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University of Arizona (1972)

Evaluating selected methods for estimating reservoir evaporation in northeast Brazil

Matias Filho, Jose

Titre : Evaluating selected methods for estimating reservoir evaporation in northeast Brazil

Auteur : Matias Filho, Jose

Université de soutenance : University of Arizona

Grade : Master of Science (MS) 1972

Résumé
The Northeast of Brazil is a semiarid region with a mean annual precipitation between 600 and 700 mm. The mean annual temperature is about 27°C, and the vegetation is characterized by cactus and other xerophytic plants. The extreme variability of its precipitation occurrence requires water storage in lakes during periods of excess rainfall for use during periods of deficient or no precipitation when evaporation plays an important role in the management of these reservoirs. The present work evaluates various approaches for estimating lake evaporation by using different devices, a small lake, and available meteorological data. Daily observations covering the period from June, 1967, to December, 1970, were taken at the Agricultural Experimental Station of the University of Ceara, in the Guru Valley, NE Brazil. Lake evaporation estimates in NE Brazil can be obtained by using standard Class A pan or standard Piche atmometer records with dry-season (June to February) con version coefficients of 1.00 and 1.20, respectively. A mean daily evaporation of 7.3 mm can be used to estimate dry-season evaporation from small lakes where meteorological conditions are similar to those observed at the experimental area. Monthly conversion coefficients, although less accurate, represent reliable indices for estimating evapora tion from small lakes.

Mots clés : Reservoirs — Evaporation control.

Présentation

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Page publiée le 7 mai 2016, mise à jour le 15 décembre 2017