scl3/task_hii_power
Earth Engine task for calculating power driver
132
This task calculates the impact of power on the terrestrial surface as one of the key drivers for a combined
Human Impact Index.
"Impact" is a pressure score based on the intensity of electricity usage as measured by "Night Time Lights" datasets.
An inter-calibrated nighttime lights dataset with values ranging from 0 - 63 is transformed to a pressure score of
0 - 10 using equal interval quantiles, calculated from the earliest available image (1992) using the quantile_calc
function in input_preprocess.py
. These are:
quantiles = {
"0": {"value": 0, "min": 0, "max": 0},
"1": {"value": 1, "min": 1, "max": 4},
"2": {"value": 2, "min": 5, "max": 5},
"3": {"value": 3, "min": 6, "max": 6},
"4": {"value": 4, "min": 7, "max": 7},
"5": {"value": 5, "min": 8, "max": 9},
"6": {"value": 6, "min": 10, "max": 11},
"7": {"value": 7, "min": 12, "max": 16},
"8": {"value": 8, "min": 17, "max": 30},
"9": {"value": 9, "min": 31, "max": 62},
"10": {"value": 10, "min": 63, "max": 63},
The output HII driver calculated by this task is, like all other HII drivers, unitless; it refers to an absolute 0-10 scale but is not normalized to it, so the actual range of values may be smaller than 0-10.
The HII power driver (0-10) is calculated from the previous calendar year's calibrated nightlights dataset, which is
produced on demand by the task by using the HIIPowerPreprocessTask
task. Two distinct source nightlight datasets are
used to calculate this calibrated version following the methods below; these are the
Defense Meteorological Satellite Program (DMSP)/Operational Linescan System (OLS) and the
Visible Infrared Imaging Radiometry Suite (VIIRS) on the Suomi National Polar-orbiting Partnership Satellite.
DMSP provides data from 1992 - 2013 and VIIRS provides data from 2012 through the present.
Inconsistencies within the DMSP time series require implementing intra-calibration within the DMSP dataset. Here the intra-calibrated dataset produced by Li et al. 2020 is used. Key differences between the DMSP and VIIRS datasets also require inter-calibration of the two datasets. In addition to the calibration process to match VIIRS to DMSP, VIIRS requires substantial noise reduction. These key differences are:
Description | DMSP | VIIRS | Calibrated |
---|---|---|---|
Date Range | 1992 - 2013 | 2012 - present | 1992 - present |
Temporal Resolution | Annual | Monthly | Annual |
Spatial Resolution | 30 arc-second | 15 arc-seconds | 30 arc-second |
Pixel Value | Digital Number | Radiance | Digital Number |
Data Range | 0 - 63 | -1.5 - 193564.92 | 0 - 63 |
t = (|lat|4 / 604) x (tmax - tmin) + (tmin)
Where:
t is the final threshold image
lat is a latitude image
tmin is the minimum threshold
tmax is the maximum threshold
stable_light_points
function in input_preprocess.py
.The result and goal is an annual night lights dataset derived from VIIRS that is calibrated to the pre-2013 DMSP values, which is then transformed into the HII power driver by the main task.
SERVICE_ACCOUNT_KEY=<GOOGLE SERVICE ACCOUNT KEY>
scale=300
All parameters may be specified in the environment as well as the command line.
/app # python task.py --help
usage: task.py [-h] [-d TASKDATE] [--overwrite]
optional arguments:
-h, --help show this help message and exit
-d TASKDATE, --taskdate TASKDATE
--overwrite overwrite existing outputs instead of incrementing
In addition, the HIIPowerPreprocessTask
task can be called to run one of three preprocessing steps used in the
main task.py
, with the following constants available as arguments:
BUCKET = "hii-scratch"
CALC_PREVIOUS_ANNUAL_VIIRS = "viirs"
CALC_CALIBRATION_COEFFICIENTS = "coefficients"
CALC_WEIGHTING_QUANTILES = "quantiles"
The first of these, viirs
, is used on demand by the main power task.py
.
/app# python input_preprocess.py --help
usage: input_preprocess.py [-h] [-d TASKDATE] [-j [{viirs,coefficients,quantiles}]] [--overwrite]
optional arguments:
-h, --help show this help message and exit
-d TASKDATE, --taskdate TASKDATE
-j [{viirs,coefficients,quantiles}], --job [{viirs,coefficients,quantiles}]
Calculation to run with HIIPowerPreprocessTask.
--overwrite overwrite existing outputs instead of incrementing
Copyright (C) 2022 Wildlife Conservation Society The files in this repository are part of the task framework for calculating Human Impact Index and Species Conservation Landscapes (https://github.com/SpeciesConservationLandscapes) and are released under the GPL license: https://www.gnu.org/licenses/#GPL See LICENSE for details.
docker pull scl3/task_hii_power