• 한국관개배수논문집
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• 제21권1호
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• pp.89-98
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• 2014

This study is to evaluate the future potential impact of climate change on soil erosion loss in a metropolitan area using Revised Universal Soil Loss Equation(RUSLE) with land use information of the Ministry of Environment and rainfall data for present and future years(30-year period). The spatial distribution map of vulnerable areas to soil erosion was prepared to provide the basis information for soil conservation and long-term land use planning. For the future climate change scenario, the MIROC3.2 HiRes A1B($CO_2720ppm$ level 2100) was downscaled for 2040-2069(2040s) and 2070-2099(2080s) using the stochastic weather generator(LARS-WG) with average rainfall data during past 30 years(1980-2010, baseline period). By applying the climate prediction to the RUSLE, the soil erosion loss was evaluated. From the results, the soil erosion loss showed a general tendency to increase with rainfall intensity. The soil loss increased up to 13.7%(55.7 ton/ha/yr) in the 2040s and 29.8%(63.6 ton/ha/yr) in the 2080s based on the baseline data(49.0 ton/ha/yr).

• 한국환경과학회지
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• 제19권6호
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• pp.665-670
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• 2010

Pollutants from urban pavement consists various kinds of substances which are originated from dry deposition, a grind out tire, corrosive action of rain to pavement and facilities and raw materials of the road etc.. These are major pollutants of urban NPS (Non-point source) during rainfall period. However there is not enough information to control such pollutants for appropriate management of natural water quality. In this study of transportation areas, three monitoring stations were set up at trunk road, urban highway and national road in Gyeongnam province. Runoff flow rate was measured at every 15minutes by automatic flow meters installed at the end of storm sewer pipe within the road catchment area for water quality analysis. Data was collected every 15 minutes for initial two hours of rainfall. Additional samples were collected 1-4 hours interval till the end of rainfall. The monitoring parameters were $COD_{Mn}$, SS, T-N & T-P and heavy metals. The average EMCs of TSS and $COD_{Mn}$ were 62.0 mg/L and 24.2 mg/L on the city trunk road, which were higher than those of urban highway and national road, indicating higher pollutant loads due to activities in the city downtown area beside the vehicle. On the other hand, the average EMC of T-N and T-P were in the range of 2.67-3.23 mg/L and 0.19-3.21 mg/L for all the sampling sites. Heavy metals from the roads were mainly Fe, Zn, Cu and Mn, showing variable EMCs by the type of road. From the TSS wash-off analysis in terms of FF(first flush) index, first flush phenomenon was clearly observed in the trunk road(FF : 0.89-1.43). However, such mass delivery behavior was not apparently shown in urban highway(FF : 0.90-1.11) and national road(FF : 0.81-1.41).

• 한국환경과학회지
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• 제31권12호
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• pp.1013-1025
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• 2022

This study was carried out to analyze water cycle characteristics and evaluate water retention function in Jeju Gotjawal forest from 2013 to 2017. The average ratio of throughfall, stemflow, interception loss in Seonhul Gotjawal (SH) and Cheongsu Gotjawal (CS) was 43.1%, 15.8%, and 41.1%, respectively. Rainfall-throughfall, rainfall-stemflow, and rainfall-interception loss were expressed as linear regression equation (p<0.001). The comparison results showed that SH was higher than CS (p<0.05), indicating that the canopy area had an important effect on the difference in stand structure. The average water resources retention rate of the Gotjawal region was 41.9%, which is similar to the total water resources retention rate (40.6%) of Jeju Special Self-Governing Province (JSSGP). Currently, the development of Gotjawal is in progress in JSSGP. The development of Gotjawal will lead to a decrease in the water resources retention rate due to changes in the surface environment such as an increase in impervious areas, which will affect the total groundwater content of JSSGP. Therefore, the conservation of the Gotjawal area is judged to be very important from the point of view of water conservation.

• 지적과 국토정보
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• 제47권1호
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• pp.191-211
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• 2017

호우의 평가는 관측소의 강우자료를 이용하여 호우의 지속기간과 면적에 의해 이루어진다. 호우를 평가하기 위한 방법 중 DAD 분석방법은 지속시간 및 면적에 따른 강우 깊이를 나타내기 때문에 가장 많이 사용되고 적용된다. 하지만 기존의 DAD 분석 방법은 오차를 발생시킬 가능성이 크다. 따라서 본 연구에서는 오차발생가능성을 줄인 격자기반의 DAD 분석프로그램을 이용하여 DAD를 분석하고 적용성을 검토하였다. 적용성을 검토하기 위해 3가지의 공간보간 기법을 이용하여 지점강우를 면적강우로 변환하였다. 그 후, 변환된 격자기반의 강우자료를 이용하여 DAD 분석을 실시하였다. 그 결과, 각 지속시간 별로 면적 별로 MAAR 값을 추정할 수 있었고, OK 기법을 이용한 강우자료에서 높은 적용성을 나타냈다.

• 한국농공학회지
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• 제17권3호
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• pp.3840-3847
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• 1975

With 30 excisting reservoirs in the Chin-Young area, the Sedimentation of the reservoirs has been calculated by comparing the present capacity with the original value, which revealed its reduced reservoir capacity. The reservoirs has a total drainage area of 3l4l ha, with a total capacity of 43.23 ha-m, and are short of water supply due to reduction of reservoir capacity, Annual sedimentation in the reservoir is relation to the drainage area, the mean of annual rainfall, and the slop of drainage area. The results of obtained from the investigation are summarized as follows: (1) A Sediment deposition rate is high, being about 7.03㎥/ha of drainage area, and resulting in the overage decrease of reservoir capacity by 16.1%. This high rate of deposition coule be mainly attributed to the serve denudation of forests due to disorderly cuttings of tree. (2) An average unit storageof 116mm as the time of initial construction is decreased to 95.6mm at present. This phenomena cause a greater storage of irrigation water, sinceit was assumed that original storage quantity itself was already in short. (3) A sediment deposition rate as a relation to the capacity of unit drainge area is as follow: Qs=1.27(C/A)0.6 and standard deviation is 185.5㎥/$\textrm{km}^2$/year. (4) A sediment deposition rate as a relation to the mean of annual rainfall is as follow: Qs=21.9p10.5 and the standard deviation is 364.8㎥/$\textrm{km}^2$/year. (5) A sediment deposition rate as a relation to the mean slop of drainage area is follow: Qs=39.6S0.75 and the standard deviation is 190.2㎥/$\textrm{km}^2$/year (6) Asediment deposition rate as a relation to the drainage area, mean of rainfall, mean of slope of drainage area is: Log Qs=0.197+0.108LogA-6.72LogP+2.20LogS and the standard deviation is 92.4㎥/$\textrm{km}^2$/year

• 한국지리정보학회지
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• 제7권2호
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• pp.47-56
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• 2004

본 연구는 강우-유출 침식성 인자의 빈도별에 따른 토양유실량을 평가하고 이롤 바탕으로 유역의 토침칭식 위험지역을 분석하는 것을 목적으로 한다. RUSLE는 토양침식량을 분석하는데 이용하였다. 연구지역은 섬진강 수계의 관촌유역을 선정하였다. 빈도별 강우-유출 침식성인자를 얻기 위하여 39년간의 일일최대 강우량 자료를 이용하였다. 확률강우량은 Normal 분포, Log-Normal 분포, Pearson type III 분포, log-Pearson type III 분포 및 Extreme-I 분포를 이용하였다. 이 중 적합도가 가장 높은 것으로 판단되는 Log-Pearson type III 분포를 채택하였다. Log-Pearson type III 분포는 24시간 확률 강우량을 산정하는데 이용하였고, 빈도별 강우-유출 침식성 인자는 Huff 분포비로 평가하였다. 분석결과 2년빈도에서 200년 빈도까지 토양유실량은 평균 $12.8{\sim}68.0ton/ha{\cdot}yr$로 분석되었다. 유역의 토양유실량 분포를 4개 분류등급으로 구분하여 토양침식 위험지역을 분석하였으며, 침식발생 위험지역으로 판단되는 지역은 분류등급 IV로 하였다. 분류등급 IV의 면적은 $0.01{\sim}5.28km^2$로 전체 농경지 면적의 0.02~9.00%로 나타났다. 특히, 200년빈도의 경우 분류등급 IV에서 밭작물 재배지역이 전체 농경지 면적의 77.1%를 차지하는 것으로 나타났다. 농경지의 경작상태에 따라 토양유실이 큰 영향을 받는 것으로 판단된다.

• 한국수자원학회논문집
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• 제53권11호
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• pp.1025-1037
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• 2020

본 연구는 호우경보에 사용되는 Limited area ENsemble prediction System (LENS) 강우예측자료에 대한 공간적 특성 및 적용성을 평가하였다. LENS는 13개의 강우앙상블 멤버를 가지고 있어 호우경보를 발령하는데 있어 확률적인 방법을 활용할 수 있다. 그러나 LENS의 자료의 접근성은 매우 낮아 강우예측자료의 적용성에 대한 연구가 미흡한 실정이다. 본 연구에서는 행정구역별로 활용되는 호우경보 시스템에 따라 하나의 지점값과 면적평균값을 관측값과 비교하여 평가지수를 산정하였다. 또한, LENS의 발령시간에 따르는 각 앙상블 멤버들의 정확성을 평가하였다. LENS는 멤버별로 과대 혹은 과소 예측의 불확실성을 보여줬다. 면적단위의 예측이 지점단위의 예측보다 더 높은 예측성을 보여주었다. 또한, 다가오는 72시간의 강우를 예측하는 LENS 자료는 수재해의 영향성이 있을 수 있는 강우 사상에 대하여 예측성능이 좋은 것으로 평가되었다. 추후 국지강우앙상블시스템(LENS) 자료는 행정구역 또는 유역면적 단위의 홍수 대비에 기초자료로 활용될 수 있을 것으로 기대된다.

• 한국농공학회논문집
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• 제59권1호
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• pp.71-79
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• 2017

Climate change phenomenon is posing a serious threat to sustainable corn production in Ghana. This study investigated the impacts of climate change on the rain-fed corn yield in the Dangme East district, Ghana by using Aquacrop model with a daily weather data set of 22-year from 1992 to 2013. Analysis of the weather data showed that the area is facing a warming trend as the numbers of years hotter and drier than the normal seemed to be increasing. Aquacrop model was assessed using the limited observed data to verify model's sufficiency, and showed credible results of $R^2$ and Nash-Sutcliffe efficiency (NSE). In order to simulate the corn yield response to climate variability four climate change scenarios were designed by varying long-term average temperature in the range of ${\pm}1^{\circ}C{\sim}{\pm}3^{\circ}C$ and average annual rainfall to ${\pm}5%{\sim}{\pm}30%$, respectively. Generally, the corn yield was negatively correlated to temperature rise and rainfall reduction. Rainfall variations showed more prominent impacts on the corn yield than that of temperature variations. The reduction in average rainfall would instantly limit the crop growth rate and the corn yield irrespective of the temperature variations.

• 한국농공학회지
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• 제38권5호
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• pp.55-63
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• 1996

The situation and cause of bund collapse in steep sloping paddy area by a heavy rainfall of Chungbuk Province were investigated by field surveys. Shapes of paddy plots are irregular and average size of them is 12.6a. Surface, groundwater and plot-to-plot irrigations are being carried out in the study plots. The type of bund collapse can be divided as follows: overflow type and inundation type. The overflow type generally occurs at the bund with slope lacking the design standard. The inundation type damages paddy plots more seriously than the overflow type. It induces continuous bund collapse from a inflow-plot to a outflow-plot and includes lots of type (inside paddy) collapse, which results in much subsoil erosion. The installation of mountain stream weir and maintenance of mountain stream are proposed to prevent the inundation type collapse.

• 산업기술연구
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• 제31권A호
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• pp.87-94
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• 2011

This paper is results of analyzing characteristics of landslides occurred in Wonju, Gangwondo, around July, 16 in 2006, caused by heavy rainfall and antecedent precipitation by two typhoons of Ewiniar and Bilis. The main causes of landslides were antecedent precipitation during July 8 to 15, resulting in weakening grounds by increasing the degree of saturation previously, and the heavy rainfall during July 15 to 16. Most of landslides in natural slopes were transitional failures occurred along the boundary between the residual weathered soil in shallow depth and the hard mother rock. From results of conclusive analyses regarding 28 sites in Wonju region where landslides occurred, the slope length of landslide, the slope width, and the slope area were less than 50m with 71% of frequency, 20m with 79% of frequency and $300m^2$ of 64% of frequency respectively. The average value of slope angle was $35^{\circ}$. The most probable direction of slope was found to be north because of topography and advancing direction of seasonal rain front.