Persistent Link:
http://hdl.handle.net/10150/191087
Title:
Soil moisture and the water balance in a border-irrigated field
Author:
Ottoni Filho, Theophilo Benedicto.
Issue Date:
1984
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Sampling and analysis of the soil moisture distribution and the overall water balance in an irrigated area are the central topics of this work. An experimental study was made in a 14-ha, border-irrigated, alfalfa field near Coolidge, in Final County, Arizona, during the summer/fall 1983. The water stored in the soil profile and its change with time were normally distributed, with coefficients of variation of about 10 and 25 percent, respectively. Temporal correlations were significant for storage (about .60), but absent in the other. Variograms were calculated to show the spatial structure of the distributions. An analogous statistical description was presented for the alfalfa yield. Also shown is a methodology to infer errors due to the field calibration of the neutron probe. Another task was to assess a methodology to minimize sample numbers for soil-water storage. Following the ideas of Vachaud and co-workers in France, it was verified that rankings of the measurements were approximately time-preserved. As a consequence, only a few key locations need to be sampled to evaluate the mean in those circumstances. Included also is an approximation to predict confidence intervals for estimating the mean, when such "representative sites" are used. Using irrigation inflow and rainfall, a procedure is defined to make use of the soil moisture data to evaluate irrigation efficiency and uniformity. Evapotranspiration (ET) distribution can also be assessed by soil moisture measurements, but only conditionally. For example, adaptation of the "field capacity" concept in the field study led to average daily ET rates in the range of 3-11 mm day⁻¹. ET and potential ET (PET) were also determined from weather data. Crop temperature was required in the ET calculation. Such a model, developed by Hatfield and co-workers, was judged satisfactory in our application, but not the Penman PET estimates. It is concluded that the ET model is promising, particularly if remote sensing of the temperatures is successful in the future. Also shown as a possibility is the use of plant temperature and pan evaporation data to infer crop water stress.
Type:
Dissertation-Reproduction (electronic); text
Keywords:
Hydrology.; Soil moisture -- Measurement.; Soils, Irrigated.; Irrigation.
Degree Name:
Ph. D.
Degree Level:
doctoral
Degree Program:
Hydrology and Water Resources; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Warrick, Arthur W.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleSoil moisture and the water balance in a border-irrigated fielden_US
dc.creatorOttoni Filho, Theophilo Benedicto.en_US
dc.contributor.authorOttoni Filho, Theophilo Benedicto.en_US
dc.date.issued1984en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractSampling and analysis of the soil moisture distribution and the overall water balance in an irrigated area are the central topics of this work. An experimental study was made in a 14-ha, border-irrigated, alfalfa field near Coolidge, in Final County, Arizona, during the summer/fall 1983. The water stored in the soil profile and its change with time were normally distributed, with coefficients of variation of about 10 and 25 percent, respectively. Temporal correlations were significant for storage (about .60), but absent in the other. Variograms were calculated to show the spatial structure of the distributions. An analogous statistical description was presented for the alfalfa yield. Also shown is a methodology to infer errors due to the field calibration of the neutron probe. Another task was to assess a methodology to minimize sample numbers for soil-water storage. Following the ideas of Vachaud and co-workers in France, it was verified that rankings of the measurements were approximately time-preserved. As a consequence, only a few key locations need to be sampled to evaluate the mean in those circumstances. Included also is an approximation to predict confidence intervals for estimating the mean, when such "representative sites" are used. Using irrigation inflow and rainfall, a procedure is defined to make use of the soil moisture data to evaluate irrigation efficiency and uniformity. Evapotranspiration (ET) distribution can also be assessed by soil moisture measurements, but only conditionally. For example, adaptation of the "field capacity" concept in the field study led to average daily ET rates in the range of 3-11 mm day⁻¹. ET and potential ET (PET) were also determined from weather data. Crop temperature was required in the ET calculation. Such a model, developed by Hatfield and co-workers, was judged satisfactory in our application, but not the Penman PET estimates. It is concluded that the ET model is promising, particularly if remote sensing of the temperatures is successful in the future. Also shown as a possibility is the use of plant temperature and pan evaporation data to infer crop water stress.en_US
dc.description.notehydrology collectionen_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.typetexten_US
dc.subjectHydrology.en_US
dc.subjectSoil moisture -- Measurement.en_US
dc.subjectSoils, Irrigated.en_US
dc.subjectIrrigation.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineHydrology and Water Resourcesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairWarrick, Arthur W.en_US
dc.contributor.committeememberSimpson, Eugene S.en_US
dc.contributor.committeememberMatthias, Allan D.en_US
dc.contributor.committeememberWilson, Lorne G.en_US
dc.contributor.committeememberEvans, Daniel D.en_US
dc.identifier.oclc213299448en_US
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