IPEAT+: A Built-In Optimization and Automatic Calibration Tool of SWAT+

Abstract

For almost 30 years, the Soil and Water Assessment Tool (SWAT) has been successfully implemented to address issues around various scientific subjects in the world. On the other hand, it has been reaching to the limit of potential flexibility in further development by the current structure. The new generation SWAT, dubbed SWAT+, was released recently with entirely new coding features. SWAT+ is designed to have far more advanced functions and capacities to handle challenging watershed modeling tasks for hydrologic and water quality processes. However, it is still inevitable to conduct model calibration before the SWAT+ model is applied to engineering projects and research programs. The primary goal of this study is to develop an open-source, easy-to-operate automatic calibration tool for SWAT+, dubbed IPEAT+ (Integrated Parameter Estimation and Uncertainty Analysis Tool Plus). There are four major advantages: (i) Open-source code to general users; (ii) compiled and integrated directly with SWAT+ source code as a single executable; (iii) supported by the SWAT developer group; and, (iv) built with efficient optimization technique. The coupling work between IPEAT+ and SWAT+ is fairly simple, which can be conducted by users with minor efforts. IPEAT+ will be regularly updated with the latest SWAT+ revision. If users would like to integrate IPEAT+ with various versions of SWAT+, only few lines in the SWAT+ source code are required to be updated. IPEAT+ is the first automatic calibration tool integrated with SWAT+ source code. Users can take advantage of the tool to pursue more cutting-edge and forward-thinking scientific questions.

Impacts of Land‐Use Change on the Hydrology of Lake Tana Basin, Upper Blue Nile River Basin, Ethiopia

“…It is more flexible, easier to maintain, and more developed than the old SWAT model. [ 51 , 52 ] Streamflow data from the Gumera, Ribb, Gilgel Abay, and Megech river basins were used to calibrate and validate the model for the 1980–1999 and 2000–2007 time periods, respectively. The model performance assessment selected the parameters REVAL_MIN, REVAL_CO, FLOW_MIN, ALPHA, DELAY, ESCO, AWC, and CN2.…”

The application of SWAT+ model to quantify the impacts of sensitive LULC changes on water balance in Guder catchment, Oromia, Ethiopia

“…The SWAT + model is a QGIS extension that integrates a wide range of available geospatial data to represent the characteristics of the watershed at the hydrological response unit (HRU) level rather than the sub-basin level [ 25 ]. In the model, the impacts of spatial heterogeneity of topography, land use, soil, and slope on catchment hydrology were described in subdivisions at the watershed level [ 26 ].…”

Assessing the Impact of Land Use and Climate Change on Surface Runoff Response Using Gridded Observations and SWAT+

“…Sequential Uncertainty Fitting version 2 (SUFI-2) algorithm [43] has been widely used for automatic calibration and sensitivity analysis of SWAT models. QSWAT, however, can be calibrated using: (1) SWATCup-plus SUFI-2, a premium version of the public domain SWAT-CUP; (2) a novel Integrated Parameter Estimation and Uncertainty Analysis Tool Plus (IPEAT+) [79] explicitly designed for SWAT+; and (3) inbuilt SWAT Editor hard and soft calibration. In this study, sensitivity analysis and calibration were performed in two phases: first, sensitive model parameters from Table 2 were identified using relative sensitivity analysis suggested by Haan [80], and then calibration was done using IPEAT+ after identifying the sensitive parameters.…”