title: Size and stochasticity in irrigated social-ecological systems.
abstract: This paper presents a systematic study of the relation between the size of irrigation systems and the management of uncertainty. We specifically focus on studying, through a stylized theoretical model, how stochasticity in water availability and taxation interacts with the stochastic behavior of the population within irrigation systems. Our results indicate the existence of two key population thresholds for the sustainability of any irrigation system: or the critical population size required to keep the irrigation system operative, and N* or the population threshold at which the incentive to work inside the irrigation system equals the incentives to work elsewhere. Crossing irretrievably leads to system collapse. N* is the population level with a sub-optimal per capita payoff towards which irrigation systems tend to gravitate. When subjected to strong stochasticity in water availability or taxation, irrigation systems might suffer sharp population drops and irreversibly disintegrate into a system collapse, via a mechanism we dub 'collapse trap'. Our conceptual study establishes the basis for further work aiming at appraising the dynamics between size and stochasticity in irrigation systems, whose understanding is key for devising mitigation and adaptation measures to ensure their sustainability in the face of increasing and inevitable uncertainty.
authors.affiliation: Department of Maritime Civilizations, Recanati Institute for Maritime Studies, University of Haifa, 199 Aba Koushy Ave, Mount Carmel, 3498838 Haifa, Israel.|Geographisches Institut, Universität zu Köln, Zülphicher Strasse 45, 50674 Cologne, Germany.
authors.forename: Arnald
authors.initials: A
authors.lastname: Puy
authors.affiliation: Department of Agricultural and Biological Engineering, University of Florida, Gainesville, Florida, PO Box 110570, USA.
authors.forename: Rachata
authors.initials: R
authors.lastname: Muneepeerakul
authors.affiliation: Research Group Climate Change and Security (CLISEC), KlimaCampus, Center for Earth System Research and Sustainability (CEN), University of Hamburg, Grindelberg 5/7, 20144 Hamburg, Germany.
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Balbo
mesh_terms: D057914:Agricultural Irrigation / Q000191:economics* / Q000458:organization & administration*; D017753:Ecosystem; D006801:Humans; D008962:Models, Theoretical; D011156:Population Density; D011157:Population Dynamics