Displaying 16 - 30 of 93 records found.
Title | Type |
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Effect of infrastructure design on commons dilemmas | Model |
The authors address the question of how infrastructure design affects SES sustainability in two stages. First, they explore the effects of design variations in shared infrastructure on long-term system behavior in a model system. They examine two types of distribution infrastructure, one with and one without upstream−downstream asymmetry, and different threshold characteristics of infrastructure maintenance. Second, they evaluate how these design variations influence the robustness of... | 09 Oct 2016 |
Pumpa Irrigation System | Model |
In this case, the surface water level is modeled by a first order differential equation. There are six sections with equal area that are allocated water based on institutions that determine how long each sector receives water, and in what order. Water is allocated to a given sector by opening and closing gates along the irrigation canals. Based on these allocations, each sector maintains a crop yield depending on the amount of time that maintains their water level within the bounds of a desired... | 09 Aug 2016 |
Lorenz Model | Model |
This simple model was developed by Edward Lorenz in 1963 to study fluid mechanics (based on Navier-Stokes equations). It is the first ever model of a chaotic dynamical system. Chaos arises when a deterministic, nonlinear dynamical system exhibits long-term unpredictability in behavior due to sensitivity to initial conditions.The model is a three-dimentional system of differential equations. Specifically, the model describes the convection motion of a fluid in a small idealized "Rayleigh-... | 09 Aug 2016 |
Waterwheel Model | Model |
This model describes the dynamics of a waterwheel. The wheel has 10 cups that are filled when as they pass over the top of the arc of the wheel (imagine a Ferris wheel where instead of seats there are buckets. Water is flowing down on the Ferris wheel filling the buckets). The weight of the water makes the wheel turn. However, in this model, the buckets leak. So if the flow of the water from the top is too slow, some interesting motion can occur. This waterwheel model is a perfect physical... | 09 Aug 2016 |
Brander-Taylor Model | Model |
This is the original Brander-Taylor Easter Island model. Brander and Taylor (1998) describes the model as the following: "The paper presents a general equilibrium model of renewable resource and population dynamics related to the Lotka-Volterra predator-prey model, with man as the predator and the resource base as the prey. We apply the model to the rise and fall of Easter Island, showing that plausible parameter values generate a 'feast and famine" pattern of cyclical adjustment in... | 09 Aug 2016 |
Pezzey-Anderies Model | Model |
This model describes the Pezzey-Anderies extension to the Brander-Taylor Easter Island model. In addition to the parameters in the Brandor-Taylor model, Pezzey and Anderies have introduced $tax$ and $h_m$. Pezzey and Anderies (2003) gives the following overview: "We extend the Brander–Taylor model of population and resource development in an isolated society by adding a resource subsistence requirement to people's preferences. This improves plausibility; amplifies population overshoot and... | 09 Aug 2016 |
A Two-Sector Growth Model: Economic Development, Demographics, and Renewable Resources | Model |
This is a two-sector growth model that couples the dynamics of human demographics and a renewable resource base. The two sectors are agricultural and manufacturing sectors. To capture both the positive (Malthusian) and negative (modern growth) type relationships between population growth and output, it is important to model the shifting composition of output from agricultural to manufacturing as growth occurs. Thus, the model is a two sector (productions and consumptions in... | 09 Aug 2016 |
Animated demonstration of the Lorenz Model | Model |
Animated demonstration of the Lorenz model and its sensitivity to initial conditions. The simulation starts with twenty points very close to each other, and follows them as they move further away. The starting values differ in the fifth and sixth significant digits of a single coordinate. The Lorenz model was developed by Edward Lorenz in 1963 to study fluid mechanics.The model is a three-dimentional system of differential equations. Specifically, the model describes the convection motion of a... | 09 Aug 2016 |
The Discrete Logistic | Model |
The logistic is the simplest representation of population dynamics that contains a minimum level of biological realism. If we imagine a population of individuals at time t, the number of individuals in the next period (periods can range from seconds to days to decades depending on the organism) is the number of individuals now plus the number of births minus the number of deaths. If we assume in the simplest case there are no environmental constraints on births or deaths... | 09 Aug 2016 |
San Pedro Fishery, Belize | Case |
San Pedro, Belize is an island village of approximately 1,200 residents in 1979. Located off the coast of Belize in a strategic place on Ambergris Cay it is close to abundant local fishing and has easy access to nearby commercial markets (Belize city, Corozal, and Chetumal). The fishing cooperative, Caribena Cooperative Limited, was San Pedro’s official fishing organization handling capture, processing and sale of the village’s primary resource: marine produce consisting of... | 09 Aug 2016 |
Mount Desert Island Lobster Fishery | Case |
The lobster grounds of Mount Desert Island are located within Hancock County, Maine, some 250 miles northeast of Boston and 150 miles southwest of the U.S. - Canada border. The original case spans from 1969 to1974 and catalogues an action situation involving approximately 75 lobster fishermen; lobster is the stationary resource unit.This case study is part of the original Common-Pool Resource (CPR) database. A summary of the original CPR coding conducted in the 1980s by Edella Schlager and Shui... | 09 Aug 2016 |
Alanya Coastal Fishery, Turkey | Case |
The coastal fishery in Alanya is situated in Antalya Province along the southern Mediterranean coast of Turkey. The original case, which spans from 1976-1978, catalogues approximately 100 registered farmers operating 45 small inboard boats; pelagic fish (including bonits and large carangids) are the target resource unit. There is only one user group organization and no subgroups (just one group of small boat fishermen). The fishermen cooperate with one another and have access rules that involve... | 09 Aug 2016 |
Cat Harbour Cod Fishery, Newfoundland, Canada | Case |
Cat Harbour (now known as Lumsden) was a rural fishing community located on a peninsula stretching into the Atlantic off the northeastern coast of Newfoundland, Canada. The original case study is based on fieldwork conducted from 1964-1965 and catalogs an action situation involving 21 fishing crews that had 72 active fishermen during the summer cod-trapping season and 38 active fishermen exploiting the late summer/fall cod fishing grounds. The community is described as homogenous and... | 09 Aug 2016 |
Nam Tan Irrigation Project | Case |
The Muong Phieng Valley is located in the Nam Tam watershed in the Sainyabuli Province of western Laos. The main agricultural product is rice. The area suffered major infrastructural changes in two periods. First, during the Nam Tam Irrigation project administered by USAID and the Lao government in the late 1960s and early 1970s. Second, during the Nam Tam Rehabilitation project in the 1990s, supervised by UNDP, UNCF and the Lao government.This case was part of the original CPR database... | 09 Aug 2016 |
Messolonghi-Etolico Lagoon Fishery | Case |
The Messolonghi-Etolico lagoon is in the northern part of Patraikos Gulf, on the west coast of central Greece. The original case, which was published in 1984, catalogues an action situation with approximately 200 independent fishermen and 170 fishermen in 11 co-ops. The resource units are mullets, sea-bream, eel, and sea-bass. The co-ops feel the independents are free-riders on co-op efforts to trap fish; independents resent the co-ops' privileges, power, and subterfuges to restrict membership... | 09 Aug 2016 |