Changes between Version 8 and Version 9 of Eda Description

Timestamp:

Feb 11, 2010 4:19:18 PM (15 years ago)

Author:

celine

Comment:

--

Eda Description

@@ -2 +2 @@
 
 
-Since the early 1980s, the European eel ('' Anguilla anguilla '') stock has been declining and continues to decline at an alarming rate. It is presently considered to be outside safe biological limits (ICES 1999).
+Since the early 1980s, the European eel (''Anguilla anguilla'') stock has been declining and continues to decline at an alarming rate. It is presently considered to be outside safe biological limits (ICES 1999).
 
-''' EDA 2.0 (Eel Density Analysis) ''' is a modelling tool based on a geolocalized river network database to predict yellow eel densities and silver eel escapement. The principle of this approach is (1) to relate observed yellow eel densities to different parameters: sampling method, environmental conditions (distance to the sea, relative distance, temperature, Strahler stream order, elevation and slope…), anthropogenic conditions (obstacles, fisheries, …) and time (year trends), (2) to calculate the yellow eel density in each reach of river the network by applying the statistical model calibrated in step 1, (3) to calculate the overall yellow eel stock abundance by multiplying these densities by the surfaces of the reaches and by summing them (4) to calculate a potential silver eel escapement by converting the yellow eel stock estimated in step 3 into silver eel stock (5) when silver eel mortalities (fisheries, turbines) are know (are estimated) they can be used to assess the silver eel escapement (not yet implemented).
+''' EDA 2.0 (Eel Density Analysis) ''' is a modelling tool based on a geolocalized river network database to predict yellow eel densities and silver eel escapement. The principle of this approach is (1) to relate observed yellow eel densities to different parameters: sampling methods, environmental conditions (distance to the sea, relative distance, temperature, Strahler stream order, elevation and slope…), anthropogenic conditions (obstacles, fisheries, …) and time (year trends), (2) to calculate the yellow eel density in each reach of river the network by applying the statistical model calibrated in step 1, (3) to calculate the overall yellow eel stock abundance by multiplying these densities by the surfaces of the reaches and by summing them (4) to calculate a potential silver eel escapement by converting the yellow eel stock estimated in step 3 into silver eel stock (5) when silver eel mortalities (fisheries, turbines) are know (are estimated) they can be used to assess the silver eel escapement (not yet implemented).
 It is also possible to give an estimate of the pristine escapement by running the EDA model with anthropogenic conditions artificially set to zero and time variable sets before 1980.
 
@@ -10 +10 @@
 The presence/absence and densities of yellow eel in France are obtained from the Aquatic environment and fish database (BDMAP - more than 11 787 fishing samples used collected on 6 007 sampling stations) from the French National Office of Water and the Aquatic Environments (ONEMA) and other databases from the Brittany watershed.
 
-Values of the explanatory variables are calculated for each segment of the river network. The distance to the sea, the relative distance (between sea limit and the more upstream source) are directly calculated from the river network topology. The temperatures are extracted from the CRU (Mitchell et al., 2004), and Worlclim (www.worldclim.org/). Elevation and slope are extracted from the National Height Elevation Database (BD ALTI® - spatial resolution of 50m) from the National Geographic Institute. The obstacle pressure (characteristics, Steinbach rank…) comes from the National list of obstacles to river flows (ROE) from the ONEMA. Glass eel fisheries data set comes from Castelnaud (1994), non-professional/leisure fisheries and professional fisheries data setfrom the ONEMA.
+Values of the explanatory variables are calculated for each segment of the river network. The distance to the sea, the relative distance (between sea limit and the more upstream source) are directly calculated from the river network topology. The temperatures are extracted from the CRU (Mitchell et al., 2004), and Worlclim (www.worldclim.org/). Elevation and slope are extracted from the National Height Elevation Database (BD ALTI® - spatial resolution of 50m) from the National Geographic Institute. The obstacle pressure (characteristics, Steinbach rank…) comes from the National list of obstacles to river flows (ROE) from the ONEMA. Glass eel fisheries data set comes from Castelnaud (1994), non-professional/leisure fisheries and professional fisheries data set from the ONEMA.
 The data sets used to extract the water quality parameters are obtained from the ROM database of ONEMA.