scholarly journals Modeling Resilience and Sustainability of Water-Subsidized Systems: An Example from Northwest Costa Rica

2021 ◽  
Vol 13 (4) ◽  
pp. 2013
Author(s):  
Kathleen Vazquez ◽  
Rachata Muneepeerakul
Keyword(s):  
Power Generation ◽  
Costa Rica ◽  
Dynamical Systems ◽  
Regime Shift ◽  
Water Transfer ◽  
Irrigated Agriculture ◽  
Systems Model ◽  
Hydrologic Systems ◽  
Hydrologic Regimes ◽  
Interbasin Water Transfer

Water-subsidized systems are growing in number and maintaining the sustainability of such complex systems presents unique challenges. Interbasin water transfer creates new sociohydrological dynamics that come with tradeoffs and potential regime shifts. The Tempisque-Bebedero watershed in Northwest Costa Rica typifies this class of watershed: Transferred water is used for power generation and irrigated agriculture with significant downstream environmental impacts. To improve and clarify our understanding of the effects of social and biophysical factors on the resilience of such systems, a stylized dynamical systems model was developed, using as a guide the situation in the Tempisque-Bebedero watershed. This model was analyzed to understand the nature of socio-hydrologic regimes that exist in this class of basins and what factors determine these regimes. The model analysis revealed five distinct regimes and different regime shift behaviors dependent on environmental and policy conditions. This work offers insights into other complex socio-hydrologic systems with similar processes.

scholarly journals A computational framework for finding parameter sets associated with chaotic dynamics

2021 ◽  
pp. 1-11
Author(s):  
S. Koshy-Chenthittayil ◽  
E. Dimitrova ◽  
E.W. Jenkins ◽  
B.C. Dean
Keyword(s):  
Experimental Data ◽  
Dynamical Systems ◽  
Lyapunov Exponents ◽  
Parameter Space ◽  
Chaotic Dynamics ◽  
Chaotic Behavior ◽  
Computational Framework ◽  
Independent Variables ◽  
Systems Model ◽  
Small Support

Many biological ecosystems exhibit chaotic behavior, demonstrated either analytically using parameter choices in an associated dynamical systems model or empirically through analysis of experimental data. In this paper, we use existing software tools (COPASI, R) to explore dynamical systems and uncover regions with positive Lyapunov exponents where thus chaos exists. We evaluate the ability of the software’s optimization algorithms to find these positive values with several dynamical systems used to model biological populations. The algorithms have been able to identify parameter sets which lead to positive Lyapunov exponents, even when those exponents lie in regions with small support. For one of the examined systems, we observed that positive Lyapunov exponents were not uncovered when executing a search over the parameter space with small spacings between values of the independent variables.

Macrobrachium Spence Bate, 1868 (Decapoda: Palaemonidae): New records, range extension and geographic distribution in the Northeastern Caatinga & Coastal Drainages, and São Francisco hydrographic ecoregions, Northeast of Brazil

Zootaxa ◽  
2021 ◽  
Vol 4964 (1) ◽  
pp. 37-60
Author(s):  
ALEX BARBOSA DE MORAES ◽  
DANIELE COSME SOARES DE MORAES ◽  
CARLOS EDUARDO ROCHA DUARTE ALENCAR ◽  
ALLYSSON PONTES PINHEIRO ◽  
SERGIO MAIA QUEIROZ LIMA ◽  
...  
Keyword(s):  
Biological Diversity ◽  
New Records ◽  
First Record ◽  
River Basins ◽  
Water Transfer ◽  
Northeastern Brazil ◽  
Distribution Maps ◽  
Interbasin Water Transfer ◽  
Faunal Diversity ◽  
Scientific Collections

This study constitutes the most comprehensive effort ever done to assess the faunal diversity of the Macrobrachium genus within two ecoregions that encompass part of the northeastern Brazil: the Northeastern Caatinga & Coastal Drainages, and the São Francisco (Lower-middle and Lower portions). Through sampling in several of their hydrographic basins, bibliographic research, and consulting scientific collections, our results reveal the occurrence of five species along these ecoregions: Macrobrachium acanthurus, M. amazonicum, M. carcinus, M. jelskii and M. olfersii. We also provide the first record of these species for several river basins in both ecoregions. Additionally, we confirm the occurrence of M. carcinus from Rio Grande do Norte State and provide updated distribution maps for each species in the studied area. This carcinofauna survey may form the basis for future evaluations of eventual anthropic impacts on biological diversity resulting from projects being implemented in these regions, which involve the São Francisco interbasin water transfer.

scholarly journals Interbasin water transfer in a changing world: A new conceptual model

2021 ◽  
pp. 030913332110650
Author(s):  
Edward Rollason ◽  
Pammi Sinha ◽  
Louise J Bracken
Keyword(s):  
Water Scarcity ◽  
Conceptual Models ◽  
Management Strategies ◽  
Temporal Distribution ◽  
Water Transfer ◽  
Decision Makers ◽  
Global Issue ◽  
Proposed Model ◽  
Interbasin Water Transfer ◽  
Water Scarce

Water scarcity is a global issue, affecting in excess of four billion people. Interbasin Water Transfer (IBWT) is an established method for increasing water supply by transferring excess water from one catchment to another, water-scarce catchment. The implementation of IBWT peaked in the 1980s and was accompanied by a robust academic debate of its impacts. A recent resurgence in the popularity of IBWT, and particularly the promotion of mega-scale schemes, warrants revisiting this technology. This paper provides an updated review, building on previously published work, but also incorporates learning from schemes developed since the 1980s. We examine the spatial and temporal distribution of schemes and their drivers, review the arguments for and against the implementation of IBWT schemes and examine conceptual models for assessing IBWT schemes. Our analysis suggests that IBWT is growing in popularity as a supply-side solution for water scarcity and is likely to represent a key tool for water managers into the future. However, we argue that IBWT cannot continue to be delivered through current approaches, which prioritise water-centric policies and practices at the expense of social and environmental concerns. We critically examine the Socio-Ecological Systems and Water-Energy-Food (WEF) Nexus models as new conceptual models for conceptualising and assessing IBWT. We conclude that neither model offers a comprehensive solution. Instead, we propose an enhanced WEF model (eWEF) to facilitate a more holistic assessment of how these mega-scale engineering interventions are integrated into water management strategies. The proposed model will help water managers, decision-makers, IBWT funders and communities create more sustainable IBWT schemes.

Dynamical systems model of entrainment due to coherent structures

2005 ◽  
Vol 72 (4) ◽  
Author(s):  
Srevatsan Muralidharan ◽  
K. R. Sreenivas ◽  
Rama Govindarajan
Keyword(s):  
Dynamical Systems ◽  
Coherent Structures ◽  
Systems Model

scholarly journals A dynamical systems model of the effect of Locus Coeruleus firing on single trial cortical state dynamics

2014 ◽  
Vol 15 (S1) ◽  
Author(s):  
Houman Safaai ◽  
Ricardo Neves ◽  
Oxana Eschenko ◽  
Nikos K Logothetis ◽  
Stefano Panzeri
Keyword(s):  
Dynamical Systems ◽  
Locus Coeruleus ◽  
Single Trial ◽  
Systems Model

scholarly journals Temporal subharmonic amplitude and phase behaviour in a jet shear layer: wavelet analysis and Hamiltonian formulation

1999 ◽  
Vol 394 ◽  
pp. 205-240 ◽  
Author(s):  
S. V. GORDEYEV ◽  
F. O. THOMAS
Keyword(s):  
Dynamical Systems ◽  
Shear Layer ◽  
Hamiltonian Formulation ◽  
Phase Variation ◽  
Phase Behaviour ◽  
Mode Suppression ◽  
Systems Model ◽  
Planar Jet ◽  
Highly Correlated ◽  
Effective Phase

Fourier and wavelet transformation techniques are utilized in a complementary manner in order to characterize temporal aspects of the transition of a planar jet shear layer. The subharmonic is found to exhibit an interesting temporal amplitude and phase variation that has not been previously reported. This takes the form of intermittent π-shifts in subharmonic phase between two fixed phase values. These phase jumps are highly correlated with local minima of the subharmonic amplitude. In contrast, the fundamental amplitude and phase show no such behaviour. The temporal phase behaviour of the subharmonic has the effect of intermittently disrupting the phase lock with the fundamental. A dynamical systems model is developed which is based on a classic vortex representation of the shear layer. The Hamiltonian formulation of the problem is shown to provide remarkable agreement with the experimental results. All the essential aspects of the temporal amplitude and phase behaviour of the subharmonic are reproduced by the model including amplitude-dependent effects. The model is also shown to provide a dynamical systems based explanation for time-averaged amplitude and phase behaviour observed in these as well as earlier experiments. The results of experiments involving both bimodal forcing at fundamental and subharmonic frequencies with prescribed initial effective phase angle as well as experiments involving only fundamental excitation over an amplitude range extending two orders of magnitude are presented. The temporal subharmonic amplitude and phase behaviour is observed in bimodal forcing experiments in those regions of the flow characterized by subharmonic mode suppression and vortex tearing events (even if the forcing amplitudes are quite large). In addition, temporal subharmonic amplitude and phase behaviour is the rule in experiments involving low-amplitude forcing of the fundamental and the natural development of the subharmonic.

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