• Title/Summary/Keyword: geo-environmental

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Estimation of Nitrogen Mass Balance in Sihwa-ho Watershed, 2010 (2010년 시화호유역 질소 물질수지 산정)

  • Choi, Jung-Kil;Lee, Hyo-Jin;Kim, Tea-ha;Choi, Jea-hun;Woo, Jun-Sik;Lee, Kang-Wung
    • Journal of Environmental Science International
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    • v.27 no.3
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    • pp.179-193
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    • 2018
  • Nitrogen budgets in Sihwa-ho in 2010 were estimated using a mass balance approach. Major nitrogen fluxes sources can be divided into three sections: cities, agricultural area, and forest. Surplus nitrogen 2,030~2,214 ton/yr (2,123 ton/yr in average) was discharged to Sihwa Lake. 20% of the surplus nitrogen is removed from the wetland and 60% is removed tidal flats. Therefore net nitrogen discharge from Sihwa basin is estimated to be 650~708 ton/yr (679 ton/yr in average). Wet and dry nitrogen deposition and load from non-point sources ware estimated to be 97 ton/yr and 69 ton/yr, deposition is using CAMx model. So estimated total nitrogen discharge into Sihwa-ho was 817~875 ton/yr (846 ton/yr in average). The atmospheric load explains 11.1~11.9% (11.5% in average) of the total nitrogen load Sihwa-ho.

Application and Comparison of GeoWEPP model and USLE model to Natural Small Catchment - A Case Study in Danwol-dong, Icheon-si (소유역에서의 토사유출 산정을 위한 GeoWEPP model과 USLE의 비교.적용 연구 - 이천시 단월동 유역을 사례로)

  • Kim, Min-Seok;Kim, Jin-Kwan;Yang, Dong-Yoon
    • Economic and Environmental Geology
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    • v.40 no.1 s.182
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    • pp.103-113
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    • 2007
  • The empirical USLE and the physically-based GeoWEPP which were distributed model linked with GIS (Geographical Information System) were applied to small natural catchment located in Icheon-si, Gyeonggi-do, South Korea. The results using by two models were total sediment yield from study catchment between January, 2004 and January, 2005. During the study period, the observed total sediment yield was 270.54 ton and the total sediment yield computed by USLE and GeoWEPP model were 358.1 ton and 283.30 ton, respectively. Each of results computed by USLE and GeoWEPP overestimated more than the observed total sediment yield, but, based on the results, the total sediment yield computed by GeoWEPP approximated to the observed result. We suggest that the reason why the total sediment yield using by models overestimated was that computed amounts by two models did not contain the amount of suspended sediment flowed over the weir.

Estimated groundwater recharge including water pipes leakage in Kumagaya City

  • Saito, Keisuke;Ogawa, Susumu;Takamura, Hiroki;Yashiro, Yusuke
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.735-737
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    • 2003
  • The drying up of seepage in Kumagaya City was caused by the increase of impermeable area with urbanization. The project of rain fall infiltration facilities has been planned for improvement of a hydrological cycle in Kumagaya City. With GIS and remote sensing, the most suitable arrangement for the rainfall infiltration inlets was examined. Distribution maps for infiltration, evapotranspiration and groundwater recharge at each town in Kumagaya City was designed from the land cover classification map with hydrological analysis. In these distribution maps, influence of the leak from drinking water and sewage networks was counted to the hydrological cycle.

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Analysis of Rainfall-Runoff Characteristic at Mountainous Watershed Using GeoWEPP and SWAT Model (GeoWEPP과 SWAT 모델을 이용한 산지 유역 강우-유출량 특성 분석)

  • Kim, Jisu;Kim, Minseok;Kim, Jin Kwan;Oh, Hyun-Joo;Woo, Choongshik
    • Journal of The Geomorphological Association of Korea
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    • v.28 no.2
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    • pp.31-44
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    • 2021
  • Due to recent climate change, continuous soil loss is occurring in the mountainous watershed. The development of geographic information systems allows the spatial simulation of soil loss through hydrological models, but more researches applied to the mountain watershed areas in Korea are needed. In this study, prior to simulating the soil loss characteristics of the mountainous watershed, the field monitoring and the SWAT and GeoWEPP models were used to simulate and analyze the rainfall and runoff characteristics in the mountainous watershed area of Jirisan National Park. As a result of monitoring, runoff showed a characteristic of a rapid response as rainfall increased and decreased. In the simulation runoff results of calibrated SWAT models, R2, RMSE and NSE was 0.95, 0.03, and 0.95, respectively. The runoff simulation results of the GeoWEPP model were evaluated as 0.89, 0.30, and 0.83 for R2, RMSE, and NSE, respectively. These results, therefore, imply that the runoff simulated through SWAT and GeoWEPP models can be used to simulate soil loss. However, the results of the two models differ from the parameters and base flow of actual main channel, and further consideration is required to increase the model's accuracy.