APPLICATIONS OF ARC SWAT MODEL FOR HYDROLOGICAL MODELLING
• SWAT (Soil & Water Assessment Tool) is a river basin
scale and continuous-time model
• Used to predict the impact of management on water,
sediment, and agricultural chemical yields in large
In SWAT, a watershed is divided into multiple
subwatersheds, and the subwatersheds are divided into
Hydrological Response Units (HRUs)
are aggregated land areas with in sub basin
represent percentages of the subwatershed area
comprise of unique land use, soil and management
The model setup involves the following five steps
Weather data definition
Edit SWAT input
Figure 2: Menu for Automatic Delineation of Watershed in
Figure 3: Menu for Hydrologic Response Unit
Analysis in ArcSWAT model
Figure 4: Menu for Weather Data Definition in
Figure 5: Menu for Setup and Run SWAT model
Benedini et al.,(2003) developed an inflow-outflow
model for the Alban Hills using SWAT model.
For the simulation: SCS-Curve number-runoff,
Hargreaves- evapotranspiration computations.
Pierluigi et al.,(2003) presented the application of
SWAT model to evaluate the water budget for several
sardinian catchments and to predict future scenarios.
Parameters: land use, soil type, surface water
For daily weather inputs, statistical analysis of the
sardinian climatic data has been carried out.
Jain et al.,(2010) selected the swat model for the
estimation of runoff and sediment yield for an
intermediate watershed of Satluj river, Himachal
Parameters: Digital elevation model, Landuse, Soil,
Tesfahunegn et al.,(2012) presented the application of
SWAT model to identify hotspot soil degradation sub-
Based on estimated runoff, sediment yield and
nutrient losses in the Mai-Negus catchment, northern
parameters: digital elevation model (DEM), land use-
cover, soils and daily observed weather data.
Ashok et al.,(2003) analysed the potential
applicability of SWAT in managing check dams
constructed as on-stream reservoirs and impoundment
Study area: BANHA, Jharkhand, India.
Figure 6: BANHA WATERSHED
Data used: Daily rainfall, runoff and sediment
discharge, and maximum and minimum temperature
Figure 7: Measured Rainfall, runoff and sediment (June to
o Divided into 5 sub watersheds based on the drainage
and land use pattern.
o Calibrated the model for 1996 and then for nine years
o Validated by comparing the measured water yield and
sediment load with their measured counterparts for the
Varanou et al.,(2003) presented a method for
quantifying the impacts from specific land use
changes on the runoff . The water cycle was simulated
with the use of the SWAT, and the land use change
scenarios were created using the Land Use
Development Model (LADEMO).
Study area: Pinios catchment in Thessaly, Greece.
The result of a (LADEMO) model run is a digital map
of future land use.
Land use change scenarios:
Expansion of agricultural land
Expansion of urban areas
Swat model can be effectively used for
• development of inflow-outflow model,
• estimating available water resources,
• managing check dams,
• quantifying the impacts from land use changes on the
• modelling the long term impacts of best management
practices in watershed.
Check dams contribute to enormous reduction of
sediment transport from the watershed.
The simulated and observed sediment transport from
the watershed compares closely and thus shows a
strong applicability of the SWAT model in accounting
for these processes in small watersheds.
SWAT makes an accurate estimation of the deposited
sediments in check dams.
The land use change which is causing a greater
modification of daily and monthly total discharge is
the change introduced by the deforestation scenario.
Ashok., 2003: Potentials and Applicability of the
SWAT Model in Check Dam Management in a Small
Watershed. 2nd international swat conference, 2003,
Benedini., 2003: Model SWAT Application in the
Alban Hills. 2nd international swat conference, 2003,
Jain., 2010: Simulation of Runoff and Sediment Yield
for a Himalayan Watershed Using SWAT Model. J.
Water Resource and Protection, 2010, 2, 267-281
Pierluigi., 2003: Estimating Available Water
Resources of the Sardinian Island Using the SWAT
model. 2nd international swat conference, 2003, 64-70
Tesfahunegn., 2012: Application of SWAT model to
assess erosion hotspot for sub-catchment management
at Mai-Negus catchment in northern Ethiopia. East
African Journal of Science and Technology, 2013,
Varanou., 2003: Application of the SWAT model for
the Sensitivity Analysis of Runoff to Land Use
Change. 2nd international swat conference, 2003, 90-