Artigo
Catastrophic regime shift in water reservoirs and São Paulo water supply crisis
Registro en:
Plos One, v. 10, n. 9, 2015.
1932-6203
10.1371/journal.pone.0138278
PMC4570716.pdf
26372224
PMC4570716
Autor
Coutinho, Renato M. [UNESP]
Kraenkel, Roberto A. [UNESP]
Prado, Paulo I.
Resumen
The relation between rainfall and water accumulated in reservoirs comprises nonlinear feedbacks. Here we show that they may generate alternative equilibrium regimes, one of high water-volume, the other of low water-volume. Reservoirs can be seen as socio-environmental systems at risk of regime shifts, characteristic of tipping point transitions. We analyze data from stored water, rainfall, and water inflow and outflow in the main reservoir serving the metropolitan area of São Paulo, Brazil, by means of indicators of critical regime shifts, and find a strong signal of a transition. We furthermore build a mathematical model that gives a mechanistic view of the dynamics and demonstrates that alternative stable states are an expected property of water reservoirs. We also build a stochastic version of this model that fits well to the data. These results highlight the broader aspect that reservoir management must account for their intrinsic bistability, and should benefit from dynamical systems theory. Our case study illustrates the catastrophic consequences of failing to do so. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenadoria de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Instituto de Física Teórica, Universidade Estadual Paulista-UNESP, São Paulo, Brazil LAGE do Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo-USP, São Paulo, Brazil Instituto de Física Teórica, Universidade Estadual Paulista-UNESP, São Paulo, Brazil FAPESP: 2010/09464-1 CNPq: 308180/2013-5 CNPq: 306183/2014-5