basins 3 0 swat model l.
Skip this Video
Loading SlideShow in 5 Seconds..
BASINS 3.0 – SWAT Model PowerPoint Presentation
Download Presentation
BASINS 3.0 – SWAT Model

Loading in 2 Seconds...

play fullscreen
1 / 9

BASINS 3.0 – SWAT Model - PowerPoint PPT Presentation

  • Uploaded on

BASINS 3.0 – SWAT Model. Kristina Schneider Kristi Shaw. Focus of Presentation. SWAT – An Overview. SWAT stands for Soil and Water Assessment Tool Spatial Scale: watershed or river basin Data Organization: subbasins or hydrologic response units (HRU’s)

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'BASINS 3.0 – SWAT Model' - benjamin

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
basins 3 0 swat model

BASINS 3.0 – SWAT Model

Kristina Schneider

Kristi Shaw


SWAT – An Overview

  • SWAT stands for Soil and Water Assessment Tool
  • Spatial Scale: watershed or river basin
  • Data Organization: subbasins or hydrologic response units (HRU’s)
  • Time scale: Continuous time model (long term yield model)
        • based on a daily scale
  • Not for a single event
  • Data Inputs: weather, soil properties, topography,
  • vegetation, and land management practices
  •   From the BASINS databases
swat an overview
SWAT – An Overview
  • SWAT separates soil profiles into 10 layers to model inter
  • and intra-movement between layers.
  • The model is applied to each soil layer independently starting
  • at the upper layer.
  • SWAT soil water routing feature consists of four main pathways:
  • 1. soil evaporation
  • 2. plant uptake and transpiration
  • 3. lateral flow
  • 4. percolation.

Soil Evaporation

      • Actual soil water evaporation stimulated using exponential
  • functions of soil depth and water content.
  • Potential soil water evaporation considering ground covering
  • Es= potential soil water evaporation rate (mm/day)
  • EA=soil cover index
  • Eo=potential evaporation rate at the surface (mm/day) 
  • Potential soil water evaporation for a layer
  • SEV= potential soil water evaporation rate for layer (mm/day)
  • EV=total soil water evaporation in mm from soil of depth Z in mm
plant uptake and transpiration
Plant Uptake and Transpiration
    • SWAT model computes evaporation from soils and
  • plants by Eo = 128 (ho)
    • Plant transpiration function potential
      • Evapotranspiration and
      • Leaf area index (area of plant leaves relative to
      • area of the HRU
    • Potential evapotranspiration calculated with
      • Hargreaves
      • Priestley-Taylor
      • Penman-Monteith.

Si = drainable volume of water stored in the saturated zone mm-1

qlat = lateral flow in m3h-1

i = rate of water input to the saturated zone in m2h-1

L = hillslope length in m

Lateral Flow

  • The stream flow contribution below the surface
  • but above saturated zone.
  • It is calculated simultaneously with redistribution
  • using a kinematic storage model.
  • The model accounts for variation in conductivity,
  • slope, soil water content, and allows flow upward to surface.
  • Kinematic storage model finite difference mass continuity equation:


  • Storage routing technique combined with a crack-flow model to predict flow through each soil layer
  • Cracked flow model allows percolation of infiltrated rainfall though soil water content is less than field capacity.
  • Portion that does become part of layer stored water cannot percolate until storage exceeds field capacity.
  • Storage routing technique based on the following equation:
  • Swi=soil water contents at end of the day (mm)
  • Swoi=soil water contents at beginning of the day
  • TT=travel time through layer (hr)

Evaporation and Transpiration


(Rainfall & Snow)

Surface Runoff

Infiltration/plant uptake/ Soil moisture redistribution

Lateral Flow

Percolation to shallow aquifer