Impermeable Surface Research Articles

Poroelastic Response of a Semi-Permeable Borehole Subjected to Non-Hydrostatic In Situ Stresses

AbstractIn the existing models of wellbore stability, the borehole wall is idealized as either a fully permeable or a completely impermeable surface. However, the widely observed fact that a shale borehole is permeable to solvent molecules but impermeable to solutes suggests that the borehole wall should be considered as a non-ideal semi-permeable medium. When the wellbore is exposed to the drilling fluid, the dynamic modification of pore pressure on the borehole surface is required to account for fluid entering the formation. In this paper, we present an analytical solution for a semi-permeable borehole subjected to a non-hydrostatic stress in a poroelastic medium, where a Robin boundary condition for pore pressure is adopted, with the fluid flux into the rock matrix being proportional to the pore pressure difference across the borehole wall. Integral transform and load decomposition techniques are employed to assist in the derivation of analytical solutions. The results reveal that, compared to the permeable and impermeable borehole models, the semi-permeable model predicts a sharp difference in the stress and pore pressure fields.

Significance of gyrotactic microorganism and bioconvection analysis for radiative Williamson fluid flow with ferromagnetic nanoparticles

Research on nanotechnology took interest of scientists as well as researchers because of its vast range of applications like curing cancer, medicines, aircraft manufacturing industry, use of nano-robot technology, bio-nano, heat exchanger instruments, used as coolants in engines of vehicles, microelectronics, water distillation, pharmaceutical procedures and rubber materials. Major purpose of this inspection is to examine the usefulness of radiation phenomena with magnetic effects micro-polar nanofluid by use of impermeable surface. The concept of microorganism’s notion is used to make suspended nano-particles stable by using effect of bioconvection influenced by synchronizing deliberation of suitable magnetic field. Since bioconvection is also an appealing research field for bioengineering and biotechnology, in recent year’s variety of bio-convection models are studied for production of microorganisms. The determination of current exploration is to compute the 2-dimensional flow of Williamson ferrofluid under the influence of magnetic dipole. Characteristics of Brownian motion parameter and thermophoresis diffusion for Williamson ferrofluid model apprehending the properties of convective boundary conditions, thermal motile as well as thermal gradients are considered. The system of nonlinear PDEs is transformed in form of ODEs with the help of apt transformations; additionally obtained ODEs are then solved with the help of bvp4c numerical scheme. Impacts of some important physical parameters are expressed pictorially. Results perceived that fluids temperature increases by increasing thermal radiation as well as thermophoresis parameter moreover shows declining behavior in case of Prandtl number. Moment of motile microorganism rises for larger δ1 and Pe whereas microorganism have opposite trend againstLb.

Extraction of Impermeable Surfaces Based on Multi-Source Nighttime Light Images of Different Geomorphological Partitions

Accurate extraction of impermeable surfaces is important for assessing land use change and improving the urban heat island effect. Nighttime light imagery has the advantage of being efficient and cost effective, providing a new perspective for monitoring and extracting impermeable surfaces and analyzing urban expansion processes. However, for the vast Karst terrain fragmentation area located in southwest China, the extraction of impermeable surface information faces many challenges due to surface landscape fragmentation and nighttime light image resolution. These challenges include light spillover, oversaturation and limited understanding of spatial links with surface types at fine scales. This study uses Luojia1-01, NPP-VIIRS, and Flint as remote sensing data sources to examine the applicability of nighttime light images in extracting impermeable surfaces from geomorphologically complex areas. The results show that Luojia1-01 data can provide finer spatial details and more accurate impermeable surface extraction results than NPP-VIIRS and Flint data. The relative error of extracted area in regions with large topographic relief is higher than that in regions with flat topographic cuttings. The extraction results of the three images are spatially similar; however, the overall accuracy is poor, and a single nighttime light image is not the best solution for obtaining impermeable surface information in large scale terrain fragmentation areas. However, the integrated application of multi-source light images is a trend for future regional research and development, and the best way to extract impermeable surfaces in complex terrain areas should be explored in conjunction with other remote sensing data sources in the future.

Unified formulation of convective heat flux and mass flux vectors with thermodynamic coupling and related transfer coefficients

Based on the inherent thermodynamic relations of compressible species in binary mixtures at constant pressure, the general three-dimensional (3D) convective heat flux and mass flux vectors are formulated including the contributions of simultaneous advection, thermal diffusion and mass diffusion and their coupling effects between temperature and concentration gradients. The novel expressions for the diffusion-thermo and thermo-diffusion effects do not require the meager data of thermal diffusion ratio and are valid for both gas and liquid mixtures in laminar flows. The unified flux forms of the Maxwell's electromagnetic equation type are obtained in convective processes. It is further shown that the surface convective heat and mass transfer coefficients can be expressed in terms of the convective heat fluxes and mass fluxes away from surfaces in steady laminar flows, and that the expression of each transfer coefficient yields the identical form on both impermeable and permeable surfaces.

Evaluation of Workplace Exposures to Volatile Chemicals During COVID-19 Building Disinfection Activities with Proton Transfer Reaction Mass Spectrometry.

We conducted an experimental case study to demonstrate the application of proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) for mobile breathing zone (BZ) monitoring of volatile chemical exposures in workplace environments during COVID-19 disinfection activities. The experiments were conducted in an architectural engineering laboratory-the Purdue zero Energy Design Guidance for Engineers (zEDGE) Tiny House, which served as a simulated workplace environment. Controlled disinfection activities were carried out on impermeable high-touch indoor surfaces, including the entry door, kitchen countertop, toilet bowl, bathroom sink, and shower. Worker inhalation exposure to volatile organic compounds (VOCs) was evaluated by attaching the PTR-TOF-MS sampling line to the researcher's BZ while the disinfection activity was carried out throughout the entire building. The results demonstrate that significant spatiotemporal variations in VOC concentrations can occur in the worker's BZ during multi-surface disinfection events. Application of high-resolution monitoring techniques, such as PTR-TOF-MS, are needed to advance characterization of worker exposures towards the development of appropriate mitigation strategies for volatile disinfectant chemicals.

Use of Satellite Images to Determine the Temperature of Urban Surfaces for Landscape Management Purposes, Case Study Bratislava (Slovak Republic)

This contribution deals with the use of data obtained from Landsat 8 satellite imaging to identify surface temperature variability in the example of the city of Bratislava, with an emphasis on identifying hotspots outside the built-up area, for example, on agricultural land—locations which are part of the European Network of Protected Areas. Surface temperature variability is presented in two time periods, on the daytime image taken on 26 July 2021 and on the nighttime image from 28 June 2021. Surface temperature is projected in a profile cut of the area. It vertically illustrates the temperatures of individual types of surfaces. Surfaces are classified by Urban Atlas classes. Areas reflecting the spatial distribution of the residential development in the city of Bratislava have been identified by satellite images in the studied area, and they represent a phenomenon of the urban heat island. Such areas were also identified outside the built-up area, in agricultural areas. The results of our research show that it is important to deal with UHI outside the built-up areas of cities and to orient the attention the territory planning and also to the proposal of measures for the management of these areas. Especially if these areas also include territories of the European system of protected areas, as it is in the case of Bratislava city (e.g., SPA029 Sysľovské polia). The results of reducing the impacts of climate change in cities concern not only the residents. In spatial planning, it is also necessary to address the management of non-built-up areas—localities with a quasi-natural character (e.g., areas with diverse vegetation cover). In order to recognize UHI within residential areas, it is essential to identify areas with significant differences between daytime and nighttime surface temperatures. Large differences between night and daytime surface temperatures can be seen in areas outside the built-up area in Bratislava on arable land where the difference is up to 8.0 °C (in the continuous housing class where the proportion of impermeable surfaces is higher than 80% with a temperature difference of 7.6 °C). Identification of overheated surfaces in the territory makes an important basis for modification of the landscape management and management of nature protection areas. It is important to propose measures related to the reduction in the negative impacts of climate change on the landscape and biodiversity.

Comparative study of surface integral methods in aeroacoustic prediction

Introduction: Surface integral methods based on the acoustic analogy and Kirchhoff formulation are widely employed in computational aeroacoustics. The computational accuracy is usually highly dependent on the selections of the acoustic prediction method and of the integral surfaces.Methods: This paper analyzes the pros and cons of each aeroacoustic prediction method and studies numerically sound generated from flow past a circular cylinder by employing different surface integral methods. The acoustic analogy based on the impermeable solid surfaces either ignores the quadrupole contribution or needs high computational cost to calculate the quadrupole contribution, and the acoustic analogy based on the permeable integral surfaces usually suffers from the spurious source issue.Results: Both the pressure-based or density-based Kirchhoff formulations can be used in aeroacoustic prediction, however, the numerical results indicate that the pressure-based Kirchhoff formulation also suffers from the issue of the spurious sound because the pressure fluctuations at the permeable integral surfaces are contaminated by hydrodynamic component.Discussion: It seems that only the density-based Kirchhoff formulation does not suffer from the issue of the spurious sound, but this formulation requires the acoustic sources should be extracted from compressible flow simulations.

Influences of Urban Discharges and Urban Heat Effects on Stream Temperature

Urban areas with dark and impermeable surfaces are known to have a heating effect on air and still water compared to surrounding areas, called the urban heat island effect (UHI). UHI and stormwater discharges’ collective impact on stream temperature, especially regarding seasonal changes, is a less-studied field. In this study, the temperature effect of the urban village Aarslev on Stream Vindinge in Southern Denmark was examined. Loggers (ID A–L) were placed in Stream Vindinge in 2020–2021, measuring temperature (°C) and pressure (kPa). Outlets were analyzed with respect to origin: Direct stormwater outlets (rain ÷ basin), stormwater delayed by ponds (rain + basin), common overflow, and common sewage from WWTP. Data showed the stream temperature rise through Aarslev village in all months (except March) with 0.3–1.9 °C, most notably in the summer months. A one-way ANOVA confirmed that the upstream station A and downstream station K were significantly different (p-values < 0.001). No significant difference in temperatures between the different outlet types was found. An increase in stream temperature was observed in response to rain events, followed by a temperature decrease. This was assumed to be a “first heat flush”. This was speculated to mean less optimal conditions for trout and sensitive macroinvertebrates not because of heat shock, but rather to lower O2 concentrations and higher mineralization. River and lake temperatures are projected to increase, and this effect might become more pronounced. A decrease in stream temperature was observed after the village (station L). Therefore, it was concluded that the rise in temperature through the village was due to UHI.

The mineralization of urban soils facing the risk of climate change: Case of the flooding phenomenon in the city of Annaba

Urbanization exerts changes on the environment and on the ecosystems and it leads to a modification of the nature of the soil or even a soil impermeability via the infrastructures carried out. This impermeability acts as an aggravating factor for the effects of climate change and causes local environmental stresses. These are particularly urban heat island and urban flooding. The city of Annaba (located in the northeast of Algeria) is among these dense coastal cities, which have experienced rapid and abrupt urban development resulting in the expansion of impermeable infrastructure at the expense of the removal of natural and vegetal cover. The problem of soil sealing in Annaba therefore put it face to face with the direct risk of climate change.Urban flooding is a phenomenon directly linked to soil sealing. The combined effects of climate change, in terms of changes in rainfall patterns and intensities, make some sewerage networks unable to evacuate increasingly large quantities of runoff water from impermeable surfaces causing important material and human damages. In fact, this city has experienced strong periods of heat in recent years, reaching 47°C in summer 2021 [1]. Winter was not so different, intense rainfall causes repeated flooding every year, amplifying the sensitivity and exposure of city dwellers and properties to multiple risks. The present consideration, aims to identify and measure sealed surfaces and to determine the areas vulnerable to the impacts of soil sealing.

The Impacts of Land Use Changes in Urban Hydrology, Runoff and Flooding: A Review

The issue of Land Use (LU) change has received considerable critical attention because it is one of the most significant factors caused by human activities worldwide. Recent critical changes in this direction have affected urban hydrology. LU change affects water resources and hydrological characteristics such as runoff and urban flooding. The development of LU causes a rapid increase in impermeable surfaces, increasing the flooding rate. LU also plays a vital role in extending water drainage, groundwater intrusion, and flooding during and after rainfall. This paper aims to investigate LU change impacts on runoff and urban flooding. This review focused on most articles, conference papers, and book chapters published in SCOPUS, including Google Scholar. The study was limitation to the last published from 2017-2021 and also extended some published theories for different years published. In addition, in the short and long term, the development of LU affects the environment, and most factors are involved at a catchment level. However, there is a strong relationship between human activities at the catchment level and runoff. The study concluded that LU strongly influences topography and the landscape in arid, semi-arid, and humid zones. This is why runoff and water distribution happen in urban areas. Furthermore, this study found that built-up area is a critical factor that increases urban flood risk, especially in lowlands along floodplains. It is common for the frequency of floods to become more severe due to a rapid increase in impervious surfaces brought on by urbanisation, increasing runoff. The review concludes that runoff affects by catchment size and its condition. Finally, humans can be reduced runoff and flood risk with a sensibility strategy.

A Subpixel Mapping Method for Urban Land Use by Reducing Shadow Effects

Urban land use classification is significant for urban development planning. Considering complex environments of urban surface features, traditional semantic segmentation methods are difficult to solve the problems of mixed pixels and limited spatial resolution of images. The subpixel mapping technology is an effective method to solve the above problems in urban land use classification. However, traditional subpixel mapping methods are sensitive to mountain shadow, high-rise building shadow and impermeable surface heterogeneity, resulting in false classification. Therefore, we propose a subpixel mapping method that can reduce the shadow effect. This method uses a multi-index feature fusion strategy to optimize the abundance of the shadow errors in the abundance image, and uses a super-resolution reconstruction neural network model to reconstruct the optimized abundance image for the subpixel mapping of urban land use. Experiments were conducted on sentinel-2 images obtained over Yuelu District of Changsha City, Hunan Province, China. The experimental results show that the method proposed in this article can effectively overcome the influence of building shadows and mountain shadows in urban land cover classification and is superior to traditional subpixel/pixel spatial attraction model, radial basis function, super-resolution subpixel mapping, and other methods in the effect and accuracy of urban land use subpixel mapping.

Membrane sound absorber with a granular activated carbon infill

An impervious membrane sound absorber with an air cavity partially filled with a porous material is a viable alternative to perforated panels when impermeable surfaces are required. On the other hand, due to its unusually high sound absorption properties at low frequencies, using activated carbon (AC) in granular form as an absorbing material has recently received attention. This paper reports the sound absorption performance of a novel system consisting of a thin stretched impervious circular membrane made of silicone, backed by an air cavity partially filled with granular AC. The system is analyzed theoretically using the impedance translation theorem. The normal-incidence sound absorption was measured in an impedance tube for combinations of cavity depth, membrane tension, and membrane surface density. The results of using an AC and a fiberglass infill material of the same thickness in the air cavity were also compared. The findings validated the advantage of AC as porous infill material of a membrane sound absorber in the low-frequency range. Furthermore, the outcomes of the impedance tube experiments were in good agreement with theoretical predictions. The findings reported in this work could be used to design new innovating sound-absorbing metamaterials based on activated carbon and stretched membranes.

Improving Risk Projection and Mapping of Coastal Flood Hazards Caused by Typhoon-Induced Storm Surges and Extreme Sea Levels

Seawater inundation mapping plays a crucial role in climate change adaptation and flooding risk reduction for coastal low-lying areas. This study presents a new elevation model called the digital impermeable surface model (DISM) based on the topographical data acquired by unmanned aerial vehicle (UAVs) for improving seawater inundation mapping. The proposed DISM model, along with the bathtub model, was used to assess coastal vulnerability to flooding in significant tropical cyclone events in a low-lying region of Victoria Harbor in Hong Kong. The inundation simulations were evaluated based on the typhoon news and reports which indicated the actual storm surge flooding conditions. Our findings revealed that the proposed DISM obtains a higher accuracy than the existing digital elevation model (DEM) and the digital surface model (DSM) with a RMSE of 0.035 m. The DISM demonstrated a higher skill than the DEM and the DSM by better accounting for the water-repellent functionality of each geospatial feature and the water inflow under real-life conditions. The inundation simulations affirmed that at least 88.3% of the inundated areas could be recognized successfully in this newly-designed model. Our findings also revealed that accelerating sea level rise in Victoria Harbor may pose a flooding threat comparable to those induced by super typhoons by the end of the 21st century under two representative emission scenarios (RCP4.5 and RCP8.5). The seawater may overtop the existing protective measures and facilities, making it susceptible to flood-related hazards.

Effect of Urban Road Trees on Temperature Caused by Surface Materials

Urban roads play a significant role for analyzing the complex structure of the city. The climatic features of the city provide information about the comfort of the inhabitants. The climate changes may be observed on a micro-scale due to the increase of impermeable surfaces. Surfaces such as concrete and asphalt contribute to the formation of an urban heat island as they store the temperature. This study aims to determine the effects of plant material, which is a significant element of urban roads, on temperature arising from surface materials. In this context, the effect of Ficus retusa-nitida on the formation of temperature caused by the surface material has been revealed. The study was carried out in Iskenderun, the second largest district of Hatay province in terms of population, in 3 stages in a periold of 6-months between July and December 2020. In the first stage, the studies on the subject were brought together and the points to be measured in the area were determined. At this stage, asphalt (shade-under F.retusa-nitida, sun) and parquet (shade-under F.retusa-nitida, sun) surfaces were selected at a total of 8 points located mutually on the main road axis. The second stage of the study is the stage where surface temperature measurements are made. Measurements were performed once a month at 06:00, 09:00; 12:00, 15:00; 18:00; 21:00 and 24:00 using an infrared thermometer at a height of 150 cm from the surface with 3 repetitions. At the third stage, all data were transferred to GIS using ArcGIS 10.5 software and modelled by using the Kriging Interpolation Method. In line with the results obtained, suggestions for the selection of surface material and the use of plant materials on urban roads have been developed.

Spatial Analysis of the Water Harvesting Potential of Permeable Pavements in Australia

An increase in impermeable surface areas with urban development contributes to the rapid and large amount of surface runoff during rainfall. This often requires higher capacity stormwater collection systems, which can cause stress on the existing drainage system and this subsequently contributes to urban flooding. However, urban runoff can be reduced and managed for flood control and converted into a useful resource by harvesting and reusing the water. This can be achieved by switching from impermeable to permeable pavements. However, the amount of stormwater that can be harvested in a permeable pavement system depends on many factors, including rainfall, the water reuse demand and the materials used. This research aims to assess the requirements for permeable pavement design across Australia to balance demand, runoff reduction and construction requirements. A design approach employing the hydrological effects of the infiltration system was adopted for the analysis, along with a spatial analysis for a probabilistic prediction. A relationship was also established to predict a probable design thickness of pavement for various parameters. The research showed that in most Australian cities, for a 120 mm permeable pavement thickness, 40–80% of rainfall-runoff could be harvested, meeting about 10–15% of domestic water demand. The approach developed in this study can be useful for screening the potential of permeable pavements for water harvesting and for predicting spatially where a circular economic approach can be more efficient.

Конвективный теплообмен и трение в тонком ламинарно-турбулентном пограничном слое на проницаемой поверхности затупленного конуса малого удлинения

Solving the problem of calculating convective heat transfer and friction in the laminar-turbulent boundary layer involves the need for numerical integration of differential equations, supplemented by those or other semiempirical models of apparent turbulent viscosity, which should be validated on the results of experimental studies, carried out in conditions, providing simulation of the gas dynamic picture of body flowing by a gas stream. Unfortunately, at present, there are no literature data on studies of laminar-turbulent heat exchange on the permeable surface of a blunted body, and under these conditions, one has to go by the way of comparing the calculated data with the results of experiments carried out on sharp bodies. Literature sources describe the results of studies carried out for a hemisphere, in which one of the semi-empirical models of apparent turbulent viscosity is used, tested on the results of experiments carried out on the impermeable surface of such shaped body. In this case, it was possible to obtain a physically consistent picture of the influence exerted by blowing gas through the wall on the degree of blocking of the convective heat flow. In the absence of qualitative experimental data on this issue, it seems reasonable to apply in practice the considered semi-empirical model of apparent turbulent viscosity to estimate the degree of blocking of convective heat flow and friction under the specified conditions. This article is devoted to the solution of a similar problem for the lateral surface of a blunted cone

도심지 침수대응 시민안전 지원기술개발에 관한 연구

Recently, the frequency of flooding caused by abnormal weather has been increasing. Basically, the damage of flooding in urban areas is because the size of the outflow increases due to the increase in the impermeable surface due to urbanization. In addition, due to reasons such as problems with sewage pipes, there is a lot of damage from flooding in urban areas. This study developed a simulation technology for flood prediction in Daejeon Metropolitan City in areas at risk of flooding in urban areas. A system of flood prediction was established by applying the developed simulation. In addition, an information provision system was developed to determine evacuation and bypass routes linked to local traffic conditions. Also, it is an empirical study that minimizes damage to citizens in the event of flooding by developing a rapid real-time situation transmission system. This study created new technologies and services to solve problems in cooperation with experts and public officials through Living Lab for citizens' safety in case of flooding.

Non-Newtonian Nano-Fluids in Blasius and Sakiadis Flows Influenced by Magnetic Field

Current study solves heat transfer and fluid flow problem in Newtonian and non-Newtonian nano-fluids through a permeable surface with a magnetic field effects which is done in the presence of injection and suction for the first time. In order to solve the governing partial differential equations numerically, we used the Runge-Kutta Fehlberg (RKF45) technique in which the similarity transformation method is applied. This approach converts the governing partial differential equations into ordinary differential equations. In this particular investigation nano-particles of copper, copper oxide, titanium dioxide, and aluminium oxide are studied by considering CMC/water as a base fluid with the effect of magnetic field on the classical Blasius and Sakiadis flows of nano-fluids. Validation is carried out using the previously obtained numerical findings. We looked at the power-law index (n), the volume fraction (φ) of nano-particles and the permeability parameter (fw) which affects the flow of nano-fluid and the transfer of heat. Non-Newtonian nano-fluid demonstrates superior performance in terms of heat transfer when compared to Newtonian nano-fluid in both the injection and the impermeable surfaces. Altering the nano-particles' composition, on the other hand, has a far greater impact on the heat transfer process that occurs during suction. Graphics show the impacts of governing physical parameters on Blasius and Sakiadis flow velocity, temperature, skin friction coefficient, and reduced Nusselt number. Physical and engineering interest are explored in detail.

Integrated SWAT-MODFLOW Modeling-Based Groundwater Adaptation Policy Guidelines for Lahore, Pakistan under Projected Climate Change, and Human Development Scenarios

Urban aquifers are experiencing increasing pressures from climate change, land-use change, and abstraction, consequently, altering groundwater levels and threatening sustainable water availability, consumption, and utilization. Sustainability in such areas requires the adaptation of groundwater resources to these stressors. Consequently, this research made projections about future climate, land use, and abstraction, examines how these drives will affect groundwater levels, and then proposes adaptation strategies to reduce the impact on Lahore’s groundwater resources. The objectives are achieved using an integrated modeling framework involving applications of Soil Water Assessment Tool (SWAT) and MODFLOW models. The results indicated a projected rise in Tmin by ~2.03 °C and Tmax by ~1.13 °C by 2100 under medium (RCP 4.5) and high-end (RCP 8.5) scenarios, respectively. Future precipitation changes for mid, near and far periods are projected to be −1.0%, 25%, and 24.5% under RCP4.5, and −17.5%, 27.5%, and 29.0% under RCP8.5, respectively. The built-up area in the Lahore division will dominate agricultural land in the future with an expansion from 965 m2 to 3716 km2 by the year 2100 under R1S1 (R2S2) land-use change scenarios (significant at p = 5%). The future population of the Lahore division will increase from 6.4 M to 24.6 M (28.7 M) by the year 2100 under SSP1 (SSP3) scenarios (significant at p = 5%). Groundwater level in bult-up areas will be projected to decline from 185 m to 125 m by 2100 due to increasing groundwater abstraction and expansion in the impermeable surface under all scenarios. In contrast, agricultural areas show a fluctuating trend with a slight increase in groundwater level due to decreasing abstraction and multiple recharge sources under combined scenarios. The results of this study can be a way forward for groundwater experts and related institutions to understand the potential situation of groundwater resources in the Lahore division and implement adaptation strategies to counteract diminishing groundwater resources.

Potential for rain water capture in semi-arid urban areas

The semi-arid region of Paraiba is devastated by extreme climatic conditions, in which the low index and the irregularity of the rains are factors of great negative impact for the development of the region. We found in rainwater collection systems, an important alternative for the region, which can increase the volume of water available to a municipality, for the same rainfall regime. Therefore, one of the main objectives of the study was to estimate the Potential Volumes of Rainwater Capture (VPC) for the urban area of ​​São João do Cariri. These volumes will be estimated based on the proposed use of the city's impermeable surfaces as rainwater catchment areas for non-potable purposes. Such an estimation is important for the adequate dimensioning of cisterns, in order to guarantee the supply of thenon-potablewater demands of the population during the dry season.