Calculadora de Escoamento de Bacia Hidrográfica
Calcule o volume de escoamento superficial após precipitação.
Runoff Volume
1,357,700 gallons
Runoff Volume vs Watershed Area
Formula
How to Calculate Watershed Runoff
The rational method estimates stormwater runoff based on rainfall, area, and land cover.
Formula
Runoff = Area * Rainfall * Runoff Coefficient
Typical Runoff Coefficients (C)
Exemplo Resolvido
A 50-acre suburban watershed with 2 inches of rainfall and runoff coefficient of 0.5.
- 01Runoff acre-inches: 50 * 2 * 0.5 = 50 acre-inches
- 02Runoff gallons: 50 * 27,154 = 1,357,700 gallons
- 03Runoff acre-feet: 1,357,700 / 325,851 = 4.17 acre-feet
- 04Retained: 50 * 2 * 0.5 * 27,154 = 1,357,700 gallons
Perguntas Frequentes
What is a runoff coefficient?
The runoff coefficient (C) is the fraction of rainfall that becomes surface runoff. A value of 0.5 means 50% of rain runs off and 50% infiltrates or evaporates.
Why does urbanization increase runoff?
Impervious surfaces like pavement and roofs prevent water from soaking into the ground. A natural area may have C = 0.15, while a commercial area can be C = 0.90, creating 6x more runoff.
How does stormwater runoff cause pollution?
Runoff picks up pollutants including oil, fertilizers, pesticides, sediment, and litter, carrying them directly into streams and lakes without treatment.