scholarly journals Assessment of Rainwater Harvesting Potential from Roof Catchments through Clustering Analysis

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2623
Author(s):  
Rubén Villar-Navascués ◽  
Alfredo Pérez-Morales ◽  
Salvador Gil-Guirado

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.

Author(s):  
Crisbin Joseph Mathew

Abstract: Due to the rise in population and increase in urbanisation levels in our country, most of the settlements are in urban areas. As the cities that already existing are heavily populated along with a great deal of limitations in the infrastructure, emergence of an advanced township away from the vicinity of these overpopulated urban areas offer safer and better accommodation for the people. The planning and layout of the project is shown using autoCAD and for the structural analysis we use STADD Pro V.18i. Demographic analysis is done among specific clientele. Development of roof top rainwater harvesting(sump)has been carried out in order to provide source of water for the whole population of the township. Use of intze tank which is a circular overhead tank to meet the daily water requirement of the population inside the township.For the proper disposal and processing of the waste generated, almost 30 acres of land is being used to hold the per capita waste generated which managed after calculating factors like total waste generated, estimated landfill, total area required for land etc. The salient features a major advantages of this township is discussed in detail. Keywords: IS - Indian Standard BM - Bending Moment BIS - Bureau of Indian Standards cm - CentiMeters mm - MilliMeters m - Meter C - Celsius


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3163
Author(s):  
Husnna Aishah Zabidi ◽  
Hui Weng Goh ◽  
Chun Kiat Chang ◽  
Ngai Weng Chan ◽  
Nor Azazi Zakaria

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.


2014 ◽  
Vol 15 (3) ◽  
pp. 490-498 ◽  
Author(s):  
Wen Liu ◽  
Weiping Chen ◽  
Chi Peng ◽  
Laosheng Wu ◽  
Yuguo Qian

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.


RBRH ◽  
2017 ◽  
Vol 22 (0) ◽  
Author(s):  
Felipe Eugenio de Oliveira Vaz Sampaio ◽  
Conceição de Maria Albuquerque Alves

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.


2016 ◽  
Vol 73 (8) ◽  
pp. 1842-1847 ◽  
Author(s):  
Cristina M. Monteiro ◽  
Cristina S. C. Calheiros ◽  
Carla Pimentel-Rodrigues ◽  
Armando Silva-Afonso ◽  
Paula M. L. Castro

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.


Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1389 ◽  
Author(s):  
Gabriele Freni ◽  
Lorena Liuzzo

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.


Author(s):  
Timotheus B. Darikwa ◽  
Samuel O. Manda

Background: Cardiovascular diseases (CVDs) are part of the leading causes of mortality and morbidity in developing countries, including South Africa, where they are a major public health issue. Understanding the joint spatial clustering of CVDs and associated risk factors to determine areas in need of enhanced integrated interventions would help develop targeted, cost-effective and productive mediations. We estimated joint spatial associations and clustering patterns of 2 CVDs (stroke and heart attack) and 3 risk factors (hypertension, high blood cholesterol (HBC) and smoking) among adults in South Africa. Methods: We used cross-sectional secondary adult (15–64-year olds) health data from the South African Demographic Health Survey 2016. Age and gender standardized disease incidence ratios were analyzed using joint spatial global and local bivariate Moran’s Index statistics. Results: We found significantly positive univariate spatial clustering for stroke (Moran; s Index = 0.128), smoking (0.606) hypertension (0.236) and high blood cholesterol (0.385). Smoking and high blood cholesterol (0.366), smoking and stroke (0.218) and stroke and high blood cholesterol (0.184) were the only bivariate outcomes with significant bivariate clustering. There was a joint stroke-smoking local “hot spots” cluster among four districts in the urban western part of the country (City of Cape Town; Cape Winelands; Overberg and Eden) and a joint “cold spots” cluster in the rural north-western part of the country. Similar joint “hot spots” clustering was found for stroke and high blood cholesterol, which also had “cold spots” cluster in the rural east-central part of the country. Smoking and high blood cholesterol had a “hot spots” cluster among five districts in the urban western part of the country (City of Cape Town; Cape Winelands; Overberg; Eden, and West Coast) and “cold spots” around the rural districts in east-southern parts of the country. Conclusions: Our study showed that districts tended to co-cluster based on the rates of CVDs and risk factors, where higher rates were found in urban places than in rural areas. These findings are suggestive of a more contagious and spatial diffusion process among interdependent districts in urban districts. Urbanization or rurality needs to be considered when intervention initiatives are implemented with more general approaches in rural areas. The finding of “hot spot” co-clusters in urban areas means that integrated intervention programmes aimed at reducing the risk of CVDs and associated risk factors would be cost-effective and more productive.


2019 ◽  
Vol 42 (7) ◽  
pp. 503-513
Author(s):  
Gina C. Rowe

The use of emergency departments (EDs) for potentially preventable visits is costly and inefficient. In Maryland, about 20%–30% of such visits are ambulatory care sensitive and thus potentially preventable. The uninsured are often perceived to account for a disproportionate share of such visits. This analysis aimed to (a) compare and explain the geographic variance in Maryland’s potentially preventable ED visit (PPV) rates for the total and uninsured populations and (b) test the predictive value of regression models developed. Geographic hot spots of increased PPV rates were highly correlated for uninsured and total populations, but uninsured rates were more clustered in urban areas. Poisson and geographically weighted regression (GWR) models best fit the data and predicted 40%–52% and 46% of the variance in 2009 total and uninsured rates, respectively. Significant predictors of increased PPV rates were social determinants of health: lower per capita income and education levels, and higher percentage of female-headed households.


2020 ◽  
Author(s):  
Ágnes Gulyás ◽  
Ákos Csete

<p>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.</p><p>Providing adequate data on the role of green infrastructure <strong>–</strong> even on a city-wide scale <strong>–</strong> 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.</p><p>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.</p>


Author(s):  
Mohamed Shabani Kariburyo ◽  
Lauri Andress ◽  
Alan Collins ◽  
Paul Kinder

High rates of chronic diseases and increasing nutritional polarization between different income groups in the United States are issues of concern to policymakers and public health officials. Spatial differences in access to food are mainly blamed as the cause for these nutritional inequalities. This study first detected hot and cold spots of food providers in West Virginia and then used those places in a quasi-experimental method (entropy balancing) to study the effects of those places on diabetes and obesity rates. We found that although hot spots have lower rates of chronic diseases than non-hot spots and cold spots have higher rates of chronic diseases than non-cold spots—the situation is complicated. With the findings of income induced chronic disease rates in urban areas, where most hot spots are located, there is evidence of another case for "food swamps." However, in cold spots which are located mainly in rural areas, higher rates of chronic diseases are attributed to a combination of access to food providers along with lacking the means (i.e., income for low-income households) to form healthier habits.


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