Storm Runoff Research Articles

Probabilistic model for the annual number of storm overflow discharges in a stormwater drainage system

The paper presents an attempt to develop a probabilistic model for predicting an annual number of storm overflow discharges. Forecasting the occurrence of an overflow discharge event involved the application of the logistic regression, which does not require the development of complex hydrodynamic catchment models. The performed calculations showed that the logistic regression model can be successfully used to evaluate the performance of the emergency overflow weir. The resultant logit model eliminates the necessity to develop hydrodynamic models, to conduct continuous measurements of the flow intensity in the stormwater drainage system and to collect detailed information on the characteristics of the subcatchments within the analyzed catchment. The hydrodynamic model was used to simulate the annual number of discharges. The analysis of the results demonstrated that they are in the range of stochastic values, which indicates an application-related character of the method.

Characteristics of Storm Runoff and Analysis of Its Correlation with Forest Properties

Characteristics of Storm Runoff and Analysis of Its Correlation with Forest Properties

Assessment of the effect of rainfall dynamics on the storm overflow performance

Abstract Assessment of the effect of rainfall dynamics on the storm overfl ow performance. This research study analyzes the effect of the rainfall characteristics (total and maximum 10-, 15- and 30-minute rainfall depth, its duration, the dry weather period) on the performance of the emergency overflow weir located at the inflow to an existing treatment plant. The analyses used the numerical calculation results of the inflow hydrographs performed in the SWMM (Storm Water Management Model) program on the basis of six-year-long rainfall measurement sequence. The obtained simulation results for the analysed catchment allowed for the performance of statistical analyses, which demonstrated that the volume of stormwater discharge, the maximum instantaneous flow and the share of stormwater volume discharged through the emergency overflow weir in relation to the total volume of the inflow hydrograph from the catchment are affected by the maximum 30-minute rainfall depth, whereas the discharge duration is affected by the depth of the catchment rainfall layer. Taking into account the results of statistical and hydraulic calculations it can be concluded that in the case of the analysed catchment the performance of the emergency overflow weir is affected to the greatest extent by the rainfall intensity distribution.

Green roofs may cast shadows

A “green roof” is a roof on a structure created by humans, which has a plant community (and various hangers-on) established on it. There are many potential benefits of green roofs, ranging from moderation of local microclimates to modulations of storm runoffs, and green roofs may serve the enhancement of biodiversity conservation, as well. Green roofs would seem to be quintessential examples of a “novel ecosystem”. Here, I first outline some dimensions of the novelty that warrant more research. Green roofs can provide many opportunities for creative ecological research in the assembly, dynamics and functioning of novel ecosystems. Then, I briefly discuss some potential biodiversity hazards that are created along with green roofs. Recognizing these potential “shadows” of a green roof by no means belies the strong and compelling rationale for promoting green roofs, in terms of sustainability and livability of human structures; instead the points I raise are simply issues which should be evaluated and quantified when promoting green roofs broadly as a design strategy in new buildings or retrofitted existing structures.

Potential effects of sediment processes on water quality of an artificial reservoir in the Asian monsoon region

Sediment processes in lakes may affect water chemistry through the internal loading of phosphorus, ammonia, and sulfides released under anoxic conditions. Lake Soyang is a deep warm monomictic reservoir with a dendritic shape, located in the Asian summer monsoon region, South Korea. During summer, the lake is stratified and receives a large nutrient input via storm runoff, which forms a turbid intermediate layer with high concentrations of suspended particles. The lake water, the main inflowing stream (the Soyang River), bottom sediment, and porewater of the lake sediments were studied over a 2-year period (2012–2013). After intensive monsoon rain events, particulate organic carbon (POC), total phosphorus (TP), and turbidity were high in the inflowing water (C: 1.21 mg L−1 in June 2013) and in the metalimnion (2.8 mg L−1, 17.6 μg L−1, and 58.5 NTU, respectively in July 2013). Higher concentrations of iron (Fe) and manganese (Mn) were also associated with the turbid intermediate layer (37 and 8 μg L−1, respectively, in July 2013). During the summer stratification period, oxygen started to deplete in the hypoliminion (down to 0.5 mg L−1 in September 2013), and sediment became anoxic, showing negative oxidation redox potential (ORP) in core samples. Diffusion of dissolved inorganic P and ammonia from sediment to the water column can be substantial, considering the concentration difference between the porewater and hypolimnetic water. Fe and Mn were abundant in the sediment porewater at the dam site, implying inorganic nutrients and minerals are well transported along the 60 km long lake axis by the density current of storm runoff. Sulfate and reduced sulfur were larger in the porewater of the top sediment than in the lower layer of the sediment core (below 10 cm). The results show that substantial amounts of inorganic nutrients and minerals are supplied to the lake by storm runoffs during monsoon and distributed through the lake by a density current, controlling the material cycle and flux at the sedimen tsurface.

분포형 강우유출모형 KIMSTORM을 이용한 침수실적자료와의 비교를 통한 레이더강우의 효용성 연구

The purpose of this study is to explore the effectiveness of dual-polarization radar rainfall by comapring with the flood inundation record map through KIMSTORM(Grid-based KIneMatic wave STOrm Runoff Model). For Namgang dam () watershed, the Bisl dual-polarization radar data for 3 typhoons (Khanun, Bolaven, Sanba) and 1 heavy rain event in 2012 were prepared. For both 28 ground rainfall data and radar rainfall data, the model was calibrated using observed discharge data at 5 stations with , Nash and Sutcliffe Model Efficiency (ME) and Volume Conservation Index (VCI). The calibration results of , ME and VCI were 0.85, 0.78 and 1.09 for ground rainfall and 0.85, 0.79, and 1.04 for radar rainfall respectively. The flood inundation record areas (SY and MD/SG district) by typhoon Sanba were compared with the distributed modeling results. The spatial distribution by radar rainfall produced more surface runoff from the watershed and simulated higher stream discharge than the ground rainfall condition in both SY and MD/SG district. In case of MD/SG district, the stream water level by radar rainfall near the flood inundation area showed 0.72 m higher than the water level by ground rainfall.

Can Urban Trees Reduce the Impact of Climate Change on Storm Runoff?

Can Urban Trees Reduce the Impact of Climate Change on Storm Runoff?

The Effects of Storm Runoff on Water Quality and the Coping Strategy of a Deep Canyon-Shaped Source Water Reservoir in China.

Storm runoff events in the flooding season affect the water quality of reservoirs and increase risks to the water supply, but coping strategies have seldom been reported. The phenomenon of turbid current intrusion resulting in water turbidity and anoxic conditions reappearing after storm runoff, resulting in the deterioration of water quality, was observed in the flooding season in the deep canyon-shaped Heihe Reservoir. The objective of this work was to elucidate the effects of storm runoff on the Heihe Reservoir water quality and find a coping strategy. In this study, an intensive sampling campaign measuring water temperature, dissolved oxygen, turbidity, nutrients, and metals were conducted in the reservoir over a period of two years, and the water-lifting aerators were improved to achieve single aeration and a full layer of mixing and oxygenation functions using different volumes of gas. The operation of the improved water-lifting aerators mixed the reservoir three months ahead of the natural mixing time, and good water quality was maintained during the induced mixing period, thereby extending the good water quality period. The results can provide an effective coping strategy to improve the water quality of a source water reservoir and ensure the safety of drinking water.

Evaluation of Seasonal and Large Storm Runoff Volume Capture of an Infiltration Green Infrastructure System

Green infrastructure, including stormwater control measures (SCMs), meant to reduce runoff volumes are typically designed for smaller, frequently occurring events (e.g., 2.5 cm or the 2-year, 24 h event), and their performance are not always considered for larger, more infrequent extreme event management. However, even during larger rainfall events, a SCM is still capturing at least the design rainfall and reducing runoff volume. Further, if a SCM relies on infiltration as its primary volume reduction strategy, infiltration continues throughout the rainfall event indicating that SCMs can be considered in flood mitigation strategies. This phenomenon of greater than designed runoff volume removal has been noted in several infiltrating SCMs, and the present work uses the Villanova green infrastructure site comprising an infiltration trench with pretreatment (i.e., linear vegetated SCMs) designed for the 2.5 cm rainfall event as a basis for discussion. The analysis focuses on the infiltration trench volume capture and includes the effect of storm volume, duration, intensity, and antecedent dry time. Seasonally, infiltration rates within the infiltration trench were shown to vary with temperature in the lower ponding depths. While there was some decrease in infiltration rates in the lowest depth increment (0–0.3 m) in the systems’ third winter and spring seasons, there was a general increase in infiltration rates over the course of the study period demonstrating the infiltrating SCMs’ ability to be a reliable stormwater management solution. With regards to large storm event performance, the results from 2 years of monitoring the infiltration SCM system have been quite impressive. The system has consistently met the volume reduction design goals and usually exceeded them by significantly contributing to storm runoff mitigation during large extreme events. The infiltration SCM system captured and removed at least 59% of the volume of every storm event analyzed from July 2012 through June 2014, with an average of 93% capture for events greater than the design volume of 2.5 cm. Furthermore, there were 159 storm events totaling 259 cm of rainfall during the study period. Given the drainage area loading, approximately 2,365 m3 of rainfall entered the linear vegetated component, with approximately 420 m3 (18%) reaching the infiltration trench and only 103 m3 (4%) of rainfall determined to overflow from the system. These performance results demonstrate that infiltration SCMs can reduce significant volumes of runoff during larger events and that new design strategies are needed to account for their performance.

Evolutionary Multi-Objective Optimal Control of Combined Sewer Overflows

This paper presents a novel multi-objective evolutionary optimization approach for the active control of intermittent unsatisfactory discharges from combined sewer systems. The procedure proposed considers the unsteady flows and water quality in the sewers together with the wastewater treatment costs. The distinction between the portion of wastewater that receives full secondary treatment and the overall capacity of the wastewater treatment works (including storm overflow tanks) is addressed. Temporal and spatial variations in the concentrations of the primary contaminants are incorporated also. The formulation is different from previous approaches in the literature in that in addition to the wastewater treatment cost we consider at once the relative polluting effects of the various primary contaminants in wastewater. This is achieved by incorporating a measure of the overall pollution called the effluent quality index. The differences between two diametrically opposed control objectives are illustrated, i.e. the minimization of the pollution of the receiving water or, alternatively, the minimization of the wastewater treatment cost. Results are included for a realistic interceptor sewer system that show that the combination of a multi-objective genetic algorithm and a stormwater management model is effective. The genetic algorithm achieved consistently the frontier optimal control settings that, in turn, revealed the trade-offs between the wastewater treatment cost and pollution of the receiving water.

Study on an Automated Construction Method of Minute Road Segments aiming at Urban Storm Runoff Analysis

Study on an Automated Construction Method of Minute Road Segments aiming at Urban Storm Runoff Analysis

Functional approach to exploring climatic and landscape controls on runoff generation: 2 Timing of runoff storm response

AbstractHortonian overland flow, Dunne overland flow, and subsurface stormflow are the three most dominant mechanisms contributing to both the volume and timing of streamflow in headwater catchments. In this paper, guided by the Dunne diagram, we explore the impacts of climate, soil, and topography on estimated probability distributions of the travel times of each of these three runoff components. In each case, these are expressed in terms of the Connected Instantaneous Response Functions (CIRF) and account for the dynamics of their individual partial effective contributing areas that retain the connectivity to the outlet (instead of the whole catchment area). A spatially distributed hydrological model is used to derive the CIRFs numerically under multiple combinations of climate, soil, and topographic properties. The mean travel times and dimensionless forms of the CIRFs (i.e., scaled by their respective mean travel times) are used to examine both advective and dispersive aspects of catchment's runoff routing response. It is found that the CIRFs, upon nondimensionalization, collapsed to common characteristic shapes, which could be explained in terms of the relative contributions of hillslope and channel network flows, and the size of runoff contributing areas. The contributing areas, particularly for the Dunne overland flow, are themselves found to be governed by the competition between drainage of and recharge to the water table, and could be explained by a dimensionless drainage index which quantifies this competition. The study also reveals simple indicators based on landscape properties that can explain the magnitude of travel times in different catchments.

The Influence of Sewage System on the Functioning and Quality of Krakow’s Watercourses

The content of heavy metals, pH, Eh, and EC were measured for the Vistula River and its two tributaries, Prądnik-Białucha and Wilga, functioning as rainwater collectors for Krakow. Water sediments were collected from several inlets of the rainwater canals into the Prądnik-Białucha and Wilga. The Vistula was examined to catch the change of water environment quality of those two tributaries as well as storm overflow systems installed on both its left and right bank. In this last case the research was based on the bottom sediments of the storm overflow system, from its inlets into the Vistula River, and from the inside of the waste water collector. Also, samples of suspension and water were collected where the bridges are located and also near Dębnicki bridge bottom sediments. The sampling was conducted in 2004-2005 but because of financial constraints after ten years the tests were not repeated, but it was decided to publish the results. The attention was paid to the Cd and Pb content in the sediments of sanitary catch basins from the Wilga and the Prądnik, in Vistula sediments from storm overflow system, in the siphon, in the suspension of Vistula waters, and in fine-grain river silts.

Assessing the effectiveness of green infrastructures on urban flooding reduction: A community scale study

The risk of urban flooding is increasing as a result of rapid urbanization. Green infrastructure (GI) is an emerging planning and design concept to mitigate urban flooding. A community scale simulation model was developed to quantify the effectiveness of GI on reducing the volume and peak flow of urban flooding. Five scenarios, namely expanding green space, converting to concave green space, constructing a runoff retention structure, converting to porous brick pavement, and combining previous four measures were considered for an urban community in Beijing. The outcomes showed that the model performed responsively to simulate the storm runoffs at varying recurrence intervals under these scenarios. Simulation results showed that, the impervious surfaces have the most contribution to the storm runoffs of the community. The reduction capacity for single GI facility was limited, especially in bigger storm events. The integrated GI configuration has effective reduction percentage, such as the total runoff reduction was ranged from 100% to 85.0% and the peak flow reduced 100–92.8%. This work can guide local planners and decision makers in their actions on green infrastructures in community scale.

충주댐 유역 홍수추적을 위한 소백산 레이더 강우자료의 적용성 검토

본 연구는 충주댐 유역(<TEX>$6,625.8km^2$</TEX>)을 대상으로 지점강우와 소백산 이중편파 레이더강우자료를 격자기반 분포형 강우-유출 모형인 KIMSTORM(KIneMatic wave STOrm Runoff Model)에 적용하여 홍수추적을 수행하여 레이더의 적용성을 검토하였다. 2012년 4개의 강우 이벤트(집중호우, 카눈, 볼라벤, 산바)에 대하여 한강홍수통제소로부터 보정된 소백산 레이더 강우자료를 제공받아 사용하였다. 레이더 강우와 지점 강우를 비교분석한 결과, 41개 지점의 지상강우보다 레이더의 면적평균강우량을 비교한 결과, 강우의 시공간적 패턴은 상당히 일치하였고 지상강우에 대한 레이더 강우의 비율은 0.97로 분석되었다. 이후 분포형 홍수추적을 위해 KIMSTORM을 이용하였으며, 격자크기 <TEX>$500{\times}500m$</TEX> 해상도의 198행<TEX>${\times}$</TEX>231열의 총 45,738개의 셀로 모형을 구축하였다. KIMSTORM 모형의 보정 결과, 평균 <TEX>$R^2$</TEX>(coefficient of determination), ME(model efficiency), VCI(volume conservation index)는 지상강우의 경우, 각각 0.83, 0.68, 1.10로 분석되었고, 레이더강우의 경우는 각각 0.80, 0.62, 1.08의 결과를 보였다. The purpose of this study is to evaluate the availability of dual-polarization radar rain for flood routing in Chungju Dam watershed(<TEX>$6,625.8km^2$</TEX>) using KIMSTORM (Grid-based KIneMatic wave STOrm Runoff Model). The Sobaek dual-polarization radar data for 1 heavy rain and 3 typhoon(Khanun, Bolaven, and Sanba) events in 2012 were obtained from Han River Flood Control Office. The spatio-temporal patterns between the two data were similar showing the ratio of radar rain to ground rain with 0.97. The KIMSTORM was set to <TEX>$500{\times}500m$</TEX> resolution and a total of 45,738 cells(198 rows<TEX>${\times}$</TEX>231 columns) for the watershed. For radar rain and 41 ground rains, the model was independently calibrated using discharge data at 3 streamflow gauging stations(YW1, YC, and CJD) with coefficient of determination(<TEX>$R^2$</TEX>), Nash and Sutcliffe Model Efficiency(ME), and Volume Conservation Index(VCI). The <TEX>$R^2$</TEX>, ME, and VCI 0.80, 0.62 and 1.08 for radar rain and 0.83, 0.68 and 1.10 for ground rain respectively.

Application of distributed KIneMatic wave STOrm Runoff Model (KIMSTORM) for flood simulation considering dam release in the NamHan river basin of Korea

This study describes the application of distributed hydrologic model, KIneMatic wave STOrm Runoff Model (grid-based KIMSTORM) to simulate the flood discharge considering dam releases during storm event. The model adopts single flowpath algorithm, and simulates surface and subsurface water depth by routing the water balance of hydrologic components at each cell. For the 12,373 km2 watershed having four dams (two multipurpose, one hydroelectric, and one flood regulation) of NamHan river in Korea, the model was calibrated and verified at five stream locations (two on main and three on tributary) for six flood events with the average Nash–Sutcliffe model efficiency of 0.77. The release amount from dam cell was successfully delivered to the next down cell as an inflow and propagated to the downstream because the model solves the flow routing with hydrologic approach. From the spatiotemporal model results, we could trace the growth of overland flow discharge, the flood flow progress, and the regulation effect by the dams.

A Modeling Method to Evaluate the Management Strategy of Urban Storm Runoff

Design of treatment strategy considering the behavior of pollutant with respect to runoff hydrograph is important for effective management of storm runoff. In this study, a mathematical model for storm runoff management was developed. The model determines the storm runoff management strategy and the associated probability under the constraint of regulatory discharge limit, and can quantify the volume or fraction of a storm runoff that should be treated. The model application was demonstrated for total suspended solids (TSS) and benzo(a)pyrene (BaP) in urban storm runoff. The samples were collected from 15 storm runoff events in six impervious sites in Beijing urban area, and. For TSS, the probability that the whole runoff can be discharged without treatment was 46 %, and the whole runoff should be intercepted for treatment was 31 %. While under the constraint of the discharge limit for BaP, the dominant strategy was that the whole runoff should be intercepted for treatment, with a probability of 88 %. Compared with the treatment strategies, it was noted that the need for runoff treatment was more for BaP than TSS. This was because the pollution level of TSS was lower than BaP from the aspect of compliance with discharge limit. Because the most seriously contaminated and toxic pollutant should be taken as the primary indicator for runoff treatment, the treatment option for the study area should follow the strategies for BaP. This methodology may be applied for other pollutants in different watersheds.

Areal rainfall intensity distribution over an urban area and its effect on a combined sewerage system

The application of 21 pluviometers over the whole area of Łódź, Poland, enabled an examination of areal distribution of intense rainfalls during 2010–2011. On the basis of collected data the distribution of rainfall intensity was analysed and a circular zone model with exponential shape in all directions has been proposed for describing rain storms. Also, the velocity of storm zone movement between 2 and 30 km/h was determined. Using the SWMM 5.0 software, adapted for non-standard use, runoff from three real catchments and combined storm overflow discharge was examined for selected measured rainfalls. An effect of storm zone range and movement was also studied for the same catchments using model storms. It was confirmed that using data from the city pluviometric network enables significantly better simulation results for CSO overflows to be obtained compared to an option based on a single pluviometric station, especially for large catchments greater than 200 hectares.

Comparison of an Automated and Manual Method for Calculating Storm Runoff Response in Ungauged Catchments in Serbia

Abstract Estimation of discharge from ungauged catchments based on rainfall-runoff analysis is a very frequent task in engineering hydrology. Very often, design discharges are needed for streams or small rivers where no streamflow data is available (river training works, culverts, small hydropower plants, etc). This study uses a well established lumped hydrologic rainfall-runoff model to compare two different approaches in data preparation. The traditional method of manual obtainment of catchment parameters was compared to a more contemporary methodology using automation with geographic information systems, digital terrain models and available datasets, with an emphasis on open-source tools and freely available datasets. Both techniques were implemented on more than 100 catchments in Serbia to calculate storm runoff response. The results show minor differences that are insignificant compared to the time and resources saved with the automated techniques. The use of such automated methods enables the hydrologist to direct more attention to other factors that influence discharge even more than catchment parameters, such as rainfall, soil and land use data.

Hydrological modeling of typhoon-induced extreme storm runoffs from Shihmen watershed to reservoir, Taiwan

Typhoon-induced extreme storm runoffs often cause flood hazards. In this study, a hydrological model (HEC-HMS) was applied to Shihmen watershed located in Taiwan. Three typhoon-induced storm events, with return period ranging from 1 to 90 years, were used in case studies to characterize storm runoff. With a 5-year storm for model calibration, model parameters were carefully calibrated through the comparison between model simulated and observed flows at a stream gage station. The calibrated model was then verified for a 90-year storm and a 1-year storm event. Results indicate that the calibrated and verified HEC-HMS hydrological model is capable of providing satisfactory predictions of the typhoon-induced extreme storm runoff to support reservoir operation and flood hazard mitigation. Based on model simulations, typhoon-induced water table increases for different initial water volumes at Shihmen Reservoir was derived by adding storm-runoff volume to the reservoir’s initial elevation-volume rating curve. Water tables above the top elevation of the dam in the reservoir indicate the need for immediate water releases to avoid the risk of overflow over the dam.