1. Slides excerpted from the Ecosystem Services module
Systems & Modeling
Slides excerpted from the Ecosystem Services module

2. Hydrologic cycle & systems
watershed
outlet
What are the:
Elements
Interconnection/processes
Function/ purpose

3. Watersheds as systems Characteristics of systems: Nested/ hierarchial
Subwatershed
Watershed
Divide
Watershed Outlet
Subwatershed Outlet
Characteristics of systems:
Nested/ hierarchial
Dynamic
Resilient

4. (soil moisture or groundwater)
Modeling systems
Watershed
Evapotranspiration
Precipitation
Runoff
Abstract model
Storage
(soil moisture or groundwater)

5. Mathematical modeling Water balance equation
Evapotranspiration
Watershed
Precipitation
Storage
(soil moisture or groundwater)
Runoff
where,
P = precipitation (inches)
Q = runoff (inches)
ET = evaporation (inches)
ΔS = the change in storage (inches)
P = Q + ET + ΔS

6. EPA National Stormwater Calculator
Evaporation
(current & future)
Watershed
Precipitation
(long-term & future)
Soil type
Soil drainage
Topography
Land cover
Development
Infiltration
Transpiration
(current & modeled land cover)
Red = items from previous abstract model
Runoff
(current & modeled)