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DIDAS

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DIDAS

DIDAS

Drip Irrigation Design and Scheduling

Gregory Communar, Alon Gamliel and Shmulik P. Friedman

Department of Environmental Physics and Irrigation, Agricultural Research Organization, Israel

 

Website

http://app.agri.gov.il/didas

 

Description

The DIDAS software package was developed for the purpose of assisting irrigators in the design of drip irrigation systems and in irrigation scheduling. The program performs computations based on analytical solutions of the relevant linearized water flow and uptake problems. Water flow is described by superposition of solutions for positive sources (on-surface or subsurface emitters) and negative sinks (plant root systems). Steady water flow is assumed in the design module and unsteady flow is used in the irrigation scheduling module.

The design tool is based on a new, relative water uptake rate (RWUR, ratio between water uptake rate and irrigation rate) criterion suggested for deciding upon the distances between emitters along drip lines and between drip lines. The maximum possible RWUR is evaluated assuming no plant-atmosphere resistance to water uptake. Namely, the plant roots apply maximum possible suction and the water uptake is determined just by the capability of the soil to conduct water from the emitters to the rooting zones. The computations of the RWUR requires only a minimum number of three parameters describing the soil texture, the size of the root zone and the potential evaporation, in the few cases when it is important to account for also evaporation form the soil surface.

The irrigation scheduling optimizing tool is based on a relative water uptake volume (RWUV, ratio between daily water uptake volume and daily irrigation volume) criterion. The computations of the diurnal patterns of the water uptake rates and the daily RWUV for a given irrigation scenario require additional information on the diurnal pattern of the plant resistance to water uptake and on the hydraulic conductivity of the soil.

DIDAS includes also a module of quasi-steady flow for evaluating the diurnal water uptake patterns that accounts for the diurnal plant resistance and evaporation patterns and serves for fine-tuning of the design and preliminary evaluation of scheduling scenarios. DIDAS is programmed in Delphi and runs on any Windows operating system-PC, with no further software requirements. The construction of the drip irrigation scenario is performed via few GUI windows, which contain also a library of the required input parameters, and several best-fitting procedures. The computed RWURs and RWUVs are displayed graphically and the tabulated output results can be exported to e.g. Windows Excel for further processing.

 

Scientific articles

Communar, G and Friedman, S.P. (2010a). Relative water uptake rate as a criterion of trickle irrigation systems design: 1. Coupled source-sink steady water flow model.  Soil Sci. Soc. Am. J., 74:1493-1508.

Communar, G and Friedman, S.P. (2010b). Relative water uptake rate as a criterion of trickle irrigation systems design: 2.Surface trickle irrigation. Soil Sci. Soc. Am. J., 74:1509-1517.

Communar, G and Friedman, S.P. (2010c). Relative water uptake rate as a criterion of trickle irrigation systems design: 3.Subsurface trickle irrigation. Soil Sci. Soc. Am. J., 74:1518-1525.

Communar, G and Friedman, S.P. (2010d). Steady infiltration from point sources and water uptake in confined cylindrical domains.  Soil Sci. Soc. Am. J., 74:1861-1867.

Communar, G and Friedman, S.P. (2011). General solution for steady infiltration and water uptake in strip-shaped, rectangular and cylindrical domains. Soil Sci. Soc. Am. J., 75:2085–2094.

Meiri, A. Naftaliev, B. Shmuel, D., Yechezkel, H. Communar, G and Friedman, S.P. (2011). Short-term watering-distance and symmetry effects on root and shoot growth of bell pepper plantlets. Agricultural Water Management, 98:1557-1568.

Communar, G and Friedman, S.P. (2012a). Generalized coupled source-sink model for evaluating transient water uptake in trickle irrigation: I. Model formulation for soils with vertical heterogeneity. Soil Sci. Soc. Am. J., 76:779-790.

Communar, G and Friedman, S.P. (2012b). Generalized coupled source-sink model for evaluating transient water uptake in trickle irrigation: II. Illustrative irrigation scheduling scenarios. Soil Sci. Soc. Am. J., 76:791-805.

Communar, G and Friedman, S.P. (2013). Unsteady infiltration from point and line sources in laterally confined domains. Soil Sci. Soc. Am. J., 77: 1529-1541.

Communar, G and Friedman, S.P. (2014). Determination of soil hydraulic parameters with cyclic irrigation tests. Vadose Zone J., doi: 10.2136/vzj2013.09.168.

 

Technical information

Operating system(s): Windows XP and higher

Licence: free for individuals

Output(s):  Steady relative water uptake rates, Diurnal patterns of water uptake, evaporation and deep percolation rates, Relative daily water uptake , evaporation and deep percolation volumes, Flow fields (equi-potential and stream lines), Temporal  patterns of water potential at specified locations.     

Export format(s): text (csv and rtf)

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