scholarly journals Characteristics and release of road runoff pollution under artificial rainfall intensity

2019 ◽  
Vol 358 ◽  
pp. 022064
Author(s):  
Dong Ni ◽  
Ming Zhao ◽  
Chao Wang ◽  
Shegang Shao
Keyword(s):  
Rainfall Intensity ◽  
Road Runoff ◽  
Artificial Rainfall ◽  
Runoff Pollution

The use of simulated rainfall to study the discharge process and the influence factors of urban surface runoff pollution loads

2015 ◽  
Vol 72 (3) ◽  
pp. 484-490 ◽  
Author(s):  
Li Qinqin ◽  
Chen Qiao ◽  
Deng Jiancai ◽  
Hu Weiping
Keyword(s):  
Surface Runoff ◽  
Rainfall Intensity ◽  
Influence Factors ◽  
Early Period ◽  
Urban Surface ◽  
Discharge Process ◽  
Simulated Rainfall ◽  
Surface Dust ◽  
Pollution Loads ◽  
Runoff Pollution

An understanding of the characteristics of pollutants on impervious surfaces is essential to estimate pollution loads and to design methods to minimize the impacts of pollutants on the environment. In this study, simulated rainfall equipment was constructed to investigate the pollutant discharge process and the influence factors of urban surface runoff (USR). The results indicated that concentrations of total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) appeared to be higher in the early period and then decreased gradually with rainfall duration until finally stabilized. The capacity and particle size of surface dust, rainfall intensity and urban surface slopes affected runoff pollution loads to a variable extent. The loads of TP, TN and COD showed a positive relationship with the surface dust capacity, whereas the maximum TSS load appeared when the surface dust was 0.0317 g·cm−2. Smaller particle sizes (<0.125 mm) of surface dust generated high TN, TP and COD loads. Increases in rainfall intensity and surface slope enhanced the pollution carrying capacity of runoff, leading to higher pollution loads. Knowledge of the influence factors could assist in the management of USR pollution loads.

scholarly journals Removal Effect of Basic Oxygen Furnace Slag Porous Asphalt Concrete on Copper and Zinc in Road Runoff

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5327
Author(s):  
Tianyuan Yang ◽  
Meizhu Chen ◽  
Shaopeng Wu
Keyword(s):  
Heavy Metal ◽  
Asphalt Concrete ◽  
Rainfall Intensity ◽  
Removal Rate ◽  
Basic Oxygen Furnace ◽  
Road Runoff ◽  
Basic Oxygen ◽  
Porous Asphalt ◽  
Bof Slag ◽  
Porous Asphalt Concrete

In order to improve the utilization efficiency of road runoff and the remove effects of heavy metals, porous asphalt pavements have been used as an effective measure to deal with heavy metals in road runoff. However, the removal effect on dissolved heavy metal is weak. In this paper, basic oxygen furnace (BOF) slag was used as aggregate in porous asphalt concrete to improve the removal capacity of heavy metal. Road runoff solution with a copper concentration of 0.533 mg/L and a zinc concentration of 0.865 mg/L was artificially synthesized. The removal effect of BOF slag porous asphalt concrete on cooper and zinc in runoff was evaluated by removal tests. The influence of rainfall intensity and time on the removal effect was discussed. The results obtained indicated that BOF slag porous asphalt concrete has a better removal effect on copper. The removal rate of copper is 57–79% at the rainfall intensity of 5–40 mm/h. The removal rate of zinc is more susceptible to the changes of rainfall intensity than copper. The removal rate of zinc in heavy rain conditions (40 mm/h) is only 25%. But in light rain conditions (5 mm/h), BOF slag porous asphalt concrete maintains favorable removal rates of both copper and zinc, which are more than 60%. The heavy metal content of runoff infiltrating through the BOF slag porous asphalt concrete meets the requirements for irrigation water and wastewater discharge. The results of this study provide evidence for the environmentally friendly reuse of BOF slag as a road material and the improvement of the removal of heavy metal by porous asphalt concrete.

scholarly journals Uji Laboratorium Pengaruh Kemiringan Lereng Terhadap Kejadian Longsoran Aliran Debris Pasir Merapi

2020 ◽  
Vol 16 (1) ◽  
pp. 23-34
Author(s):  
Bayu Seto Waseso Utomo ◽  
Jati Iswardoyo ◽  
Ruzardi Ruzardi
Keyword(s):  
Debris Flow ◽  
Laboratory Test ◽  
Early Warning ◽  
Debris Flows ◽  
Rainfall Intensity ◽  
Laboratory Scale ◽  
Artificial Rainfall ◽  
Rain Simulator

The debris flow that happen on the of Mount Merapi is really hard to be seen, therefore, it is necessary to conduct laboratory-scale simulations to know when debris flows will happen as regard to rainfall intensity and the slope of Mount of Merapi. This research examines the correlation between the slope and the potential for debris flow at 25 mm/h rainfall intensity. This will be a reference for early warning of landslides on Mount of Merapi. This research uses a tool such as flume that sized 3 x 5 x 0,15 m as a model of slope of Mount of Merapi, and artificial rainfall apparatus as the rain simulator. The simulation is conducted using five years rainfall intensity of 25 mm/h in combination of slope i.e. 15, 20, 25, 30 and 35 degrees whereas the material used to represent the sediment is in form of sand taken from Gendol River upstream with 4,75 mm passing mesh sieves. The result of this simulation is the steeper the slope is, the faster the duration for the rain to cause debris flow. This research can be continued with change variation of rainfall intensity to understand the debris flows behavior. Keywords: Debris flow, Mount of Merapi, laboratory test, rainfall intensity, flume model

Characteristics of heavy metal pollution in road runoff in the Nanjing urban area, East China

2020 ◽  
Vol 81 (9) ◽  
pp. 1961-1971
Author(s):  
Hongqin Xue ◽  
Li Zhao ◽  
Xiaodong Liu
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Rainfall Intensity ◽  
Rainfall Amount ◽  
Road Runoff ◽  
Residential Areas ◽  
Metal Concentrations ◽  
Maximum Rainfall ◽  
Average Rainfall ◽  
The Impact

Abstract An extensive field survey was conducted in four types of road area to study heavy metals in road runoff. Eleven rainfall events were monitored from February 2011 to March 2012, which were classified into four categories according to the relationship between peak of the rainfall amount, rainfall duration, and average rainfall intensity. Runoff samples were collected from overpass sections, college areas, residential areas, and road sidewalks. Heavy metal concentrations were obtained to investigate the outflow laws governing heavy metals in runoff. The concentration fluctuations of seven heavy metals were monitored to assess the influence of rainfall characteristics on metal concentrations. To estimate the impact of heavy metals on the water environment, the event mean concentrations (EMCs) were determined to describe the overall pollution degree of heavy metal in runoff, and then the EMC values of heavy metals in runoff were compared with surface water environmental quality standard thresholds. The results indicate that the EMC values of heavy metals varied widely in different rainfall fields and under the same rainfall at different sampling points. Average rainfall intensity has a significant impact on the EMC of heavy metal outflow, followed by maximum rainfall intensity and rainfall amount.

scholarly journals Determining the susceptibility of soils materials to erosion by rain-impacted flows

2016 ◽  
Author(s):  
P. I. A. Kinnell
Keyword(s):  
Drop Size ◽  
Rainfall Intensity ◽  
Rainfall Erosivity ◽  
Soil Erodibility ◽  
Flow Depth ◽  
Empirical Coefficient ◽  
Artificial Rainfall ◽  
Spatial Uniformity ◽  
Absolute Measure ◽  
The Relationship

Abstract. Conceptually, rain has a capacity to cause erosion (rainfall erosivity) and soils have a susceptibility to erosion by rainfall (soil erodibility) but no absolute measure of rainfall erosivity exists. Consequently, soil erodibility is nothing more than an empirical coefficient in the relationship between an index of rainfall erosivity and soil loss. Erosion by rain-impacted flow is influenced by the size, velocity and impact frequency of the raindrops but also flow depth and velocity. Experiments with artificial rainfall falling on sloping surfaces in the field usually do not enable flow depth and velocity to be well measured or controlled. Also, sprays produce artificial rainfall where the spatial uniformity in rainfall intensity, drop size and frequency is often less than desirable. Artificial rainfall produced by pendant drop formers can produce rainfall that has better spatial uniformity. Equipment for controlling flow depth and velocity over eroding surfaces has been developed and used to calibrate the effect of flow depth on the discharge of sediment by rain-impacted flow using artificial rainfall having a uniform drop-size distribution under laboratory conditions. Once calibrated, laboratory experiments can be conducted to rank soils according to their susceptibility to erosion under the flows impacted by the artificial rainfall under conditions where the erosive stress applied to the eroding surface is well controlled.

Column studies to determine mercury settling in road runoff

2012 ◽  
Vol 65 (3) ◽  
pp. 463-470
Author(s):  
XiaoJun Zuo ◽  
DaFang Fu ◽  
He Li
Keyword(s):  
Rainfall Intensity ◽  
Removal Rate ◽  
Initial Distribution ◽  
Road Runoff ◽  
Column Studies ◽  
Rainfall Characteristics ◽  
Settling Column ◽  
The Impact ◽  
The Relationship ◽  
Settling Process

A study was performed using a settling column to remove mercury (Hg) from road runoff. The emphasis was placed on the relationship between Hg removal and critical settling velocities, as well as the distribution of total suspended solids (TSS). The impact of rainfall characteristics and temperature on Hg removal was also discussed. Results indicated that Hg removal was significant within the initial 30 min of the settling process. The Hg removal rate increased with the decrease of critical settling velocity, and this trend became gradually significant, which could be used as an important reference for the optimization of sedimentation basin design. Hg removal at different settling times was significantly related to initial distribution of TSS. The impact of rainfall intensity on Hg removal was greater than other parameters of precipitation features, followed by rainfall. In addition, Hg removal was moderately related to temperature. The effect of antecedent dry periods on Hg removal was restricted by rainfall and rainfall intensity.

Enhancing the spatial rainfall uniformity of pressurized nozzle simulators

2017 ◽  
Vol 28 (1) ◽  
pp. 17-31 ◽  
Author(s):  
Alexandre Silveira ◽  
Jorge M.G.P. Isidoro ◽  
Fábio P. de Deus ◽  
Simone Siqueira dos Reis ◽  
Antônio Marciano da Silva ◽  
...  
Keyword(s):  
Urban Areas ◽  
Rainfall Intensity ◽  
Physical Models ◽  
Variation Coefficient ◽  
Rainfall Simulation ◽  
Operating Pressure ◽  
Content Type ◽  
Artificial Rainfall ◽  
Average Rainfall

Purpose Rainfall simulators are used on experimental hydrology, in areas such as, e.g., urban drainage and soil erosion, with important timesaving when compared to real scale hydrological monitoring. The purpose of this paper is to contribute to increase the quality of rainfall simulation, namely, for its use with scaled physical models. Design/methodology/approach Two pressurized rainfall simulators are considered. M1 uses three HH-W 1/4 FullJet nozzles under an operating pressure of 166.76 kPa and was tested over a 4.00 m length by 2.00 m width V-shaped surface. M2 was prepared to produce artificial rainfall over an area of 10.00 m length by 10.00 m width. The spatial distribution of rainfall produced from a single nozzle was characterized in order to theoretically find the best positioning for nozzles to cover the full 100 m2 area with the best possible rainfall uniformity. Findings Experiments with M1 led to an average rainfall intensity of 76.77-82.25 mm h−1 with a 24.88 per cent variation coefficient and a Christiansen Uniformity Coefficient (CUC) of 78.86 per cent. The best result with M2 was an average rainfall intensity of 75.12-76.83 mm h−1 with a 21.23 per cent variation coefficient and a CUC of 83.05 per cent. Practical implications This study contributes to increase the quality of artificial rainfall produced by pressurized rainfall simulators. Originality/value M2 is the largest rainfall simulator known by the authors worldwide. Its use on rainfall-runoff studies (e.g. urban areas, erosion, pollutant transport) will allow for a better understanding of complex surface hydrology processes.

scholarly journals Slope–velocity equilibrium and evolution of surface roughness on a stony hillslope

2017 ◽  
Vol 21 (6) ◽  
pp. 3221-3229 ◽  
Author(s):  
Mark A. Nearing ◽  
Viktor O. Polyakov ◽  
Mary H. Nichols ◽  
Mariano Hernandez ◽  
Li Li ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Rainfall Intensity ◽  
Overland Flow ◽  
Surface Condition ◽  
Relative Increase ◽  
Unique Function ◽  
Slope Gradient ◽  
Hydraulic Roughness ◽  
Artificial Rainfall ◽  
Discharge Rates

Abstract. Slope–velocity equilibrium is hypothesized as a state that evolves naturally over time due to the interaction between overland flow and surface morphology, wherein steeper areas develop a relative increase in physical and hydraulic roughness such that flow velocity is a unique function of overland flow rate independent of slope gradient. This study tests this hypothesis under controlled conditions. Artificial rainfall was applied to 2 m by 6 m plots at 5, 12, and 20 % slope gradients. A series of simulations were made with two replications for each treatment with measurements of runoff rate, velocity, rock cover, and surface roughness. Velocities measured at the end of each experiment were a unique function of discharge rates, independent of slope gradient or rainfall intensity. Physical surface roughness was greater at steeper slopes. The data clearly showed that there was no unique hydraulic coefficient for a given slope, surface condition, or rainfall rate, with hydraulic roughness greater at steeper slopes and lower intensities. This study supports the hypothesis of slope–velocity equilibrium, implying that use of hydraulic equations, such as Chezy and Manning, in hillslope-scale runoff models is problematic because the coefficients vary with both slope and rainfall intensity.

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