Data supporting the soil salinity evolution appraisals in the Flumen irrigation district, NE Spain.

The dataset presented comprises (raw data) scans of the marked paper contact prints from a dedicated photogrammetric flight and a diagram showing the location of each of these photograms. The flight was commissioned specifically for the soil survey presented herein. The scanned paper prints are those used in the field to characterize the soil salinity of 27,500 ha within the Flumen irrigation district, in the semi-arid Central Ebro Basin, in Spain. On these prints, the soil surveyors marked the locations of the sampling sites. IRYDA, the extinct Spanish Ministry of Agriculture agency, in charge of designing and implementing new irrigation districts, commissioned the flight in 1975. These paper prints enabled us to resample the soils years later, to: (i) determine the soil salinity evolution from 1975 to 1985 [1], and from 1975 to 1999 [2]; (ii) apply electromagnetic induction (EMI) [3] for the same purpose; (iii) use multivariate analysis to discriminate the salinity trends from 1975 to 1999 in the different soil units [4]; and (iv) for land evaluation [5]. The report and two volumes of annexes [6], [7], [8], prepared by the contractor INYPSA for IRYDA, contain data on the soluble salts and other soil components sampled in 1975 as well as soil descriptions and agronomical data. The aerial photographs presented herein allow the sites sampled in 1975 to be located. This is the first step in exploiting the legacy data to appraise [9] the effects on the salinity and other soil properties recorded in 1975. The irrigation and the change from basin and border flooding to pressurized techniques, with the merging of many plots, govern these effects.