Performance assessment of rainwater harvesting considering rainfall variations in Asian tropical monsoon climates

Abstract

Abstract:Rainwater harvesting is increasingly recognized as an important source of water supply. However, the technique is practiced for very different purposes depending on region and rainfall conditions. In this study, the performance of rainwater harvesting was evaluated in accordance with local user practice to determine its suitability as a primary water supply. A water balance model using a long-term time series was applied to simulate system behavior under various scenarios of tank size and monsoon patterns in the Asian tropical monsoon region, investigated at 111 sites in Vietnam. The results of the study show that a limited range of 20-110 L/d can meet basic demand with 95% reliability. However, an additional water of 50-400 L/d is available for extra supply during rainy season. The diversity of monsoon patterns leads to considerable variation of additional available water (AAW) despite uniform amounts of annual precipitation. Tank size is recognized as playing a crucial role in improvement of supply capacity for basic demand while roof area and precipitation exerts a higher influence on AAW.

Exploring optimal tank size for rainwater harvesting systems in Asian tropical climates

“…Figure 1 presents the variation of average annual rainfall between locations across climates, ranging from approximately 700 to over 4000 mm. Monsoon monthly rainfall distribution in climatic area differs in terms of intensity, duration and onset of monsoon season (Nguyen-Le et al, 2014;Vuong et al, 2016). The diversity of annual rainfall and temporal distribution are expected to result in significant impacts on rainwater harvesting.…”

“…Rainwater harvesting was simulated using a behavior model (Vuong et al, 2016). The continuity equation of the model was as follows:…”

“…The Asian tropical region has traditionally had interest in rainwater harvesting (Özdemir et al, 2011). The region also covers several different climatic patterns resulting in a large range of annual precipitation and seasonality (Vuong et al, 2016). Despite abundant rainfall and strong user interests, only a few studies are available which document the economic benefit and optimal tank size such as Hashim et al (2013) reporting optimal tank size for a large-scale rainwater harvesting system in Malaysia.…”

Seasonal household variation in harvested rainwater availability in Siaya County, Kenya: a modelling analysis

“…Rainwater harvesting (RWH) is where rainfall runoff is collected on premises from surfaces, typically a roof catchment, and stored in a container or reservoir for drinking or other purposes. Being natural and decentralised, RWH offers good perceived quality, low environmental impact, health bene ts, energy saving and convenience at household level 7,8 , and thus may improve rural drinking water availability in rural areas of developing countries where groundwater and surface water resources are limited or contaminated [9][10][11] . The WHO/UNICEF JMP have classi ed RWH as an 'improved water source' given its potential to deliver safe water 12 .…”

Performance of a RBSN under the RCP Scenarios: A Case Study in South Korea

“…Therefore, similar approaches have been applied to determine the optimal-sizing of a rainwater storage system, such as an analytical equation for storm-water detention [10], a general storage-reliability-yield (SRY) relationship [11], and a method with different results depending on the scenario [12], or a dimensionless method [12]. On the other hand, the regional performance of RWHS has drawn great attention as it is necessary to comprehend how regional characteristics, such as social and natural components, affect the performance of a RWHS [13][14][15][16][17].…”