Next Article in Journal
Ecological Status of Rivers and Streams in Saxony (Germany) According to the Water Framework Directive and Prospects of Improvement
Previous Article in Journal
Scenario Planning to Address Critical Uncertainties for Robust and Resilient Water–Wastewater Infrastructures under Conditions of Water Scarcity and Rapid Development
Water 2012, 4(4), 869-886; doi:10.3390/w4040869
Article

A Simple Scheme for Modeling Irrigation Water Requirements at the Regional Scale Applied to an Alpine River Catchment

* ,
 and
Received: 11 September 2012; in revised form: 31 October 2012 / Accepted: 1 November 2012 / Published: 7 November 2012
View Full-Text   |   Download PDF [1676 KB, uploaded 7 November 2012]   |   Browse Figures
Abstract: This paper presents a simple approach for estimating the spatial and temporal variability of seasonal net irrigation water requirement (IWR) at the catchment scale, based on gridded land use, soil and daily weather data at 500 × 500 m resolution. In this approach, IWR is expressed as a bounded, linear function of the atmospheric water budget, whereby the latter is defined as the difference between seasonal precipitation and reference evapotranspiration. To account for the effects of soil and crop properties on the soil water balance, the coefficients of the linear relation are expressed as a function of the soil water holding capacity and the so-called crop coefficient. The 12 parameters defining the relation were estimated with good coefficients of determination from a systematic analysis of simulations performed at daily time step with a FAO-type point-scale model for five climatically contrasted sites around the River Rhone and for combinations of six crop and ten soil types. The simple scheme was found to reproduce well results obtained with the daily model at six additional verification sites. We applied the simple scheme to the assessment of irrigation requirements in the whole Swiss Rhone catchment. The results suggest seasonal requirements of 32 × 106 m3 per year on average over 1981–2009, half of which at altitudes above 1500 m. They also disclose a positive trend in the intensity of extreme events over the study period, with an estimated total IWR of 55 × 106 m3 in 2009, and indicate a 45% increase in water demand of grasslands during the 2003 European heat wave in the driest area of the studied catchment. In view of its simplicity, the approach can be extended to other applications, including assessments of the impacts of climate and land-use change.
Keywords: Swiss Rhone catchment; agriculture; irrigation; climate; statistical modeling Swiss Rhone catchment; agriculture; irrigation; climate; statistical modeling
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.

Export to BibTeX |
EndNote


MDPI and ACS Style

Smith, P.C.; Calanca, P.; Fuhrer, J. A Simple Scheme for Modeling Irrigation Water Requirements at the Regional Scale Applied to an Alpine River Catchment. Water 2012, 4, 869-886.

AMA Style

Smith PC, Calanca P, Fuhrer J. A Simple Scheme for Modeling Irrigation Water Requirements at the Regional Scale Applied to an Alpine River Catchment. Water. 2012; 4(4):869-886.

Chicago/Turabian Style

Smith, Pascalle C.; Calanca, Pierluigi; Fuhrer, Jürg. 2012. "A Simple Scheme for Modeling Irrigation Water Requirements at the Regional Scale Applied to an Alpine River Catchment." Water 4, no. 4: 869-886.


Water EISSN 2073-4441 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert