SWAT‐LUT: A Desktop Graphical User Interface for Updating Land Use in SWAT

Abstract

Long‐term simulations of agricultural watersheds have often been done assuming constant land use over time, but this is not a realistic assumption for many agricultural regions. This paper presents the soil and water assessment tool (SWAT)‐Landuse Update Tool (LUT), a standalone, user‐friendly desktop‐based tool for updating land use in the SWAT model that allows users to process multi‐year land use data. SWAT‐LUT is compatible with several SWAT model interfaces, provides users with several options to easily prepare and incorporate land use changes (LUCs) over a simulation period, and allows users to incorporate past or emerging land use categories. Incorporation of LUCs is expected to provide realistic model parameterization and scenario simulations. SWAT‐LUT is a public domain interface written in Python programming language. Two applications at the Fort Cobb Reservoir Experimental Watershed located in Oklahoma and pertinent results are provided to demonstrate its use. Incorporating LUCs related to implementation of recommended conservation practices over the years reduced discharge, evapotranspiration, sediment, total nitrogen, and total phosphorus loads by 59%, 9%, 68%, 53%, and 88%, respectively. The user’s manual is included in this article as Supporting Information. The SWAT‐LUT executable file and an example SWAT project with three land use rasters and the user’s manual are available at the United States Department of Agriculture‐Agricultural Research Service Grazinglands Research Laboratory website under Software. Editor’s note: This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.

The Impacts of Land-Use Input Conditions on Flow and Sediment Discharge in the Dakbla Watershed, Central Highlands of Vietnam

“…In modeling approach, emerging land-use change categories have been updated as important inputs in a model [18]. By using multiple land-use maps with linear interpolation (the same methodology in this research), updated time stamps have led to more realistic conditions in the modeling [18].…”

“…The land-use change modules were developed for SWAT via SWAT2009_LUC [16], SWAT-LUT [18], or scripting with R [17], which is a free software package for statistical computing and graphics developed by the R Foundation for Statistical Computing [38]. The software enables updated land-use changes to be considered in the SWAT model by linear interpolation at the chosen time.…”

“…The software enables updated land-use changes to be considered in the SWAT model by linear interpolation at the chosen time. With many approaches, land-use changes with time stamps are simulated, while other factors remain stable [18]. In the traditional SWAT applications, only a single land-use map is utilized to simulate target elements for a whole target period.…”

Appraisal of Climate Change and Its Impact on Water Resources of Pakistan: A Case Study of Mangla Watershed

“…Soil characteristics such as soil texture, soil bulk density, soil composition, soil electric conductivity, and soil possible water retention were collected from the FAO website. Wetland forests (WETF) are tree type crops [47]. The SWAT model has a built-in function to handle WETF by using several crop parameters, such as the ratio of erosion from land cropped to the clean tilled fallow continuous (USLE C factor), temperature responses, leaf area development, energy biomass conversion, light interception, stomatal conductance, canopy height, and root depth, plant nutrient content, and harvest.…”

“…The SWAT model has a built-in function to handle WETF by using several crop parameters, such as the ratio of erosion from land cropped to the clean tilled fallow continuous (USLE C factor), temperature responses, leaf area development, energy biomass conversion, light interception, stomatal conductance, canopy height, and root depth, plant nutrient content, and harvest. Detailed information on these parameters is given in [47].…”