13 zonal statistics by group

Uncomment the following line to install geemap if needed.

In [1]:

# !pip install geemap

# !pip install geemap

In [2]:

import ee
import geemap
import os

import ee import geemap import os

Analyzing National Land Cover Database (NLCD)¶

In [3]:

Map = geemap.Map()
Map

Map = geemap.Map() Map

Out[3]:

Make this Notebook Trusted to load map: File -> Trust Notebook

Add NLCD data¶

In [4]:

dataset = ee.Image('USGS/NLCD_RELEASES/2019_REL/NLCD/2019')
landcover = ee.Image(dataset.select('landcover'))
Map.addLayer(landcover, {}, 'NLCD 2016')

states = ee.FeatureCollection("TIGER/2018/States")
Map.addLayer(states, {}, 'US States')

dataset = ee.Image('USGS/NLCD_RELEASES/2019_REL/NLCD/2019') landcover = ee.Image(dataset.select('landcover')) Map.addLayer(landcover, {}, 'NLCD 2016') states = ee.FeatureCollection("TIGER/2018/States") Map.addLayer(states, {}, 'US States')

In [5]:

Map.add_legend(builtin_legend='NLCD')

Map.add_legend(builtin_legend='NLCD')

Calculate land cover compostion of each US state¶

In [6]:

out_dir = os.path.join(os.path.expanduser('~'), 'Downloads')
nlcd_stats = os.path.join(out_dir, 'nlcd_stats.csv')

if not os.path.exists(out_dir):
    os.makedirs(out_dir)

# statistics_type can be either 'SUM' or 'PERCENTAGE'
# denominator can be used to convert square meters to other areal units, such as square kilometers
geemap.zonal_statistics_by_group(
    landcover,
    states,
    nlcd_stats,
    statistics_type='SUM',
    denominator=1000000,
    decimal_places=2,
)

out_dir = os.path.join(os.path.expanduser('~'), 'Downloads') nlcd_stats = os.path.join(out_dir, 'nlcd_stats.csv') if not os.path.exists(out_dir): os.makedirs(out_dir) # statistics_type can be either 'SUM' or 'PERCENTAGE' # denominator can be used to convert square meters to other areal units, such as square kilometers geemap.zonal_statistics_by_group( landcover, states, nlcd_stats, statistics_type='SUM', denominator=1000000, decimal_places=2, )

Computing ... 
Generating URL ...
Downloading data from https://earthengine.googleapis.com/v1alpha/projects/earthengine-legacy/tables/133d101cfb013c1f804933a0d6c5b076-89868a9f243fe90531fc7bc1ce15a962:getFeatures
Please wait ...
Data downloaded to /home/runner/Downloads/nlcd_stats.csv

In [7]:

geemap.create_download_link(nlcd_stats)

geemap.create_download_link(nlcd_stats)

Out[7]:

Click here to download: nlcd_stats.csv

Analyzing Global Land Cover¶

In [8]:

Map = geemap.Map()
Map

Map = geemap.Map() Map

Out[8]:

Make this Notebook Trusted to load map: File -> Trust Notebook

Add MODIS global land cover data¶

MODIS MCD12Q1.006 Land Cover Type Yearly Global 500m

https://developers.google.com/earth-engine/datasets/catalog/MODIS_006_MCD12Q1

In [9]:

landcover = ee.Image('MODIS/006/MCD12Q1/2013_01_01').select('LC_Type1')

vis = {
    'min': 1.0,
    'max': 17.0,
    'palette': [
        '05450a',
        '086a10',
        '54a708',
        '78d203',
        '009900',
        'c6b044',
        'dcd159',
        'dade48',
        'fbff13',
        'b6ff05',
        '27ff87',
        'c24f44',
        'a5a5a5',
        'ff6d4c',
        '69fff8',
        'f9ffa4',
        '1c0dff',
    ],
}

Map.setCenter(6.746, 46.529, 2)
Map.addLayer(landcover, vis, 'MODIS Land Cover')

landcover = ee.Image('MODIS/006/MCD12Q1/2013_01_01').select('LC_Type1') vis = { 'min': 1.0, 'max': 17.0, 'palette': [ '05450a', '086a10', '54a708', '78d203', '009900', 'c6b044', 'dcd159', 'dade48', 'fbff13', 'b6ff05', '27ff87', 'c24f44', 'a5a5a5', 'ff6d4c', '69fff8', 'f9ffa4', '1c0dff', ], } Map.setCenter(6.746, 46.529, 2) Map.addLayer(landcover, vis, 'MODIS Land Cover')

In [10]:

Map.add_legend(builtin_legend='MODIS/006/MCD12Q1')

Map.add_legend(builtin_legend='MODIS/006/MCD12Q1')

In [11]:

countries_shp = '../data/countries.shp'
countries = geemap.shp_to_ee(countries_shp)
Map.addLayer(countries, {}, 'Countries')

countries_shp = '../data/countries.shp' countries = geemap.shp_to_ee(countries_shp) Map.addLayer(countries, {}, 'Countries')

In [12]:

out_dir = os.path.join(os.path.expanduser('~'), 'Downloads')
global_stats = os.path.join(out_dir, 'global_stats.csv')

# statistics_type can be either 'SUM' or 'PERCENTAGE'
# denominator can be used to convert square meters to other areal units, such as square kilimeters
geemap.zonal_statistics_by_group(
    landcover,
    countries,
    global_stats,
    statistics_type='PERCENTAGE',
    denominator=1000000,
    decimal_places=2,
)

out_dir = os.path.join(os.path.expanduser('~'), 'Downloads') global_stats = os.path.join(out_dir, 'global_stats.csv') # statistics_type can be either 'SUM' or 'PERCENTAGE' # denominator can be used to convert square meters to other areal units, such as square kilimeters geemap.zonal_statistics_by_group( landcover, countries, global_stats, statistics_type='PERCENTAGE', denominator=1000000, decimal_places=2, )

Computing ... 
Generating URL ...
Downloading data from https://earthengine.googleapis.com/v1alpha/projects/earthengine-legacy/tables/e9d7fd3bbb8e0fe7705dc60777027980-c7466b37b504e737f7da41d7eebaf0d5:getFeatures
Please wait ...
Data downloaded to /home/runner/Downloads/global_stats.csv

In [13]:

geemap.create_download_link(global_stats)

geemap.create_download_link(global_stats)

Out[13]:

Click here to download: global_stats.csv

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Last update: 2022-03-14