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Add Lake Context from NHD

Source: R/nhd_integration.R
add_lake_context.Rd

Add hydrological context to fetch results using the National Hydrography Dataset (NHD). Includes outlet/inlet locations, watershed area, connectivity classification, and stream order.

Usage

add_lake_context(fetch_results, lake_polygons, utm_epsg)

Arguments

fetch_results

sf object with fetch calculation results

lake_polygons

sf object with lake polygons

utm_epsg

EPSG code for UTM projection

Value

sf object with additional columns for NHD context

Details

Requires the hydrogeofetch package. If not available, returns the input with NA columns added for consistent output format.

Added columns include:

  • nhd_permanent_id: NHD permanent identifier

  • nhd_gnis_name: GNIS name from NHD

  • nhd_areasqkm: Area in square kilometers from NHD

  • outlet_dist_m: Distance to outlet in meters

  • outlet_bearing: Compass direction to outlet

  • inlet_nearest_dist_m: Distance to nearest inlet

  • inlet_nearest_bearing: Compass direction to nearest inlet

  • inlet_count: Number of inlets

  • connectivity_class: Headwater/Drainage/Terminal/Isolated

  • outlet_stream_order: Strahler stream order at outlet

  • watershed_area_ha: Watershed area in hectares

  • lake_watershed_ratio: Lake area / watershed area

Examples

if (FALSE) { # interactive()
csv_path <- system.file("extdata", "sample_sites.csv", package = "lakefetch")
sites <- load_sites(csv_path)
lake <- get_lake_boundary(sites)
results <- fetch_calculate(sites, lake)
results_with_context <- add_lake_context(results$results, results$lakes, lake$utm_epsg)
}