A16b Checkpoint

Import libraries¶

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import ee
import geemap

import ee import geemap

Create an interactive map¶

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Map = geemap.Map(center=[40, -100], zoom=4)

Map = geemap.Map(center=[40, -100], zoom=4)

Add Earth Engine Python script¶

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

#  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#  Chapter:      A1.6 Health Applications
#  Checkpoint:   A16b
#  Author:       Dawn Nekorchuk
#  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

# Section 1: Data Import
woredas = ee.FeatureCollection("projects/gee-book/assets/A1-6/amhara_woreda_20170207")
# Create region outer boundary to filter products on.
amhara = woredas.geometry().bounds()
gpm = ee.ImageCollection("NASA/GPM_L3/IMERG_V06")
LSTTerra8 = ee.ImageCollection("MODIS/061/MOD11A2").filterDate("2001-06-26", Date.now())
brdfReflect = ee.ImageCollection("MODIS/006/MCD43A4")
brdfQa = ee.ImageCollection("MODIS/006/MCD43A2")

# Visualize woredas with black borders and no fill.
# Create an empty image into which to paint the features, cast to byte.
empty = ee.Image().byte()
# Paint all the polygon edges with the same number and width.
outline = empty.paint({"featureCollection": woredas, "color": 1, "width": 1})
# Add woreda boundaries to the map.
Map.setCenter(38, 11.5, 7)
Map.addLayer(outline, {"palette": "000000"}, "Woredas")

# -----------------------------------------------------------------------
# CHECKPOINT
# -----------------------------------------------------------------------

# Section 2: Handling of dates

# 2.1 Requested start and end dates.
reqStartDate = ee.Date("2021-10-01")
reqEndDate = ee.Date("2021-11-30")

# 2.2 LST Dates
# LST MODIS is every 8 days, and a user-requested date will likely not match.
# We want to get the latest previous image date,
#  i.e. the date the closest, but prior to, the requested date.
# We will filter later.
# Get date of first image.
LSTEarliestDate = LSTTerra8.first().date()
# Filter collection to dates from beginning to requested start date.
priorLstImgCol = LSTTerra8.filterDate(LSTEarliestDate, reqStartDate)
# Get the latest (max) date of this collection of earlier images.
LSTPrevMax = priorLstImgCol.reduceColumns(
    {"reducer": ee.Reducer.max(), "selectors": ["system:time_start"]}
)
LSTStartDate = ee.Date(LSTPrevMax.get("max"))
print("LSTStartDate", LSTStartDate)

# 2.3 Last available data dates
# Different variables have different data lags.
# Data may not be available in user range.
# To prevent errors from stopping script,
#  grab last available (if relevant) & filter at end.

# 2.3.1 Precipitation
# Calculate date of most recent measurement for gpm (of all time).
gpmAllMax = gpm.reduceColumns(ee.Reducer.max(), ["system:time_start"])
gpmAllEndDateTime = ee.Date(gpmAllMax.get("max"))
# GPM every 30 minutes, so get just date part.
gpmAllEndDate = ee.Date.fromYMD(
    {
        "year": gpmAllEndDateTime.get("year"),
        "month": gpmAllEndDateTime.get("month"),
        "day": gpmAllEndDateTime.get("day"),
    }
)

# If data ends before requested start, take last data date,
# otherwise use requested date.
precipStartDate = ee.Date(gpmAllEndDate.millis().min(reqStartDate.millis()))
print("precipStartDate", precipStartDate)

# 2.3.2 BRDF
# Calculate date of most recent measurement for brdf (of all time).
brdfAllMax = brdfReflect.reduceColumns(
    {"reducer": ee.Reducer.max(), "selectors": ["system:time_start"]}
)
brdfAllEndDate = ee.Date(brdfAllMax.get("max"))
# If data ends before requested start, take last data date,
# otherwise use the requested date.
brdfStartDate = ee.Date(brdfAllEndDate.millis().min(reqStartDate.millis()))
print("brdfStartDate", brdfStartDate)
print("brdfEndDate", brdfAllEndDate)

# -----------------------------------------------------------------------
# CHECKPOINT
# -----------------------------------------------------------------------

# Add Earth Engine dataset image = ee.Image("USGS/SRTMGL1_003") # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # Chapter: A1.6 Health Applications # Checkpoint: A16b # Author: Dawn Nekorchuk # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # Section 1: Data Import woredas = ee.FeatureCollection("projects/gee-book/assets/A1-6/amhara_woreda_20170207") # Create region outer boundary to filter products on. amhara = woredas.geometry().bounds() gpm = ee.ImageCollection("NASA/GPM_L3/IMERG_V06") LSTTerra8 = ee.ImageCollection("MODIS/061/MOD11A2").filterDate("2001-06-26", Date.now()) brdfReflect = ee.ImageCollection("MODIS/006/MCD43A4") brdfQa = ee.ImageCollection("MODIS/006/MCD43A2") # Visualize woredas with black borders and no fill. # Create an empty image into which to paint the features, cast to byte. empty = ee.Image().byte() # Paint all the polygon edges with the same number and width. outline = empty.paint({"featureCollection": woredas, "color": 1, "width": 1}) # Add woreda boundaries to the map. Map.setCenter(38, 11.5, 7) Map.addLayer(outline, {"palette": "000000"}, "Woredas") # ----------------------------------------------------------------------- # CHECKPOINT # ----------------------------------------------------------------------- # Section 2: Handling of dates # 2.1 Requested start and end dates. reqStartDate = ee.Date("2021-10-01") reqEndDate = ee.Date("2021-11-30") # 2.2 LST Dates # LST MODIS is every 8 days, and a user-requested date will likely not match. # We want to get the latest previous image date, # i.e. the date the closest, but prior to, the requested date. # We will filter later. # Get date of first image. LSTEarliestDate = LSTTerra8.first().date() # Filter collection to dates from beginning to requested start date. priorLstImgCol = LSTTerra8.filterDate(LSTEarliestDate, reqStartDate) # Get the latest (max) date of this collection of earlier images. LSTPrevMax = priorLstImgCol.reduceColumns( {"reducer": ee.Reducer.max(), "selectors": ["system:time_start"]} ) LSTStartDate = ee.Date(LSTPrevMax.get("max")) print("LSTStartDate", LSTStartDate) # 2.3 Last available data dates # Different variables have different data lags. # Data may not be available in user range. # To prevent errors from stopping script, # grab last available (if relevant) & filter at end. # 2.3.1 Precipitation # Calculate date of most recent measurement for gpm (of all time). gpmAllMax = gpm.reduceColumns(ee.Reducer.max(), ["system:time_start"]) gpmAllEndDateTime = ee.Date(gpmAllMax.get("max")) # GPM every 30 minutes, so get just date part. gpmAllEndDate = ee.Date.fromYMD( { "year": gpmAllEndDateTime.get("year"), "month": gpmAllEndDateTime.get("month"), "day": gpmAllEndDateTime.get("day"), } ) # If data ends before requested start, take last data date, # otherwise use requested date. precipStartDate = ee.Date(gpmAllEndDate.millis().min(reqStartDate.millis())) print("precipStartDate", precipStartDate) # 2.3.2 BRDF # Calculate date of most recent measurement for brdf (of all time). brdfAllMax = brdfReflect.reduceColumns( {"reducer": ee.Reducer.max(), "selectors": ["system:time_start"]} ) brdfAllEndDate = ee.Date(brdfAllMax.get("max")) # If data ends before requested start, take last data date, # otherwise use the requested date. brdfStartDate = ee.Date(brdfAllEndDate.millis().min(reqStartDate.millis())) print("brdfStartDate", brdfStartDate) print("brdfEndDate", brdfAllEndDate) # ----------------------------------------------------------------------- # CHECKPOINT # -----------------------------------------------------------------------

Display the interactive map¶

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Map

Map