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ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Publications at this Location » Publication #352984
Research Project: Resilient Management Systems and Decision Support Tools to Optimize Agricultural Production and Watershed Responses from Field to National Scale

Location: Grassland Soil and Water Research Laboratory

Title: Use of decision tables to simulate management in SWAT+

Author
item Arnold, Jeffrey
item BIEGER, K - Texas Agrilife Research
item White, Michael
item SRINIVASAN, R - Texas A&M University
item DUNBAR, J - Baylor University
item ALLEN, P - Baylor University

Submitted to: Water
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2018
Publication Date: 5/31/2018
Citation: Arnold, J.G., Bieger, K., White, M.J., Srinivasan, R., Dunbar, J.A., Allen, P.M. 2018. Use of decision tables to simulate management in SWAT+. Water. 10:713-723. https://doi.org/10.3390/w10060713.
DOI: https://doi.org/10.3390/w10060713

Interpretive Summary: Simulation models are commonly used to predict the input of agricultural and water management on the environment. Most models use complex rule sets to determine management options. Current algorithms to input management decisions in existing models struggle to mimic complex, real world decision making. In this study, decision tables were modified and utilized to simulate automated irrigation and reservoir release management with SWAT+ (Soil and Water Assessment Tool). Decision tables have been used for years in data processing and business applications and are an efficient way to simulate complex rule sets. We demonstrated that decision tables had several advantages over current approaches used in models including: 1) the ability to accurately model complex decision making, 2) efficient, modular code, and 3) the ability to easily maintain and support the tables. Going forward, decision tables will be an integral component for simulating land management scenarios.

Technical Abstract: Decision tables have been used for many years in data processing and business applications to simulate complex rule sets. Several computer languages have been developed based on rule systems and they are easily programmed in several current languages. Land management and river-reservoir models simulate complex land management operations and reservoir management in highly regulated river systems. Decision tables are a precise yet compact way to model the rule sets and corresponding actions found in these models. In this study, we discuss the suitability of decision tables to simulate management in the river basin scale Soil and Water Assessment Tool (SWAT+) model. Decision tables are developed to simulate automated irrigation and reservoir releases. A simple auto irrigation application of decision tables was developed using plant water stress as a condition for irrigating corn in Texas. Sensitivity of the water stress trigger and irrigation application amounts were shown on soil moisture and corn yields. In addition, the Grapevine Reservoir near Dallas, Texas was used to illustrate the use of decision tables to simulate reservoir releases. The releases were conditioned on reservoir volumes and flood season. The release rules as implemented by the decision table realistically simulated flood releases as evidenced by a daily NSE (Nash-Sutcliffe Efficiency) of 0.52 and a percent bias of -1.1%. Using decision tables to simulate management in land, river and reservoir models was shown to have several advantages over current approaches including: 1) mature technology with considerable literature and applications, 2) ability to accurately represent complex, real world decision making, 3) code that is efficient, modular and easy to maintain, and 4) tables that are easy to maintain, support, and modify.