Evaluating Efficiency Improvement of Deep-Cut Curb Inlets for Road-Bioretention Stripes

Accurately characterizing rainfall runoff processes in plain farmland, especially at the plot scale with significant micro-topographic features, has presented challenges. Integrated surface–subsurface flow models with high-precision surface flow modules are appropriate tools, yet open-source versions are rare. To address this gap, we proposed an open-source integrated surface–subsurface flow model called the FullSWOF-Plain model, in which the one-dimensional subsurface module Hydrus-1D was integrated with a modified two-dimensional surface water flow module (FullSWOF-2D) using the sequential head method. Various experimental scenarios were simulated to validate the model’s performance, including two outflow cases (i.e., 1D and 2D) without infiltration, a classical one-dimensional infiltration case, and two typical rainfall events at the experimental field. The results demonstrate the accuracy of this proposed model, with the Nash–Sutcliffe efficiency (NSE) of the simulated discharge exceeding 0.90 in the experimental field case and the root mean squared error (RMSE) values for soil moisture at five depths consistently below 0.03 cm3/cm3. However, we observed a lag in the simulated response time of soil moisture due to the neglect of preferential flow. The micro-topography significantly influenced ponding time and ponding areas. Lower local terrain normally experienced earlier surface ponding. Scattered surface ponding water first occurred in the ditch and followed in the relatively low areas in the main field. The concentration process of surface runoff exhibited hierarchical characteristics, with the drainage ditch contributing the most discharge initially, followed by the connection of scattered puddles in the main field, draining excess surface water to the ditch through rills. This quantitative study sheds light on the impact of micro-topography on surface runoff in plain farmland areas.

Section: Introductionmentioning

confidence: 99%

Development and Application of a New Open-Source Integrated Surface–Subsurface Flow Model in Plain Farmland

Yang,

Zhou,

Jiang

et al. 2024

“…The curb inlet length is L ci (see the description for all symbols listed in Abbreviation part). The RB stripe that combine green/gray infrastructures to facilitate road runoff control through infiltration and ponding as well as relieve road local flood inundation risk is widely used in pilot SPC construction in China [7].…”

Section: Introductionmentioning

confidence: 99%

“…length is Lci (see the description for all symbols listed in Abbreviation part). The RB stripe that combine green/gray infrastructures to facilitate road runoff control through infiltration and ponding as well as relieve road local flood inundation risk is widely used in pilot SPC construction in China [7]. Traditional curb inlets are to intercept the surface runoff into the underground stormwater pipeline network, but the curb inlets for the RB stripes are to intercept the surface runoff into the bioretention facilities to store, retain, infiltrate the runoff to remove the pollutants and improve the water quality.…”

Section: Introductionmentioning

confidence: 99%

“…The third type of curb inlet is the local depressed curb inlet shown in Figures 1d and 2c which has a local depression over the opening length of the inlet but a single cross slope S x for all other parts of the road. The local depressed inlet is widely used in some SPC pilot projects in China [7] for improving the inlet interception efficiency. In various construction projects, the local depressed inlet could be constructed using a composite slope S w over the gutter width w com (Figure 1d) or just simply cuts the road to form a small depression (Figure 2c) over the curb inlet length.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Performance Analysis for Road-Bioretention with Three Types of Curb Inlet Using Numerical Model

Fang

Wang

et al. 2021

Self Cite

The FullSWOF-ZG (Full Shallow Water Overland Flow with infiltration determined by Zones and Grate-inlet submodules) program was used to simulate the road-bioretention (RB) stripe and evaluate the performance of the RB stripe with three types of curb inlet. The program was revised from the open-source FullSWOF-2D program and the validation results indicated FullSWOF-ZG predicts the RB stripe performance accurately. The model cases of 27 RB with different longitude slopes (S0), cross slopes (Sx), and curb inlet lengths (Lci) for the undepressed, composite depressed, and local depressed curb inlets were established in this study. Therefore, 81 cases in total were simulated to explore the curb inlet type and design parameter’s influence on the RB stripe performance. Overall, it was found that the bioretention control efficiency will increase with the S0 decrease, Sx increase, and Lci increase. The composite depressed curb inlet was the most efficient to intercept the road runoff into the bioretention strip, the next best is the local depressed curb inlet, and the undepressed curb inlet was the least efficient. The curb inlet and grate inlet combination in composite depressed curb inlet cases were able to deal with all the road surface runoff for the small longitudinal slope (S0 = 0.1% and 0.3%) to relieve the road local flood inundation.

Urban Rainwater and Flood Management

Zeleňáková¹

2021