Water Management causes increment of reservoir silting and reduction of water yield in the semiarid State of Ceará, Brazil

Autor: J.C. de Araújo, T. Landwehr, P.H.L. Alencar, W.D. Paulino
Rok vydání: 2023
Předmět:
Zdroj: XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG)
ISSN: 0895-9811
DOI: 10.1016/j.jsames.2022.104102
Popis: In 1993, a water management system was installed in the Brazilian State of Ceará, Brazil, deeply marked by recurrent droughts. Water in Ceará is mainly supplied by theaçudes,on-river reservoirs artificially created by dams. However, these reservoirs are vulnerable to silting, which reduces water availability both quantitatively and qualitatively. Data from 141açudes(ca. 95% of the State storage capacity), processed with the help of artificial neural networks, show that their silting ratio increased after 1993 when water extraction from the reservoirs started to increase systematically due to the waterrationaliseduse policy, which tries to systematically reduce spilling. This procedure lowers the average storage volume of theaçudes, reducing the spilling probability and leading to both higher siltation rates and enhanced evaporation volumes. Data from our sample indicates that, in the next 30 years, water availability may reduce by 6%, whereas demand continuously increases. This process is not expected to continue indefinitely, because siltation reduces water residence time, which increases spilling, generating a new equilibrium pattern within some decades. Conclusively, decision-makers are invited to consider reservoir spillage also as a positive asset, capable of reducing siltation and improving water quality.
The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)
Databáze: OpenAIRE
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