SWAT Literature Database for Peer-Reviewed Journal Articles

Title:An improved SWAT vegetation growth module and its evaluation for four tropical ecosystems 
Authors:Alemayehu, T., A. van Griensven, B.T. Woldegiorgis and W. Bauwens 
Year:2017 
Journal:Hydrology and Earth System Sciences 
Volume:21(9) 
Pages:4449–4467 
Article ID: 
DOI:10.5194/hess-21-4449-2017 
URL (non-DOI journals): 
Model:SWAT-T & SWAT 
Broad Application Category:hydrologic only 
Primary Application Category:crop growth/yield or plant parameters 
Secondary Application Category:evapotranspiration assessment 
Watershed Description:13,750 km^2 Mara River, which drains portions of southwest Kenya and northeast Tanzania before flowing into Lake Victoria. 
Calibration Summary: 
Validation Summary: 
General Comments: 
Abstract:The Soil and Water Assessment Tool (SWAT) is a globally applied river basin ecohydrological model used in a wide spectrum of studies, ranging from land use change and climate change impacts studies to research for the development of the best water management practices. However, SWAT has limitations in simulating the seasonal growth cycles for trees and perennial vegetation in the tropics, where rainfall rather than temperature is the dominant plant growth controlling factor. Our goal is to improve the vegetation growth module of SWAT for simulating the vegetation variables – such as the leaf area index (LAI) – for tropical ecosystems. Therefore, we present a modified SWAT version for the tropics (SWAT-T) that uses a straightforward but robust soil moisture index (SMI) – a quotient of rainfall (P) and reference evapotranspiration (ETr/ – to dynamically initiate a new growth cycle within a predefined period. Our results for the Mara Basin (Kenya/Tanzania) show that the SWAT-Tsimulated LAI corresponds well with the Moderate Resolution Imaging Spectroradiometer (MODIS) LAI for evergreen forest, savanna grassland and shrubland. This indicates that the SMI is reliable for triggering a new annual growth cycle. The water balance components (evapotranspiration and streamflow) simulated by the SWAT-T exhibit a good agreement with remote-sensing-based evapotranspiration (ET-RS) and observed streamflow. The SWAT-T model, with the proposed vegetation growth module for tropical ecosystems, can be a robust tool for simulating the vegetation growth dynamics in hydrologic models in tropical regions. 
Language:English 
Keywords: