Water Demand Estimation and Population Forecasting Methods: Standard Per Capita Consumption Standards
Designing a municipal water supply system requires accurately projecting future population growth and total daily water demand over a specified design period (typically 30 years). Total municipal water demand includes domestic, commercial, industrial, public use, and unaccounted-for water (losses and thefts). Population forecasting relies on several standard mathematical methods based on growth kinetics: Arithmetic Increase Method: Assumes a constant rate of population growth over time ($\frac{dP}{dt} = k$). It is suitable for large, established, and fully developed cities. $$P_n = P_0 + n \cdot \bar{x}$$ Where $P_n$ is the forecast population after $n$ decades, $P_0$ is the current population, and $\bar{x}$ is the average algebraic increase per decade. Geometric Increase Method: Assumes percentage growth rate remains constant over time ($\frac{dP}{dt} = k \cdot P$). It is suitable for young, rapidly growing cities. $$P_n = P_0 \cdot \left(1 + \frac{r_g}{100...