Tag: Environment
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Velocity Reversal in Pool-riffle Sequences
There is an exponential decline of bed material particle size as you move downstream due to the fining as a result of abrasion and sorting. Smaller particles are preferentially entrained and transported creating a set of bedforms. The most common are pool-riffle sequences which are characteristic of many single-channel alluvial rivers (Carling & Orr, 2000). They…
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Reducing CO2: Conversion Factors
There is a simple way of reducing CO2 emissions year on year without having to put any effort in at all. It requires no changing of habits, reduction in energy use or in fact any changes at all. Just by continuing to use the same amount of energy each year a reduction in carbon production…
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The Lake as a Microcosm
Lakes are ‘a little world within itself, a microcosm within which all the elemental forces are at work and the play of life goes on in full, but on so small a scale as to bring it easily within the mental grasp’ (Forbes, 1887). A microcosm is an isolated system, independent from the wider environment.…
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A Systems Approach to Port Phillip Bay
Port Phillip Bay is capable of providing for the 3.5 million people who dwell on the coast with a diverse and wealthy level of opportunity and exploitable capital. It is the combination of which that gives Port Phillip Bay a reputable identity. Port Phillip Bay is a complex system, socially, economically and environmentally. It operates…
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Adaptive Management
Port Phillip Bay is home to multiple formal and informal institutions across a variety of scales. Government stakeholders (Table 11) operate on larger scales and have a greater level of resources. Decisions on this scale tend to be more long term and reactionary. Formal institutions take time to set up studies and then implement their…
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Stable States and Thresholds
Disturbances can result in the collapse of the relationships between adaptive cycles at different scales. The collapse occurs when the relationship is pushed past a threshold. Systems reorganise themselves and produce a new identity as new relationships are formed. Thresholds therefore determine the system identity.
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System Disturbances
To improve the resilience of a system, potential perturbations must be identified along with their foreseen effects. Managers will not be able to identify all the disturbances that a system can undergo or the effects that could result. Surprise events are inevitable and could be beyond the scale of influence of managers.
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Historic Indicators
As discussed adaptive cycles function at a variety of scales. Each component of a system also has its own adaptive cycle and they are linked in a spatial and temporal context. Interactions between the cycles involves the sharing of information or matter and as long as transfers are maintained, the system overall is sustained. Systems…
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Component and Service Scales
Systems change over time and space, it is unavoidable. To manage resilience, understanding that systems change across and influence multiple scales is needed. Scales above the focal system are also significant to maintaining resilience.
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The Focal System
In order to ascertain the resilience of a system it must first be defined and bound. Port Phillip Bay as the focal system will include the water body and the major conurbations around its coast (Figure 5).