Editor’s Note

This issue of the Journal of Irrigation and Drainage Engineering has eight papers and a technical note that focus on different aspects of irrigation and water resources.

The first three papers discuss different aspects of reference evapotranspiration $\left({\mathrm{ET}}_{\mathrm{o}}\right)$ . The first paper, by Yoder et al., takes a look at the effect of some common vapor pressure deficit and net radiation calculation methods on the accuracy of reference ${\mathrm{ET}}_{\mathrm{o}}$ values using the standardized ASCE Penman-Monteith equation for short grass. The second paper, by Nandagiri and Kovoor, discusses the use of nonrecommended alternative procedures for estimating parameters for calculating reference ${\mathrm{ET}}_{\mathrm{o}}$ for the FAO-56 version of the Penman-Monteith equation. Thirteen alternative algorithms for ET estimation were formulated involving modified procedures for parameters associated with weighting factors, net radiation, and vapor pressure deficits. The third paper, by Snyder et al., discusses a new method to estimate ET from pan evaporation data for arid climate conditions.

The next three papers deal with optimization techniques. The two papers by Smout and Gorantiwar discuss the methodology and applications of an area and water allocation model (AWAM), which incorporates deficit irrigation for optimizing the use of water for irrigation. The model was applied to a case study in Maharashtra State, in India. The third paper, by Planells et al., discusses a procedure the author developed to aid in the selection and regulation of irrigation pumping stations.

The other two papers and technical note cover different aspects of water resources. The paper by Deltour et al. discusses the development of software for data reconciliation, based upon measurements from hydraulic networks. The software was tested and is being used to check the measured flow on the main canal of the Canal de Provence, in France. The paper by Schneider and McCuen discusses a set of guidelines to produce a new runoff curve number table based on peak discharge measurements rather than depths of rainfall and runoff, which are the current practices used.

The technical note by Anwar and Clarke presents a design of a parabolic channel in which freeboard is introduced as an additional parameter.