how to calculate watershed area

Note logical places for downspouts, like building corners. Calculating the size, or area, of a lake can be done a couple of different ways. 1, 2. Generally, surface water runoff from rain falling anywhere in this area Draw the general shape of the pond on paper (graph paper works best). 3. (Show students the Figure 1 watershed, or a similar image). Related Surface Area Calculator | Volume Calculator. Learn More At this point you have delineated the watershed of the wetland being evaluated. ft. of roof area is directed onto 3,000 sq. For example, if 5,000 sq. CN = overall curve number for the watershed. This will give you a rectan-gle on which to base the calcula-tion of area (See Figure 2 below). You can estimate the size by treating the lake as a the closest geometric figure, such as a circle, rectangle or triangle, or you can try to directly count the square footage of the lake by using graph paper on a scaled area map. Measure the roof to get the watershed area, the area from which water will run off. A watershed is an area or region that is drained by a common river system. The Capture Ratio is the ratio of the pervious area receiving the runoff (such as a lawn area) to the impervious area that generates the runoff. the watershed and down the opposite side of the watercourse. The area is based on the “footprint” of the roof, which can be calculated by finding the area of the building and adding the area of the roof’s overhang. The image below shows how differences in roof slope do not change this building’s catchment area. Draw a rectangle on the pond shape that would approximate the area of the pond if some water was eliminated and placed onto an equal amount of land. Area is a quantity that describes the size or extent of a two-dimensional figure or shape in a plane. It can be visualized as the amount of paint that would be necessary to cover a surface, and is the two-dimensional counterpart of the one-dimensional length of a curve, and three-dimensional volume of a solid. Write down those dimensions. 2. StreamStats Application. scale of the map and longitude and latitude marks to calculate the size of your watershed then convert to acres. area; B, the basin lag factor, which is the basin length divided by the square root of the channel slope; C, the basin length in miles; D, the main channel slope in feet per mile; E, the total impervious area, in percent of the basin area; and F, the basin Eventually it will connect with the circle from which you started. It may be ... Often in hydrology, we talk about the hydrology of a watershed. Optional: Calculate the amount of rain that falls on the watershed by finding out the average rainfall and multiplying the value by the watershed area. Multiply length (peak to eave) by width to determine square footage. ft. of lawn area then the Capture Ratio would be 3,000 / 5,000 or 60%. StreamStats is a Web application that provides access to an assortment of Geographic Information Systems (GIS) analytical tools that are useful for water-resources planning and management, and for engineering and design purposes. calculate area. The delineation appears as a solid line around the watercourse. Calculate the regional water balance equation using conservation of mass. To calculate how … (Contact the local Soil Conservation service for watershed acreage.) where: A = total watershed area (mile 2). Note places where two roofs form a valley, which will affect runoff because water will come from two sides.
how to calculate watershed area 2021