. Further studies may concentrate on the application of models, i.e., establish a hydrological model of the Yellow river basin to make the accurate estimation of river volume and even monitor the whole hydrological progress.

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토양의 물리적 특성을 고려한 DAWAST 모형의 매개변수결정 (Estimation of DAWAST Model Parameters by the Soil Physical characteristics)

  • 박승기;문종필;김태철;안병기;김병규
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1998년도 학술발표회 발표논문집
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    • pp.8-13
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    • 1998
  • DAWAST model considering the meteorologic and geographic characteristics of the Korean watersheds was newly developed to simulate the daily streamflow. From the condition of soil water storage just before the storm event from DAWAST model, realtime flood can be forecasted by FLOCON model. The purpose of study is that Umax and FC of DAWAST model parameter is obtained by the soil physical characteristics.

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GIS와 PRISM을 이용한 고해상도 격자형 기온자료 추정 (Estimation of High Resolution Gridded Temperature Using GIS and PRISM)

  • 홍기옥;서명석;나득균;장동호;김찬수;김맹기
    • 대기
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    • 제17권3호
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    • pp.255-268
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    • 2007
  • This study generated and evaluated the high resolution (5 km) gridded data of monthly mean, maximum and minimum temperature from 2002 to 2005 over South Korea using a modified PRISM(Parameter-elevation Regressions on Independent Slopes Model: K-PRISM) developed by Daly et al. (2003). The performance of K-PRISM was evaluated by qualitative and quantitative ways using the observations and gridded data derived by inverse distance weighting (IDW) and hypsometric methods (HYPS). For the generation of high resolution gridded data, geographic informations over South Korea, such as the digital elevation, topographic facet and coastal proximity, are derived from the 1 km digital elevation data. The spatial patterns of temperature derived by K-PRISM were more closely linked to topography and coastal proximity than those by IDW. The K-PRISM performed much better than IDW for all months and temperatures, but it was equal to or slightly better than the HYPS. And the performances of K-PRISM were better in the minimum and mean temperature (winter) than the in maximum temperature (summer).

도시유출 및 수질관리를 위한 지리정보체계 및 전문가시스템의 적용 (Applications of Geographic Information System and Expert System for Urban Runoff and Quality Management)

  • 이범희
    • 한국수자원학회논문집
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    • 제34권3호
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    • pp.253-263
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    • 2001
  • 도시유역의 수자원 개발 및 재해예방을 위해서는 정확한 입력정보의 생성방안을 개발하였고, 급속한 도시화의 영향에 따른 수자원 및 환경문제를 보다 효율적으로 해결하기 위하여 전문가시스템의 개발 및 적용방안을 제안하였다. ARC/INFO를 사용한 지리정보체계의 적용과 인공위성 관측자료를 사용함으로써 넓은 공간에서 시간적 변화가 큰 안양천 유역의 자료들을 합리적으로 획득하였으며, CLIPS 6.0을 적용하여 전문가시스템 ESPE를 개발하였다. 재현결과가 측정자료들과 전반적으로 일치하였고, 이러한 방법들은 급속히 변화하는 도시유역의 유출 및 수질 모의에 효율적으로 활용될 수 있을 것으로 기대된다.

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GIS를 이용한 기저-유출 바탕의 수문모델 (Store-Release based Distributed Hydrologic Model with GIS)

  • 강광민;윤세의
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2012년도 학술발표회
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    • pp.35-35
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    • 2012
  • Most grid-based distributed hydrologic models are complex in terms of data requirements, parameter estimation and computational demand. To address these issues, a simple grid-based hydrologic model is developed in a geographic information system (GIS) environment using storage-release concept. The model is named GIS Storage Release Model (GIS-StoRM). The storage-release concept uses the travel time within each cell to compute howmuch water is stored or released to the watershed outlet at each time step. The travel time within each cell is computed by combining the kinematic wave equation with Manning's equation. The input to GIS-StoRM includes geospatial datasets such as radar rainfall data (NEXRAD), land use and digital elevation model (DEM). The structural framework for GIS-StoRM is developed by exploiting geographic features in GIS as hydrologic modeling objects, which store and process geospatial and temporal information for hydrologic modeling. Hydrologic modeling objects developed in this study handle time series, raster and vector data within GIS to: (i) exchange input-output between modeling objects, (ii) extract parameters from GIS data; and (iii) simulate hydrologic processes. Conceptual and structural framework of GIS StoRM including its application to Pleasant Creek watershed in Indiana will be presented.

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Cytochrome oxidase subunit I (COI) DNA sequence divergence between two cryptic species of Oryzias in South Korea

  • In, Dong-Su;Choi, Eun-Sook;Yoon, Ju-Duk;Kim, Jeong-Hui;Min, Jun-Il;Baek, Seung-Ho;Jang, Min-Ho
    • Journal of Ecology and Environment
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    • 제36권3호
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    • pp.159-166
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    • 2013
  • Oryzias latipes and Oryzias sinensis are indigenous species found in Japan, China, and other East Asian countries, including Korea. Based on morphological differences, the species have been classified distinctly. However, the range of morphological characters such as the number of gill rakers, vertebrae, and spots on the lateral body overlaps and is too vague for clear identification, so their classification based on their morphological characteristics remains uncertain. In this study, the mitochondrial cytochrome oxidase subunit I (COI) gene, which is used for DNA barcoding, was applied to clarify interspecific variation of O. latipes and O. sinensis. Intraspecific genetic diversity was calculated to identify correlations with geographic distributions. We studied two species collected from 55 locations in Korea. All individuals carried a 679-base pair gene without deletion or insertion. Between species, 525 base pairs of the gene were shared. The Kimura two parameter (K2P) distance of O. latipes and O. sinensis was 0.41% and 1.39%, respectively. Mean divergence within genera was 23.5%. Therefore, the species were clearly different. The distance between O. latipes and O. sinensis was 14.0%, which is the closest within genera. Interestingly O. latipes from the Japanese and Korean group represented 16.5% distant. These results were derived from geohistorical and anthropogenic environmental factors. The O. latipes haplotypes were joined in only one group, but O. sinensis was divided into two groups, one is found in the Han River and upper Geum River watershed; the other is found in the remaining South Korean watersheds. Further studies will address the causes for geographic speciation of O. sinensis haplotypes.

항공 LiDAR 자료기반 DEM 생성기법의 산림지역 최종산출물 품질에 미치는 영향에 관한 연구 - FUSION Software의 GroundFilter 및 GridsurfaceCreate 알고리즘을 중심으로 - (A Study on the Effects of Airborne LiDAR Data-Based DEM-Generating Techniques on the Quality of the Final Products for Forest Areas - Focusing on GroundFilter and GridsurfaceCreate in FUSION Software -)

  • 박주원;최형태;조승완
    • 한국지리정보학회지
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    • 제19권1호
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    • pp.154-166
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    • 2016
  • 본 연구는 항공 LiDAR 원자료를 활용하여 Fusion 소프트웨어의 필터링 과정을 수행하는 GroundFilter(GF) 알고리즘과 격자화 과정을 수행하는 GridsurfaceCreate(GC) 알고리즘의 패러미터 수준의 조합 변화에 따라 해발고도 정확도에 어떠한 영향을 미치는지에 대하여 비교분석하였다. GF 패러미터(1, 3, 5, 7, 9) 및 GC 패러미터(1, 3, 5, 7, 9)의 조합 변화에 따른 해발고도 정확도에 대하여 유의미한 영향이 있는지 분석하기 위해 DEM과 현장 해발고도의 잔차로 이원분산분석을 실시하고, Tukey HSD 사후분석을 실시하였다. 이원분산분석 결과, GF 패러미터 변화는 정확도에 유의미한 영향을 미쳤으나(F-value : 27.340, p<0.01), GC 패러미터의 수준 변화는 유의미한 영향이 없었다(F-value : 0.457). 아울러 GF와 GC의 상호작용효과는 정확도에 대하여 유의미한 영향이 없는 것으로 나타났다(F-value : 0.247). 유의미한 영향이 나타난 GF에 대하여 사후분석을 실시한 결과, 잔차들의 평균 차이에 따라 '7', '5', '9', '3' 집단과 '1' 의 두 집단으로 나뉘었다. 또한 보다 신뢰성 있는 해발고도 정보를 제공하는 항공 LiDAR-DEM을 생성하는데 적정 GF 및 GC 패러미터는 각각 수준 '7', '3' 인 조건일 때로 판단되었다.

2SFCA 기반 공간적 접근성의 변화 특성에 관한 연구 : 구미시 노인복지시설을 중심으로 (An Analysis of Variation of Spatial Accessibility Pattern Based on 2SFCA : A Case Study of Welfare Facilities for the Aged in Gumi City)

  • 안재성;김이배;박미라
    • 한국지리정보학회지
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    • 제17권4호
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    • pp.112-128
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    • 2014
  • 본 연구에서는 구미시를 사례로 매개 변수값의 변화에 따른 2SFCA(2 Step Floating Catchment Area) 기반 접근성 변화의 지역 특성을 분석하였다. 2SFCA는 기본인구가 증가하면 접근성이 감소하고, PPR(Provider to Population Ratio)이 증가하면 접근성이 증가하는 일반적인 경향을 보였다. 구미시 내부의 지역 특성을 분석하기 위해서 민감도 분석 과정에서 군집분석을 수행하였다. 지역 특성은 다음과 같다. 첫째, 구미시 읍면 외곽지역처럼 노인복지시설과 멀리 떨어져 있는 지역은 매개 변수값의 변화에 따른 접근성 변화가 미미하였다. 둘째, 기존 노인복지시설 주변 지역은 매개 변수값의 변화에 따라 접근성이 개선되거나 약화되는 다양한 양상을 보였다. 노인인구가 많고 노인복지시설이 밀집해 있는 동 지역에서는 PPR의 변화에 따른 접근성 변화가 크고, 나머지 지역은 기본인구 변화에 따른 접근성 변화가 크게 나타났다. 셋째, 매개 변수값이 커지면 여러 곳의 노인복지시설을 이용할 수 있는 구미시 중앙구역에서 전반적으로 접근성이 양호해지는 양상을 보였다. 향후, 2SFCA 기반의 접근성 분석 과정에서 매개 변수값 선택을 위한 신중한 시나리오 적용이 필요할 것이다.

디지털 카메라를 활용한 컬러 지상영상의 분광학적 특성 분석 (Analysis of the spectroscopic characteristics of Ground color images using a digital camera)

  • 고인철;서수영
    • 한국GIS학회:학술대회논문집
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    • 한국GIS학회 2010년도 춘계학술대회
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    • pp.137-144
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    • 2010
  • DSLR 카메라를 이용하여 획득한 지상 디지털 영상자료는 지상 사진 측량, 공간모델링에 활용할 수 있다. 지상 디지털 영상에서 각 화소의 명암도는 영상을 결정하는 가장 중요한 매개변수(parameter)이다. 따라서 좀 더 명확한 명암도의 수치 자료를 획득하고 활용하기 위하여 디지털 카메라의 분광학적 특성과 파라미터를 추정해볼 필요가 있다. 본 연구에서는 Sony DSC-F828 DSLR 카메라로 연속촬영(프레임속도 0.38초)을 통하여 얻은 7장의 같은 디지털 컬러 사진으로부터 각각 RGB 밴드의 명암도 값을 추출하여 프레임 간 화소별 명암도 차이를 확인하고, 각 컬러 밴드에 대한 각 화소의 통계학적인 분석을 통하여 분광학적인 특성의 프레임별, 화소별, 밴드별 변화와 그에 따른 상관관계에 대하여 추정해 보는 것을 목적으로 한다.

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UNDX연산자를 이용한 계층적 공정 경쟁 유전자 알고리즘을 이용한 퍼지집합 퍼지 모델의 최적화 (Optimization of Fuzzy Set Fuzzy Model by Means of Hierarchical Fair Competition-based Genetic Algorithm using UNDX operator)

  • 김길성;최정내;오성권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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    • pp.204-206
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    • 2007
  • In this study, we introduce the optimization method of fuzzy inference systems that is based on Hierarchical Fair Competition-based Parallel Genetic Algorithms (HFCGA) and information data granulation, The granulation is realized with the aid of the Hard C-means clustering and HFCGA is a kind of multi-populations of Parallel Genetic Algorithms (PGA), and it is used for structure optimization and parameter identification of fuzzy model. It concerns the fuzzy model-related parameters such as the number of input variables to be used, a collection of specific subset of input variables, the number of membership functions, the order of polynomial, and the apexes of the membership function. In the optimization process, two general optimization mechanisms are explored. The structural optimization is realized via HFCGA and HCM method whereas in case of the parametric optimization we proceed with a standard least square method as well as HFCGA method as well. A comparative analysis demonstrates that the proposed algorithm is superior to the conventional methods. Particularly, in parameter identification, we use the UNDX operator which uses multiple parents and generate offsprings around the geographic center off mass of these parents.

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