A water balance approach to assess rainwater availability potential in urban areas: the case of Beijing, China

Rainwater is an underutilized water resource that has become more important in recent years; due to severe water logging and water shortage in cities. The evaluation of rainwater harvesting potential is of fundamental importance in planning rainwater harvesting systems and management policies. In this study, we used minute-interval rainfall data and the water mass balance method coupling urban hydrological processes to assess the annual rainwater availability potential (RAP) of different underlying surfaces in the urban areas of Beijing (inside the 5th Ring Road). The estimated total RAP was 154.49 million m3 in 2013. About 53% of rainwater could be effectively harvested for use, among which the rooftops had the highest harvesting ratio of 70%, and contributed about half of the total RAP. Indirect use of rainwater can be achieved through infiltration facilities, of which concave green land construction and porous brick pavement can increase the amount of rainfall that infiltrates into the soil by 18.89% and 55.69%, respectively. Rainwater harvesting and utilization could serve as a significant water source for the urban areas in Beijing.

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Multi-method efficiency analysis of Rainwater Harvesting Systems in Corredor Seco region, Central America

10.5194/egusphere-egu2020-16844 ◽

2020 ◽

Author(s):

Elena Bresci ◽

Giulio Castelli ◽

Nadia Ursino ◽

Antonio Giacomin ◽

Federico Preti

Keyword(s):

Rainwater Harvesting ◽

Smallholder Farmers ◽

Water Source ◽

Extreme Weather Events ◽

Rainfall Time Series ◽

Vegetable Production ◽

Water Harvesting ◽

Storage Tanks ◽

Balanced Diet ◽

Harvesting Systems

The region of Corridor Seco (Dry Corridor, including parts of Guatemala, Honduras and El Salvador) has been facing multiple food crises caused by extreme weather events, water scarcity and land degradation phenomena. In this situation, Rooftop Water Harvesting (RWH) systems can effectively enhance local livelihoods, especially in marginalized communities, by providing an additional water source for domestic use, livestock, and irrigation of small horticultural plots which are key for vegetable production and thus for vitaminic input in a well-balanced diet.Dimensioning sufficient storage tanks for rainwater collection is key, since smallholder farmers&#8217; capabilities are often hindered by low financial capacity as well as by limited land extension for reservoir building.Efficiency of storage tanks and design criteria for water harvesting systems are investigated on the base of rainfall time series analysis, probabilistic risk assessment and Monte Carlo simulation (Ursino, 2016). The approach is tested on a series of (RWH) systems built in Guatemalan part of the Corredor Seco, Chiquimula department, with sustainable and appropriate building techniques, but with variable size due to the variability of each household. Factors affecting efficiency of storage tanks are discussed to inform future sustainable water management planning in the area.Reference:Ursino, N. Risk Analysis Approach to Rainwater Harvesting Systems. Water 2016, 8, 337. https://doi.org/10.3390/w8080337

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A Review of Roof and Pond Rainwater Harvesting Systems for Water Security: The Design, Performance and Way Forward

Water ◽

10.3390/w12113163 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3163

Author(s):

Husnna Aishah Zabidi ◽

Hui Weng Goh ◽

Chun Kiat Chang ◽

Ngai Weng Chan ◽

Nor Azazi Zakaria

Keyword(s):

Urban Areas ◽

Rainwater Harvesting ◽

Water Security ◽

Small Scale ◽

Rapid Urbanization ◽

Harvesting Systems ◽

Alternative Water ◽

The Many ◽

Equatorial Climate

Rapid urbanization, population explosion and climate change have threatened water security globally, regionally and locally. While there are many ways of addressing these problems, one of the innovative techniques is the recent employment of Sustainable Urban Drainage Systems (SUDS) which include rainwater harvesting systems (RWHS). Therefore, this paper reviews the design and component of two types of RWHS, the namely roof harvesting system (RHS) and the pond harvesting system (PHS). The performance in terms of quantity and quality of collected rainwater and energy consumption for RWHS with different capacities were evaluated, as well as the benefits and challenges particularly in environmental, economic and social aspects. Presently, the RHS is more commonly applied but its effectiveness is limited by its small scale. The PHS is of larger scale and has greater potentials and effectiveness as an alternative water supply system. Results also indicate the many advantages of the PHS especially in terms of economics, environmental aspects and volume of water harvested. While the RHS may be suited to individual or existing buildings, the PHS has greater potentials and should be applied in newly developed urban areas with wet equatorial climate.

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Assessment of Rainwater Harvesting Potential from Roof Catchments through Clustering Analysis

Water ◽

10.3390/w12092623 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2623

Author(s):

Rubén Villar-Navascués ◽

Alfredo Pérez-Morales ◽

Salvador Gil-Guirado

Keyword(s):

Hot Spots ◽

Clustering Analysis ◽

Urban Areas ◽

Supervised Classification ◽

Rainwater Harvesting ◽

Spatial Clustering ◽

Runoff Coefficient ◽

Harvesting Systems ◽

Cold Spots ◽

Per Capita

Rainwater harvesting from rooftop catchments represents a climate change adaptation measure that is especially significant in areas affected by water scarcity. This article develops a Geographic Information Systems-based methodology to evaluate the spatial distribution of rainwater catchment potential to identify the most favorable urban areas for the installation of these infrastructures. Since performance and water saving potential of rainwater harvesting systems greatly depends on population density and roof size, this assessment was performed for each residential plot on a per capita basis, based on cadastral data and a method of demographic disaggregation. Furthermore, to evaluate spatial variation of runoff coefficient per building, a supervised classification was carried out to consider the influence of roof types on the rainwater catchment potential. After calculating rainwater catchment potential per capita for each residential plot, the spatial clustering of high (hot spots) and low values (cold spots) was assessed through the Getis-Ord General G statistic. Results indicate a spatial pattern of high rainwater catchment potential values in low-density urban areas, where rainwater catchment systems are expected to offer a better performance and a shorter amortization period. These results may be useful for the enactment of local legislation that regulates the obligation to install these infrastructures or offers subsidies for their implementation.

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A procedure to analyze the viability of rainwater harvesting systems in urban areas based on pre-defined diagrams

RBRH ◽

10.1590/2318-0331.0217160012 ◽

2017 ◽

Vol 22 (0) ◽

Author(s):

Felipe Eugenio de Oliveira Vaz Sampaio ◽

Conceição de Maria Albuquerque Alves

Keyword(s):

Urban Areas ◽

Rainwater Harvesting ◽

Supply System ◽

Design Parameters ◽

Alternative Source ◽

Precipitation Regimes ◽

Simplified Method ◽

Harvesting Systems ◽

Drinking Water Supply System ◽

Definition Of

ABSTRACT Giving some specific precipitation regimes and technical design parameters, urban Rainwater Harvesting Systems (RWHS) may represent an alternative source to drinking water supply system promoting its conservation and rational use. The use of RWHS requires the definition of generic and simplified method for sizing RWHS accumulation tanks, which is has being considered the most expensive component of the system. Additionally, several methods have being used to define reservoir volumes leading to a wide variety of final reservoir volumes many of them over estimated. The main objective of this article is to present a new methodology to define RWHS reservoir volumes considering technical and economic viabilities of the systems. The proposed methodology was incorporated into a Decision Support System (DSS), named SARA. The method provides an alternative way to define smaller RWHS reservoir volumes once it accepts lower levels of reliabilities giving that the RWHS is considered a complimentary system, better suited for urban areas. RWHS design diagrams are built as a result of the methodology in an attempt to offer a tool to initial and rapid design of reservoir volumes for RWSH. The method was applied to different urban areas in Brazil.

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Contributions to the design of rainwater harvesting systems in buildings with green roofs in a Mediterranean climate

Water Science & Technology ◽

10.2166/wst.2016.034 ◽

2016 ◽

Vol 73 (8) ◽

pp. 1842-1847 ◽

Cited By ~ 11

Author(s):

Cristina M. Monteiro ◽

Cristina S. C. Calheiros ◽

Carla Pimentel-Rodrigues ◽

Armando Silva-Afonso ◽

Paula M. L. Castro

Keyword(s):

Urban Areas ◽

Mediterranean Climate ◽

Rainwater Harvesting ◽

Oxygen Demand ◽

Green Roofs ◽

Atmospheric Pollutants ◽

Water Runoff ◽

Mediterranean Countries ◽

Harvesting Systems ◽

Monthly Runoff

Green roofs (GRs) are becoming a trend in urban areas, favouring thermal performance of buildings, promoting removal of atmospheric pollutants, and acting as possible water collection spots. Rainwater harvesting systems in buildings can also contribute to the management of stormwater runoff reducing flood peaks. These technologies should be enhanced in Mediterranean countries where water scarcity is increasing and the occurrence of extreme events is becoming very significant, as a result of climate change. An extensive pilot GR with three aromatic plant species, Satureja montana, Thymus caespititius and Thymus pseudolanuginosus, designed to study several parameters affecting rainwater runoff, has been in operation for 12 months. Physico-chemical analyses of roof water runoff (turbidity, pH, conductivity, NH4+, NO3−, PO43−, chemical oxygen demand) have shown that water was of sufficient quality for non-potable uses in buildings, such as toilet flushing. An innovative approach allowed for the development of an expression to predict a ‘monthly runoff coefficient’ of the GR system. This parameter is essential when planning and designing GRs combined with rainwater harvesting systems in a Mediterranean climate. This study is a contribution to improving the basis for the design of rainwater harvesting systems in buildings with extensive GRs under a Mediterranean climate.

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Effectiveness of Rainwater Harvesting Systems for Flood Reduction in Residential Urban Areas

Water ◽

10.3390/w11071389 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1389 ◽

Cited By ~ 18

Author(s):

Gabriele Freni ◽

Lorena Liuzzo

Keyword(s):

Water Consumption ◽

Flood Risk ◽

Urban Areas ◽

Rainwater Harvesting ◽

Single Family ◽

Residential Areas ◽

Harvesting Systems ◽

Daily Water ◽

Alternative Water ◽

Area Of Study

Rainwater harvesting (RWH) systems have many benefits being an effective alternative water supply solution, not only in arid and semi-arid regions. Also, these systems can be useful in the reduction of flood risk in urban areas. Nevertheless, most of the studies in literature focused on the potential of RWH in reducing water consumption, whereas few examples examined their efficiency in the retention of stormwater in flood-susceptible residential areas. The aim of this work was to investigate the reliability of RWH systems in terms of stormwater retention. Specifically, the performance of RWH tanks to supply water for toilet flushing, in more than 400 single-family houses in a residential area of Sicily (Southern Italy) was analyzed. The area of study was chosen due to its high susceptibility to flooding. A flushing water demand pattern was defined using water consumption data collected during a measurement campaign. The yield-after-spillage algorithm was used to simulate the daily water balance of the RWH tanks. The effect of the RWH implementation on flood volumes in the area of study was quantified using FLO-2D. Results point out that the potential of neighborhood RWH installation in the mitigation of flood risk is highly related to rainfall amount.

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Investigation of the Current Situation and Prospects for the Development of Rainwater Harvesting as a Tool to Confront Water Scarcity Worldwide

Water ◽

10.3390/w11102168 ◽

2019 ◽

Vol 11 (10) ◽

pp. 2168 ◽

Cited By ~ 9

Author(s):

Stavros Yannopoulos ◽

Ioanna Giannopoulou ◽

Mina Kaiafa-Saropoulou

Keyword(s):

Water Scarcity ◽

Rainwater Harvesting ◽

Groundwater Resources ◽

Water Source ◽

Water Shortage ◽

Global Scale ◽

Current Situation ◽

Frequency Peak ◽

Alternative Water ◽

Social Causes

Nowadays, available water resources face severe pressures due to demographic, economic, social causes, environmental degradation, climate change, and technological changes on a global scale. It is well known that rainwater harvesting, a simple and old method, has the potential to supplement surface and groundwater resources in areas that have inadequate water supply. In recent decades, many countries have supported the updated implementation of such a practice to confront the water demand increase and to reduce the frequency, peak, and volume of urban runoff. These considerations motivate interest in examining the current situation and the prospect of further development of this method worldwide. The present paper aims at the investigation of the current situation of rainwater harvesting (RWH) as an alternative water source to confront water scarcity in various countries around the world. In particular, the paper presents the following: (a) the causes of water shortage; (b) a concise historical overview of the temporal development of the RWH method; (c) the evolution of the concept of RWH; (d) the efforts to renew interest in RWH; and (e) incentives and perspectives for the spreading of the RWH method in various countries worldwide.

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Establishment of sustainable water supply system in small islands through rainwater harvesting (RWH): case study of Guja-do

Water Science & Technology ◽

10.2166/wst.2010.299 ◽

2010 ◽

Vol 62 (1) ◽

pp. 148-153 ◽

Cited By ~ 7

Author(s):

Mooyoung Han ◽

Jaehong Ki

Keyword(s):

Water Supply ◽

Rainwater Harvesting ◽

Empty Space ◽

Water Source ◽

Water Shortage ◽

System Capacity ◽

Small Islands ◽

Design Modification ◽

Sustainable Water Supply ◽

Unfavorable Condition

Many islands in Korea have problems related to water source security and supply. In particular, the water supply condition is worse in small islands which are remote from the mainland. A couple of alternatives are developed and suggested to supply water to islands including water hauling, groundwater extraction, and desalination. However, these alternatives require much energy, cost, and concern in installation and operation. Rainwater harvesting is a sustainable option that supplies water with low energy and cost. However, lack of practical or comprehensive studies on rainwater harvesting systems in these regions hinders the promotion of the system. Therefore, this research examines defects of current RWH systems on an existing island, Guja-do, and provides technical suggestions in quantitative and qualitative aspects. A simple system design modification and expansion of system capacity using empty space such as a wharf structure can satisfy both the qualitative and the quantitative water demand of the island. Since rainwater harvesting is estimated to be a feasible water supply option under the Korean climate, which is an unfavorable condition for rainwater harvesting, implies a high potential applicability of rainwater harvesting technology to other regions over the world suffering from water shortage.

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A Critical Evaluation of the Water Supply and Stormwater Management Performance of Retrofittable Domestic Rainwater Harvesting Systems

Water ◽

10.3390/w12041184 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1184 ◽

Cited By ~ 1

Author(s):

Ruth Quinn ◽

Peter Melville-Shreeve ◽

David Butler ◽

Virginia Stovin

Keyword(s):

Climate Change ◽

Water Supply ◽

Stormwater Management ◽

Rainwater Harvesting ◽

Critical Evaluation ◽

Water Source ◽

Management Tool ◽

Retention Capacity ◽

Harvesting Systems ◽

Alternative Water

Rainwater harvesting systems are often used as both an alternative water source and a stormwater management tool. Many studies have focused on the water-saving potential of these systems, but research into aspects that impact stormwater retention—such as demand patterns and climate change—is lacking. This paper investigates the short-term impact of demand on both water supply and stormwater management and examines future and potential performance over a longer time scale using climate change projections. To achieve this, data was collected from domestic rainwater harvesting systems in Broadhempston, UK, and used to create a yield-after-spillage model. The validation process showed that using constant demand as opposed to monitored data had little impact on accuracy. With regards to stormwater management, it was found that monitored households did not use all the non-potable available water, and that increasing their demand for this was the most effective way of increasing retention capacity based on the modelling study completed. Installing passive or active runoff control did not markedly improve performance. Passive systems reduced the outflow to greenfield runoff for the longest time, whereas active systems increased the outflow to a level substantially above roof runoff in the 30 largest events.

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Assessment of the role of green infrastructure in sustainable urban water management

10.5194/egusphere-egu2020-17994 ◽

2020 ◽

Author(s):

Ágnes Gulyás ◽

Ákos Csete

Keyword(s):

Green Infrastructure ◽

Surface Runoff ◽

Urban Areas ◽

Rainwater Harvesting ◽

Water Cycle ◽

Urban Water ◽

Urban Water Management ◽

Sustainable Urban Water Management ◽

Harvesting Systems

Due to the climate change caused uncertainty, the urban areas face new challenges. In addition to mitigating the negative effects, it is important the developments need to implemented in a sustainable manner. The problem of urban areas is substantial on account of their growing spatial size and population, furthermore the inadequate infrastructure. Urban districts with inadequate infrastructure can be a major source of water pollution, but also have a significant impact on the well-being of the citizens. In modern urban planning the sustainable urban water management based on the usage of green infrastructure. Green infrastructure is an important tool to make urban water cycle sustainable by linking artificial, engineered elements (gray infrastructure) with the services provided by vegetation. Green infrastructure can help to make the urban water cycle sustainable in many ways. Its primary role is the mitigating effect, such as reducing and retaining surface runoff with the process of interception and evaporation. Due to the complex structure of vegetation, it can also play an important role in infiltration (by root system), thus also reducing surface runoff.Providing adequate data on the role of green infrastructure &#8211; even on a city-wide scale &#8211; can help decision makers. To accomplish this, hydrological models can play an important role. If these models (i-Tree Hydro) based on appropriate meteorological and land cover data, they can help to estimate the runoff and infiltration of study areas and the reducing effect of vegetation (interception, evaporation). In our study, we attempted to compare two significantly different urban district based on these aspects and to analyze the differences. Analyzes in the two study areas of Szeged (Hungary) all suggest the vegetation can significantly contribute to the reduction of surface runoff. Differences between these urban districts can be quantified so these data can serve as a basis for decision making in urban planning processes.As another element of our research, we analyzed the relationship between surface runoff and infiltration in modeling study (SWMM) of rainwater harvesting systems in public institutions (kindergartens). In this part of the research, besides the efficiency of the rainwater harvesting systems, we got data about the extent of surface runoff, evaporation and infiltration on yard of kindergartens.

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