Roof Water Harvesting Research Articles

Effect of automated sensor-driven irrigation and fertigation on green pepper (Capsicum annuum L.) growth, phenology, quality and production

This research aimed to optimize green pepper cultivation with automated sensor-based irrigation and fertigation, supplemented by roof water harvesting under protected cultivation. The findings demonstrated that employing a sensor-based irrigation regimen at 75 % available soil moisture (ASM) coupled with 125 % of the recommended dose of fertilizer (RDF) significantly improved both the growth and yield characteristics of pepper. This combination notably improved yield attributing parameters as well as total fruit yield (60,089 kg ha−1). Also, the resource use efficiency metrics viz., water use efficiency (16.75 kg m−3), energy productivity (0.80 kg MJ−1), nutrient use efficiency (79.5 kg kg−1) and benefit-cost ratio of 2.07, indicated superiority. Correlation between yield and variables viz., individual fruit weight (r = 0.98), number of fruits per plant (r = 0.96), total dry matter accumulation (r = 0.96), and fruit volume (r = 0.94) found positive at 1 % probability, displaying the strongest associations. Growth variables such as dry matter of leaves (R2=0.927), individual fruit weight (R2=0.922), and fruit volume (R2=0.847) at P ≤ 0.0001 contributed significantly to the yield. Remarkably, during the year 2020, the system collected 774 m3 of water, satisfying 100 % of the green pepper's water requirement for two seasons.

Orographic effects on droughts in a monsoon climate with the world's highest rainfall

AbstractDrought, a recurring natural phenomenon in South Asia's monsoon climate, presents challenges in delineating its spatiotemporal patterns within complex topographies. This study investigated the impact of the orographic barrier in the rice‐dominated agricultural region of northeastern India and Bangladesh on drought characteristics during 1951–2020, employing the relative Standardized Precipitation Index (rSPI) and relative Standardized Precipitation‐Evapotranspiration Index (rSPEI) across 3‐, 6‐ and 12‐month scales. The results indicate that even in the rainiest region of the world, droughts extend beyond the limits of the dry season inherent in the monsoon regime. These mostly regional droughts exhibit weak correlations with the core of the Indian subcontinent and other parts of Bangladesh. The region's orographic barrier has a greater influence on drought intensity than on frequency. The rSPI index, which depends solely on rainfall, may overestimate drought intensity and frequency in regions with high seasonal/annual rainfall and substantial intermonthly variability. In contrast, the rSPEI index, which depends on both rainfall and potential evapotranspiration (PET), better reflects the spatial variation of drought in complex terrain, identifying the leeward hinterland of the orographic barrier as the most drought‐prone area. The two indices give similar results for drought characteristics away from the barrier. Furthermore, the orographic barrier exerts a negligible influence on the trends in rSPI and rSPEI. Principal component analysis (PCA) highlights the influences of the rainfall coefficient of variation and elevation on rSPI, while the PET coefficient of variation strongly influences rSPEI. Strategies to minimize the adverse effects of drought in complex topography and year‐round cropping should be local and season‐specific. These include using shorter‐growing, drought‐resistant rice varieties and adjusting planting schedules in rain shadow areas during the summer monsoon. These efforts should be complemented by integrating indigenous irrigation methods with modern practices such as roof water harvesting and tube wells in winter.

An integrated groundwater resource management approach for sustainable development in a tropical river basin, southern India.

Evaluation of aquifer potential is essential, as thepotable water demand has increased globally over the last few decades. The present study delineated different zones of groundwater potential and groundwater quality of the Kallada River basin (KRB) in southern India, using geo-environmental and hydrogeochemical parameters, respectively. Geo-environmental variables considered include relative relief, land use/land cover, drainage density, slope angle, geomorphology, and geology, while hydrogeochemical parameters include pH, electrical conductivity (EC), Cl-, Fe3+, and Al3+ concentrations. Analytical hierarchy process (AHP) was used for categorizing groundwater potential and quality zones. Nearly 50% of KRB is categorized as very high and high groundwater potential zones, occupying the western and midland regions. The central and west-central parts of KRB are characterized by excellent groundwater quality zones, while the eastern and western parts are characterized by good and poor groundwater quality zones, respectively. By integrating the groundwater potential and groundwater quality, sustainable groundwater management is observed to be necessary at about 54% of the basin, where site-specific groundwater management structures such as percolation ponds, injection wells, and roof water harvesting have been proposed using a rule-based approach. This integrated groundwater potential-groundwater quality approach helps policymakers to implement the most suitable management strategies with maximum performance.

Evaluation of the operational effectiveness and feasibility of small-scale water supply systems in the hinterlands in Ethiopia: Case of Afar Regional State

Access to clean and sufficient drinking water is difficult in much of Ethiopia’s Afar Region. It is observed that many schemes in the region are non-functional. The study was conducted to overcome the observed problem in seven selected districts of the region. The study regarded hand-dug wells and roof water collection systems, which are the two most common features in the research areas. Eight hand-dug wells and sixteen roof water harvestings are purposively included in the study. All the water points are constructed by Kelem Ethiopia which is a non-governmental organisation and the foremost local organisation for the communities. As per the research survey, the average functional status of the hand-dug well schemes is 65.75% and the roof water harvesting schemes is 22.94%. The research was based on the qualitative data collected on site. The hand-dug well sites were evaluated using 10 parameters, and the roof water harvesting schemes were analysed using 12 parameters. The main non-functional aspects of the scheme are lack of community ownership, drying up of water sources, lack of maintenance and rehabilitation, poor coordination of beneficiaries and school roofs blowing off. Most schemes still require minor to major maintenance and rehabilitation. According to the research, the solutions for water supply are identified in relation to the desired objective.

Roof water harvesting: A Case study

The study was conducted at Shri Ram college, Muzaffarnagar- 251001 located at 29° 28’N, 77°41’E at 272 meters MSL. The climate of Muzaffarnagar is subtropical characterized by much hot summer and cooler winter. The average temperature of the area is 24.2°C which range from 45°C to 0.9°C. The average rainfall of the area is 929 mm. The dries month is November with 8 mm of rain and highest rainfall in July with an average 261.4 mm. Shri Ram College is spread in more than 5.7 hac lands. For this study the roof of block B having 894.14 square meter area was selected. Based on last thirty years rainfall data (maximum 40 mm rain in a day) a rain water collecting well of 36 m3 was manufactured to store water. The study indicates that from 894.14 m2 catchment area 35.78 m3 water is generated which required almost 36 m3 well size for storing the water. The 9 feet depth of collecting well with 6 feet diameter was found appropriate if 40 mm rain in a day occurs. To drain out 36 m3 water stored on the roof of 894.14 m2 area 7 pipes of 10cm diameter required. The study also found that 3x4 feet size two siltation tank may be sufficient before the rain water enters into the collecting well. The 6 inch (15 cm) perforated pipe was found suitable to percolate the water into ground.

Assessment of roof water harvesting potential of Navsari city of Gujarat State, India by Remote sensing and Geographic information system (GIS)

Due to the water scarcity scenario in many parts of the Navsari city, Gujarat State in India, it is imperative to adopt cost-effective technologies that could harvest rainwater for satisfying drinking water requirements. The study was conducted with the aim of assessing the rainwater harvesting potential of Navsari city using remote sensing and Geographic Information System (GIS). The built-up areas of Navsari that could harness rainwater were identified by remote sensing and GIS. The effective built-up area contributing to rainwater harvesting was found to be 3.37 km2. The classification was carried out using “Remap” to assess the extent of the built-up area. The city was divided into equal grids and classification of each grid was implemented. The ground truth data was used for the evaluation of the built-up area. The roof water harvesting potential was estimated considering the average annual rainfall of 1621 mm and adopting suitable runoff coefficients. The rainwater harvesting potential of roofs for rainfall of different probabilities was estimated. For return periods of 10 years, 25 years, 50 years and 100 years, the roof water harvesting potentials were estimated to be 0.226, 0.261, 0.287 and 0.312 Million Cubic Metres (MCM), respectively. The estimated average roof water harvesting potential of Navsari city was 164 million litres per year, capable of satisfying the drinking water demand of approximately 1.12 lakh people annually. The rainwater harnessed from the rooftop could augment the current water supply and immensely help in fulfilling the drinking water demand of Navsari.

Household Coping Strategies of Water Scarcity: The Case of Madina, A Suburb of the La- Nkwantanang District in the Greater Accra Region

The study examines the precipitating factors for water shortage and water shortage effects on Madina residents, a peri-urban community of Accra, and the forms of coping mechanisms adopted due to water scarcity. The study utilised both primary and secondary data; results revealed that the following effects of water scarcity on residents: lateness to school, inadequate sleep, a more significant percentage of family income and time used on water, increased poverty, low productivity and poor sanitation among others. The forms of coping mechanisms include harvesting rainwater, using bagged or sachet water, multiple uses of water, depending on public toilets. The topography of the Madina, few boreholes or wells, lack of pipe-born water, lack of maintenance of pipelines, increase in population, and lack of projections for the future constitute reasons for water shortage in the study area. The effects of water shortage gave rise to coping strategies and social conflict, which also have socioeconomic implications on residents. The study concludes that GWCL has not been able to satisfy the ever-increasing water demands of urban dwellers, including peri-urban communities such as Madina, that the age-long water crisis in Madina affects all aspects of the social and economic lives of its residents. Recommendations include the incorporation of roof–water harvesting techniques into modern buildings' design. Also, the hygienic use of greywater must be vigorously promoted. The Government of Ghana must also continue to engage in open consultation with stakeholders regarding alternative approaches to expanding access to clean and affordable water, mainly to the urban dwellers where the problem is most severe. Keywords: water scarcity, coping strategies, households. DOI: 10.7176/JRDM/76-05 Publication date: June 30 th 2021

Studies on mechanical, vegetative, and roof water harvesting: strategies to enhance recharge of spring and its discharge in Himalaya

Studies on mechanical, vegetative, and roof water harvesting: strategies to enhance recharge of spring and its discharge in Himalaya

Rooftop and natural springs water harvesting for promotion of vegetable cultivation in drought prone Morni Hills of Haryana State

The Shivalik hill region of Haryana faces acute shortage of water limiting scope of high value vegetable crops in spite of good rainfall and favorable climate. The natural spring water (SW) tapping and roof rainwater (RW) harvesting was not attempted earlier for drought proofing and hence attempted in this study. Seven brick masonry water storage tanks for (SW) and eight for roof water (RW) harvesting were constructed @Rs 1.2 lakh each including accessories having 6mx4mx1.8m size. The economic gains by the cultivation of vegetable crops with supplemental irrigation were analyzed for three samples of SW harvesting and five for RW harvesting. In case of SW harvesting, the traditional maize-mustard sequence generated net saving of Rs. 9, 900/-but net gain over the traditional crops was Rs. 47, 800, Rs. 51, 000 and Rs. 1, 38, 000/acre/yr by the first, second and third beneficiary farmer, respectively. In case of RW harvesting, water of five tanks was shared by seventeen farmers. The area under tomato increased from 8 to 12.2, cucumber from 2.6 to 4.7 acres and new crops of chilies and coriander were introduced over 2.1 and 1.47 acres. The total increase in gross and net income from five tanks was Rs. 14.86 and Rs. 5.94 lakh/yr over control. The aim of crop diversification, more crops per drop or doubling the income of farmers was realized by this initiative having good scope of replication.

Computer aid for roof water harvesting systems analysis in rural areas of Mexico

Abstract Lack of sufficient good quality water to fulfill the rural population's needs in many countries, such as Mexico, has become one of the main issues governments have to cope with to provide adequate living conditions. The situation has worsened due to rainfall pattern variability influenced by climate change. Water harvesting is an ancient practice that provides an additional water supply for different uses. The lack of sufficient readily available decision tools within these environments has hindered adequate decision-making. The computer aid presented in this paper serves the purpose of a decision tool for use in marginal rural areas where a water harvesting system is to be implemented. Input variables are easily obtained and the system has preloaded information for use in the water balance. The interface is user-friendly, enabling users to plug local information in to obtain outputs on which to base a decision. Input variables can be changed as needed to achieve an acceptable output. The system generates rainfall amounts stochastically enabling posterior analysis to be used in terms of designing roof water harvesting under different runoff occurrence probabilities.

RWRE–A WEB BASED OPEN SOURCE GIS TOOL FOR ROOF WATER RUNOFF ESTIMATION

In rural areas of low rainfall, roof top rainwater harvesting is an ideal method for collecting rainwater because it helps not only in meeting at least a part of the water requirement but also prevents storm runoff and flooding during heavy rains. Individual houses and buildings are the best units for collecting the roof water. In this work an interactive web-based GIS tool named RWRE (Roof Water Runoff Estimator) has been developed to estimate the runoff from the rooftops of the buildings. REWE tool was designed using open source geospatial development tools like Geoserver and OpenLayers. The developed tool provides a polygon drawing tool to delineate the rooftop of individual buildings. The area of rooftop of each building is listed. The runoff coefficient for each building is also taken as input. The annual average rainfall is required to calculate the total amount of water available from the rooftops of all the delineated buildings. For the testing and development of RWRE, the municipal area of Bhopal city of Madhya Pradesh was taken. This tool can be configured to be used for any rural or other area and can be of great help in planning and designing of the roof water harvesting structures as it quickly and accurately estimates the volume of water available from the buildings.

Roof Water Harvesting in Hills - Innovations for Farm Diversification and Livelihood Improvement

The north eastern region (NER) of India receives bountiful rains (>2000 mm) annually. However, there is extreme water scarcity during post- and premonsoon season (November-March). In such a situation, roof water harvesting (RWH) holds promise for multiple livelihood opportunities. RWH unit with polyfilm lined water collection tank of 37 m 3 storage capacity (i.e. 5.5 x 4.5 x 1.5 m 3 ) was demonstrated at 11 farmers fields mostly on hill tops in the Ri-Bhoi district (Meghalaya). The average demonstration area was 500 m 2 /farmer in the vicinity of homesteads (kitchen gardens). Volume of water harvested in a collection tank was about 53 m 3 including about 16 m 3 harvested during dry season due to seasonal replenishment. The cost of water harvesting was estimated at about Rs 144 and Rs 119/m 3 considering lifespan of five and ten years respectively. Farmers used harvested water for diversified activities such as raising crops [maize, broccoli, French bean, laipatta ( Brassica juncea ), tomato, etc.] and livestock (pig or poultry) in addition to domestic use. The farmers without RWH could use land only during rainy season for crop cultivation. On an average, the net income from each RWH based model (500 m 2 demonstration area) was Rs 14,910 for crop + piggery and Rs 11,410 for crop + poultry farming which was 261 and 176% higher, respectively than the normal farmers' practice. Similarly, employment and water use efficiency enhanced by 221 and 586%; and 168 and 218% under crop + piggery and crop + poultry based farming respectively.

Developing water resources management strategies for South Sikkim District, India

Abstract This study was an effort to analyse the problems and prospects of water resource management and for suggesting strategies to meet the perceptive demand of 410 L of water per family during the winter period in South Sikkim district of Sikkim state, India. The district is of hilly terrain with an average rainfall of 1,500 mm per year, yet the district faces acute water shortage during the winter period. The hydro-geological and meteorological characteristics of the sub-watersheds were also studied. The district had very poor soil depth (<50 cm), low water holding capacity of soils (27–28%) with mostly sandy-loam texture. The sub-watersheds were found to have more than 70% first-order streams, higher bifurcation ratio (3.31), higher drainage density (3.99 km/km2) and higher stream density (8.65/km2). Sub-watersheds are mostly elongated with average form factors of 0.21. The rainfall pattern, soil type and morphometry of sub-watersheds indicated poor in situ moisture storage and limited possibility of stream water harvesting. To mitigate the scarcity of water in South Sikkim, the only option left for the planners is to promote household roof water harvesting so that water demand can be met during the average consecutive dry period of 30 days.

Combating water scarcity through roof water harvesting: planning and design with stakeholders' perception in Sikkim (India)

Sikkim is one of the constituent states of India, endowed with huge water resources. However, due to steep terrain and non availability of a groundwater aquifer, water conservation is a challenge. The water received as rainfall drains away through the steep terrain in the deep valleys, thereby creating a water stress after withdrawal of the monsoon. To overcome such a situation, a study was undertaken to design a suitable rain water harvesting system for the state. To design a suitable water harvesting system, we estimated the water demand of the end users, assessed the water availability during the non-rainy period, and designed the volume of storage structure. The study revealed that more than 80% of the respondents experienced water stress during the period from December to March. The average daily water demand of individual households was observed to be around 400 litres. The rainfall pattern indicated that 90% of the rainfall is concentrated during 6 rainy months. On average, 24 consecutive dry days were observed in the state. The volume of storage structure obtained, based on water availability and demand, was 5 m3 per household. It is felt that this volume can take care of the domestic water demand.

GREEN LIBRARIES IN ACADEMIC INSTITUIONS: NEED OF THE HOUR

Explains term “Green” and special challenges met by libraries to be Green. Points out steps involved such as site selection, water and energy conservation, building material and indoor air quality. Briefly narrates few green libraries initiatives such as Fayetteville Public Library, Minneapolis (2004), Seattle Central Library (2004), National Library, Singapore (2005), Minneapolis Public Library (2006), and University of California (2005). Also discusses steps taken by TERI in developing GRIHA. Suggests for proper planning of buildings with solar energy system and roof water harvesting, etc.

Development of rainwater harvesting technology for securing domestic water supply in Ibadan, Nigeria

In both rural and urban areas, supplying adequate water to meet increasing population water demand is a major challenge faced by decision-makers in developing countries like Nigeria. This is as a result of the failure of conventional or municipal water supply systems to meet the challenges of providing clean water for the populace. People result to digging shallow and deep wells indiscriminately to supplement their daily water needs. As a result, the groundwater table would have been falling, causing hydrological imbalance. Domestic Roof-water Harvesting (DRWH) and groundwater recharge provide innovative solution to the inadequate water supply. In this study, a complete RWH technology was designed and constructed for a household, where public water system was non-existent. The RWH technology was incorporated into the existing shallow well water system. Water samples from the RWH system and shallow well were analysed using standard methods. With roof area of 70 m2, 21 m3 reservoirs was required for dry period. The Hardness, Alkalinity, Chloride, Iron and Nitrate of the harvested water showed values of 20.0, 21.0, 15.0, 0.2 and 2.0 mg/l respectively while pH was 6.8. The values were below WHO guideline limits for drinking water. Safety measures were taken to ensure that the harvested rainwater was of good quality. The study revealed that RWH technology is a viable and reliable water supply option in both urban and rural areas for domestic purposes.

Hydrological Impacts of Urbanization and Urban Roof Water Harvesting in Water-limited Catchments: A Review

Roof water harvesting is a potential source of water for domestic and livelihood uses in water-scarce urban areas of the world such as sub-Saharan Africa (SSA). However, little is known about the hydrological impacts of incorporating roof water harvesting on on-site and downstream hydrology of urbanized catchments. Therefore, the current review investigates the effects of urbanization and urban roof water harvesting on hydrological processes, rainfall-runoff relationships, groundwater recharge and water contamination, and highlights future research directions. The review showed that the urban heat island effect increases the frequency and magnitude of convective storms. The high proportion and connectivity of impervious surfaces reduce infiltration, thereby increasing the runoff coefficient and Hortonian runoff. Urbanization reduces the minimum threshold rainfall for runoff generation, resulting in multi-peak hydrographs reflecting the contribution of both pervious and impervious surfaces. Urban roof water harvesting increases catchment lag time, but reduces downstream peak and total discharge, baseflow and flow velocity. Utility trenches, tunnels and buried structures form a complex network resembling a shallow urban karst system, which provides preferential flow pathways for groundwater recharge by imported water via leakages. Contrary to the widely held notion that urbanization reduces groundwater recharge by increasing impervious surfaces, empirical evidence shows significant urban-enhanced recharge in water-limited urban catchments. However, we contend that excessive groundwater abstraction for multiple uses in water-scarce regions offsets the urban-enhanced recharge, resulting in groundwater depletion. Due to the overriding collective effects of reduced soil moisture and vegetation cover on evapotranspiration in water-limited environments, we conclude that urbanization lowers evapotranspiration. Urban roof water harvesting short-cuts the urban water cycle, thereby minimizing the risk of runoff contamination that could occur during its extended flow over contaminated land surfaces. Contaminated sources of recharge, such as wastewater leakages coupled with the urban karst system, promote groundwater pollution. Overall, urban roof water harvesting imparts additional complexity to urban catchments, and has potentially adverse effects on ecohydrology. Understanding these impacts is critical for planning, designing and operation of urban roof water harvesting systems. Future research may provide a comprehensive understanding of these impacts by combining hydrological measurements and process modelling in urbanized catchments incorporating roof water harvesting.

WATER SECURITY FOR VILLAGE GAVHALI THROUGH ROOF TOP RAIN WATER HARVESTING

The objective of this work is to compile and review the literature on Rain water harvesting, estimate the consumption of liter per capita per demand ( LPCD ) for domestic and potable consumption and establish that rain water harvesting is a practical, economical and sustainable system with ecosystem specially for rural areas Fresh water is a precious and limited resource that nourishes innumerable life forms. As population pressures increase, the majority of communities around the world face the prospect decreasing supplies of fresh water in general and many would have no access to potable water at all. This lack of access impacts human health around the globe as many dies from water borne diseases and related illnesses every year. In those communities where access to fresh water is limited and watershed health is of concern, one viable “lowtech” solution is to build a roof water harvesting system. By creating the means to store water on site, using the existing rainfall as the source and infiltrate on of the grey water and remaining run-off, one can eliminate the need to draw from precious ground water supplies and avoid the high costs (economic and environmental) of dependence on centralized conveyance and treatment systems. Humans benefit from having a self sufficient ecosystem. The ecosystem receives benefits from the reduced erosion, flooding and pollution caused by run-off and the reduction of demand on groundwater supplies. More than 60 % of Indian population lives the rural area, deforestation is the main reasons of imbalance in rainfall in every reasionof India; Satpuda is the top most range of mountain in Maharashtra which is situated on boundaries of Maharashtra – Gujarat, and Maharashtra- Madhyapradesh. This part of boundary area had a thick forest cover but now-a-days the percentage of forest area has depleted. Day by day it is going on decreasing ,Adiwasi people situated along the mountain regions face the water scarcity problem ,due to inadequate rainfall and ground water depletion, Gavhali villagers are face water scarcity in the month of April, May and June. A brief methodology of the work is put forth herein; Villagers of Gavhali face water shortage during the months from April to June. The aim of this project work is to ascertain the potential of roof - top rain water harvesting for three water scarce months. Case one is to estimate per capita daily demand of water which works out to 40lpcd for three months and cost of the system. Case two is to work out the per capita daily demand of only potable water which is calculated at the 10lpcd for three months and cost of the system.

The limitations of roofwater harvesting in developing countries

Many tropical countries often have poorly performing or absent piped-water supplies in their rural and suburban areas. Fetching water from point sources such as wells is often arduous and such sources are vulnerable to pollution. Domestic roofwater harvesting (DRWH in this article) is a promising alternative self-supply technology and is supported by many agencies and associations. However take-up of DRWH has been very limited due to the six constraints discussed in this article. These are: inadequacy of annual roof run-off volume; excessive cost; difficulty of water management; uncertain water quality; poor installation/maintenance/longevity; and ugliness. While these constraints rule against DRWH becoming a universal first choice for less economically developed countries, (LEDC) domestic water supply, there are many specific scenarios where it outperforms, or is cheaper than, the alternatives. The paper identifies some of these scenarios and also how the constraints can be minimized by prudent application and ongoing R&D.

Field report: Roofwater harvesting on the coastal islands of Guinea-Bissau: rainwater tank construction adapted to the local context

The Republic of Guinea-Bissau in West Africa is not a well-known country. The islands in the south-west are part of a flat and ‘salty’ coastal landscape with severe drinking water problems. The NGO ‘Iagu Limpo – Tabanka San’ (Clean Water – Healthy Village) has adapted cement water tanks – called Balanta tanks – to the context in this part of the world. Using clay blocks as a stable and inexpensive formwork avoids the problem of an unstable mould and thus reduces materials needed. More than 1,000 of these tanks exist in Guinea-Bissau and numbers are increasing fast. A MAPP (Method of Assessment of Projects and Programmes) exercise has shown the importance users attach to the tanks; they are an integral part of their lives. People appreciate them as a source of clean water for drinking, whereas water for other purposes (such as cleaning, washing) usually comes from wells (often with brackish water). Readers interested in this innovative and simple way to build and spread rainwater tanks can join training courses or send masons to work with trained masons in Guinea-Bissau.