Some Basic Hydrologic Concepts Weir are used to measure volume of water flowing past a point.

What Happens to Precipitation? Hydrologic cycle P = RO + ET + S, Where, P ≡ precipitation RO ≡ runoff ET ≡ evapotranspiration S ≡ storage

Components of Vaporization Chang, p. 169, Munich Germany

Evapotranspiration Loss of water from a given area during a specified time by evaporation from the soil surface and by transpiration from the plants. Supports plant life Reduces water yield

Runoff Provides Major Benefits RO = P – ET Moose Creek, Clearfield County, PA (WLH)

Where does runoff go to? RO = CI + SRO + SSF + BF, –where, CI ≡ channel interception SRO ≡ surface run off SSF ≡ subsurface flow BF ≡ base flow

Where does runoff go to? –CI ≡ channel interception Precipitation falling directly into channel Susquehanna River, Clearfield, PA, (WLH)

Where does runoff go to? –SRO ≡ surface runoff or overland flow Precipitation not infiltrating soil Sheet erosion of cropland resulting from surface runoff Source:

Where does runoff go to? –SSF ≡ subsurface flow, or interflow Infiltrating precipitation intercepted by hardpan or bedrock before entering groundwater pool

Where does runoff go to? –BF ≡ base flow or ground water flow Precipitation entering water table

Research results come from experimental watersheds such as:

What We’ll Look At Erosion –Impacts of Roads Harvests Water flows –Storm events –Storage Water yield –Amount –Timing Montgemory Reservoir, Clearfield, PA, WLH