Next Article in Journal
Statistical Dependence of Pipe Breaks on Explanatory Variables
Next Article in Special Issue
Influence Mechanisms of Rainfall and Terrain Characteristics on Total Nitrogen Losses from Regosol
Previous Article in Journal
Applications of Coupled Explicit–Implicit Solution of SWEs for Unsteady Flow in Yangtze River
Previous Article in Special Issue
Effect of Climate Change on Hydrology, Sediment and Nutrient Losses in Two Lowland Catchments in Poland
Article Menu
Issue 3 (March) cover image

Export Article

Open AccessArticle
Water 2017, 9(3), 157;

Modeling Crop Water Productivity Using a Coupled SWAT–MODSIM Model

Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
Department of Earth and Atmospheric Sciences, Faculty of Science, University of Alberta, Edmonton, AB T6G 2E3, Canada
Department of Ecosystem Science and Management, Texas A & M University, College Station, TX 77843, USA
Grassland, Soil and Water Research Laboratory, USDA Agricultural Research Service, Temple, TX 76502, USA
Author to whom correspondence should be addressed.
Academic Editor: Athanasios Loukas
Received: 30 December 2016 / Revised: 9 February 2017 / Accepted: 17 February 2017 / Published: 24 February 2017
Full-Text   |   PDF [5592 KB, uploaded 24 February 2017]   |  


This study examines the water productivity of irrigated wheat and maize yields in Karkheh River Basin (KRB) in the semi-arid region of Iran using a coupled modeling approach consisting of the hydrological model (SWAT) and the river basin water allocation model (MODSIM). Dynamic irrigation requirements instead of constant time series of demand were considered. As the cereal production of KRB plays a major role in supplying the food market of Iran, it is necessary to understand the crop yield-water relations for irrigated wheat and maize in the lower part of KRB (LKRB) where most of the irrigated agricultural plains are located. Irrigated wheat and maize yields (Y) and consumptive water use (AET) were modeled with uncertainty analysis at a subbasin level for 1990–2010. Simulated Y and AET were used to calculate crop water productivity (CWP). The coupled SWAT–MODSIM approach improved the accuracy of SWAT outputs by considering the water allocation derived from MODSIM. The results indicated that the highest CWP across this region was 1.31 kg·m−3 and 1.13 kg·m−3 for wheat and maize, respectively; and the lowest was less than 0.62 kg·m−3 and 0.58 kg·m−3. A close linear relationship was found for CWP and yield. The results showed a continuing increase for AET over the years while CWP peaks and then declines. This is evidence of the existence of a plateau in CWP as AET continues to increase and evidence of the fact that higher AET does not necessarily result in a higher yield. View Full-Text
Keywords: Karkheh River Basin; dynamic irrigation scheduling; irrigated wheat; irrigated maize; uncertainty analysis; coupled SWAT-MODSIM Karkheh River Basin; dynamic irrigation scheduling; irrigated wheat; irrigated maize; uncertainty analysis; coupled SWAT-MODSIM

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Supplementary material


Share & Cite This Article

MDPI and ACS Style

Ashraf Vaghefi, S.; Abbaspour, K.C.; Faramarzi, M.; Srinivasan, R.; Arnold, J.G. Modeling Crop Water Productivity Using a Coupled SWAT–MODSIM Model. Water 2017, 9, 157.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Water EISSN 2073-4441 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top