Gannon Molumby - Runoff & Erosion Project_ Calculations

Procedure a. Calculate the area of each type of land cover. Land Cover Identifier Curve Number % total area Poor Condition Grass 79 8.89% Fair Condition Grass 69 29.50% Good Condition Grass 61 8.53% Impervious Areas 98 36.35% Paved; curbs and storm sewers 98 0.00% Paved; open ditches 89 0.00% Gravel 85 12.55% Dirt 82 4.18% Sums 100.00% b. Calculate the storage, S, and the initial abstraction, Ia S 2.150560184 Ia 0.4301120368 c. Calculate the runoff, Q (in inches) for each month in inches, cubic feet, and liters and put it in d. Calculate the Nitrogen and Phosphorus in the runoff each month. Remember to convert mg t Month Inches of Rain Runoff (inches) Jan 4.64 2.78646350894289 Feb 3.82 2.07408139156679 March 4.35 2.5312005426037 April 3.25 1.59980908954451 May 4.16 2.36581700404051 June 3.86 2.10809797525077 July 4.39 2.56621319800932 Aug 4.46 2.62764068383967 Sep 4.86 2.98215363566907 Oct 3.3 1.64054217468888 Nov 3.46 1.77209013751177 Dec 3.43 1.74729024243156 TOTAL 26.8013995840994

Soil Loss Calculation a. Find the rainfall energy factor R= b. Record the Erodability factor (K) from the figure. K= c. Calculate the slope-length factor length= slope= LS= d. Pick a suitable cropping factor and protection factor. C= e. Calculate the soil loss in tons/ha using the universal soil loss equation. f. Calculate the expected mass of soil loss in kg using the table below. Q1: Is there more nitrogen and phosphorus carried away in the water or in the sediment? Q2: What assumptions are you most unsure of? Q3: Name at least one thing that could be done on campus to Reduce Runoff Reduce Sediment Transfer away and more than 12 times as much phosphorus. hydrologic soil type they belonged to was quite difficult. creating denser bodies of grass can substantially reduce runoff.

Area (sq ft) % * Curve Number 3618.72384937238 7.02405857740586 12005.6485355649 20.3535564853556 3469.71757322176 5.20031380753138 14794.1945606695 35.6223849372385 0 0 0 0 5108.78661087866 10.6694560669456 1702.92887029289 3.43096234309623 40700 Curve Number 82.30073222 *I used Urban/Built-Up landuse n the table. There are 28.32 liters per cubic foot. Dissolved N (mg/l) Dissolved P (mg/l) to kg. Record your table factors to the right --> 0.33 2.18 Runoff (liters) Nitrogen (kg) Phosphorus (kg) 9450.75540116465 267645.392960983 0.089222979677124 0.58436695665494 7034.59271973071 199219.665822774 0.066642489721515 0.43519887149365 8584.98850699754 243126.87451817 0.081131868590996 0.53091658644961 5426.01916203847 153664.86266893 0.051609404680747 0.33588940061827 8024.06267203738 227241.454872099 0.075889680107793 0.49628637162118 7149.96563272554 202487.026718787 0.0677207188172 0.44232171824696 8703.73976324828 246489.910095191 0.082241670331413 0.53824800400752 8912.08131935622 252390.142964168 0.084188747178176 0.55111051166189 10114.4710809776 286441.821013285 0.095425800934384 0.62534316980896 5564.17220915312 157577.356963216 0.052900527797861 0.34441863817981 6010.33904972742 170212.801888281 0.057070224623133 0.37196390811645 5926.22607224703 167830.722366036 0.056284138380792 0.36677097475796 90901.413589404 2574328.03285192 0.850428250841134 5.61293511161719 Runoff (cubic feet)

230 0.15 370 change in elevation= 14 <-use same units! 0.03783783784 slope% 3.78% 0.65 0.1 P= 1 Item Value Unit A - Annual soil loss 2.2425 tons/ha ha per square meters 0.0001 ha/m2 tons per m2 0.00022425 tons / m2 Square feet of land open to erosion 25905.80544 ft2 square meters per square foot 0.0929 m2/ft2 Square meters of land open to erosion 2406.649325 m2 tons of soil loss 0.5396911112 tons kg per ton 907.2 kg/ton kg of soil loss 489.6077761 kg Nitrogen load 900 mg/kg Annual nitrogen from sediment 0.4406469985 kg Phosphorus load 900 mg/kg Annual phosphorus from sediment 0.4406469985 kg ? most similar to the cropping factor of concrete and gravel.