In the SCS-CN method, Antecedent Moisture Condition (AMC) is categorized into three levels (AMC-I, AMC-II, AMC-III). Which AMC corresponds to dry soil condition with lowest runoff potential?
Options:
(A) AMC-I (lowest runoff potential, dry soils)
(B) AMC-II (average condition)
(C) AMC-III (heavy rainfall, near saturation)
(D) AMC-IV (flooded watershed)
Answer Key:
A
Step-by-Step Solution & Explanation
In SCS hydrology:
- AMC-I represents dry conditions (lowest runoff, lowest CN).
- AMC-II represents average catchment condition (standard reference CN).
- AMC-III represents wet condition following high 5-day antecedent rainfall.