급사면에 형성된 일시적 포화대의 지하수면깊이에 대한 TOPMODEL의 예측능력 검증

안중기,An, Jung-Gi 한국수자원학회 2003 한국수자원학회논문집 Vol.36 No.6

TOPMODEL의 지하수면길이 분포에 대한 예측능력을 평가하기 위해 2개 기본가정과 지하수면깊이에 대한 지배방정식을 검증하였다. 검증에는 토양두께가 얇은 급경사 사면의 수문관측과 토양조사 자료를 이용하였다. 조사사면에서 지하수면반응과 토양의 수리적 특성은 지형경사와 평행하는 수리경사, 지하수면깊이에 지수함수적으로 감소하는 투수량계수 등과 같은 TOPMODEL의 기본가정과 일치하였다 토양의 투수량계수감소율(f)과 토성은 지표부터 깊이 0.3m까지 사면전체에서 공간적으로 균질하지만, 토성과 f의 수직적인 변화로 깊이 0.3m 아래부터 공간적으로 불균질한 특성을 보인다. 조사사면에서 TOPMODEL의 지배방정식은 f값이 공간적로 균질한 깊이의 지하수면깊이 분포를 예측하는데 적용할 수 있는 것으로 나타났다. In order to evaluate the TOPMODEL's prediction ability for spatial distribution of water table depths, two major assumptions and governing equation of water table depth are tested. For the test, data of hydrological observations are used and a soil survey is made in the steep hillslope with thin soils. Responses of water table and hydraulic properties of soil are coincident with two major assumptions of the TOPMODEL's such as water table gradient parallel to the local topographical slope and exponential decline in transmissivity with depths. Soil texture and the decline rate of transmissivity(f) we homogeneous in space at the 0∼0.3m depths of the soil of the hillslope, but they are heterogeneous in space below its 0.3m depths due to the vertical change of soil texture and the ‘f’. It is shown that the TOPMODEL's equation can be used for simulating distribution of water table depth at the depths with uniform values of the 'f'.

격자기반의 토양물수지방법에 의한 지하수함양의 공간분포 추정

안중기,이용두,황종환,An Jung-Gi,Lee Yong-Doo,Hwang Jong-Hwan 한국지하수토양환경학회 2006 지하수토양환경 Vol.11 No.1

본 논문은 지하수함양의 공간분포를 분석할 수 있는 격자기반의 토양물수지방법을 제시하고, 제주도의 외도천유역에 적용하였다. 유역을 격자로 분할하고, 각 격자의 5년 동안의 물수지를 일단위로 계산하였으며, 격자의 일별 강수량은 10개 지점의 강수량자료로 보간법에 의해 산정하였다. SCS유출곡선지수, 토양수분보유능, 작물계수 등 매개변수의 분포는 토양과 토지이용특성에 대한 GIS분석으로 부터 구하였다. 유출곡선지수는 하천유출량 관측자료로 보정하였다. 사례유역에 대한 분석결과 강수량은 표고가 증가함에 따라 1,665 mm/년부터 3,382 mm/년까지 증가하며 지하수함양량은 강수량이 증가함에 따라 372 mm/년부터 2,576 mm/년까지 증가한다. 강수량이 상대적으로 적은 지역에서 유출율과 증발산율이 다른 지역보다 더 크기 때문에 지하수함양이 강수, 직접유출, 증발산, 지하수함양과 같은 물수지 성분 중에서 공간적인 변이가 가장 큰 것으로 나타나고 있다. This paper outlines the methodology of grid-based water balance for estimating the spatial distribution of recharge, which is applied to Woedo catchment in the northern area of the Jeju Island. The catchment is divided into grids and a daily water balance in each grid is computed for the period of 5 years. Daily rainfall data in each grid is interpolated from the data of 10 rainfall gauging stations. The spatial distributions of parameters such as SCS curve number, soil water retention capacity and crop coefficients are derived from GIS analyses of soil and land use characteristics. The SCS curve number is obtained by calibrating simulated runoffs with respect to the observed runoffs. The results show that the average annual rainfall increases from 1,665 mm/year to 3,382 mm/year in accordance with the topographic elevation, and the average annual recharge varies from 372 mm/year to 2,576 mm/year according to the average annual rainfall increases. Spatial variability of recharge is the highest among the water balance components such as rainfall, direct runoff, evaprotranspiration and recharge because the rate of runoff and evapotranspiration in the area with relatively low rainfall is higher than the other area.

다목적 용수를 고려한 제주도 농업용 지하수 이용량 모델 개발

안중기 ( Jung Gi An ),송성호 ( Sung Ho Song ),이동림 ( Dong Rim Lee ) 한국환경과학회 2015 한국환경과학회지 Vol.24 No.4

The estimation of groundwater usage in Jeju island is important to understand hydrologic cycle system and to plan management of water resource because large amounts of groundwater have been used for agricultural and domestic purpose. The model has been developed to estimate agricultural groundwater usage for garlic at uplands and citrus at orchards raising outdoors using the soil water balance model from FAO 56, respectively. The total amount of water supplied for the crop evapotranspiration and the multipurpose function such as sprout promotion can be simulated by the model. However, due to the discrepancy of water use in initial stage between calculated and observed, the model was calibrated and verified using actual groundwater usage monitoring data for 3.5 years (2011.6 to 2014.12) at three uplands for garlic and three orchards for citrus. Consequently, it would be concluded that the model simulated efficiently actual water usage in that root mean square (RMS) and normalized RMS of the validation stage were less than 8.99 mm and 2.43%, respectively, in two different conditions.

제주도 중산간지대의 지표수 이용시설에 대한 수문지형학적 접근

안중기 ( Jung Gi An ),김태호 ( Tae Ho Kim ) 한국지형학회 2015 한국지형학회지 Vol.22 No.1

Before supplying underground water through a tubular well, irrigation facilities for surface water were used in the transition zone to mountain area of Jeju Island. This paper has examined the hydrogeomorphologic characteristics of irrigation facilities in Dongbaekdongsan such as distribution, structure, water source and water balance. There are ten facilities including two wells and eight reservoirs. The well was constructed in a collapsed hollow of lava flow and has a stair to scoop up water which originates from boundaries between lava flow units below two or three meters deep. By contrast, the reservoir was constructed on a lava flow abundant in a micro-relief by building a stone wall with a sluice to have surface water easily introduced into the reservoir. Since a lava flow, particularly pahoephoe, often produces an impermeable layer, depressions and collapsed hollows developed in the lava flow could become small wetlands largely maintained by rainfall and provide a base for constructing irrigation facilities. Surface water flows into four reservoirs through temporary channels in addition to direct rainfall. Water storage of Meonmulggak consists of direct rainfall of 60.8% and water flow of 39.2%. Heavy rainfall produces overflow and subsequent surface runoff from Meonmulggak which contains an annual water volume of 1,860 m3. The water balance of catchment area including Meonmulggak demonstrates that rainfall is partitioned into evapotranspiration of 31.4%, deep percolation of 67.8% and surface water runoff of 0.8%, respectively.

제주도 서귀포지역 용천수의 기원 대수층 및 용출 유형

안중기 ( Jung Gi An ),정차연 ( Cha Yeon Jung ),박현주 ( Hyun Ju Park ),김태호 ( Tae Ho Kim ) 한국지형학회 2007 한국지형학회지 Vol.14 No.3

제주도 단성화산 소유역에서의 강우의 분배

안중기(Jung Gi An),김태호(Tae Ho Kim) 한국지역지리학회 2008 한국지역지리학회지 Vol.14 No.3

3세부과제_제주형 지하수자원원단위 산정 및 용수 수요량 예측 프로그램 개발

송성호,안중기,김진성,최광준,서구원,전병칠,이동림,Song, Seong-Ho,An, Jung-Gi,Kim, Jin-Seong,Choe, Gwang-Jun,Seo, Gu-Won,Jeon, Byeong-Chil,Lee, Dong-Rim 한국수자원학회 2015 물과 미래(한국수자원학회지) Vol.48 No.3

농업용 관정의 기계적 처리 이후 성능 개선 효과의 정량적 평가 사례

송성호,이병선,안중기,Song, Sung-Ho,Lee, Byung-Sun,An, Jung-Gi 한국지하수토양환경학회 2016 지하수토양환경 Vol.21 No.4

Step-drawdown pumping tests for identifying the improvement of groundwater well performance after rehabilitation treatments were conducted in three longstanding wells. Three selective mechanical treatment methods including power bubble, high-voltage electric pulse, and air surging were applied to these wells and the applicability of these methods to secure additional groundwater resources were evaluated quantitatively. Commonly, drawdown at final stage of stepdrawdown pumping tests after rehabilitation decreased by as much as 0.61~0.70 meters compared to those before rehabilitation. In addition, final specific drawdown values of three wells increased from 9% to 14% after rehabilitation. Formation loss coefficient and well loss coefficient decreased to 6.1% and 60.6%, respectively, indicating some clogging materials by precipitation/corrosion/microbe within pores of aquifer materials, gravel packs, and screens were effectively removed by applied methods. Decrease of formation loss coefficient was higher in the well applied by the power bubble method meanwhile high-voltage electric pulse method demonstrated the higher decrease of well loss coefficient. Additionally secured groundwater amounts after rehabilitation ranged from 23.3 to 32.1 m³/day, which account for 8~16% of initially developed pumping rates of the wells. From the results of this study, the effective selection of rehabilitation treatments considering aquifer characteristics are expected to contribute to secure groundwater resources for irrigation as well as to plan systematic management program for groundwater resources in rural area.

지형면과 수문지질단위 분류를 이용한 북한의 지하수 부존량 추정

송성호,박종철,안중기,Song, Sung-Ho,Park, Jongchul,An, Jung-Gi 한국지하수토양환경학회 2015 지하수토양환경 Vol.20 No.7

This study was conducted to provide the preliminary data on preparation for policy decisions regarding the groundwater supply scheme for N. Korea vulnerable to drought. Agricultural activities oriented to upland field due to the mountainous terrain more than 79% as well as the diversity of rainfall distribution over the country make more vulnerable to structural problems in the drought in N. Korea. Therefore, in anticipation of the expansion of exchange policies in agricultural sector, the available amount of groundwater needed for sustainable water resources supply was estimated for each administrative district after analyzing alluvium and hydrogeology distribution in N. Korea. Overall, the available amount of groundwater was estimated to 22.3 billion m³ (0.18 million m³/km²). The available amount of groundwater per unit area in Ryanggangdo and Gaesungsi was appeared very high in each of 0.56 and 0.39 million m³/km², respectively, and it would be interpreted that two districts have relatively wide area of volcanic rocks and alluvium with highly permeable characteristics, respectively. Finally, to maximize the utilization of this study result, the available amount of groundwater distribution map was developed on the basis of the 1 × 1 km grid network over the entire N. Korea.

국내 농업용 지하댐의 현황 및 활용 사례

용환호,송성호,명우호,안중기,홍순욱,Yong, Hwan-Ho,Song, Sung-Ho,Myoung, Woo-Ho,An, Jung-Gi,Hong, Soon-Wook 한국지하수토양환경학회 2017 지하수토양환경 Vol.22 No.3

The increasing frequency of droughts has been increasing the necessity of utilizing subsurface dams as reliable groundwater resources in areas where it is difficult to supply adequate agricultural water using only surface water. In this study, we analyzed the current status and actual conditions of five agricultural subsurface dams as well as the effect of obtaining additional groundwater from subsurface dams operated as one aspect of the sustainable integrated water management system. Based on the construction methods and functions of each subsurface dam, the five subsurface dams are classified into three types such as those that derive water from rivers, those that prevent seawater intrusion, and those that link to a main irrigation canal. The classification is based on various conditions including topography, reservoir location, irrigation facilities, and river and alluvial deposit distributions. Agricultural groundwater upstream of subsurface dams is obtained from four to five radial collector wells. From the study, the total amount of groundwater recovered from the subsurface dam is turned out to be about 29~44% of the total irrigation water demand, which is higher than that of general agricultural groundwater of about 4.6%.