Impacts of Changes in Precipitation Amount and Distribution on Water Resources Studied Using a Model Rainwater Harvesting System

Abstract

Water supply reliability is expected to be affected by both precipitation amount and distribution changes under recent and future climate change. We compare historical (1951‐2010) changes in annual‐mean and annual‐maximum daily precipitation in the global set of station observations from Global Historical Climatology Network and climate models from the Inter‐Sectoral Impact Model Intercomparison Project (ISI‐MIP), and develop the study to 2011‐2099 for model projections under high radiative forcing scenario (RCP8.5). We develop a simple rainwater harvesting system (RWHS) model and drive it with observational and modeled precipitation. We study the changes in mean and maximum precipitation along with changes in the reliability of the model RWHS as tools to assess the impact of changes in precipitation amount and distribution on reliability of precipitation‐fed water supplies. Results show faster increase in observed maximum precipitation (10.14% per K global warming) than mean precipitation (7.64% per K), and increased reliability of the model RWHS driven by observed precipitation by an average of 0.2% per decade. The ISI‐MIP models show even faster increase in maximum precipitation compared to mean precipitation. However, they imply decreases in mean reliability, for an average 0.15% per decade. Compared to observations, climate models underestimate the increasing trends in mean and maximum precipitation and show the opposite direction of change in reliability of a model water supply system.

Spatial and Temporal Analysis of Rainfall Concentration Using the Gini Index and PCI

“…In this context, Westra et al [33] analyzed the relationship between maximum daily rainfall and the global near-surface temperature, finding a positive relationship between both variables. Similarly, worldwide studies done by O'gorman [34] and Asadieh & Krakauer [35], found that the maximum daily precipitations are growing faster than the average annual precipitation, implying that rainfall intensity is generally increasing, which is similar to what Sarricolea & Martin-Vide [27] and Sarricolea et al [28] found in Chile, through a CI analysis. Therefore, the objective of this study was to characterize in time and space the behavior and concentration of daily and monthly rainfall in two climatic zones (arid-semiarid and humid-subhumid) of the country.…”

Optimization of Water-Supply and Hydropower Reservoir Operation Using the Charged System Search Algorithm

“…Loss (t) is net amount of gain and loss of the reservoir resulting from precipitation and evaporation in time step t. Ev(t) is the evaporation height during the time step t, and x 0 , x 1 , x 2 and x 3 are constants that can be obtained by fitting Equation 15to the existing data. In cases where the evaporation loss is not considered in the formulations, Loss (t) is excluded from the Equation (11). In a hydropower reservoir operation, the objective is to obtain a set of releases from the reservoir (or a set of reservoir storage volumes) such that the power generation from the reservoir is maximum, or as close as possible to the installed capacity of the hydro-electric plant.…”

A Review of Rainwater Harvesting in Malaysia: Prospects and Challenges

“…RWHS can be defined as direct collection of rainwater from roof and other purpose-built catchments and the collection of sheet runoff from man-made ground or natural surface catchment and rock catchment for potable and non-potable uses. Studies on RWHS have been intensively carried out, since this system has several advantages for the environment and community [82][83][84][85][86][87][88][89][90][91]. Over the past four decades, the number of studies related to RWHS has increased exponentially as shown in Figure 3 based on a keyword 'RWHS' in Scopus database.…”