Is the hydrological response of Nature-Based Solutions related to the spatial variability of rainfall?

Mapping Intimacies ◽

10.5194/egusphere-egu2020-1100 ◽

2020 ◽

Author(s):

Yangzi Qiu ◽

Ioulia Tchiguirinskaia ◽

Daniel Scherzter

Keyword(s):

Spatial Variability ◽

Green Roof ◽

Urban Environments ◽

Rainfall Data ◽

Percentage Error ◽

Small Scale ◽

Hydrological Response ◽

Urban Catchment ◽

Rainfall Events ◽

Porous Pavement

Nature-Based Solutions (NBS) practices provide many benefits for sustainable development of urban environments, one of which is their ability to mitigate the urban waterlogging. In many previous studies, the performances of NBS practices are analysed with the semi-distributed model and artificial rainfall without considering the spatial variability of rainfall. However, the NBS practices are decentralized in urban areas, their hydrological response is very depends on the small-scale heterogeneity of urban environments. Therefore, this research aims to investigate the impacts of small-scale rainfall variability on the hydrological responses of NBS practices.In this study, the hydrological response of NBS practices was analysed at the urban catchment scale. A 5.2 km2 semi-urban catchment (Guyancourt, located in the South-West of Paris) are investigated under various future NBS implementation scenarios (porous pavement, green roof, rain garden and combined). Regarding the objective of this research, three typical rainfall events are selected. Three sets of distributed rainfall data at a high resolution of 250 m&#215;250 m&#215;3.41 min were obtained from the X-band radar of Ecole des Ponts ParisTech (ENPC). In addition, three sets of corresponded homogeneous rainfall data are applied and used for comparing with the distributed one. Furthermore, a fully distributed and grid based hydrological model (Multi-Hydro), developed at ENPC, which takes into consideration the spatial variability of the whole catchment at 10 m scale. The hydrological response of NBS scenarios was analysed with the percentage error on total volume and peak discharge, with regards to the baseline scenario (current configuration).Results show that the spatial variability of rainfall has the impact on the hydrological response of NBS scenarios in varying degrees, and it is more evident for green roof scenario. In three rainfall events, the maximum percentage error on peak discharge of green roof scenario under distributed rainfall is 23 %, while that of the green roof scenario under homogeneous rainfall is 17.7%. Overall, the results suggest that the implementation of porous pavement and rain garden is more flexible than implementation of green roof in a semi-urban catchment.

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Spatial and temporal variability of rainfall and their effects on hydrological response in urban areas – a review

Hydrology and Earth System Sciences ◽

10.5194/hess-21-3859-2017 ◽

2017 ◽

Vol 21 (7) ◽

pp. 3859-3878 ◽

Cited By ~ 69

Author(s):

Elena Cristiano ◽

Marie-Claire ten Veldhuis ◽

Nick van de Giesen

Keyword(s):

Temporal Variability ◽

Urban Areas ◽

Rainfall Variability ◽

Urban Environments ◽

Hydrological Processes ◽

Small Scale ◽

Spatial And Temporal Variability ◽

Hydrological Response ◽

Weather Radars ◽

New Instruments

Abstract. In urban areas, hydrological processes are characterized by high variability in space and time, making them sensitive to small-scale temporal and spatial rainfall variability. In the last decades new instruments, techniques, and methods have been developed to capture rainfall and hydrological processes at high resolution. Weather radars have been introduced to estimate high spatial and temporal rainfall variability. At the same time, new models have been proposed to reproduce hydrological response, based on small-scale representation of urban catchment spatial variability. Despite these efforts, interactions between rainfall variability, catchment heterogeneity, and hydrological response remain poorly understood. This paper presents a review of our current understanding of hydrological processes in urban environments as reported in the literature, focusing on their spatial and temporal variability aspects. We review recent findings on the effects of rainfall variability on hydrological response and identify gaps where knowledge needs to be further developed to improve our understanding of and capability to predict urban hydrological response.

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Trend and spatial variability of 1-day extreme rainfall from 1980 - 2015: study at the adminisitrative area of UPT PSDA Pasuruan

Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) ◽

10.23960/jtep-l.v8i1.29-39 ◽

2019 ◽

Vol 8 (1) ◽

pp. 29

Author(s):

Indarto Indarto

Keyword(s):

Spatial Variability ◽

Daily Rainfall ◽

Extreme Rainfall ◽

Statistical Test ◽

Rainfall Event ◽

Rainfall Data ◽

Rainfall Events ◽

Significance Level ◽

Main Input ◽

Crossing Test

This study aims to analyze trends, shift and spatial variability of extreme-rainfall in the area of UPT PSDA Pasuruan. The daily rainfall data from 64 stations from 1980 until 2015 were used as main input. The 1-day extreem rainfall data is determined as the maximum annual of 24-hour rainfall events. The statistical analysis using Mann-Kendall, Rank-Sum, and Median Crossing Test using significance level α = 0,05. The spatial variability of extrem rainfall data is described using average annual 24-hour rainfall during the periods of record. Each station is represented by one value. The values are then interpolated using IDW interpolation methods to maps the spatial variability of extreem rainfall event. The results show the value of statistical test for each stations that show the existing trend, shift, or randomness of data. The result also produce thematic maps show the spatial variability of extreme rainfall and the value of each trend.

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Assessment of SWAT Model Performance in Simulating Daily Streamflow under Rainfall Data Scarcity in Pacific Island Watersheds

Water ◽

10.3390/w10111533 ◽

2018 ◽

Vol 10 (11) ◽

pp. 1533 ◽

Cited By ~ 3

Author(s):

Olkeba Leta ◽

Aly El-Kadi ◽

Henrietta Dulai ◽

Kariem Ghazal

Keyword(s):

Spatial Variability ◽

Swat Model ◽

Model Performance ◽

Rain Gauge ◽

Rainfall Data ◽

Small Scale ◽

Pacific Island ◽

Rain Gauge Data ◽

Gauge Data ◽

Low Performance

Evaluating the performance of watershed models is essential for a reliable assessment of water resources, particularly in Pacific island watersheds, where modeling efforts are challenging due to their unique features. Such watersheds are characterized by low water residence time, highly permeable volcanic rock outcrops, high topographic and rainfall spatial variability, and lack of hydrological data. The Soil and Water Assessment Tool (SWAT) model was used for hydrological modeling of the Nuuanu area watershed (NAW) and Heeia watershed on the Island of Oahu (Hawaii). The NAW, which had well-distributed rainfall gauging stations within the watershed, was used for comparison with the Heeia watershed that lacked recoded rainfall data within the watershed. For the latter watershed, daily rain gauge data from the neighboring watersheds and spatially interpolated 250 m resolution rainfall data were used. The objectives were to critically evaluate the performance of SWAT under rain gauge data scarce conditions for small-scale watersheds that experience high rainfall spatial variability over short distances and to determine if spatially interpolated gridded rainfall data can be used as a remedy in such conditions. The model performance was evaluated by using the Nash–Sutcliffe efficiency (NSE), the percent bias (PBIAS), and the coefficient of determination (R2), including model prediction uncertainty at 95% confidence interval (95PCI). Overall, the daily observed streamflow hydrographs were well-represented by SWAT when well-distributed rain gauge data were used for NAW, yielding NSE and R2 values of > 0.5 and bracketing > 70% of observed streamflows at 95PCI. However, the model showed an overall low performance (NSE and R2 ≤ 0.5) for the Heeia watershed compared to the NAW’s results. Although the model showed low performance for Heeia, the gridded rainfall data generally outperformed the rain gauge data that were used from outside of the watershed. Thus, it was concluded that finer resolution gridded rainfall data can be used as a surrogate for watersheds that lack recorded rainfall data in small-scale Pacific island watersheds.

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Spatial Rainfall Variability in Urban Environments—High-Density Precipitation Measurements on a City-Scale

Water ◽

10.3390/w12041157 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1157 ◽

Cited By ~ 1

Author(s):

Roman Maier ◽

Gerald Krebs ◽

Markus Pichler ◽

Dirk Muschalla ◽

Günter Gruber

Keyword(s):

Spatial Variability ◽

Rainfall Variability ◽

Past Research ◽

Urban Environments ◽

Return Periods ◽

Rainfall Events ◽

Rain Gauges ◽

Temporal And Spatial Variability ◽

One Year ◽

Available Information

Rainfall runoff models are frequently used for design processes for urban infrastructure. The most sensitive input for these models is precipitation data. Therefore, it is crucial to account for temporal and spatial variability of rainfall events as accurately as possible to avoid misleading simulation results. This paper aims to show the significant errors that can occur by using rainfall measurement resolutions in urban environments that are too coarse. We analyzed the spatial variability of rainfall events from two years with the validated data of 22 rain gauges spread out over an urban catchment of 125 km2. By looking at the interstation correlation of the rain gauges for different classes of rainfall intensities, we found that rainfall events with low and intermediate intensities show a good interstation correlation. However, the correlation drops significantly for heavy rainfall events suggesting higher spatial variability for more intense rainstorms. Further, we analyzed the possible deviation from the spatial rainfall interpolation that uses all available rain gauges when reducing the number of rain gauges to interpolate the spatial rainfall for 24 chosen events. With these analyses we found that reducing the available information by half results in deviations of up to 25% for events with return periods shorter than one year and 45% for events with longer return periods. Assuming uniformly distributed rainfall over the entire catchment resulted in deviations of up to 75% and 125%, respectively. These findings are supported by the work of past research projects and underline the necessity of a high spatial measurement density in order to account for spatial variability of intense rainstorms.

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Spatial and temporal variability of rainfall and their effects on hydrological response in urban areas -– a review

10.5194/hess-2016-538 ◽

2016 ◽

Cited By ~ 1

Author(s):

Elena Cristiano ◽

Marie-Claire ten Veldhius ◽

Nick van de Giesen

Keyword(s):

Temporal Variability ◽

Urban Areas ◽

Rainfall Variability ◽

Urban Environments ◽

Hydrological Processes ◽

Small Scale ◽

Spatial And Temporal Variability ◽

Hydrological Response ◽

Weather Radars ◽

New Instruments

Abstract. In urban areas, hydrological processes are characterised by high variability in space and time, making them sensitive to small-scale temporal and spatial rainfall variability. In the last decades new instruments, techniques and methods have been developed to capture rainfall and hydrological processes at high resolution. Weather radars have been introduced to estimate high spatial and temporal rainfall variability. At the same time, new models have been proposed to reproduce hydrological response, based on small-scale representation of urban catchment spatial variability. Despite these efforts, interaction between input variability and model resolution remains poorly understood, and further investigations are needed. This paper presents a review of our current understanding of hydrological processes in urban environments as reported in the literature, focusing on their spatial and temporal variability. We review recent findings on the effects of rainfall variability on hydrological response and identify gaps where knowledge need to be further developed to improve our understanding of and capability to predict urban hydrological response.

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Origins and characteristics of urban wet weather pollution in combined sewer systems: the experimental urban catchment “Le Marais” in Paris

Water Science & Technology ◽

10.2166/wst.1998.0010 ◽

1998 ◽

Vol 37 (1) ◽

pp. 35-43 ◽

Cited By ~ 13

Author(s):

Marie-Christine Gromaire-Mertz ◽

Ghassan Chebbo ◽

Mohamed Saad

Keyword(s):

Waste Water ◽

Sewer System ◽

Urban Catchment ◽

Rainfall Events ◽

Sources Of Pollution ◽

Sewer Systems ◽

Combined Sewer ◽

Wet Weather ◽

Wet Weather Flow ◽

Different Sources

An experimental urban catchment has been created in the centre of Paris, in order to obtain a description of the pollution of urban wet weather flows at different levels of the combined sewer system, and to estimate the contribution of runoff, waste water and sewer sediments to this pollution. Twenty-two rainfall events were studied from May to October 1996. Dry weather flow was monitored for one week. Roof, street and yard runoff, total flow at the catchment outlet and waste water were analysed for SS, VSS, COD and BOD5, on both total and dissolved fraction. Results show an evolution in the characteristics of wet weather flow from up to downstream: concentrations increase from the catchment entry to the outlet, as well as the proportion of particle-bound pollutants and the part of organic matter. A first evaluation of the different sources of pollution establishes that a major part of wet weather flow pollution originates from inside the combined sewer, probably through erosion of sewer sediments.

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Omnipresent distribution of herbicides and their transformation products in all water body types of an agricultural landscape in the North German Lowland

Environmental Science and Pollution Research ◽

10.1007/s11356-021-13626-x ◽

2021 ◽

Author(s):

Uta Ulrich ◽

Matthias Pfannerstill ◽

Guido Ostendorp ◽

Nicola Fohrer

Keyword(s):

Drinking Water ◽

Oxalic Acid ◽

Water Body ◽

Sulfonic Acid ◽

Stream Water ◽

Parent Compound ◽

Shallow Groundwater ◽

Transformation Products ◽

Small Scale ◽

Rainfall Events

AbstractThe research of the environmental fate of pesticides has demonstrated that applied compounds are altered in their molecular structure over time and are distributed within the environment. To assess the risk for contamination by transformation products (TP) of the herbicides flufenacet and metazachlor, the following four water body types were sampled in a small-scale catchment of 50 km2 in 2015/2016: tile drainage water, stream water, shallow groundwater, and drinking water of private wells. The TP were omnipresent in every type of water body, more frequently and in concentrations up to 10 times higher than their parent compounds. Especially metazachlor sulfonic acid, metazachlor oxalic acid, and flufenacet oxalic acid were detected in almost every drainage and stream sample. The transformation process leads to more mobile and more persistent molecules resulting in higher detection frequencies and concentrations, which can even occur a year or more after the application of the parent compound. The vulnerability of shallow groundwater and private drinking water wells to leaching compounds is proved by numerous positives of metazachlor-TP with maximum concentrations of 0.7 μg L−1 (drinking water) and 20 μg L−1 (shallow groundwater) of metazachlor sulfonic acid. Rainfall events during the application period cause high discharge of the parent compound and lower release of TP. Later rainfall events lead to high displacement of TP. For an integrated risk assessment of water bodies, the environmental behavior of pesticide-TP has to be included into regular state-of-the-art water quality monitoring.

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Understanding Spatial Variability of NO2 in Urban Areas Using Spatial Modelling and Data Fusion Approaches

Atmosphere ◽

10.3390/atmos12020179 ◽

2021 ◽

Vol 12 (2) ◽

pp. 179

Author(s):

Said Munir ◽

Martin Mayfield ◽

Daniel Coca

Keyword(s):

Data Fusion ◽

Spatial Variability ◽

Urban Areas ◽

Road Traffic ◽

Dispersion Model ◽

Low Cost ◽

Spatial Modelling ◽

City Centre ◽

Small Scale ◽

The City

Small-scale spatial variability in NO2 concentrations is analysed with the help of pollution maps. Maps of NO2 estimated by the Airviro dispersion model and land use regression (LUR) model are fused with measured NO2 concentrations from low-cost sensors (LCS), reference sensors and diffusion tubes. In this study, geostatistical universal kriging was employed for fusing (integrating) model estimations with measured NO2 concentrations. The results showed that the data fusion approach was capable of estimating realistic NO2 concentration maps that inherited spatial patterns of the pollutant from the model estimations and adjusted the modelled values using the measured concentrations. Maps produced by the fusion of NO2-LCS with NO2-LUR produced better results, with r-value 0.96 and RMSE 9.09. Data fusion adds value to both measured and estimated concentrations: the measured data are improved by predicting spatiotemporal gaps, whereas the modelled data are improved by constraining them with observed data. Hotspots of NO2 were shown in the city centre, eastern parts of the city towards the motorway (M1) and on some major roads. Air quality standards were exceeded at several locations in Sheffield, where annual mean NO2 levels were higher than 40 µg/m3. Road traffic was considered to be the dominant emission source of NO2 in Sheffield.

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