• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.894-898
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• 2006

A model, which can analyze the hydrological performance for small hydropower(SHP) plants having no flow duration characteristics has been studied and developed. System performance of existing SHP plant under operating was analyzed by using the developed model. The annual operational rate of SHP plant showed that the data were in good agreement with predicted results from the model. Based on these results, several SHP sites to be exploited were selected and the performance characteristics were analyzed by using the developed model. Also, primary design values such as design flow rate, plant capacity, and operational rate were suggested. As a result, it was found that the methodology used in this study is useful tool to predict the hydrological system performances of SHP sites.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.319-322
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• 1999

Land surface hydrological conditions have been considered to play an important role in the global and regional climate variability. Especially, snow, soil moisture, surface temperature, vegetation and rain are the key parameters which should be observed in the global scale. In this paper, new algorithms for these land surface hydrological parameters have been developed by introducing frequency and polarization dependencies of these parameters in the microwave radiative-transfer equations. The algorithms were applied to the TRMM Microwave Radiometer. (TMI) and validated by using the ground data obtained in the Tibetan Plateau. The estimated snow, soil moisture, surface temperature, water content of vegetation and rain patterns corresponded reasonably to the observed ones.

• Environmental Engineering Research
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• v.14 no.1
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• pp.13-18
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• 2009

In this study, specific pollutant releases during the Asian monsoon season were estimated and the information was applied to the non-point pollutant sources management from two forested watersheds of the Soyang Lake. The two watersheds are part of the 2,703 km2 Soyang Lake watershed in the northern region of the Han River. The outlets of the two watersheds were respectively analyzed for continuous water quality concentration and for discharge during various single rainfall events. Statistical power function methods are utilized to compare stream discharge and pollutant flux release during the study period. Based on the monitoring data during the study period, the specific load flux method using simulated discharge was conducted and validated in the two watersheds. The model predictions corresponded well with the measured and calculated pollutant releases. The modeling approach taken in this study was found to be applicable for the two forested watersheds.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.174-177
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• 2004

Differential interferometric phases from JERS-1 L­band data sets show spatial variation of path-length ranging from a few mm to several cm. The variation may be caused by changes in soil moisture contents, i.e. variation of penetration depth and the swelling of soils. Although the amount of total effect caused by soil moisture is not measurable, it is clear that the soil moisture according to precipitation is another factor to be considered in DInSAR analysis. We also discuss DInSAR characteristics in a rice paddy according to irrigation conditions, and discrimination of hydrological features such as stream channels and watershed boundaries by applying DInSAR technique.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.742-747
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• 2005

A model, which can analyze the hydrological performance for small hydropower(SHP) plants having no flow duration characteristics has been studied and developed. System performance of existing SHP plant under operating was analyzed by using the developed model. The annual operational rate of SHP plant showed that the data were in good agreement with predicted results from the model. Based on these results, several SHP sites to be exploited were selected and the performance characteristics were analyzed by using the developed model. Also, primary design values such as design flow rate, plant capacity, and operational rate were suggested. As a result, it was found that the methodology used in this study is useful tool to predict the hydrological system performances of SHP sites.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1047-1051
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• 2004

The design storm is a crucial element in urban drainage design and hydrological modeling. The total rainfall depth of a design storm is usually estimated by hydrological frequency analysis using historic rainfall records. The different geostatistical approaches (ordinary kriging, universal kriging) have been used as estimators and their results are compared and discussed. Variogram parameters, the sill, nugget effect and influence range, are analysis. Kriging method was applied for developing contour maps of design storm depths In bocheong stream basin. Effect to utilize weather radar data and grid-based basin model on the spatial variation characteristics of storm requires further study.

• Journal of Environmental Science International
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• v.11 no.7
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• pp.621-626
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• 2002

Depth-area-duration(DAD) relations are important to hydrological plans and designs for the water resources as well as the flood defence. And these relations have been still in analysis and use today because they can be applied to readily available data. In this paper, rational and consistent DAD models were developed using the multiple regression analysis and basic relationships of area ratio-runoff volume about heavy rainfall occurring in the Im-Jin river basin, 1999. In addition, revised DAD models and curves that can convert a maximum point rainfall to mean area rainfall were developed and evaluated. As results, these models seem to have predictive value in order to plan and design hydrological structures of flood defence in the Im-Jin river basin.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1036-1038
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• 2003

Diurnal variations in the atmospheric vapor at Banchiao of Taiwan are studied by analyzing 30 min-averaged data in the summer of 1998. The surface meteorological measurements were mainly obtained from the Central Weather Bureau (CWB) of Taiwan. It is found that precipitable water (PW) is increased in the afternoon. The maximum of precipitable water appears at around 0900 LST. The diurnal range of precipitable water is larger on the days with than without rainfall events. Rainfall events often occur in the afternoon and early morning. We also examine the difference in the characteristics of the PW signatures with and without rainfall according to the occurrence of the times for the rainfall peak and the onset of rainfall.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.226-226
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• 2015

The complex climate system regarding human actions is well represented through global climate models (GCMs). The output from GCMs provides useful information about the rate and magnitude of future climate change. Especially, the temperature variable is most reliable among other GCM outputs. However, hydrological variables (e.g. precipitation) from GCM outputs for future climate change contain too high uncertainty to use in practice. Therefore, we propose a method that simulates temperature variable with increasing in a certain level (e.g. 0.5oC or 1.0oC increase) as a global warming scenario from observed data. In addition, a hydrometeorological variable can be simulated employing block-wise sampling technique associated with the temperature simulation. The proposed method was tested for assessing the future change of the seasonal precipitation in South Korea under global warming scenario. The results illustrate that the proposed method is a good alternative to levy the variation of hydrological variables under global warming condition.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.173-173
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• 2018

본 연구는 기상-수문 분야에서 고해상도 수문기상요소를 산출하기 위해 WRF-Hydro(Weather Research and Forecasting and Model Hydrological modeling extension package) 모형을 한반도 대상으로 구축하였다. 모형은 미국 대기 연구 국립센터(NOAA)에서 개발된 커뮤니티형 고해상도 예측모델이므로 미국 등에서 활발히 활용되기 시작하였으나 아직 우리나라 적용성에 대한 연구는 많지 않다. 본 연구에서는 WRF-Hydro 모형을 한반도에 적절히 사용하기 위해 표면유출, 보수깊이, 표면거칠기와 같은 파라미터를 보정하였다. WRF-Hydro는 지역 기상모형인 WRF와 연계하여 coupled WRF/WRF-Hydro 모형을 구동하였으며, 고해상도 유출값을 얻기 위해 미국 지질조사국(USGS)에서 제공한 HydroSHEDS(Hydrological data and map based on SHuttle Elevation Derivatives at multiple Scales)를 이용하였다. 본 연구에서는 관측된 유출값을 Markov Chain Monte Carlo(MCMC) 방법을 활용하여 모형값과 비교하여 파라미터 보정을 수행하였으며, 파라미터 보정된 WRF/WRF-Hydro를 활용해 한반도 과거 홍수 및 가뭄 사상을 모의하여 결과를 분석하였다.