A graph of flow past a point in a river versus time.
A graphical representation of rainfall over time.
A graph of water table versus time.
A chart or graphic representation of the average distribution of rain over the surface of the earth.
A hydrograph is a graph showing the rate of flow (discharge) versus time past a specific point in a river, channel, or conduit carrying flow. The rate of flow is typically expressed in cubic meters or cubic feet per second (cms or cfs).
A hyetograph is a graphical representation of the distribution of rainfall intensity over time. For instance, in the 24-hour rainfall distributions as developed by the Soil Conservation Service (now the NRCS or National Resources Conservation Service), rainfall intensity progressively increases until it reaches a maximum and then gradually decreases.