• 환경영향평가
• /
• 제24권2호
• /
• pp.163-174
• /
• 2015

도시화로 인하여 자연적인 물순환이 파괴되었고 이는 도시 홍수 등의 문제를 야기하였다. 이를 해결하기 위해, 개발 이전의 상태로 물순환을 회복하는 것을 목표로 하는 저영향개발(Low Impact Development, LID) 기법이 대두되었다. 기존의 LID관련 연구는 주로 유출 저감 효과에 집중되어 있었으며 강우 유형에 따른 LID 기법별 효과에 관한 연구는 부족한 실정이다. 본 연구는 수문 모의를 통하여 LID의 물수지 개선 효과를 강우 및 공간 유형별로 정량적으로 평가하는 것을 목표로 하였다. 경기도 하남의 택지개발지구의 한 블록을 연구 대상지로 하여, 개별 LID시설의 모의가 가능한 STORM모형을 사용하였다. 강우 유형은 강우 강도에 따라서 두 가지로 구분하였으며 모의한 LID시설은 옥상녹화, 투수성 포장, 식생수로에 한하였다. 연구 결과 LID의 물수지 개선은 극한 강우 사상보다 낮은 강우강도의 강우에 더 효과적이며 기법별로는 낮은 강우강도일 때에는 투수포장, 높은 강우강도일 때에는 생태수로가 가장 낮은 유출률과 높은 침투율을 나타냈다. 본 연구 결과는 향후 물순환을 고려한 공간 계획 시 참고자료로 활용될 수 있을 것이다.

• 한국습지학회지
• /
• 제10권2호
• /
• pp.105-114
• /
• 2008

급격한 도시화에 따른 불투수 면적과 인구의 증가로 인하여 많은 양의 오염물이 배출되고 있고, 이로 인하여 지역 하천의 수질이 심각한 위협을 받고 있다. 특히 강우시 지표면의 쌓인 다량의 오염물질은 오수관으로 유입된 후 월류되어 하천으로 유입되기 때문에 이에 대한 연구와 관리시스템의 마련이 시급하다. 이에 본 연구에서는 청주시를 대상으로 도시배수구역의 유출특성을 분석하고 이에 영향을 미치는 인자를 추출 및 분석할 수 있는 통계적 분석방법을 제시 것에 목적이 있다. 선행된 연구를 참고하여 강우강도, 선행건기일수, 강우량과 5개의 수질분석항목(CODcr, BOD, SS, TN, TP)과의 관계를 통계적인 방법으로 분석하였으며, 강우시 도시유출특성을 지배하는 인자에 대한 규명을 시도하였다.

• 한국환경과학회지
• /
• 제16권7호
• /
• pp.805-811
• /
• 2007

The purpose of this study was to invesitigate relationship between rainfall water quality and precipitation characteristic during the accumulated rainfall and rainless period. As the results of the analysis, rainfall water quality was improved in the rainfall duration. Correlation coefficients between rainwater quality and accumulated rainfall were $0.88{\sim}0.99$ except $Cl^-$. and that between rainless period and initial rainfall water quality were $0.62{\sim}0.75$. During the Asian dust event, concentration of the turbidity, BOD and electric conductivity were high. Therefore, it shows that the rainfall water quality is effected by atmospheric conditions before the rainfall events.

• 한국농공학회논문집
• /
• 제54권4호
• /
• pp.9-17
• /
• 2012

This study was aimed to characterize non-point source (NPS) pollutant runoff and estimate event mean concentrations (EMCs) from a small rural watershed located at the headwater area of the Gyeongan stream. The study watershed consists of the two major landuse, forest (72 %) and paddy field (28 %). The nine rainfall events ranging from 18.5 to 192.6 mm in amount were monitored in this study. Stream flow was measured at the watershed outlet using a water level gauge, while a number of water samples for each event were collected and analysed for water quality. Event pollutant loads varied greatly depending on rainfall events varying from 22.6 to 3,134.2 mg/L, 0.32 to 24.56 mg/L, 0.090 to 1.320 mg/L, and 2.3 to 149.8 mg/L for SS, TN, TP, and COD, correspondently. The respective mean EMCs were estimated by 104.2, 1.00, 0.168, and 7.9 mg/L. The Pearson correlation analysis showed that COD EMC was significantly correlated with those of SS, TN, and TP. Rainfall runoff ratio appeared to be negatively correlated with EMCs of SS, TP, and COD, although not statistically significant. The event loads from the largest rainfall was greater than the sum of those from the remaining eight events. The study results suggest that the appropriate management of intensified storm events are of greater importance in curbing NPS loads, while the estimated EMCs provide base data for the unit pollutant loads determination for the forest-paddy composite upstream watershed.

• 한국물환경학회지
• /
• 제37권2호
• /
• pp.103-113
• /
• 2021

In this study, an Excel-based model (ROADMOD) was developed to estimate pollutant loading from the road and evaluate BMPs. ROADMOD employs the Chezy-Manning equation and empirical expression for estimating surface runoff, and power function for pollutant buildup, and exponential function for pollutant washoff in SWMM. The results of model calibration for buildup and washoff using observed data revealed a good match between the simulation results and the observed data. The long-term surface runoff and sediment simulated by ROADMOD demonstrated a good match with those by SWMM with 2 ~ 14% of relative error. The shorter sweeping interval (within 8 days) remarkably decreased sediment loads from the road. It was found that the effect of reducing sediment loads from the road was greatly affected not only by the sweeping interval but also by sweeping on the day before a rainfall event. The 48% of removal efficiency of sediment loads from the road was achieved with 26 times of road sweeping per year when sweeping was performed on the day before the rainfall event. A 4-day sweeping interval showed similar removal efficiency (48%) with 96 times of sweeping per year. It is considered that the road sweeping on the day before a rainfall event could maximize the effect of reducing the non-point source pollution from the road with minimization of the number of road sweeping. So, the road sweeping on the day before a rainfall event can be considered as one of the useful and best management practices (BMPs) on road.

• 한국지구과학회지
• /
• 제33권7호
• /
• pp.596-607
• /
• 2012

R-Z 관계식은 레이더 강우추정의 정확도를 결정하는 중요한 요소이다. 본 연구에서는 캐나다 궤벡주의 셍레미에서 홍수를 야기한 폭우사례에서 관측된 우적계 및 레이더 자료를 이용하여 레이더 강우추정 시 우적계 자료에서 도출된 R-Z 관계식의 효과를 분석하였다. 이를 위하여 맥길 S-밴드 레이더에서 시간 분해능 2.5분과 공간 분해능 $1^{\circ}{\times}250m$로 관측된 레이더 반사도를 사용하였다. 레이더 반사도 자료에서는 폭우를 동반한 강우세포가 셍레미를 통과한 것으로 관측되었지만 우량계 관측망에서는 낮은 공간 분해능으로 인하여 이 세포가 관측되지 않았다. 셍레미에서 30분과 1시간 최대 누적 강우량은 각각 39 mm와 42 mm였다. 강우사례 동안 두 개의 우적계(POSS; Precipitation Occurrence Sensor System)가 사용되었다. 하나의 우적계는 레이더 반사도와 우적계 반사도를 비교하여 레이더 반사도를 보정하고 다른 우적계는 R-Z 관계식을 유도하는데 사용되었다. 기후학적 R-Z 관계식을 사용하였을 때 보다 반사도에 의존적인 우적계에서 유도된 관계식을 사용하였을 때 강우 추정 오차가 크게 줄었다. 일 누적 강우량에 대하여 편차는 +12%에서 -2%, 평균제곱근오차가 16%에서 10%로 줄었다. 우적계에서 도출된 R-Z 관계식으로 추정된 레이더 강우장을 이용하였을 때 홍수사례에 대하여 강우 발생 시간 및 강우량이 잘 일치하였다.

• 한국물환경학회지
• /
• 제22권4호
• /
• pp.666-671
• /
• 2006

Effects of a rainfall event (July 28, 2005) on the hydrochemical characteristics of the Jungrang river, the biggest tributary of the Han river, was investigated. Significant spatial variations in the hydrochemical characteristics were observed. At JR2 location, concentrations of T-N and T-P were relatively low indicating occurrence of active oxidation in the stepped drop structure. At JR3 location, concentrations of Na, K, Cl, $NH_4-N$ and EC were elevated suggesting increased discharge from the nearby waste-water treatment plant and tributaries. The rain event diluted major dissolved ion concentrations in the river by 12~52%. The $NO_3-N$ levels were preserved during the rain then increased about twofold after rainfall, suggesting increased discharge of nitrate-contaminated groundwater. Heavy metals including Cd, Co, Cr, Cu and Pb were not detected in all water samples and the leachates from surface sediment samples. Concentrations of Fe, Mn, Al and Zn were below the Korean Drinking Water Guideline. Results of this study suggested that establishment of water-quality monitoring protocols describing temporal and spatial variations in parameters sensitive to rainfall events, relatively steady factors, and contaminant sources is required.

• 한국물환경학회지
• /
• 제27권5호
• /
• pp.572-579
• /
• 2011

We have examined the runoff characteristics of nonpoint source (NPS) in fields. Two monitoring sites were equipped with an automatic velocity meter and water sampler. Monitoring was conducted at fields 1 and field 2 during the rainfall event. Ten rainfall-runoff events were monitored and analyzed during the study period. The results show that runoff occurred if daily rainfall and intensity were higher than 40 mm and 1.6 mm/hr except a few extreme rainfall events with very high intensity. Runoff of field 1 was approximately twice of that of field 2. Event mean concentrations (EMC) and pollution load of analyzed water quality indices were also higher in field 2 than in field 1. Especially, TN load from field 2 was $75.4 mg/m^2$ and was about 5 times higher than that from field 1. Analysis of Pearson correlation coefficient of water quality parameter indicates that besides of TN all items in fields 1 have tight relationship respectively (p < 0.01). But those of fields 2 have a significant (p < 0.05). Estimating units loading of NPS, we suggested that variable such as soil texture, rainfall amount and intensity and slope were needed to be considered from agricultural landuses. The results of this study can be used as a basic data in the development and implementation of total maximum daily loads (TMDL) in Korea.

• 한국환경과학회지
• /
• 제20권3호
• /
• pp.417-426
• /
• 2011

This study was conducted to investigate runoff characteristics of non-point pollutants source at the urban and rural zones in sangju area. The monitoring was conducted with seven events for ten months and Event mean Concentration(EMC) and First Flush Effect(FFE) of SS and BOD were calculated on the result of the water quality parameters. During rainfall event, the peak concentrations of SS and BOD were observed after 3~4 hours of rainfall in rural areas. Whereas, the peak concentrations occurred within 1~2 hours after rainfall and then the highest concentration of NPS pollutants sharply decreased, showing strong first flush effect in urban areas. The cumulative load curves for NPS pollutants showed above the $45^{\circ}$ straight line, indicating that fist flush effect occurred in urban areas. The mean SS EMC values of rural areas ranged from 0.9~3.3mg/L, it was higher value when compare to urban areas. While the mean BOD values of urban areas were shown the highest values.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• 제2권1호
• /
• pp.29-36
• /
• 1998

An instantaneous unit sediment graph (IUSG) model is investigated for prediction of sediment yield from an upland watershed in Northwestern Mississippi. Sediment yields are predicted by convolving source runoff with an IUSG. The IUSG is the distribution of sediment from an instantaneous burst of rainfall producing one unit of runoff. The IUSG, defined as a product of the sediment concentration distribution (SCD) and the instantaneous unit hydrograph (IUH), is known to depend on the characteristics of the effective rainfall. The IUH is derived by the Nash model for each event. The SCD is assumed to be an exponential function for each event and its parameters were correlated with the effective rainfall characteristics. A sediment routing function, based on travel time and sediment particle size, is used to predict the SCD.