• Title/Summary/Keyword: water curtain cultivation (WCC)

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O/H Stable Isotopic Composition and Groundwater-surface Water Connectivity: A Case Study for Wangjeon-ri Water Curtain Cultivation Area, Nonsan, Korea (산소/수소안정동위원소를이용한지하수-지표수연계성연구: 논산시왕전리수막 재배지역 사례)

  • Moon, Sang-Ho
    • Economic and Environmental Geology
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    • v.51 no.6
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    • pp.567-577
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    • 2018
  • One of problems related with water curtain cultivation (WCC) in Korea includes severe declination of groundwater levels during the peak season, and it is likely that the problem can be resolved efficiently when the connection characteristics between groundwater and stream are well understood. This study examined temperature, and oxygen/hydrogen stable isotopic compositions of the flowing groundwater to understand the connection between stream and ground water, and the influence of stream water on the nearby aquifer. This study was performed in Wangjeon-ri (Kwangseok-myon, Nonsan City), the well-known strawberry town using WCC technique. The sampling was done during February 2010 through June 2011 for both groundwaters and nearby streams. Temperature distribution pattern indicates that stream widely affected groundwater in the right part of WCC ara. In the left part, the influence of stream seems to occur narrowly near the stream. The similar phenomenon is reflected in the oxygen and hydrogen isotopic data.

An Analysis of Groudwater Budget in a Water Curtain Cultivation Site (청원 수막재배 지역의 물수지 특성 분석)

  • Chang, Sun Woo;Chung, Il-Moon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.6
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    • pp.1259-1267
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    • 2015
  • In Korea, rural groundwater development faces new challenge, which have not been experienced so far. The problem is a groundwater depletion by the water curtain cultivation (WCC) during winter season. This study investigates the groundwater depletion using three-dimensional finite difference groundwater flow program, MODFLOW to verify the water budget of the shallow aquifer of Cheongweon area. Interdisciplinary research, which has become a worldwide trend, has been adopted in studying groundwater modeling in field scale. In particular, the method of groundwater recharge estimation adopted precise modeling techniques, SWAT to groundwater flow modeling. Based on qualified field data, the model calibrated and validated its reliability. The objective of this study is to simulate various stream-aquifer interactions according to groundwater pumping with artificial boundaries, such as weirs and drainage system. We also analyzed a seasonal variation of cumulative water budget of the site to quantify the groundwater depletion and recovery in the pumping field.

Estimation of Groundwater Usage for Water Curtain Cultivation using a Rating Curve (수위-유량 관계곡선을 이용한 수막재배용 지하수 사용량 추정)

  • Lee, Bong-Joo;Kim, YongCheol;Cho, Byung-Wook;Yoon, Uk;Ha, Kyoolchul;Lee, Byeong-Dae;Moon, Sang-Ho;Yoon, Philsun;Kim, Sung-Yun
    • The Journal of Engineering Geology
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    • v.25 no.1
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    • pp.35-43
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    • 2015
  • A method is proposed to estimate groundwater usage for water curtain cultivation (WCC) using a rating curve, and it is applied to field measurements of groundwater discharge used for WCC in Wangjeon-ri, Nonsan. During the winter season, the hydraulic components of irrigation ditches in the study area consist mainly of direct run-off and groundwater discharged from nearby pumping wells. Changes in stage of the ditches were monitored, and a baseflow separation method was applied to remove increments in stage due to direct run-off. The resulting records of stage were translated to groundwater discharge by applying the-stage-discharge relation. The estimated average groundwater discharge for the WCC in Wangjeon-ri was 10,900 m3/d or 420 m3/d/ha when the estimation is normalized by the total area for WCC facilities of this region. Applying this estimation (420 m3/d/ha) to the entire area of the WCC in Korea (10,746 ha),and considering the number of pumping days for the WCC (120 days/year), the total ground water usage for the WCC nation-wide is estimated to be 0.54 billion m3. This is equivalent to 32% of the total groundwater discharge for agricultural use in Korea (1.7 billon m3).

Analysis of Groundwater Variations using the Relationship Between Groundwater use and Daily Minimum Temperature in a Water Curtain Cultivation Site (수막재배지역에서 일최저기온과 지하수 이용량의 상관관계를 이용한 지하수위 변화 분석)

  • Chang, Sunwoo;Chung, Il-Moon
    • The Journal of Engineering Geology
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    • v.24 no.2
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    • pp.217-225
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    • 2014
  • Water curtain cultivation (WCC) systems in Korea have depleted water resources in shallow aquifers through massive pumping of groundwater. The goal of this study is to simulate the groundwater variations observed from massive groundwater pumping at a site in Cheongweon. MODFLOW was used to simulate three-dimensional regional groundwater flow, and the SWAT (Soil and Water Assessment Tool) watershed hydrologic model was employed to introduce temporal changes in groundwater recharge into the MODFLOW model input. Additionally, the estimation method for groundwater discharge in WCC areas (Moon et al., 2012) was incorporated into a groundwater pumping schedule as a MODFLOW input. We compared simulated data and field measurements to determine the degree to which winter season groundwater drawdown is effectively modeled. A simulation time of 107 days was selected to match the observed groundwater drawdown from November, 2012 to March, 2013. We obtained good agreement between the simulated drawdown and observed groundwater levels. Thus, the estimation method using daily minimum temperatures, may be applicable to other cultivation areas and can serve as a guideline in simulating the regional flow of riverside groundwater aquifers.

Groundwater-Stream Water Interaction Induced by Water Curtain Cultivation Activity in Sangdae-ri Area of Cheongju, Korea (청주 상대리지역에서 수막재배가 지하수-하천수 상호작용에 미치는 영향)

  • Moon, Sang-Ho;Kim, Yongcheol;Jeong, Youn-Young;Hwang, Jeong
    • Economic and Environmental Geology
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    • v.49 no.2
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    • pp.105-120
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    • 2016
  • Most of riverside in Korea, in case of application of water curtain cultivation (WCC) technique, has been inveterately suffering from the gradual drawdown of groundwater level and related shortage of water resources during the WCC peak time. We believe that the water resources issue in these riverside areas can be effectively solved when the interaction between groundwater and nearby surface water is well understood. To investigate the connection between stream and ground water, and the influence of stream water on the nearby aquifer, this study examined the water temperature and oxygen and hydrogen stable isotopic compositions. The study area is well-known strawberry field applying the WCC technique in Sangdae-ri, Gadeok-myon, Cheongju City, and the sampling was done from February 2012 through June 2014 for stream and ground water. Some groundwater wells near stream showed big temporal variations in water temperature, and their oxygen and hydrogen stable isotopes showed similar compositions to those of adjacent stream water. This indicates that the influence of stream water is highly reflected in the stable isotopic composition of groundwater. Four cross-sectional lines from stream to hillside were established in the study area to determine the spatial differences in water quality of wells. At the late stage of WCC in February to March, groundwater of wells in line with short cross-sectional length showed the narrow range of isotopic compositions; however, those in the long cross-sectional line showed a wide compositional range. It was shown that the influence of the stream water at the late WCC stage have reached to the distance of 160 to 165 m from stream line, which is equivalent to the whole length and one-third point in each short and long cross-sectional line, respectively. Therefore, the wide compositional range in the long cross-sectional lines was not only due to the influence of stream water, but apparently resulted from the change of relative impact of each groundwater supplying from two or more aquifers. In view of stable isotopic compositions, there seems to be three different aquifers in this study area, which is competing for dominance of water quality in wells at each period of WCC.

Setup of Infiltration Galleries and Preliminary Test for Estimating Its Effectiveness in Sangdae-ri Water Curtain Cultivation Area of Cheongju, Korea (청주 상대리 수막재배지의 지중 침투형 갤러리 설치와 예비 주입시험)

  • Moon, Sang-Ho;Kim, Yongcheol;Kim, Sung-Yun;Ki, Min-Gyu
    • Economic and Environmental Geology
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    • v.49 no.6
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    • pp.445-458
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    • 2016
  • Most of water curtain cultivation (WCC) area in Korea has been inveterately suffering from the gradual draw-down of groundwater level and related shortage of water resources at the late stage of WCC peak time. To solve this problem, artificial recharge techniques has been recently applied to some WCC area. This study introduces infiltration gallery, which is one of the artificial recharge methods, and tentatively examined the effectiveness of three galleries installed at Sangdae-ri WCC area of Cheongju City. Seven galleries are set up at each empty space between eight vinyl houses in this area and its dimension is designed as 50 cm in each width and height and 300 cm in each length. Installation process was including bed excavation, backfill with gravels and silica sands, and completion of gallery by equipment of piezometer and covering with non-woven cloth. For each B, C, D gallery, 3 types of test including preliminary, four step and one long-term injection were performed. The first preliminary test showed the rough relations between injection rates and water level rise as follows; 20 cm and 30 cm level rise for $33.29{\sim}33.84m^3/d$ and $45.60{\sim}46.99m^3/d$ in B gallery; 0 cm, 16 cm and 33 cm level rise for $21.1m^3/d$, $33.98m^3/d$ and $41.69m^3/d$ in C gallery; 29 cm and 42 cm level rise for $48.10m^3/d$ and $52.23m^3/d$ in D gallery. Afterwards, more quantitative results estimating effectiveness of artificial recharge were reasoned out through stepped and long-term injection tests, which is expected to be employed for estimating water quantity re-injected into the aquifer through these galleries by natural injection over the period of WCC peak time.

Analysis of Groundwater Use and Discharge in Water Curtain Cultivation Areas: Case Study of the Cheongweon and Chungju Areas (청원-충주지역 수막재배용 지하수 사용량 및 배출량 분석)

  • Moon, Sang-Ho;Ha, Kyoochul;Kim, Yongcheol;Yoon, Pilsun
    • The Journal of Engineering Geology
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    • v.22 no.4
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    • pp.387-398
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    • 2012
  • Korean agricultural areas that employ water curtain cultivation (WCC) have recently suffered extensive groundwater shortages due to an increase in the number of facilities. The primary focus of this study is to measure the daily groundwater use and discharge rates in the Cheongweon and Chungju pilot areas, while the second focus is to estimate the total amount of groundwater used in WCC areas nationwide in Korea. Taking into consideration several factors, including motor type, outflow abilities of wells, records of daily minimum temperatures below $0^{\circ}C$, and the number of running wells according to weather variations, we estimated that $53,138m^3/ha$ of groundwater had been used in the 4-hectare Cheongweon pilot area during the winter period of late 2011 through early 2012. On a prorated areal basis, we can calculate that the total groundwater used nationwide was 0.57 billion $m^3$ in WCC areas of $10,746m^2$. This value is equivalent to 33.7% of the total agricultural groundwater use (1.69 billion $m^3$) in Korea. During 9-22 February 2012, the daily water discharge rate in the 4-ha Cheongweon pilot area ranged from 2,079 to $2,628m^3$, averaging $2,341m^3$. Combining this value with meteorological records for 94 days with a daily minimum temperature below $0^{\circ}C$ results in an estimated groundwater volume of $54,990m^3/ha$ for the pilot area during the 2011-2012 winter period. The total amount of groundwater used nationwide in WCC areas would then be 0.59 billion $m^3$, equivalent to 34.9% of the total agricultural groundwater use in Korea. In the Chungju area, the groundwater discharge rate was estimated to be less than 805 $m^3$/ha. This value, combined with weather data for 108 days with a daily minimum temperature below $0^{\circ}C$ in this area, can be applied to infer that the total groundwater volume used in WCC areas nationwide is no more than 55% of the total agricultural groundwater use in Korea.

Water Quality in a Drainage System Discharging Groundwater from Sangdae-ri Water Curtain Cultivation Area near Musimcheon Stream, Cheongju, Korea (무심천 인근 상대리 수막재배지에서 지하수 사용 후 배출되는 최종 배수로 물의 수질 특성)

  • Moon, Sang-Ho;Kim, Yongcheol;Hwang, Jeong
    • Economic and Environmental Geology
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    • v.48 no.5
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    • pp.409-420
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    • 2015
  • The Sangdae-ri riverside around Musimcheon stream, flowing through Gadeok-myon of Cheongju City, is one of the representative strawberry fields employing water curtain cultivation (WCC) in Korea. In this area, annual groundwater use for WCC has been calculated by a few methods. On the assumption that all the water flowing through the final ditch may be mostly composed of groundwater, the discharge rate in it can be used as a good proxy for assessing the groundwater use. However, in the study area, the final ditch was set up in an unpaved state near and parallel to Musimcheon stream. Under such circumstances, the drainwater is likely to be influenced by infiltration and/or inflow of nearby stream. Hence, we examined whether or not stream water has influenced water flowing out through the final ditch in respect of ion concentrations or field parameters such as T, pH and electrical conductivity (EC) values. The period of measuring field parameters and sample collection was from February 2012 through February 2015. The drainwater in the final ditch did not show the average quality of groundwater, but similar quality of stream water in respect of pH, EC, ion contents and water type. From this, it is suggested that measuring the flow rate of the final ditch should not be directly used for assessing groundwater use in the study area. In addition, because of its sensitivity to ambient temperature, water temperature proved not to be appropriate for estimating the interaction between ditch and stream. For accuracy, additional methods will be needed to calculate mixing ratios between stream and ground water within drainage system.