Thiessen Polygon - Average depth of rainfall over an area
The Thiessen Polygon method is a graphical technique used to compute the average areal depth of precipitation over a catchment basin by assigning proper weight factors to each rain gauge station based on its area of influence.
Mass curve - Relationship of accumulated rainfall and time
A rainfall mass curve is a plot showing the cumulative or accumulated depth of rainfall over a specific time duration. Because it tracks accumulated totals, its slope never decreases over time.
Hyetograph - Relationship of rainfall intensity and time
A hyetograph is a bar chart or graph showing the distribution of rainfall intensity over time (usually expressed in mm/hour versus hours).
DAD curve - Always a falling curve
A Depth-Area-Duration (DAD) curve represents the relationship between maximum
average rainfall depth and the storm area for a given duration. Because the average rainfall
intensity drops as the storm area increases outward from the eye of the storm, a DAD curve
is always a falling curve as you move along the area axis.
