I have no idea how to calculate this, I just need some direction please (like an equation)? Consider a drainage basin 187 km2. How much water is produced (m3) if 2.5 inches of rain falls on the basin? How many people could be supported on the water produced per day? Per year? Thanks for your help.
To calculate the amount of water produced in cubic meters (m³) when 2.5 inches of rain falls on a given area, you need to follow these steps:
Step 1: Convert the area from km² to m²:
Since 1 km² is equal to 1,000,000 m², you can convert the given drainage basin area of 187 km² as follows:
187 km² * 1,000,000 m²/km² = 187,000,000 m²
Step 2: Convert the rainfall from inches to meters:
To convert inches to meters, you need to know that 1 inch is equal to 0.0254 meters. So, you can calculate the rainfall in meters as follows:
2.5 inches * 0.0254 m/inch = 0.0635 meters
Step 3: Calculate the volume of water:
To find the volume of water in cubic meters, you multiply the area by the rainfall depth. The formula is as follows:
Volume of water = Area * Rainfall depth
Using the values we obtained:
Volume of water = 187,000,000 m² * 0.0635 meters = 11,864,500 m³
Now that you have calculated the volume of water produced, you can estimate the number of people this water could support per day and per year by considering the average daily water consumption.
Typically, the average daily water consumption per person can range from 50 to 100 liters (or 0.05 to 0.1 m³). For this explanation, let's assume an average of 75 liters per person per day.
Step 4: Calculate the number of people supported per day:
Divide the volume of water by the daily water consumption per person to get the estimated number of people supported per day:
Number of people supported per day = Volume of water / Daily water consumption per person
Using the values we obtained:
Number of people supported per day = 11,864,500 m³ / 0.075 m³ = 158,193,333 people
Step 5: Calculate the number of people supported per year:
Assuming a year has 365 days:
Number of people supported per year = Number of people supported per day * 365
Using the values we obtained:
Number of people supported per year = 158,193,333 people * 365 = 57,726,166,645 people
So, based on the given information, the estimated number of people that could be supported on the water produced per day is approximately 158,193,333 people, and per year is approximately 57,726,166,645 people.