Changes between Version 2 and Version 3 of EwEugRunEcosim


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Timestamp:
2010-11-23 02:54:44 (8 years ago)
Author:
shermanl
Comment:

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  • EwEugRunEcosim

    v2 v3  
    22The Ecosim module of EwE provides two ways to explore impacts of alternative fishing policies: 
    33 
    4 1. Fishing rates can be ‘sketched’ over time and results (catches, economic performance indicators, biomass changes) examined for each sketch. This is using Ecosim in a ‘gaming’ mode, where the aim is to encourage rapid exploration of options (see below for help with this approach). 
    5  
    6 2. Formal optimization methods can be used to search for fishing policies that would maximize a particular policy goal or ‘objective function’ for management (see [wiki:EwEugFishingPolicySearch Using Ecosim for policy exploration] for help with this approach). 
     4 1. Fishing rates can be 'sketched' over time and results (catches, economic performance indicators, biomass changes) examined for each sketch. This is using Ecosim in a 'gaming' mode, where the aim is to encourage rapid exploration of options (see below for help with this approach). 
     5 1. Formal optimization methods can be used to search for fishing policies that would maximize a particular policy goal or 'objective function' for management (see [wiki:EwEugFishingPolicySearch Using Ecosim for policy exploration] for help with this approach). 
    76 
    87The first approach has been widely applied for exploring ecosystem effects of changes in fishing effort and is implemented using the Biomass form, the main form for running Ecosim (Time dynamic (Ecosim) > Output > Biomass). 
     
    4241'''Fishing rate sketch pad''' 
    4342 
    44 The sketch pad is used to display time series of relative fishing rates when the fishing mortality is applied to an individual group.  When the fishing mortality is applied to a ‘fleet’ the ''y''-scale of the sketch pad consists of effort multipliers. In either case (individual group or fleet), the default uniform series (representing the Ecopath base values) can be replaced by a time-varying shape, representing temporal changes in the pattern of fishing, by sketching with the mouse (left button held down). The ''y''-axis will automatically re-scale as you drag your mouse up or down on the sketchpad. The fishing rates are expressed relative to the fishing rates in the underlying Ecopath model. 
     43The sketch pad is used to display time series of relative fishing rates when the fishing mortality is applied to an individual group.  When the fishing mortality is applied to a 'fleet' the ''y''-scale of the sketch pad consists of effort multipliers. In either case (individual group or fleet), the default uniform series (representing the Ecopath base values) can be replaced by a time-varying shape, representing temporal changes in the pattern of fishing, by sketching with the mouse (left button held down). The ''y''-axis will automatically re-scale as you drag your mouse up or down on the sketchpad. The fishing rates are expressed relative to the fishing rates in the underlying Ecopath model. 
    4544 
    4645To set linear trend for change in fishing rates: if you first click the start point with the left mouse button, and then the end point with shift + the left mouse button, a line will be drawn between the two points. Use this to enter, e.g., a linear increase over time in relative fishing rates. 
    4746 
    48 '''''Features of the upper (Ecosim biomass output) panel''''' 
     47'''Features of the upper (Ecosim biomass output) panel''' 
    4948 
    5049[[Image(wiki:EwEugImages:Eye_open.PNG)]] '''Show groups...''' 
     
    5453'''Autoscale''' 
    5554 
    56 Use the Autoscale button to tell Ecosim to automatically set the scale of the ''''y''-''axis.''' 
     55Use the Autoscale button to tell Ecosim to automatically set the scale of the ''y''-''axis.'' 
    5756 
    5857'''Scale Y axis to''' 
     
    6665'''Sum of squared deviations (SS)''' 
    6766 
    68 This is an Ecosim output. When an Ecosim model is loaded, you can load time series ‘reference’ data on relative and absolute biomasses of various groups over a particular historical period, along with estimates of changes in fishing impacts over that period.  After time series data have been loaded and applied (see [wiki:EwEugTimeSeries Time series]), a statistical measure of goodness of fit to these data is generated each time Ecosim is run.  This goodness of fit measure is a weighted sum of squared deviations (SS) of log biomasses from log predicted biomasses, scaled in the case of relative abundance data by the maximum likelihood estimate of the relative abundance scaling factor ''q'' in the equation ''y'' = ''qB'' (''y'' = relative abundance, ''B'' = absolute abundance). 
     67This is an Ecosim output. When an Ecosim model is loaded, you can load time series 'reference' data on relative and absolute biomasses of various groups over a particular historical period, along with estimates of changes in fishing impacts over that period.  After time series data have been loaded and applied (see [wiki:EwEugTimeSeries Time series]), a statistical measure of goodness of fit to these data is generated each time Ecosim is run.  This goodness of fit measure is a weighted sum of squared deviations (SS) of log biomasses from log predicted biomasses, scaled in the case of relative abundance data by the maximum likelihood estimate of the relative abundance scaling factor ''q'' in the equation ''y'' = ''qB'' (''y'' = relative abundance, ''B'' = absolute abundance). 
    6968 
    7069See [wiki:EwEugTimeSeriesFittingInEcosimEvaluatingFisheriesAndEnvironmentalEffects Time series fitting in Ecosim] for more details about the sum of squared deviations measure. 
     
    7271'''Main display panel''' 
    7372 
    74 Displays Ecosim’s predicted time series of biomass for groups selected using the Show groups form. Biomasses are shown relative to their baseline Ecopath values. If time series have been loaded and applied, they will be displayed as coloured dots on the graph, while Ecosim’s predicted outputs will be displayed as coloured lines (Figure 9.1). 
     73Displays Ecosim's predicted time series of biomass for groups selected using the Show groups form. Biomasses are shown relative to their baseline Ecopath values. If time series have been loaded and applied, they will be displayed as coloured dots on the graph, while Ecosim's predicted outputs will be displayed as coloured lines (Figure 9.1). 
    7574 
    7675Vertical red lines indicate when to start averaging results for before/after comparisons (displayed using the Ecosim results form). Use a left mouse-click to drag the lines to their desired positions. 
     
    7877'''Group tab''' 
    7978 
    80 To the right of the upper panel, under the ''Group'' tab, a smaller panel displays the groups names, in the same colours as used for the biomass lines. Clicking on the name of any group in this panel (and releasing the mouse button) results in all other groups being greyed out so that the group of interest can be clearly seen. Click on ''All groups'' at the top of the list to return all groups to their original colours. 
     79To the right of the upper panel, under the ''Group'' tab, a smaller panel displays the groups' names, in the same colours as used for the biomass lines. Clicking on the name of any group in this panel (and releasing the mouse button) results in all other groups being greyed out so that the group of interest can be clearly seen. Click on ''All groups'' at the top of the list to return all groups to their original colours. 
    8180 
    8281'''Layer tab'''