A two-hour rainfall event steadily delivers 2.5 cm/hr to a 150-hectare watershed with the following characteristics: • 50 hectares are ½ acre residential lots, hydrologic soil group B, 25% imperviousness • 100 hectares are row crops (corn, contoured, good condition, hydrologic group C) • Antecedent soil moisture condition is AMC II • The soils are loam with 2% organic matter • The slope is 2% with slope length 100m → Assume LS factor = 0.25 a) Use a weighted average CN to estimate the runoff depth (Q) in mm over the entire 150 ha area for: i) the first 30 minutes of the storm, and ii) the entire storm. b) Estimate the gross erosion from the row crops (not the residential area) during this event in metric tonnes / ha. c) Estimate the clay enrichment ratio if the sediment transported in the storm runoff is composed of 40% clay. Remember the soils are loam.

A two-hour rainfall event steadily delivers 2.5 cm/hr to a 150-hectare watershed with the following characteristics: • 50 hectares are ½ acre residential lots, hydrologic soil group B, 25% imperviousness • 100 hectares are row crops (corn, contoured, good condition, hydrologic group C) • Antecedent soil moisture condition is AMC II • The soils are loam with 2% organic matter • The slope is 2% with slope length 100m → Assume LS factor = 0.25 a) Use a weighted average CN to estimate the runoff depth (Q) in mm over the entire 150 ha area for: i) the first 30 minutes of the storm, and ii) the entire storm. b) Estimate the gross erosion from the row crops (not the residential area) during this event in metric tonnes / ha. c) Estimate the clay enrichment ratio if the sediment transported in the storm runoff is composed of 40% clay. Remember the soils are loam.

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

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