1. Lab 13 - Predicting Discharge and Soil Erosion Estimating Runoff Depth using the Curve Number method –Land use or cover type –Hydrologic condition –Soil type Estimating Peak Runoff –A function of the Time of Concentration, Tc –The faster the runoff time => the bigger the peak Estimating Erosion Losses using the Universal Soil Loss Equation –Precipitation –Topography –Soils –Land use or land cover –Treatment or conservation practices

2. Curve Number Method

4. Peak Discharge Qp = Up · A · Q –Qp is peak runoff (L/s) –Up is unit peak (L/s/ha/mm) a function of Tc Tc is the time of concentration, or the time for water to runoff of the watershed the faster the runoff time, the bigger the peak –A is watershed area (ha) –Q is runoff depth (mm) From the curve number method

7. Universal Soil Loss Equation A = R · K · LS · C · P –A is soil loss in tons per acre per year –R is rainfall erosivity factor –K is soil erodibility factor –LS is length-slope (topographic) factor –C is the land use or land cover factor –P is the treatment or conservation practices factor

8. Rainfall Erosivity Factor