• Journal of Korea Water Resources Association
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• v.54 no.9
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• pp.657-666
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• 2021

Ecosystem biodiversity is rapidly being lost due to changes in habitat, fragmentation of habitat, climate change, and land use changes by human activities. Recently, attempts have been made to approach the watershed management level to secure the health of the watershed, but studies on how to approach biodiversity and habitat management are still in lack. The purpose of this study is to evaluate the habitat quality of Geum river basin using Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) habitat quality model. The results of habitat quality was verified to eco-natural map and ecological watershed health evaluation results. The habitat quality of watershed was evaluated from 0 to 0.86 and the results showed that habitat quality was higher in upstream than downstream. Compared the habitat quality value in each eco-natural grade, the average habitat quality of 1st, 2nd and 3rd grades were 0.80, 0.76 and 0.71 respectively. The results of the correlation analysis with ecological watershed health data, the coefficient of determination (R²) was 0.58, and the person coefficient was 0.76. The results of this study may be used as foundation data to support habitat protection and implementation of long-term biodiversity-related policies.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.2-11
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• 2006

In the processes of hydrological cycle, when precipitation reaches the ground surface, water may become surface runoff or infiltrate into soil and then possibly further percolate into groundwater aquifer. A part of the water is returned to the atmosphere through evaporation and transpiration. Soil moisture dynamics driven climate fluctuations plays a key role in the simulation of water transfer among ground surface, unsaturated zone and aquifer. In this study, a one-layer canopy and a four-layer soil representation is used for a coupled soil-vegetation modeling scheme. A non-zero hydraulic diffusivity between the deepest soil layer modeled and groundwater table is used to couple the numerical equations of soil moisture and groundwater dynamics. Simulation of runoff generation is based on the mechanism of both infiltration excess overland flow and saturation overland flow nested in a numerical model of soil moisture dynamics. Thus, a comprehensive hydrological model integrating canopy, soil zone and aquifer has been developed to evaluate water resources in the plain region of Huaihe River basin in East China and simulate water transfer among precipitation, surface water, soil moisture and groundwater. The newly developed model is capable of calculating hydrological components of surface runoff, evapotranpiration from soil and aquifer, and groundwater recharge from precipitation and discharge into rivers. Regional parameterization is made by using two approaches. One is to determine most parameters representing specific physical values on the basis of characterization of soil properties in unsaturated zone and aquifer, and vegetations. The other is to calibrate the remaining few parameters on the basis of comparison between measured and simulated streamflow and groundwater tables. The integrated modeling system was successfully used in the Linhuanji catchment of Huaihe plain region. Study results demonstrate that (1) on the average 14.2% of precipitation becomes surface runoff and baseflow during a ten-year period from 1986 to 1995 and this figure fluctuates between only 3.0% in drought years of 1986, 1988, 1993 and 1994 to 24.0% in wet year of 1991; (2) groundwater directly deriving from precipitation recharge is about 15.0% t of the precipitation amount, and (3) about half of the groundwater recharge flows into rivers and loses through evaporation.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.71-84
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• 2022

The objective of this study is to develop a two-dimensional (2D) flood model that can perform accurate flood analysis with simple input data. The 2D flood inundation models currently used to create flood forecast maps require complex input data and grid generation tools. This sometimes requires a lot of time and effort for flood modeling, and there may be difficulties in constructing input data depending on the situation. In order to compensate for these shortcomings, in this study, a grid-based model that can derive accurate and rapid flood analysis by reflecting correct topography as simple input data was developed. The calculation efficiency was improved by extending the existing 2×2 sub-grid model to a 5×5. In order to examine the accuracy and applicability of the model, it was applied to the Gamcheon Basin where both urban and river flooding occurred due to Typhoon Rusa. For efficient flood analysis according to user's selection, flood wave propagation patterns, accuracy and execution time according to grid size and number of sub-grids were investigated. The developed model is expected to be highly useful for flood disaster mapping as it can present the results of flooding analysis for various situations, from the flood inundation map showing accurate flooding to the flood risk map showing only approximate flooding.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.262-266
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• 2016

We investigated the characteristic demographics for visitors to Mujechi bog on Mt. Jungjok, with the purpose of developing a management strategy for the conservation and wise use of the montane wetland. Using daily visitor data from 2007, 2011, and 2015 we extracted and analyzed; visitation date, age, residential areas, purpose of visitation and the time allotted for the visit. The largest age cohort was the decade of the fifties(36.8%/total number of visitors) and followed by the decade of the forties(30.4%). The majority of visitors were from Ulsan(67%), Busan(16.6%), and Yangsan(10.8%). The visitors' primary objectives were to hike Mt. Jungjok(39-64.4%) or view Mujechi bog(18.7-51.8%) during the weekend. People visited more during the weekend than weekdays(F=6.19, p<0.002). In addition, there was a clear seasonality obvious in the monthly visits. The proportion of visitors were present in spring and fall, the month with the highest visitation rate was May at $15.6{\pm}2.8%$($mean{\pm}S.D.$). This increase in May was partly due to the desire to see the Korean azalea in bloom in the spring. Montane bog, like Mujechi, could be highly affected by disturbance(e.g. stamping, sediment inflow) caused by visitors. Therefore, it is suggested, based on the level of visitation that to reduce possible human disturbance effects, that either a seasonal restriction or a yearly alternation of trails be established. Visitors to the wetland should be restricted access to certain areas of the wetland, or be required to go in the accompaniment of a ranger or warden.