• Title/Summary/Keyword: Land covers

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Development of Interface System to Couple the SWAT Model and HyGIS (HyGIS와 SWAT의 연계 시스템 개발)

  • Kim, Kyung-Tak;Choi, Yun-Seok
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.3
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    • pp.136-145
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    • 2006
  • SWAT includes a lot of parameters related with geography, hydrological time series, land management and water pollution, etc. So, it needs many spatial, non-spatial and time series data to run SWAT. If SWAT is operated in conjunction with GIS, we can use database which includes model input data and do all the processes which covers data creation, model input and analysis of simulation results in a system. The objective of this study is to develop HyGIS-SWAT which is the interface system to couple the SWAT model and HyGIS. To achieve this object, system operation process based on HyGIS-SWAT data model is evaluated and databases are designed and established. As a result, HyGIS-SWAT prototype system is developed. HyGIS data model and HyGIS-Model operation process can be applied effectively to the development of HyGIS-SWAT. The technologies from this study can be used as base technology to develop another HyGIS application which connect HyGIS with models.

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Physical and Chemical Properties of Soil in Jang-San Wetland, Busan Metropolitan City (부산시 장산습지 토양의 물리적 및 화학적 특성)

  • Cha, Eun-Jee;Hamm, Se-Yeong;Kim, Hyun-Ji;Lee, Jeong-Hwan;Ok, Soon-Il
    • Journal of Environmental Science International
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    • v.19 no.11
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    • pp.1363-1374
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    • 2010
  • This study examined the physical and chemical properties of soil in Jang-San wetland in Busan Metropolitan City. The wetland covers wide and flat area comparing to its outside. The samples of the wetland soil were collected and analyzed in order to identify the profiles and chemical properties. According to the analyses of soil moisture and particle size distribution, the wetland soil mostly belongs to sandy loam with the soil moistures of 14.9-153.2%. The soil profiles are configured with O, A, B, and C horizons from the land surface. The organic matter content (2.38-16.7%) at most sampling locations decreases downwardly with the highest at 0-20 cm depth. The organic matter content has a good positive relationship with soil moisture content. According to X-ray diffraction analysis, the wetland soils contain quartz and feldspar (the main components of rhyolite porphyry) as well as montmorillonite, gibbsite, and kaolinite (the weathered products of feldspar). The wetland soil displays the highest iron concentration (average 22,052 mg/kg), indicating oxidation of iron. High concentrations of potassium (average 17,822 mg/kg) and sodium (average 5,394 mg/kg) originate from the weathering of feldspar. Among anions, sulfate concentration is highest with average 9.21 mg/kg that may originate from sulfate minerals and atmosphere.

Analyzing Season and Place of Mars Dust Storm (화성 먼지 폭풍의 공간적 분포와 발생시기 분석 연구)

  • Seo, Haingja;Kim, Eojin;Kim, Joo Hyeon;Lee, Joo Hee
    • Aerospace Engineering and Technology
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    • v.12 no.2
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    • pp.99-107
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    • 2013
  • Local dust storm and lifting to dust frequently occurs in Mars. But it is known to lift dust is associated with atmospheric circulation, the cause of dust lifting is not find yet. The height of dust storm is more than the Himalayas, and the large size dust storm covers half of hemisphere or hemisphere. The kind of dust storm is risk factor to land and to carry out a mission. In this paper, we carry out analysis on the season and place of dust storm, and construct a map with the place of dust storm. We expect that the season and place of dust storm are able to be predicted with being based on the results. And this paper can be utilized as preliminary for selection of landing site and time of launching and landing.

Estimation of Irrigation Requirements for Red Pepper using Soil Moisture Model with High Resolution Meteorological Data (고해상도 기상자료와 토양수분모형을 이용한 고추의 관개량 산정)

  • Shin, Yong-Hoon;Choi, Jin-Yong;Lee, Seung-Jae;Lee, Sung-Hack
    • Journal of The Korean Society of Agricultural Engineers
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    • v.59 no.5
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    • pp.31-40
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    • 2017
  • The aim of this study is to estimate net irrigation requirements for red pepper during growing period using soil moisture model. The soil moisture model based on water balance approach simulates soil moisture contents of 4 soil layers in crop root zone considering soil moisture extraction pattern. The LAMP (Land-Atmosphere Modeling Package) high resolution meteorological data provided from National Center for AgroMeteorology (NCAM) was used to simulate soil moisture as the input weather data. Study area for the LAMP data and soil moisture simulation covers $36.92^{\circ}{\sim}37.40^{\circ}$ in latitude and $127.36^{\circ}{\sim}127.94^{\circ}$ in longitude. Soil moisture was monitored using FDR (Frequency Domain Reflectometry) sensors and the data were used to validate the simulation model from May 24 to October 20 in 2016. The results showed spatially detailed soil moisture pattern under different weather conditions and soil texture. Net irrigation requirements were also different by location reflecting the spatially distributed weather condition. The average of the requirements was 470.7 mm and averages about soil texture were 466.8 mm, 482.4 mm, 456.0 mm, 481.7 mm, and 465.6 mm for clay loam, sandy loam, silty clay loam, clay, and sand respectively. This study showed spatial differences of soil moisture and the irrigation requirements of red pepper about spatially uneven weather condition and soil texture. From the results, it was demonstrated that high resolution meteorological data could provide an opportunity of spatially different crop water requirement estimation during the irrigation management.

Utilizing Spatial-data to Provide for U-Service Based on U-GIS

  • Lee, Seok-Ho;Lee, Ji-Yeong;Kim, Hyong-Bok
    • Spatial Information Research
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    • v.17 no.4
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    • pp.405-416
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    • 2009
  • According to the changes of the city's paradigm, the demand on u-City increases rapidly. u-City has been built at 54 areas in Korea (as of May 2009). One of the important determinants of success or failure in the increasing of u-City is how to provide u-Services. Most current u-Services are Sensor Network-based monitoring services to manage urban infrastructure. u-GIS is one of fundamental requirements to implement 'any time and any where' u-Service which covers the essential meaningful term "ubiquitous". Hence, in this paper, we 1) describe the definition of the spatial awareness, 2) discuss how to converge (Spatial Embedding) among different spatial data : topographic spatial data, sensor spatial data, and more, 3) bring forth an advanced form of u-Service, 4) analyze the state-of-the-art u-GIS techniques.

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The Meaning of Wangwei's Natural Beauty and His Garden, Wangchuan Villa (왕유의 자연미와 망천별업의 조경사적 의의)

  • 박희성;조정송
    • Journal of the Korean Institute of Landscape Architecture
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    • v.29 no.2
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    • pp.1-13
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    • 2001
  • Beginning in the Wei-Chin and Liu Ch´ao era(AD. 220-589), an awareness of natural beauty emerged as the major interest of scholars which created such a social atmosphere that served as the foundation of prosperous Chinese art. During the T´ang period, the desire to achieve natural beauty began to dominate every field of art including gardening. This study covers the T´ang period when scholars began to be conscious of aesthetics. The main objective of this study is to examine the significance of natural beauty as interpreted by Wangwei, an artist representative of the period, and of Wangchuan Villa in relation to aspects of garden theory. This study is mainly based on Wangwei´s anthology, landscape painting describing Wangchuan Villa, and historical records related to the Villa. The summary of conclusions of this study is as follows: 1) Wangwei´s concept of natural beauty is a combination of objective natural beauty and pastoral beauty, which stresses the essential beauty of nature. Moreover, he considered nature as a religious Utopia. 2)Wangchuan Villa, where Wangwei stayed until his death, was a place of seclusion representing his idea of natural beauty. There, he was able to realize the paradise of Buddhism full of zen aspirations. 3)From the perspective of garden theory, Wangchuan Villa can be classified as a suburb villa in terms of location, as a landscape garden in terms of elements, and as a villa based on a typical private land system in terms of forms. In addition, it may be considered as a garden that laid the foundation to realize a field of non-visible image and non-visible landscape, which is fundamental element of scholarly garden design.

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Application of GeoWEPP to determine the annual average sediment yield of erosion control dams in Korea

  • Rhee, Hakjun;Seo, Junpyo
    • Korean Journal of Agricultural Science
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    • v.47 no.4
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    • pp.803-814
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    • 2020
  • Managing erosion control dams requires the annual average sediment yield to determine their storage capacity and time to full sediment-fill and dredging. The GeoWEPP (Geo-spatial interface for Water Erosion Prediction Project) model can predict the annual average sediment yield from various land uses and vegetation covers at a watershed scale. This study assessed the GeoWEPP to determine the annual average sediment yield for managing erosion control dams by applying it to five erosion control dams and comparing the results with field observations using ground-based LiDAR (light detection and ranging). The modeling results showed some differences with the observed sediment yields. Therefore, GeoWEPP is not recommended to determine the annual average sediment yield for erosion control dams. Moreover, when using the GeoWEPP, the following is recommended :1) use the US WEPP climate files with similar latitude, elevation and precipitation modified with monthly average climate data in Korea and 2) use soil files based on forest soil maps in Korea. These methods resulted in GeoWEPP predictions and field observations of 0 and 63.3 Mg·yr-1 for the Gangneung, 142.3 and 331.2 Mg·yr-1 for the Bonghwa landslide, 102.0 and 107.8 Mg·yr-1 for the Bonghwa control, 294.7 and 115.0 Mg·yr-1 for the Chilgok forest fire, and 0 and 15.0 Mg·yr-1 for the Chilgok control watersheds. Application of the GeoWEPP in Korea requires 1) building a climate database fit for the WEPP using the meteorological data from Korea and 2) performing further studies on soil and streamside erosion to determine accurate parameter values for Korea.

Backward estimation of precipitation from high spatial resolution SAR Sentinel-1 soil moisture: a case study for central South Korea

  • Nguyen, Hoang Hai;Han, Byungjoo;Oh, Yeontaek;Jung, Woosung;Shin, Daeyun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.329-329
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    • 2022
  • Accurate characterization of terrestrial precipitation variation from high spatial resolution satellite sensors is beneficial for urban hydrology and microscale agriculture modeling, as well as natural disasters (e.g., urban flooding) early warning. However, the widely-used top-down approach for precipitation retrieval from microwave satellites is limited in several hydrological and agricultural applications due to their coarse spatial resolution. In this research, we aim to apply a novel bottom-up method, the parameterized SM2RAIN, where precipitation can be estimated from soil moisture signals based on an inversion of water balance model, to generate high spatial resolution terrestrial precipitation estimates at 0.01º grid (roughly 1-km) from the C-band SAR Sentinel-1. This product was then tested against a common reanalysis-based precipitation data and a domestic rain gauge network from the Korean Meteorological Administration (KMA) over central South Korea, since a clear difference between climatic types (coasts and mainlands) and land covers (croplands and mixed forests) was reported in this area. The results showed that seasonal precipitation variability strongly affected the SM2RAIN performances, and the product derived from separated parameters (rainy and non-rainy seasons) outperformed that estimated considering the entire year. In addition, the product retrieved over the mainland mixed forest region showed slightly superior performance compared to that over the coastal cropland region, suggesting that the 6-day time resolution of S1 data is suitable for capturing the stable precipitation pattern in mainland mixed forests rather than the highly variable precipitation pattern in coastal croplands. Future studies suggest comparing this product to the traditional top-down products, as well as evaluating their integration for enhancing high spatial resolution precipitation over entire South Korea.

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Effect of Thermal Environment by Green Roof and Land Cover Change in Detached Housing Area (옥상녹화 및 토양피복 변화가 단독주택지 외부 열환경에 미치는 영향 분석)

  • Kim, Jeong-Ho;Yoon, Yong-Han
    • Journal of Environmental Policy
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    • v.10 no.1
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    • pp.27-47
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    • 2011
  • Used as foundation resources for environment improvement and preservation of single-housing residential area by practicing classification of biotope with the concept of ecological area rate applied and performing urban thermal environment prediction simulation. Biotope is classified as seven types according to classification of biotope which is carried out with the concept of ecological area rate applied. The classification is listed below in descending order: building biotope(48.16%), impervious pavement biotope(39.75%), greenspace biotope(6.23%), crack permeable pavement biotope(3.26%), whole surface permeable pavement biotope(2.51%), parts permeable pavement biotope(0.04%). As a result of analysing prediction of variation and characteristics of thermal environment of single-housing residential area, land surface temperature per types of biotope are evaluated as listed below in descending temperature order: impervious pavement biotope > building biotope > greenspace biotope > permeable pavement biotope. In case 2 where vegetated roof hypothetically covers 100% of the roof area, temperature is predicted to be $33.58^{\circ}C$ Max, $23.85^{\circ}C$ Min, and $27.74^{\circ}C$ Avg. which is Approximately $5.19^{\circ}C$ lower than a non-vegetated roof. Average outdoor temperature for case 2 is studied to be $0.18^{\circ}C$ lower than case 1.

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Analysis of Thermal Environment by Urban Expansion using KOMPSAT and Landsat 8: Sejong City (KOMPSAT과 Landsat 8을 이용한 도시확장에 따른 열환경 분석: 세종특별자치시를 중심으로)

  • Yoo, Cheolhee;Park, Seonyoung;Kim, Yeji;Cho, Dongjin
    • Korean Journal of Remote Sensing
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    • v.35 no.6_4
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    • pp.1403-1415
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    • 2019
  • Urban population growth and consequent rapid urbanization involve some thermal environmental problems in the cities. Monitoring of thermal environments in urban areas such as hot spot analysis is required for effective actions to resolve these problems. This study selected 14 dongs and surrounding administrative districts of Sejong city as study areas and analyzed the characteristics of changes in surface temperature due to the urban expansion in the summer from 2013 to 2018. In the study, the surface temperature distributions in the study areas were plotted using surface temperature values from Landsat 8 and NDVI (Normalized Difference Vegetation Index) and NDBI (Normalized Difference Built-up Index) based on KOMPSAT 2/3 data, and the patterns of surface temperature changes with urban expansion were discussed using the estimated NDVI and NDBI. In particular, the distinct urbanization in the study areas were selected for case studies, and the cause of the changes in the hot spots in the regions was analyzed using high-resolution KOMPSAT images. This study results present that hot spots appeared in urbanized regions within the study areas, and it was plotted that the lower the NDVI values and the higher the NDBI values indicate the temperature values are high. The land surface temperature and satellite-based products were used to divide the study areas into continuously urbanized regions and rapidly urbanized regions and to identify the different characteristics depending on land covers. In the regions with distinct surface temperature changes by urbanization, the analysis using high-resolution KOMPSAT images as presented in this study could provide effective information for urban planning and policy utilization in the future.