• Journal of Korea Water Resources Association
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• v.45 no.12
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• pp.1243-1258
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• 2012

The objective of this study is to develop the relational formula to estimate the streamflow depletion due to groundwater pumping near stream, which has been statistically derived by using the simulated data. The integrated surface water and groundwater model, SWAT-MODFLOW was applied to the Sinduncheon and Juksancheon watersheds to obtain the streamflow depletion data under various pumping conditions. Through the multiple regression analyses for the simulated streamflow depletion data, the relational formula between the streamflow depletion rate and various factors such as pumping rate, distance between well and stream, hydraulic properties in/near stream, amount of rainfall was obtained. The derived relational formula is easy to apply for assessing the effects of groundwater pumping on near stream, and is expected to be a tool for estimate the streamflow contribution to the pumped water.

• Journal of Soil and Groundwater Environment
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• v.21 no.1
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• pp.61-71
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• 2016

Visual MODFLOW was used for quantifying stream-aquifer interactions caused by seasonal groundwater pumping. A hypothetical conceptual model was assumed to represent a stream-aquifer system commonly found in Korea. The model considered a two-layered aquifer with the upper alluvium and the lower bedrock and a stream showing seasonal water level fluctuations. Our results show that seasonal variation of the stream depletion rate (SDR) as well as the groundwater depletion depends on the stream depletion factor (SDF), which is determined by aquifer parameters and the distance from the pumping well to the stream. For pumping wells with large SDF, groundwater was considerably depleted for a long time of years and the streamflow decreased throughout the whole year. The impacts of return flow were also examined by recalculating SDR with an assumed ratio of immediate irrigation return flow to the stream. Return flow over 50% of pumping rate could increase the streamflow during the period of seasonal pumping. The model also showed that SDR was affected by both the conductance between the aquifer and the stream bed and screen depths of the pumping well. Our results can be used for preliminary assessment of water budget analysis aimed to plan an integrated management of water resources in riparian areas threatened by heavy pumping.

• Journal of Korea Water Resources Association
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• v.48 no.7
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• pp.545-552
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• 2015

The objective of this study is to spatially assess the streamflow depletion due to groundwater pumping near the main stream of Juksanchoen watershed. The surface water and groundwater integrated model, SWAT-MODFLOW, in this study, was used to simulate streamflow responses to each groundwater pumping from wells located within 500m from the stream. The simulated results showed that the streamflow depletion rate divided by the pumping rate for each well location ranges from 20% to 96%. In particular, the streamflow depletion exceeds 60% of pumping rate if the distance between stream and well is lower than 100 m, hydraulic diffusivity is higher than $500m^2/d$, and streambed hydraulic conductance is above 25m/d. The simulated results were also presented in the form of spatial distribution maps that indicate the fraction of the well pumping rate in order to show the effect of a single well more comprehensively and easily. From the developed areal distribution of stream depletion, higher and more rapid responses to pumping occur near middle-downstream reach, and the spatially averaged percent depletion is about 66.7% for five years of pumping. The streamflow depletion map can provide objective information for the near-stream groundwater permission and management.

• Journal of Korea Water Resources Association
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• v.51 no.2
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• pp.99-107
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• 2018

This study was to evaluate the stream depletion due to groundwater pumping from 17 wells near the Anseongcheon upper stream using the Baalousha's analytical solution (2012) which directly considers stream width and streambed hydraulic conductivity. The input hydraulic values of aquifer and streambed were obtained from the pumping tests and seepage experiments. The estimated streamflow depletion rates divided by pumping rate (dimensionless stream depletion) showed a range from 0.23 to 0.89 for 5 year pumping. In particular, the results revealed that the groundwater pumping has insignificant effects on streamflow when the stream depletion factor (SDF) is higher than 1,000 with values of dimensionless stream depletion lower than 0.4. A more simple Hunt's solution (1999) also applied to the same wells, and the results showed that the difference between the dimensionless stream depletions calculated by using both solutions could be negligible. From the comparison of the Baalousha's solution (2012) with the Hunt's solution (1999) with total 3,000 cases of simulations with combinations of various aquifer and stream properties, the stream-well distance should be more longer than stream width for reducing the discrepancy between both solutions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.617-625
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• 2016

The objective of this study was to evaluate the groundwater drawdown and streamflow depletion due to each groundwater pumping from 110 wells located near stream using the Hunt's analytical solution (1999). The calculated results revealed that the streamflow depletion rate divided by the pumping rate for each well location mostly exceeded about 80% of pumping rate on average for 5 years. The results also showed that the stream boundary condition has made the influence distance shorter and the drawdown distribution skewed except for the streambed hydraulic conductivity and the stream bed factor (SBF) lower than $1.0{\times}10^{-9}m/s$ and 1.0, respectively. It was found that the groundwater pumping has significant impacts on the stream depletion showing above 80 % of stream depletion rate when the streambed hydraulic conductivity is higher than $1.0{\times}10^{-7}m/s$ and the stream depletion factor(SDF) is lower than 100. However, for other conditions, the SDF is not sufficient to be used as a criterion for determining whether the pumping has great impacts on stream depletion or not. Furthermore, the variation of the streambed hydraulic conductance has little change in stream depletion rate for the condition that the stream width is greater than 400 m.

• Journal of Korea Water Resources Association
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• v.49 no.11
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• pp.923-930
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• 2016

This study was to evaluate the stream depletion from groundwater pumping in shallow aquifer using the Hunt's analytical solution (2009) which considers a two-layer leaky aquifer-stream system. From the total 2,187 cases of simulations with combinations of various aquifer and stream properties, the streamflow depletion rates divided by the groundwater pumping rate showed the low values when the stream depletion factor (SDF) is higher than 1,000-10,000, and was more sensitive to the aquitard hydraulic conductivity than the streambed hydraulic conductivity. The comparison of the Hunt's solution (2009) with the Hunt's solution (1999) of a single layer aquifer indicated that the maximum difference between the dimensionless stream depletions calculated by using both solutions is above 0.3, and the stream depletion is significantly affected by the hydraulic properties of the $2^{nd}$ layer as the SDF of the first layer increases. The Hunt's solution (2009) was applied to the real shallow groundwater well that is located in Chunju-Si, and the results revealed that the groundwater pumping has significant effects on streamflow in a short period of time, showing that the dimensionless stream depletion exceeds 0.8 within a few days. It was also found that the shallow groundwater pumping effects on stream depletion are highly dependent on the stream-well distance for the locations with high hydraulic diffusivity of $1^{st}$ layer and low vertical leakance between $1^{st}$ and $2^{nd}$ layers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.769-777
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• 2016

The objective of this study was to evaluate the stream depletion from groundwater pumping in deep aquifer using the Ward and Lough's analytical solution (2011) which considers a two-layer leaky aquifer system. The calculated results for each pumping from the 110 wells beside streams showed a wide range of non-dimensional stream depletion, that is the streamflow depletion rate divided by the groundwater pumping rate, from lower than 0.1 to more than 0.9 on average for 5 years depending on the specific properties of well location. From the comparison with Hunt's solution (1999) of a single layer aquifer, the Ward and Lough's solution showed about 50% lower than the Hunt's solution due to the difference of hydraulic properties between the first and second layers as well as the lagged effect of vertical leakance. It was also found that the groundwater pumping has a minor effect on the stream depletion if the stream depletion factor (SDF) of the 1st layer is higher than about 1,000 or the SDF of the 2nd layer is higher than about 100, or the vertical leakance is smaller than $10^{-5}s^{-1}$. Furthermore, in the present study, the variations of the stream depletion were assessed according to the magnitude of unmeasured hydraulic properties such as transmissivity and storage coefficient of the 1st layer, vertical hydraulic conductivity of the 2nd layer, the streambed hydraulic conductance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.556-562
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• 1997

Depletion of nitrite by lactic acid bacteria isolated from Kimchi and the effects of pH and temperature on depletion of nitrite in Lactobacillus MRS broth were investigated. Depletion of nitrite by Lactobacillus plantarum and Lactobacillus sake was low in initial stage of growth but increased during growth at 15 and 2$0^{\circ}C$. L. plantarum and L. sake depleted than 90 and 75% of nitrite(250$\mu\textrm{g}$/$m\ell$) in 1 day of growth at 25 and 3$0^{\circ}C$, respectively, but depleted almost all of nitrite in 2 days. While the effect of Leuconostoc mesenteroides (150$\mu\textrm{g}$/$m\ell$) was lower compared to Lactobacillus(250$\mu\textrm{g}$/$m\ell$). In addition, even high concentrations(600 and 900 $\mu\textrm{g}$/$m\ell$) of nitrite was depleted at 2 days of growth by L. plantarum. pH of growing broth decreased as the increase of growth time and temperature, and depletion of nitrite in- creased as the decrease of pH of growing culture. However, pH of broth related with the decrease of depletion of nitrite at 25 and 3$0^{\circ}C$, but not at 15 and 2$0^{\circ}C$. Therefore, depletion of nitrite was greatly affected by growth temperature rather than by pH.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.129-138
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• 2012

We investigated an ecological impact of drought simulated by discharge depletion on the water quality and benthic diatom community in the indoor experimental channel. As artificial substrates slide-glass was installed in acrylic channel for 16 days. Channels were supplied continuously with eutrophic lake water with a discharge rate of 6 L $min^{-1}$ in duplication during the colonized period. And then during the discharge depletion period, three discharge rates were provided: NDF (No depletion of flow rate (Control): 6 L $min^{-1}$), LDF (Low depletion of flow rate: 3 L $min^{-1}$) and HDF (High depletion of flow rate: 1 L $min^{-1}$). Environmental factors in the water, such as suspended solid, Chl-$a$ and nutrients concentration, were measured with periphytic algae including AFDM (ash free dry matter), Chl-$a$ concentration and cell density at 1-day intervals. Light intensity increased significantly with discharge depletion (F=229.5, p= 0.000). $NH_4$-N concentration was highest at HDF. Suspended solid in outflowing water decreased at HDF (88%), LDF (97%) and NDF (99%), compared to inflowing water (100 %). Chl-$a$ in substrates increased more than two times at LDF and HDF than NDF (F= 8.399, p=0.001). Also AFDM and benthic diatom density increased significantly at LDF and HDF than NDF (F=9.390, p=0.001; F=6.088, p=0.007). In all experimental groups, $Aulacoseira$ $ambigua$, $Achnanthes$ $minutissima$ and $Aulacoseira$ $granulata$ were dominant species accounting for greater than 10% of benthic diatom density. The most dominant species, $A.$ $ambigua$ was highest at LDF, followed by HDF and NDF (F=8.551, p=0.001). In conclusion, the effect of drought simulated by discharge depletion in an artificial stream ecosystem caused significant changes on water quality and benthic diatom biomass. This result provides a useful data to understand the effect of draught on stream ecosystem in situ.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.240-241
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• 2005