Field Name | Type | Description | Units | Level |
---|---|---|---|---|
none | 1 |
8 Features
FluvialGeomorph defines a standard set of feature classes that are used through the tool chain. The definition of a common set of derived features is an important step in standardizing the FluvialGeomorph workflow. These database objects form a tightly linked set of features that work together in a particular order to accomplish the analysis. They are presented here in the approximate order in which they are produced.
Study Area
The study_area
polygon feature class is created manually by the analyst using these instructions from the user manual.
Terrain Model Raster
The GIS analyst follows these instructions from the user manual using standard ESRI geoprocessing tools to transform a LiDAR point cloud dataset covering the study area into an appropriately resolute (pixel cell size) digital elevation model (DEM). Only points representing the ground or water surface are selected from the point cloud to derive the terrain surface DEM. This raster dataset is named dem
, but can also have a suffix added to represent its year of collection in change studies. Follow these instructions from
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
Z | 32 bit float | The z-coordinate value (elevation). | feet, NAVD88 | 1 |
Cutlines
The cutlines
polyline feature class is created manually by the analyst using these instructions from the user manual. The cutlines
polyline feature class is used to store geometry needed to hydrologically modify a terrain model to ensure that water can accurately flow over the land surface as it does in the real world. LiDAR derived terrain models frequently contain flow blockages (e.g., road berms) that must be “cut-through” to represent the presence of flow structures (e.g., culverts, bridges) that cannot be resolved directly from the LiDAR terrain model.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
none | 1 |
Hydro Modified Raster
Before the dem
terrain model raster can be used for synthetically deriving stream features, it must first be hydrologically modified using the cutlines
feature class to “burn” flow paths into the dem
raster. The 02 - Hydro DEM
tool creates a “hydro-enforced” DEM named dem_hydro
using these instructions from the user manual.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
Z | 32 bit float | The z-coordinate value (elevation). | feet, NAVD88 | 1 |
Contributing Area Raster
The 03 - Contributing Area
tool uses the dem_hydro
raster to create a contributing_area
raster whose values store the drainage area upstream of each pixel using these instructions from the user manual.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
contributing_area | 32 bit float | The specific catchment area. | linear units of fc | 1 |
Flow Accumulation Raster
The 03a - Contributing Area D8
tool is used to calculate the flow_accumulation_d8
raster whose values represent the number of upstream pixels using these instructions from the user manual.
Field Name | Type | Description | Units | Level |
---|
Flow Direction Raster
The 03a - Contributing Area D8
tool is used to calculate the flow_direction_d8
raster whose values represent the direction of flow across each pixel using these instructions from the user manual.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
flow_direction_d8 | 32 bit float | The direction of flow from each cell to its downslope neighbor. | D8 flow direction | 1 |
Stream Network
The 04 - Stream Network
tool uses the contributing_area
raster to derive a synthetic stream_network
polyline feature class representing the stream network of the study area using these instructions from the user manual.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 1 |
Stream Network Points
The 04a - Stream Network Points
tool creates the stream_network_points
point feature class to represent regularly spaced points along a stream_network
feature class using these instructions from the user manual. These stream_network_points
features are used to store elevation and route position (longitudinal stream stationing) information for a stream_network
feature.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 1 | |
POINT_X | double | The x-coordinate value (longitude). | linear units of fc | 1 |
POINT_Y | double | The y-coordinate value (latitude). | linear units of fc | 1 |
POINT_M | double | The m-coordinate value (route position). | linear units of fc | 1 |
Watershed_Area_SqMile | double | The upstream watershed drainage area. | square miles | 1 |
Z | double | The z-coordinate value (elevation). | feet, NAVD88 | 1 |
Gradient
The 04b - Slope and Sinuosity
tool creates the gradient_*
point feature class that calculates slope and sinuosity for a stream_network_points
point feature class using these instructions in the user manual. The gradient_*
point feature class is named using the moving window size specified.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 1 | |
POINT_X | double | The x-coordinate value (longitude). | linear units of fc | 1 |
POINT_Y | double | The y-coordinate value (latitude). | linear units of fc | 1 |
POINT_M | double | The m-coordinate value (route position). | linear units of fc | 1 |
Z | double | The z-coordinate value (elevation). | feet, NAVD88 | 1 |
z_smooth | double | The smoothed z-coordinate value (elevation). | feet, NAVD88 | 1 |
upstream_x | double | The x-coordinate value (longitude) of the next upsteam point in the moving window. | linear units of fc | 1 |
upstream_y | double | The y-coordinate value (latitude) of the next upsteam point in the moving window. | linear units of fc | 1 |
downstream_x | double | The x-coordinate value (longitude) of the next downsteam point in the moving window. | linear units of fc | 1 |
downstream_y | double | The y-coordinate value (latitude) of the next downsteam point in the moving window. | linear units of fc | 1 |
upstream_z | double | The z-coordinate value (elevation) of the next upstream point in the moving window. | feet, NAVD88 | 1 |
downstream_z | double | The z-coordinate value (elevation) of the next downstream point in the moving window. | feet, NAVD88 | 1 |
upstream_m | double | The m-coordinate value (route position) of the next upstream point in the moving window. | linear units of fc | 1 |
downstream_m | double | The m-coordinate value (route position) of the next downstreampoint in the moving window. | linear units of fc | 1 |
rise | double | The elevation difference between the downstream and upstream point in the moving window. | feet | 1 |
run | double | The longitudinal distance along the stream network between the downstream and upstream point in the moving window. | feet | 1 |
stream_length | double | The longitudinal distance along the stream network between the downstream and upstream point in the moving window. | feet | 1 |
valley_length | double | The longitudinal distance along the valleyline between the downstream and upstream stream network point in the moving window. | feet | 1 |
sinuosity | double | The sinuosity of the stream within the moving window (valley_length/stream_length). | 1 | |
sinuosity_gte_one | double | The sinuosity metric, values greater than or equal to one. | 1 | |
slope | double | The slope of the stream within the moving window (rise/run). | degree | 1 |
slope_gte_zero | double | The slope metric, values greater than of equal to zero. | degree | 1 |
Watershed Points
The watershed_points
feature class is manually created by the analyst using the stream_network_points
feature class following these instructions from the user manual. The watershed_points
point feature class is used to represent the downstream location of watersheds whose areal extent is to be calculated. These single points are sometimes referred to as “pour points” located along a stream network.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 1 | |
POINT_X | double | The x-coordinate value (longitude). | linear units of fc | 1 |
POINT_Y | double | The y-coordinate value (latitude). | linear units of fc | 1 |
POINT_M | double | The m-coordinate value (route position). | linear units of fc | 1 |
Watershed_Area_SqMile | double | The upstream watershed drainage area. | square miles | 1 |
Z | double | The z-coordinate value (elevation). | feet, NAVD88 | 1 |
Watershed
The 04c - Watershed tool creates the watershed
polygon feature class and represent the drainage area upstream of a single point (aka “pour point”) located along a stream network. All pixels within each watershed
polygon feature flow to the stream network point used to derive the watershed using these instructions from the user manual.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 1 | |
Shape_Area | double | The area of the watershed. | linear units of fc | 1 |
Flowline
The 05 - Flowline
tool creates the flowline
polyline feature class and is used to represent the likely flow path of a stream reach within a study area using these instructions from the user manual. This is the primary flow path feature used in the FluvialGeomorph toolbox. Since non-bathymetric LiDAR is often used to derive flowline
features, this should not be interpreted as the thalweg when water is present in the DEM.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 1 | |
from_measure | double | The start longitudinal stationing value for the reach. | kilometers | 1 |
to_measure | double | The end longitudinal stationing value for the reach. | kilometers | 1 |
Flowline Points
The 06 - Flowline Points
tool creates the flowline_points
point feature class and is used to represent regularly spaced points along a flowline
feature class using these instructions from the user manual. These flowline_points
features are used to store elevation and route position (longitudinal stream stationing) information for a flowline
feature. flowline_points
are used to calculate a series of stream longitudinal dimensions.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 1 | |
POINT_X | double | The x-coordinate value (longitude). | linear units of fc | 1 |
POINT_Y | double | The y-coordinate value (latitude). | linear units of fc | 1 |
POINT_M | double | The m-coordinate value (route position). | 1 | |
Z | double | The z-coordinate value (elevation). | feet, NAVD88 | 1 |
Detrended Raster
The 07 - Detrend DEM
tool creates the detrend
raster dataset using these instruction from the user manual. The detrend
raster is an elevation model where the downstream slope of the dem_hydro
has been removed.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
detrend_Z | 32 bit float | The detrended z-coordinate value (elevation). | feet, detrended | 1 |
Channel Slope Raster
The 09 - Channel Slope
tool creates the channel_slope
raster using these instructions from the user manual. The channel_slope
raster represents the slope of the dem_hydro
within the channel. This is not to be confused with the longitudinal slope of the stream reach, but is the pixel-wise, raster surface slope of the channel area.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
slope | 32 bit float | The terrain slope. | degree | 1 |
Centerline
The 10 - Centerline
tool creates the centerline
polyline feature class using these instructions from the user manual. The centerline
polyline feature class is used to represent a stream flow path that falls roughly equidistant between the banklines at bankfull water surface elevation.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
none | 2 |
Regular Cross Sections
The 11 - XS Layout
tool is used to create a regularly spaced cross section xs_*
polyline feature class using these instructions from the user manual. Cross sections are polyline feature classes drawn perpendicular to the flowline
feature and are long enough to extend across some portion of the channel and floodplain. Cross section features are used to define channel cross section dimensions. Regular cross sections are spaced equal distances longitudinally along the flowline
. Regularly spaced cross sections are used to sample conditions within a stream reach to display a continuous series of values and calculate aggregate stream values.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 1 | |
Seq | short | The cross section unique identifier. | 1 | |
x_start | double | The x-coordinate value at the start of the cross section. | linear units of fc | 1 |
y_start | double | The y-coordinate value at the start of the cross section. | linear units of fc | 1 |
x_end | double | The x-coordinate value at the end of the cross section. | linear units of fc | 1 |
y_end | double | The y-coordinate value at the end of the cross section. | linear units of fc | 1 |
Watershed_Area_SqMile | double | The upstream watershed drainage area. | square miles | 1 |
from_measure | double | The start longitudinal stationing value for the reach. | kilometers | 1 |
to_measure | double | The end longitudinal stationing value for the reach. | kilometers | 1 |
POINT_X | double | The x-coordinate value (longitude). | linear units of fc | 1 |
POINT_Y | double | The y-coordinate value (latitude). | linear units of fc | 1 |
POINT_M | double | The m-coordinate value (route position). | linear units of fc | 1 |
Z | double | The z-coordinate value (elevation). | feet, NAVD88 | 1 |
km_to_mouth | double | The distance to the mouth of the site. | kilometers | 1 |
loop | long | The loop number. | 3 | |
bend | long | The bend number. | 3 |
Riffle Cross Sections
Riffle cross sections (i.e., riffle_floodplain
, riffle_channel
) are a unique type of cross section manually drawn by the analyst within a riffle stream feature using these instructions from the user manual. In contrast to regularly spaced cross sections that are delineated by a script, riffles irregularly spaced along a stream and are manually drawn by a GIS analyst. Analysts are trained to identify riffles using a set of guidelines from the literature and interpretation of the DEM and aerial imagery. The riffle_floodplain
polyline feature class is drawn longitudinally within riffle features and extend laterally across the active floodplain. The riffle_channel
polyline feature class is also drawn longitudinally within riffle features, but only extend laterally across the bankfull channel area.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 2 | |
Seq | short | The cross section unique identifier. | 2 | |
Watershed_Area_SqMile | double | The upstream watershed drainage area. | square miles | 2 |
from_measure | double | The start longitudinal stationing value for the reach. | kilometers | 2 |
to_measure | double | The end longitudinal stationing value for the reach. | kilometers | 2 |
POINT_X | double | The x-coordinate value (longitude). | linear units of fc | 2 |
POINT_Y | double | The y-coordinate value (latitude). | linear units of fc | 2 |
POINT_M | double | The m-coordinate value (route position). | linear units of fc | 2 |
Z | double | The z-coordinate value (elevation). | feet, NAVD88 | 2 |
km_to_mouth | double | The distance to the mouth of the site. | kilometers | 2 |
loop | long | The loop number. | 3 | |
bend | long | The bend number. | 3 |
Cross Section Points
The 14 - XS Points
tool creates the *_points
points feature class using these instructions from the user manual for Level 1 and Level 2. Cross sections polyline feature classes (i.e., regularly spaced cross sections and riffle cross sections: riffle_floodplain
, riffle_channel
) can be converted to a set of regularly spaced points along the cross section. These points are used to store elevation and route position (lateral stream stationing) information for a cross section feature class. Cross section points are used to calculate a series of cross section dimensions.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 1,2 | |
Seq | short | The cross section unique identifier. | 1,2 | |
Watershed_Area_SqMile | double | The upstream watershed drainage area. | square miles | 1,2 |
from_measure | double | The start longitudinal stationing value for the reach. | kilometers | 1,2 |
to_measure | double | The end longitudinal stationing value for the reach. | kilometers | 1,2 |
POINT_X | double | The x-coordinate value (longitude). | linear units of fc | 1,2 |
POINT_Y | double | The y-coordinate value (latitude). | linear units of fc | 1,2 |
POINT_M | double | The m-coordinate value (route position). | linear units of fc | 1,2 |
POINT_M_units | text | The units of the POINT_M field. | 1,2 | |
km_to_mouth | double | The distance to the mouth of the site. | kilometers | 1,2 |
DEM_Z | double | The z-coordinate value (elevation). | feet, NAVD88 | 1,2 |
dem_units | double | The units of theDEM_Z field. | 1,2 | |
Detrend_DEM_Z | double | The z-coordinate value on the detrended raster. | feet, detrended | 1,2 |
loop | long | The loop number. | 3 | |
bend | long | The bend number. | 3 |
Cross Section Dimensions
Cross section dimension polyline feature classes are used to store the hydraulic dimensions calculated for each cross section. Since the FluvialGeomorph workflow is divided into three levels, cross section dimensions are calculated at each level. Each level allows for an increasingly complex set of dimensions to be calculated, with each level building on the complexity of the previous level. There are three cross section dimension feature classes, one for each level *_dims_L1
, *_dims_L2
, and *_dims_L3
. Cross section dimensions are calculated using the following tools:
- Level 1 Dimensions - The
15a XS Dimensions, Level 1
tool creates the*_dims_L1
feature class using these instructions from the user manual. - Level 2 Dimensions - The
15b XS Dimensions, Level 2
tool creates the*_dims_L2
feature class using these instructions from the user manual for L2 Initial and L2 Final. - Level 3 Dimensions - The
15c XS Planform, Level 3
tool creates the*_dims_L3
feature class using these instructions from the user manual.
Cross section dimensions can be calculated for the various types of cross sections (regular cross sections or riffle cross sections). The name of the cross section feature for which dimensions were calculated is prepended to the output dimension feature class. Metrics calculated at previous levels are included in the attribute table of each dimension feature class. Therefore, to avoid repetition only the new fields calculated at each level are included in the tables of fields in this section. The attributes of the original cross section feature class are also omitted since they depend on the cross section type used.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
z_smooth | double | The smoothed z-coordinate value (elevation). | feet, NAVD88 | 1 |
upstream_x | double | The x-coordinate value (longitude) of the next upsteam cross section in the moving window. | linear units of fc | 1 |
upstream_y | double | The y-coordinate value (latitude) of the next upsteam cross section in the moving window. | linear units of fc | 1 |
downstream_x | double | The x-coordinate value (longitude) of the next downsteam cross section in the moving window. | linear units of fc | 1 |
downstream_y | double | The y-coordinate value (latitude) of the next downsteam cross section in the moving window. | linear units of fc | 1 |
upstream_z | double | The z-coordinate value (elevation) of the next upstream cross section in the moving window. | feet, NAVD88 | 1 |
downstream_z | double | The z-coordinate value (elevation) of the next downstream cross section in the moving window. | feet, NAVD88 | 1 |
upstream_m | double | The m-coordinate value (route position) of the next upstream cross section in the moving window. | linear units of fc | 1 |
downstream_m | double | The m-coordinate value (route position) of the next downstream cross section in the moving window. | linear units of fc | 1 |
rise | double | The elevation difference between the downstream and upstream cross section in the moving window. | feet | 1 |
run | double | The longitudinal distance along the flowline between the downstream and upstream cross sections in the moving window. | feet | 1 |
stream_length | double | The longitudinal distance along the flowline between the downstream and upstream cross sections in the moving window. | feet | 1 |
valley_length | double | The longitudinal distance along the valleyline between the downstream and upstream cross sections in the moving window. | feet | 1 |
sinuosity | double | The sinuosity of the stream within the moving window (valley_length/stream_length). | 1 | |
sinuosity_gte_one | double | The sinuosity metric, values greater than or equal to one. | 1 | |
slope | double | The slope of the stream within the moving window (rise/run). | degree | 1 |
slope_gte_zero | double | The slope metric, values greater than of equal to zero. | degree | 1 |
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
bankfull_elevation | double | The detrended elevation of the water surface at bankfull discharge. | feet, detrended | 2 |
drainage_area | double | The upstream watershed drainage area. | square miles | 2 |
xs_area | double | The cross sectional area at the estimated bankfull water surface elevation. | square feet | 2 |
xs_width | double | The cross section width at the estimated bankfull water surface elevation. | square feet | 2 |
xs_depth | double | The cross section depth at the estimated bankfull water surface elevation. | square feet | 2 |
discharge | double | The stream discharge. | cubic m/s | 2 |
fp_area | double | The cross sectional area at the estimated floodprone water surface elevation. | square feet | 2 |
fp_width | double | The cross section width at the estimated floodprone water surface elevation. | feet | 2 |
fp_depth | double | The cross sectional depth at the estimated floodprone water surface elevation. | feet | 2 |
xs_width_depth_ratio | double | The width to depth ratio. | 2 | |
xs_width_depth_ratio_gte_one | double | The width to depth ratio metric, gteater than or equal to one. | 2 | |
xs_entrenchment_ratio | double | The entrenchment ratio. | 2 | |
xs_entrenchment_ratio_gte_one | double | The entrenchment ratio metric, greater than or equal to one. | 2 | |
watersurface_elev | double | The as-measured water surface elevation. | feet, NAVD88 | 2 |
bankfull_elev | double | The estimated bankfull water surface elevation. | feet, NAVD88 | 2 |
floodprone_elev | double | The estimated floodprone water surface elevation. | feet, NAVD88 | 2 |
xs_mean_depth | double | The cross section mean depth at the estimated bankfull water surface elevation. | feet | 2 |
shear_stress_density | double | The fluid shear stress, calculated using the density of water. | kg/m^2 | 2 |
shear_stress_density_gte_zero | double | The fluid shear stress density metric, greater than or equal to zero. | kg/m^2 | 2 |
shear_stress_weight | double | The fluid shear stress, calculated using the specific weight of water. | lb/ft^2 | 2 |
shear_stress_weight_gte_zero | double | The fluid shear stress specific weight metric, greater than or equal to zero. | lb/ft^2 | 2 |
shear_stress_lane | double | The fluid shear stress, calculated using the Lane’s Balance method. | 2 | |
shear_stress_lane_gte_zero | double | The fluid shear stress Lane’s metric, greater than or equal to zero. | 2 | |
unit_stream_power | double | The unit stream power. | kg/m/s | 2 |
unit_stream_power_gte_zero | double | The unit stream power metric, greater than or equal to zero. | kg/m/s | 2 |
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
bend_num | double | The bend number. | 3 | |
bend_POINT_X | double | The x-coordinate value (longitude) of the center of the bend. | linear units of fc | 3 |
bend_POINT_Y | double | The y-coordinate value (latitude) of the center of the bend. | linear units of fc | 3 |
loop_POINT_X | double | The x-coordinate value (longitude) of the center of the loop. | linear units of fc | 3 |
loop_POINT_Y | double | The y-coordinate value (latitude) of the center of the loop. | linear units of fc | 3 |
bend_radius | double | The radius of the bend. | linear units of fc | 3 |
meander_length | double | The meander length. | feet | 3 |
meander_width | double | The meander width. | feet | 3 |
rc_bfw_ratio | double | The radius of curvature to bankfull width ratio. | 3 | |
rc_bfw_ratio_lte_30 | double | The radius of curvature to bankfull width ratio less than or equale to 30. | 3 | |
mbw_bfw_ratio | double | The meander bend width to bankfull width ratio. | 3 | |
mbw_bfw_ratio_lte_30 | double | The meander bend width to bankfull width ratio less than or equal to 30. | 3 |
Bankfull Area
The 08 - Water Surface Extent
tool is used to create the bankfull_area
polygon feature class using these instructions from the user manual. The bankfull_area
polygon feature class represents the channel area typically inundated during bankfull events. The detrend
raster dataset is used to interactively “flood” the channel to define this extent.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
Id | long | The polygon unique identifier. | 2 | |
gridcode | long | Indicates if a polygon is innundated at the specified detrended elevation (1 = innundated, 0 = not innundated). | 2 | |
Shape_Area | double | Area of the polygon. | linear units of fc | 2 |
Banklines
The banklines
feature class is manually created from the bankfull_area
using these instructions from the user manual. The banklines
polyline feature class represents the stream banks at bankfull. The edge of the bankfull_area
polygon features are used to create to banklines, one representing the left descending bank and another the right descending bank.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 2 | |
bank_id | long | Bankline numeric unique identifier. | 2 | |
bank | text | Bankline text unique identifier (one of “left descending” or “right descending”). | 2 | |
from_measure | double | The start longitudinal stationing value for the bankline. | 2 | |
to_measure | double | The end longitudinal stationing value for the bankline. | 2 |
Bankline Points
The 14b - Bankline Points
tool creates the bankline_points
point feature class using these instructions in the user manual. The bankline_points
point feature class is a set of regularly spaced point features located along each banklines
feature. These points are used to store elevation and route position (longitudinal bankline stationing) information for each bankline.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 3 | |
bank_id | long | Bankline numeric unique identifier. | 3 | |
bank | text | Bankline text unique identifier (one of “left descending” or “right descending”). | 3 | |
bank_POINT_X | double | The x-coordinate value (longitude) of the bankline point. | linear units of fc | 3 |
bank_POINT_Y | double | The y-coordinate value (latitude) of the bankline point. | linear units of fc | 3 |
bank_POINT_M | double | The m-coordinate value (route position) of the bankline point. | linear units of fc | 3 |
DEM_Z | double | The z-coordinate value (elevation) of the bankline point. | feet, NAVD88 | 3 |
loop | long | The loop number. | 3 | |
bend | long | The bend number. | 3 | |
position | text | The planform location indicator. Indicates if a bankline point represents the “start” of a loop bend, the “end” of a loop bend, or the “apex” of a loop. | 3 | |
valley_POINT_X | double | The x-coordinate value (longitude) of the closest point on the valley line. | linear units of fc | 3 |
valley_POINT_Y | double | The y-coordinate value (latitude) of the closest point on the valley line. | linear units of fc | 3 |
valley_POINT_M | double | The m-coordinate value (route position) of the closest point on the valley line. | linear units of fc | 3 |
Valleyline
The valleyline
is created using these instructions from the user manual. The valleyline
polyline feature class represents the trend line of the down-valley axis. It bisects stream meanders as the stream swings from side to side across its floodplain.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 3 | |
from_measure | double | The start longitudinal stationing value for the reach. | kilometers | 3 |
to_measure | double | The end longitudinal stationing value for the reach. | kilometers | 3 |
Loop Points
The loop_points
point feature class is manually created by the analyst using these instructions from the user manual. The loop_points
point feature class is used to store the longitudinal extents of loops and bends used for planform analysis. Within the FluvialGeomorph toolbox, the term “loop” is defined as a single meander as it swings across the valleyline
. Moving downstream along a single loop, once the stream swings substantially across the valleyline, another loop begins. The point of maximum distance of a flowline from the valeyline (laterally across the floodplain) defines a loop “apex”. Moving to a finer scale, “bends” are defined as stream undulations within a particular loop. Therefore, a single loop may contain many bends. These loop and bend extents and loop apices are used to calculate a set of planform dimensions.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
ReachName | text | Name of the reach. | 3 | |
loop | long | The loop number. | 3 | |
bend | long | The bend number. | 3 | |
position | text | The planform location indicator. Indicates if a bankline point represents the “start” of a loop bend, the “end” of a loop bend, or the “apex” of a loop. | 3 |
Features
The features
point feature class is created manually by the analyst using these instructions in the user manual. The features
point feature class is used to identify and label key stream features and their longitudinal position. Instances of features typically include relevant tributaries, localities, and infrastructure built within the floodplain affecting flow.
Field Name | Type | Description | Units | Level |
---|---|---|---|---|
Name | text | Name of the stream feature. | 1 | |
km_to_mouth | double | The distance to the mouth of the site. | kilometers | 1 |