A hydrograph plots discharge versus time; what are its key components?

A hydrograph plots discharge versus time; what are its key components?

• A. Precipitation, evapotranspiration, infiltration, runoff
• B. Rising limb, peak discharge, falling limb, baseflow
• C. Groundwater storage, surface storage, interception, evaporation
• D. Infiltration, percolation, drainage density, lag time

Answer: (B)

A hydrograph shows how river discharge changes over time after a rainfall event, so the essential features are the rising limb, which depicts how quickly flow increases as runoff and groundwater are mobilized; the peak discharge, the highest flow reached; the falling limb, which shows the recession of flow as the system returns toward baseflow; and baseflow, the portion of discharge sustained by groundwater even after rainfall has stopped. These elements together describe the basin’s response to rainfall and help assess flood potential and drainage behavior. Other options describe processes, storage terms, or metrics not representing the main shape of a hydrograph, so they don’t serve as its core components.

A hydrograph shows how river discharge changes over time after a rainfall event, so the essential features are the rising limb, which depicts how quickly flow increases as runoff and groundwater are mobilized; the peak discharge, the highest flow reached; the falling limb, which shows the recession of flow as the system returns toward baseflow; and baseflow, the portion of discharge sustained by groundwater even after rainfall has stopped. These elements together describe the basin’s response to rainfall and help assess flood potential and drainage behavior.

Other options describe processes, storage terms, or metrics not representing the main shape of a hydrograph, so they don’t serve as its core components.