Changes between Version 1 and Version 2 of EwEugRunEcosim
 Timestamp:
 20100207 22:44:20 (13 years ago)
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EwEugRunEcosim
v1 v2 4 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 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] 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). 7 7 8 8 The 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). … … 16 16 '''Run''' 17 17 18 Click the ''Run'' button at the bottom right of the form to generate time series of biomasses. The magnitude of changes for each group will depend on many factors, chiefly the fishing regime and the [[Vulnerabilities flow control.htmvulnerability]]settings.18 Click the ''Run'' button at the bottom right of the form to generate time series of biomasses. The magnitude of changes for each group will depend on many factors, chiefly the fishing regime and the [wiki:EwEugVulnerabilitiesFlowControl vulnerability] settings. 19 19 20 20 Note that fishing regimes should generally change gradually from one fishing mortality level to the next, not abruptly. Also, the baseline (Ecopath) fishing mortality should be left unchanged for a year or so. 21 21 22 After running Ecosim, use [[Ecosim plot.htmEcosim plot]]and [[Ecosim results.htmEcosim results]]to see detailed results in graphic and tabular form.22 After running Ecosim, use Ecosim plot and Ecosim results to see detailed results in graphic and tabular form. 23 23 24 24 '''''Features of the lower (Fishing rate) panel''''' … … 48 48 '''''Features of the upper (Ecosim biomass output) panel''''' 49 49 50 '''../Resources/Images/Eye_open.PNGShow groups...'''50 [[Image(wiki:EwEugImages:Eye_open.PNG)]] '''Show groups...''' 51 51 52 52 Opens a form for hiding/displaying groups on the biomass graph. … … 66 66 '''Sum of squared deviations (SS)''' 67 67 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 [[Time series.htmTime 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).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). 69 69 70 See [wiki:EwEugTimeSeriesFittingInEcosimEvaluatingFisheriesAndEnvironmentalEffects Time series fitting in Ecosim]for more details about the sum of squared deviations measure.70 See [wiki:EwEugTimeSeriesFittingInEcosimEvaluatingFisheriesAndEnvironmentalEffects Time series fitting in Ecosim] for more details about the sum of squared deviations measure. 71 71 72 72 '''Main display panel'''