Using ipyleaflet drawing tools to interact with Earth Engine data¶

Video demo

Install Earth Engine API and geemap¶

Install the Earth Engine Python API and geemap. The geemap Python package is built upon the ipyleaflet and folium packages and implements several methods for interacting with Earth Engine data layers, such as Map.addLayer(), Map.setCenter(), and Map.centerObject(). The following script checks if the geemap package has been installed. If not, it will install geemap, which automatically installs its dependencies, including earthengine-api, folium, and ipyleaflet.

In [15]:

# Installs geemap package
import subprocess

try:
    import geemap
except ImportError:
    print('geemap package not installed. Installing ...')
    subprocess.check_call(["python", '-m', 'pip', 'install', '-U', 'geemap'])

In [16]:

import ee
import geemap

Create an interactive map¶

The default basemap is Google Satellite. Additional basemaps can be added using the Map.add_basemap() function.

In [17]:

Map = geemap.Map(center=[40,-100], zoom=4)
Map.add_basemap('HYBRID') # Add Google Satellite
Map

Draw any shapes on the map above using the Draw Control.¶

In [18]:

# Retrieves ee.Feature() of the last drawing object.
Map.draw_last_feature

In [19]:

# Retrieves ee.Feature() of all drawing objects.
Map.draw_features

Out[19]:

[]

Clipping Earth Engine Image layer with the Draw Control¶

In [20]:

import ipywidgets as widgets
from ipyleaflet import WidgetControl
from geemap import geojson_to_ee

Map = geemap.Map(center=[40,-100], zoom=4)
Map.add_basemap('HYBRID') # Add 

# Add Earth Engine dataset
image = ee.Image('USGS/SRTMGL1_003')

# Set visualization parameters.
vis_params = {
  'min': 0,
  'max': 4000,
  'palette': ['006633', 'E5FFCC', '662A00', 'D8D8D8', 'F5F5F5']}

# Get basemap layers
base_layers = Map.layers

# Add Earth Engine DEM to map
Map.addLayer(image, vis_params, 'SRTM DEM')

# An empty list for storing drawing geometries
feat_list = []

# Get the DrawControl
dc = Map.draw_control

# Handle draw events
def handle_draw(self, action, geo_json):

    geom = geojson_to_ee(geo_json, False)
    feature = ee.Feature(geom)
    feat_list.append(feature)
    collection = ee.FeatureCollection(feat_list)
    clip_image = image.clipToCollection(collection)
    
    Map.layers = base_layers[:3]
    Map.addLayer(clip_image, vis_params, 'SRTM DEM')
#     Map.addLayer(ee.Image().paint(collection, 0, 2), {'palette': 'red'}, 'EE Geometry')
    Map.addLayer(collection, {}, 'Drawing Features')

dc.on_draw(handle_draw)

# # Add a button to the map
# button = widgets.Button(description="Clear drawings")
# btn_control = WidgetControl(widget=button, position='bottomright')
# Map.add_control(btn_control)

# # Handle click event
# def on_button_clicked(b):
#     dc.clear()

# button.on_click(on_button_clicked)

Map

In [21]:

# Print out the geojson of the last drawing object
dc.last_draw

Out[21]:

{'type': 'Feature', 'geometry': None}

Last update: 2021-03-05