Habitat models are designed for a wide variety of planning applications where habitat information is an important consideration in the decision-making process. EE10 now supports two new types of habitat analysis tool. These are in addition to the existing temperature limit and depth criteria tool in 2DH View that was initially implemented to support studies on manatee populations in the Chassahowitzka Estuary. The two new tools generate time series critical limits, as well as support the state-of-the-art Instream Flow Incremental Method. These two methods are described below.
The Critical Limits Series form is shown in Figure 1. The user may define up to five different parameters for the critical limits. These can be selected from any parameter that is currently activated in EE. For each dropdown list under Parameter the user selects the parameter of interest and then defines the minimum and maximum values for the critical limits. In the layer box, a range of options are provided: single layer (enter layer number), a range of layers (eg 1-2), average of a series of layer (eg 2:6), or depth averaged (0). Once criteria for critical limits have been entered it is recommended the user save the settings. Selecting the Save button, the user is prompted to input the file name. EE will create a folder called #habitat to store all related files, so by default the new critical limits will be saved into this folder. Configuration files for critical limits series use “.HCL” as the extension which is displayed in Setting File frame.
The Criteria ID will be used to manage the different species. The Criteria ID will be appended to the file name “Hab_Results” of the data file extracted when generating an initial time series, as described further below. The generated data is stored in Data File frame in case of user wants to reload and view the old result instead of generating a new one.
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Figure 1 Habitat Analysis: Critical Limits Series form.
The critical limits options act as a series of toggles for each cell in each layer of the model domain. Each cell will meet either some of the criteria or all of the criteria defined. If a cell doesn’t meet all the criteria it is set to zero, whereas if a cell does meet all the criteria it is set to one. If a cell is dry it is also set to zero. Using the Series checkbox, the user turns on the generation of output for each parameter. Only one parameter may be output at a time.
The user should select the start and end date for the time series extraction in the Initial Model Results Extraction Options frame. Once this has been set the user can select the Generate Initial Time Series button. EE will then tell the user how many cells are in the domain and check if the user wants to proceed with calculating the time series. Selecting the Cell by Cell check-box will mean that every cell is calculated for every time step. Note that it is also possible to generate the time series based on only a sub-set of the model domain by browsing to and selecting a polyline file with the Sub-Set box.
EE will extract all the cell information for each parameter and save it in a post-processing file in the #habitat folder based on the criteria ID. In this example, the file will be called Hab_Results_Muskellunge Adult.dat. This file records the composite time, net weighted criteria (weighted average 0 and 1 of all the cells that meet the bathymetry criteria), area, and volume.
An example of the time series that EE displays is shown in Figure 2.
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Figure 2 Habitat Analysis: Critical Limits Series time series.
The results in the time series plots present a composite time series of velocity and the volume and area that met these criteria. The user should export the time series as it is not automatically saved by EE.
Once a time series has been generated, and the post-processing files have been extracted, a new frame is displayed, Secondary Processing of Extracted Results. This option provides the user with further post-processing options. The drop-down menu has the following options: Domain Average, Running Averages, and Single Cell Time Series. For running averages, the user must specify the number of days to be applied for the calculation of the running average.