{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "0",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Import libraries\n",
    "import ee\n",
    "import geemap"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "1",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Create an interactive map by specifying the center (lat, lon) and zoom level (1-18).\n",
    "Map = geemap.Map(center=[40, -100], zoom=4)\n",
    "Map"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "2",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Import the NLCD collection.\n",
    "dataset = ee.ImageCollection(\"USGS/NLCD_RELEASES/2019_REL/NLCD\")\n",
    "\n",
    "# Filter the collection to the 2016 product.\n",
    "nlcd2016 = dataset.filter(ee.Filter.eq(\"system:index\", \"2019\")).first()\n",
    "\n",
    "# Select the land cover band.\n",
    "landcover = nlcd2016.select(\"landcover\")\n",
    "\n",
    "# Display land cover on the map.\n",
    "Map.addLayer(landcover, {}, \"NLCD 2019\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "3",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Add the NLCD legend to the map.\n",
    "Map.add_legend(title=\"NLCD Land Cover Classification\", builtin_legend=\"NLCD\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "4",
   "metadata": {},
   "outputs": [],
   "source": [
    "# # To add a custom legend to the map, uncomment the following code and modify the legend dictionary.\n",
    "# legend_dict = {\n",
    "#     '11 Open Water': '466b9f',\n",
    "#     '12 Perennial Ice/Snow': 'd1def8',\n",
    "#     '21 Developed, Open Space': 'dec5c5',\n",
    "#     '22 Developed, Low Intensity': 'd99282',\n",
    "#     '23 Developed, Medium Intensity': 'eb0000',\n",
    "#     '24 Developed High Intensity': 'ab0000',\n",
    "#     '31 Barren Land (Rock/Sand/Clay)': 'b3ac9f',\n",
    "#     '41 Deciduous Forest': '68ab5f',\n",
    "#     '42 Evergreen Forest': '1c5f2c',\n",
    "#     '43 Mixed Forest': 'b5c58f',\n",
    "#     '51 Dwarf Scrub': 'af963c',\n",
    "#     '52 Shrub/Scrub': 'ccb879',\n",
    "#     '71 Grassland/Herbaceous': 'dfdfc2',\n",
    "#     '72 Sedge/Herbaceous': 'd1d182',\n",
    "#     '73 Lichens': 'a3cc51',\n",
    "#     '74 Moss': '82ba9e',\n",
    "#     '81 Pasture/Hay': 'dcd939',\n",
    "#     '82 Cultivated Crops': 'ab6c28',\n",
    "#     '90 Woody Wetlands': 'b8d9eb',\n",
    "#     '95 Emergent Herbaceous Wetlands': '6c9fb8'\n",
    "# }\n",
    "# Map.add_legend(title=\"NLCD Land Cover Classification\", legend_dict=legend_dict)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "5",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Print the list of system ids of all available NLCD images.\n",
    "dataset.aggregate_array(\"system:id\").getInfo()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "6",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Select the seven NLCD epoches after 2000.\n",
    "years = [\"2001\", \"2004\", \"2006\", \"2008\", \"2011\", \"2013\", \"2016\", \"2019\"]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "7",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Get an NLCD image by year.\n",
    "def getNLCD(year):\n",
    "    # Import the NLCD collection.\n",
    "    dataset = ee.ImageCollection(\"USGS/NLCD_RELEASES/2019_REL/NLCD\")\n",
    "\n",
    "    # Filter the collection by year.\n",
    "    nlcd = dataset.filter(ee.Filter.eq(\"system:index\", year)).first()\n",
    "\n",
    "    # Select the land cover band.\n",
    "    landcover = nlcd.select(\"landcover\")\n",
    "    return landcover"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "8",
   "metadata": {},
   "outputs": [],
   "source": [
    "## Create an NLCD image collection for the selected years.\n",
    "collection = ee.ImageCollection(ee.List(years).map(lambda year: getNLCD(year)))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "9",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Print the list of system ids of selected NLCD images.\n",
    "collection.aggregate_array(\"system:id\").getInfo()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "10",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Create a list of labels to populate the dropdown list.\n",
    "labels = [f\"NLCD {year}\" for year in years]\n",
    "labels"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "11",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Add a split-panel map for visualizing NLCD land cover change.\n",
    "Map.ts_inspector(\n",
    "    left_ts=collection, right_ts=collection, left_names=labels, right_names=labels\n",
    ")\n",
    "Map"
   ]
  }
 ],
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  "kernelspec": {
   "display_name": "Python 3",
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