Improved methods to estimate the effective impervious area in urban catchments using rainfall-runoff data

Abstract The concentration of human activities in coastal cities results in the increase of nutrient salts released into the coastal environment and is identified as a major environmental problem for coastal zone management. Large amounts of nitrogen and phosphorus are transported by rainwater-runoff from urban catchments to coastal zones during episodic rainfall events inducing eutrophication problems and increasing the risk of red tide occurrence. This study used a coupled model based on the Storm Water Management Model (SWMM) and Environment Fluid Dynamic Code (EFDC) to simulate the rainfall-runoff pollution load and its effects on eutrophication in Shenzhen Bay, southern China. A storm event of 2014 was used to build the modeling scenarios and thus analyzed the spatial-temporal variation of the rainfall-runoff pollution. The results indicated that: (i) rainfall-runoff pollution loads accounted for 60–80% of the total pollution loads, and rainfall-runoff pollution can result in a short-term impact pollution load on the receiving seawater body; (ii) the transportation of nutrient salts in the coastal zone and the nutrient salts absorbing process by algae are at different times, which suggests urban rainfall-runoff pollution has evidently an effect on variation of the concentration of chlorophyll-A in the bay, and with increasing distance to the city, the seawater body is gradually less affected by rainfall-runoff pollution.

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Using Remote Sensing Based Metrics to Quantify the Hydrological Response in a City

Water ◽

10.3390/w11091763 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1763 ◽

Cited By ~ 1

Author(s):

Charlotte Wirion ◽

Willy Bauwens ◽

Boud Verbeiren

Keyword(s):

Remote Sensing ◽

Potential Evapotranspiration ◽

Remote Sensing Data ◽

Hyperspectral Data ◽

Hydrological Response ◽

Area Index ◽

Impervious Area ◽

Urban Catchments ◽

The City ◽

Total Impervious Area

We propose a remote-sensing based metric approach to evaluate the hydrological response of highly urbanized areas and apply it to the city of Brussels. The model is set-up using 2 m resolution hyperspectral data. Next, it is upscaled to the city level, using multi-spectral Sentinel-2 data with 20 m resolution. We identify the total impervious area, the vegetation cover and the leaf area index as important metrics to derive a timeseries of spatially distributed net rainfall, runoff and infiltration from rainfall data. For the estimation of the actual evapotranspiration we use the potential evapotranspiration and the available water storage based on the interception, the depression storage and the infiltration. Additionally, we route the runoff to the outlet of selected sub-catchments. An important metric for the routing is the timing to the outlet which is approximated using the total impervious area and the hydrological distance to the outlet. We compare our approach to WetSpa model simulations and reach R 2 values of 98% for net rainfall, 95% for surface runoff, 99% for infiltration and 97% for cumulative evapotranspiration. The routing in the Watermaelbeek catchment is evaluated with discharge observations and reaches NSE values of 0.89 at a 2 m resolution and 0.88 at a 20 m resolution using an hourly timestep. At the timestep of 10 min and a 20 m resolution the NSE is reduced to 0.76. For the Roodebeek catchment we reach an NSE of 0.73 at a spatial resolution of 20 m and an hourly timestep. The results presented in this paper are optimistic for using spatial and temporal metrics retrieved from remote sensing data to quantify the water balance of urban catchments.

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Assessment of runoff contributing catchment areas in rainfall runoff modelling

Water Science & Technology ◽

10.2166/wst.2006.621 ◽

2006 ◽

Vol 54 (6-7) ◽

pp. 49-56 ◽

Cited By ~ 15

Author(s):

S. Thorndahl ◽

C. Johansen ◽

K. Schaarup-Jensen

Keyword(s):

Catchment Area ◽

Reduction Factor ◽

Surface Flow ◽

Impervious Surfaces ◽

Rainfall Runoff ◽

Residential Areas ◽

Sewer Systems ◽

Impervious Area ◽

Catchment Areas ◽

Essential Parameter

In numerical modelling of rainfall caused runoff in urban sewer systems an essential parameter is the hydrological reduction factor which defines the percentage of the impervious area contributing to the surface flow towards the sewer. As the hydrological processes during a rainfall are difficult to determine with significant precision the hydrological reduction factor is implemented to account all hydrological losses except the initial loss. This paper presents an inconsistency between calculations of the hydrological reduction factor, based on measurements of rainfall and runoff, and till now recommended literature values for residential areas. It is proven by comparing rainfall-runoff measurements from four different residential catchments that the literature values of the hydrological reduction factor are over-estimated for this type of catchment. In addition, different catchment descriptions are presented in order to investigate how the hydrological reduction factor depends on the level of detail regarding the catchment description. When applying a total survey of the catchment area, including all possible impervious surfaces, a hydrological reduction factor of approximately 0.5 for residential areas with mainly detached houses is recommended–contrary to the literature recommended values of 0.7–0.9.

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Rainfall-runoff modeling: a modification of the EBA4SUB framework for ungauged and highly impervious urban catchments

Journal of Hydrology ◽

10.1016/j.jhydrol.2021.127371 ◽

2021 ◽

pp. 127371

Author(s):

Andrea Petroselli ◽

Andrzej Wałęga ◽

Dariusz Młyński ◽

Artur Radecki-Pawlik ◽

Agnieszka Cupak ◽

...

Keyword(s):

Rainfall Runoff ◽

Runoff Modeling ◽

Urban Catchments

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The effects of spatial discretization on performances and parameters of urban hydrological model

Water Science & Technology ◽

10.2166/wst.2019.296 ◽

2019 ◽

Vol 80 (3) ◽

pp. 517-528 ◽

Cited By ~ 2

Author(s):

Qing Chang ◽

So Kazama ◽

Yoshiya Touge ◽

Shunsuke Aita

Keyword(s):

Spatial Resolution ◽

Scale Effects ◽

Model Performance ◽

Computation Time ◽

Rainfall Runoff ◽

Total Runoff ◽

Sensing Technology ◽

Impervious Area ◽

Runoff Modeling ◽

The Impact

Abstract Selecting a proper spatial resolution for urban rainfall runoff modeling was not a trivial issue because it could affect the model outputs. Recently, the development of remote sensing technology and increasingly available data source had enabled rainfall runoff process to be modeled at detailed and microscales. However, the models with less complexity might have equally good performance with less model establishment and computation time. This study attempted to explore the impact of model spatial resolution on model performance and parameters. Models with different discretization degree were built up on the basis of actual drainage networks, urban parcels and specific land use. The results showed that there was very little difference in the total runoff volumes while peak flows showed obvious scale effects which could be up to 30%. Generally, model calibration could compensate the scale effect. The calibrated models with different resolution showed similar performances. The consideration of effective impervious area (EIA) as a calibration parameter marginally increased performance of the calibration period but also slightly decreased performance in the validation period which indicated the importance of detailed EIA identification.

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Impact of urbanization on rainfall-runoff processes: case study in the Liangshui River Basin in Beijing, China

Proceedings of the International Association of Hydrological Sciences ◽

10.5194/piahs-373-7-2016 ◽

2016 ◽

Vol 373 ◽

pp. 7-12 ◽

Cited By ~ 7

Author(s):

Zongxue Xu ◽

Gang Zhao

Keyword(s):

Land Use ◽

Return Period ◽

Overland Flow ◽

Low Impact Development ◽

Urban Land Use ◽

Peak Time ◽

Rainfall Runoff ◽

Rapid Urbanization ◽

Impervious Area ◽

The Impact

Abstract. China is undergoing rapid urbanization during the past decades. For example, the proportion of urban population in Beijing has increased from 57.6 % in 1980 to 86.3 % in 2013. Rapid urbanization has an adverse impact on the urban rainfall-runoff processes, which may result in the increase of urban flood risk. In the present study, the major purpose is to investigate the impact of land use/cover change on hydrological processes. The intensive human activities, such as the increase of impervious area, changes of river network morphology, construction of drainage system and water transfer, were considered in this study. Landsat TM images were adopted to monitor urbanization process based on Urban Land-use Index (ULI). The SWMM model considering different urbanized scenarios and anthropogenic disturbance was developed. The measured streamflow data was used for model calibration and validation. Precipitation with different return periods was taken as model input to analyse the changes of flood characteristics under different urbanized scenarios. The results indicated that SWMM provided a good estimation for storms under different urbanized scenarios. The volume of surface runoff after urbanization was 3.5 times greater than that before urbanization; the coefficient of runoff changed from 0.12 to 0.41, and the ratio of infiltration decreased from 88 to 60 %. After urbanization, the time of overland flow concentration increased while the time of river concentration decreased; the peak time did not show much difference in this study. It was found that the peak flow of 20-year return-period after urbanization is greater than that of 100-year return-period before urbanization. The amplification effect of urbanization on flood is significant, resulting in an increase of the flooding risk. These effects are especially noticeable for extreme precipitation. The results in this study will provide technical support for the planning and management of urban storm water and the evaluation on Low Impact Development (LID) measures.

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An Analysis of First Flush Phenomenon of Non-point Source Pollution during Rainfall-Runoff Events from Impervious Area

Journal of Korean Society of Environmental Engineers ◽

10.4491/ksee.2013.35.9.643 ◽

2013 ◽

Vol 35 (9) ◽

pp. 643-653 ◽

Cited By ~ 3

Author(s):

Tae-Ung Ahn ◽

Bong-Su Bum ◽

Tae-Hoon Kim ◽

I-Song Choi ◽

Jong-Min Oh

Keyword(s):

Point Source ◽

First Flush ◽

Rainfall Runoff ◽

Point Source Pollution ◽

Impervious Area ◽

Runoff Events ◽

Non Point Source Pollution

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Assessment of two loss methods for estimation of surface runoff in Zaafrania urban catchment, North-East of Algeria

Journal of Water and Land Development ◽

10.2478/jwld-2018-0004 ◽

2018 ◽

Vol 36 (1) ◽

pp. 37-43 ◽

Cited By ~ 1

Author(s):

Yacina Dahdouh ◽

Lahbassi Ouerdachi

Keyword(s):

Return Period ◽

Surface Runoff ◽

Return Periods ◽

Rainfall Runoff ◽

Urban Catchment ◽

North East ◽

Urban Catchments ◽

Loss Method ◽

Best Fit ◽

Scs Cn

AbstractSurface runoff is a major problem in urban catchments; its generation is always related to the amount of effective rainfall dropped over the surface, however in urban catchments the process is considerably altered by the emergence of impervious areas. In this study the Soil Consevation Service – curve number (SCS-CN) and the Green–Ampt loss methods were used in rainfall-runoff modelling in the Zaafrania urban catchment which is located in Annaba city in the north east of Algeria. The two loss methods were carried out within Hydrologic Engineering Center – Hydrologic Modelling System (HEC-HMS), the choice of the appropriate method for simulating runoff hydrographs in the study area was made by comparing the simulated hydrographs versus observed data using visual inspection and statistical analysis. The results indicate that SCS-CN loss method fit better in the case of 100 years return period NSE (0.462) than in 10 years NSE (0.346) and the results of calibration of Green–Ampt loss method for the 100 years return period NSE (0.417) provide best fit than the case of 10 years NSE (0.381). Furthermore, the results of both return periods (10 and 100 years) of SCS-CN loss method provide best fit than the results of return periods (10 and 100 years) of Green–Ampt loss method. It could be concluded that SCS-CN method is preferred to the Green–Ampt method for event based rainfall-runoff modelling.

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