Using space-based technologies to predict mosquito-borne disease outbreaks

Mosquitos are often cited as one of the deadliest animals in the world, causing up to one million deaths per year (WHO, 2020; CDC, 2021). They can carry and transmit a variety of diseases, including malaria, West Nile virus, dengue fever, and Zika virus; transmitting illness across the globe (Figure 1). To help decrease the burden of disease resulting from mosquitos, researchers are utilising satellite data and remote sensing models to better predict where mosquito breeding grounds may occur in the future.

Sarhan Zerouali became fascinated with water at a young age through learning about water scarcity around the world and about traditional methods for locating groundwater. In a space applications course Sahran then learnt about space-based technologies. He is currently working on a research project on how remote sensing and other technologies can help alleviate global challenges arising from land degradation. As an aerospace engineer, Sahran has worked with various modern technologies in his work including nanosatellites, artificial intelligence, and feature extraction algorithms.

What began as the development of a cubesat (BIRD-5) at the Kyushu Institute of Technology in Japan took off on a spacecraft to the International Space Station from the Mid-Atlantic Regional Spaceport at the National Aeronautics and Space Administration's (NASA's) Wallops Flight Facility in Virginia, US on 6 November 2022 (watch the video of the launch of the CRS2 NG-18 (Cygnus) Mission (Antares), in the video below the article).

Digital Earth Africa learning platform

This learning platform helps users understand the significance of Earth observations, explore Digital Earth Africa datasets through an interactive map, and get started on the basics of python coding for spatial analysis.

Digital Earth Africa makes Earth observation (EO) data readily available, delivering decision-ready products to the African continent. Data generated by Digital Earth Africa will provide valuable insights for better decision-making across many areas, including resource management, food security and urbanisation.

Water suitability map (Samburu County, Kenya) - in development

Published on 11 Apr 2023

Water suitability map (Samburu County, Kenya) - in development

Published on 11 Apr 2023 , by

Lilian Nguracha Balanga

Founder of Women .conserve at Samburu women

Claire Muhungi

Ag Deputy Director at Kenya Space Agency

Isabel Zetina

Student

Groundwater Relief

Kenya Space Agency

Addressed challenge(s)

Samburu woman drinking (brownish) well water filtered through the fabric of her dress

Samburu tribe lacks access to safe drinking water - Dry spells due to water scarcity

Collaborating actors (stakeholders, professionals, young professionals or Indigenous voices)

Groundwater Relief

Kenya Space Agency

Lilian Nguracha Balanga

Founder of Women .conserve at Samburu women

Claire Muhungi

Ag Deputy Director at Kenya Space Agency

Isabel Zetina

Student

Suggested solution

Background information on the geology of Kenya

The geology of Kenya shows Metamorphic rocks in the western part due to high metamorphic processes. The Great Rift Valley is a plate boundary.

Tertiary and Quaternary Volcanic Rocks: East African Rift System: volcanic activity during these periods

Geology map of Kenya — Fig.1: National Atlas of Kenya - Geological Map. (n.d.). European Commission, Joint Research Centre.

Resources used for addressing the challenge

Map of community locations

Map of important community locations — Figure 2: Map of locations of the community, from where water access would be needed in the vicinity.

Software

QGIS: A Free and Open Source Geographic Information System. Version 3.32.3 / Version 3.28.11 LTR.
ArcGIS Pro. Version ArcGIS Pro 3.

Data sources

National Atlas of Kenya - Geological Map. (n.d.). European Commission, Joint Research Centre. https://esdac.jrc.ec.europa.eu/content/national-atlas-kenya-geological-map (visited: 19.10.2021).
Samburu District - Type and Location of Water Sources, Key Landforms, and Soils (Symbols - See Map 11). (n.d.). European Commission, Joint Research Centre. https://esdac.jrc.ec.europa.eu/content/samburu-district-type-and-location-water-sources-key-landforms-and-soils-symbols-see-map-11 (visited: 19.10.2021)

Publications used for methodology and background research

see references indicated below.

Steps outlining the solution

To find where water is situated, compare a topographic map with the Normalised Differentiated Vegetation Index (NDVI). Recharge occurs where water accumulates and hence vegetation is available/the healthiest at the driest times. This step could be implemented using Google Earth Engine.

Figure 3: Topographic map of Samburu province in Kenya. Credit: Topographic Map (2023)

Figure 4: NDVI made with QGIS. Version 3.32.3 / Version 3.28.11 LTR.
Develop a geology map and potentially a geophysical survey (mineral composition). Mineral data and geophysical characteristics are well mapped in Kenya. It is likely that the geology in Kenya requires a basement rock drilling using air hammers / air compressors and pneumatic hammering.

Figure 5: Zoom into Samburu county at the National Atlas of Kenya - Geological Map. (n.d.). European Commission, Joint Research Centre. Orange: Basement rock, Yellow Quarternary Sediments.
The communities are located in the South-West of Samburu County. The geology in the area is mostly magmatic and metamorphic. This suggests that the ground has very low permeability. However, near the location of the communities there are two springs. These springs point to an aquifer in the area, where a well for the communities in the area could be developed. ---
Figure 6: Water sources in the Samburu county. Map provided by Kenya Space Agency. Source: G. de Sourza, Dept. Geography, University of Nairobi, J. Keza, Ministry of Water Development.
A desk study compares the geology with the topography

Figure 7: Geology of Samburu County Krhoda et al. (2015).

Samburu county elevation map — Figure 8: Elevation Map made with QGIS. Version 3.32.3 / Version 3.28.11 LTR.

Location of water sources

The area of interest has two springs, which are natural groundwater outflow in the surface.

Map showing the Samburu county water points — Figure 9: Elevation Map made with QGIS. Version 3.32.3 / Version 3.28.11 LTR.

Groundwater resources

Aquifer in magmatic/metamorphic basement: moderate productivity

magmatic rocks have low permeability
Groundwater recharge is low

Ideal outcome: A possible groundwater source exists near the communities homes and borehole could be developed

Map showing possible groundwater resources in the Samburu County based on the geology — Figure 10. Possible groundwater resources in the Samburu County based on the geology.

Next steps to be taken with external actors

Work with hydrogeologists to prepare a borehole siting report as well as an Environmental Impact Assessment. Groundwater relief has some trusted hydrogeologists in their network in Kenya who could implement that and submit the information to the Kenya Water Resources Agency.
Kenya Water Resources Agency needs to grant permission for drilling.
Drilling and pumping test: A contractor performs drilling and a pumping test. The latter is to identify the appropriate pump to be used.
Groundwater level, type of aquifer, groundwater recharge, groundwater vulnerability.

Vegetation classification for land of Maori communtiy - in development

Published on 20 Apr 2023

Land use Land Cover Data Normalized Difference Vegetation Index (NDVI)Google Earth Engine Hydrography Flood New Zealand

Vegetation classification for land of Maori communtiy - in development

Published on 20 Apr 2023 , by

Padmi Ranasinghe

PhD Student at University of Texas at Arlington

Cadence Kaumoana

Chair, Te Huia & Rangiwherowhero Trust

Flemish Institute for Technological Research-Remote Sensing

National Water and Sanitation Agency of Brazil

United Nations Office for Outer Space Affairs

Addressed challenge(s)

Long view of Ngakoahia Stream and surrounding vegetation

Lacking historic knowledge on vegetation cover and surface water extent / river course

Collaborating actors (stakeholders, professionals, young professionals or Indigenous voices)

Flemish Institute for Technological Research-Remote Sensing

National Water and Sanitation Agency of Brazil

United Nations Office for Outer Space Affairs

Padmi Ranasinghe

PhD Student at University of Texas at Arlington

Cadence Kaumoana

Chair, Te Huia & Rangiwherowhero Trust

Suggested solution

Note: this description is a work in progress developed by the collaborating entities in a workshop. If you would like to contribute reach out to office@space4water.org, or your trusted Space4Water point of contact.

Required Software

Google Earth Engine
Google Earth Engine Apps - Global Forest Change

1. Data collection

To collect historic and high-resolution up-to-date imagery over the area, UNOOSA contacted the Land and Information New Zealand Data Service, which provided both historical aerial imagery and LIDAR data sources.
Historic data for the relevant land patch can be accessed via the Retrolens New Zealand Service.
Up-to-date aerial photos of the area can be accessed here at the New Zealand Data Service. Tile 503 and 603 are the ones of interest.
Relevant Landsat data are available from 1989. For the study area, Landsat 7 data is available from 2 July 1999, and Landsat 4 from 2 February 1989.
Global Forest Change data can be retrieved from Google Earth Engine Apps
HydroSHEDS: The core data products of HydroSHEDS are a series of gridded datasets designed for use in hydro-environmental model development and custom GIS applications. Data layers include the original digital elevation model (DEM) that underpins HydroSHEDS, a hydrologically conditioned version of the DEM, the derived flow direction and flow accumulation grids, as well as land mask and sink grids. These data products form the digital foundation of the derived secondary data products. HydroSHEDS core data products are currently available for HydroSHEDS v1 only, which is mostly based on SRTM elevation data. HydroSHEDS v2, which is derived from TanDEM-X elevation data, is currently under development and is scheduled for release in 2022.
A digital elevation model (DEM) is available at 30m resolution by Copernicus is available at the Terrascope website.

Screenshot of the New Zealand Data Serivce, Waikato Rural areal Photos — Figure 1: Screenshot of the New Zealand Data Service, Waikato Rural areal Photos

Figure 3: Google Earth Engine Apps - Global Forest Change with an overlay of the hydrograph developed in the solution linked below, as well as the boundary of the Maori communtiy in the Ngutunui region, New Zealand

Changes in tree cover - Google Earth Engine Apps - Global Forest Change — Figure 4: Changes in tree cover derived from Google Earth Engine Apps - Global Forest Change

NDVI Analysis on the lands of the Maori community and the surrounding area — Figure 5: NDVI Analysis of the area

2. Mapping the historical land use and land cover surrounding the river (in progress)

Using Google Earth Engine Apps - Global Forest Change data it is possible to identify recent deforestation (2016) upstream and near the Ngutunui region;
No other change in the land use is observed upstream the Ngutunui region between 1985-1999.
According to the vegetation cover analysis, there have not been many changes over the past 20+ years. It has been observed that the Manori community and the surrounding area have maintained almost the same vegetation cover, however some patches adjacent to the community boundary downstream have caused some distractions.
Limitation- In the case of a small land mass and narrow river, limits many satellite-based analyses.

Other methods - Conducting a community survey

To obtain historical knowledge on the identification of vegetation, tree species, a community survey appears to be the only option available, since the challenge requires data extending back 50 years. While space-based data (aerial photos) are available, the possibility of identifying each species of tree is very limited, because of the canopy layer, understory plant species cannot be seen.
This approach will enable to gather data on dominant plant species, their abundance, tree diameters, and the boundaries between different vegetation.
Data obtained from the community survey provide a valuable historical record of vegetation patterns over the decades and help identify any changes or disruptions.
"i-nature" app- tree species can be identified by taking a simple picture of a leaf. The app then provides a detailed description of the identified tree species, including information about its characteristics and habitat.

Further information on vegetation identification

Using NDVI allows for identifying the type of vegetation but not the specific species. One can see whether the type of vegetation has changed from trees to grassland, but specific plants cannot be seen.

Retrolense provides aerial photographs taken from an aeroplane at which the relevant bands for NDVI calculation (infrared and red) are missing.

We can examine vegetation cover over the last 30+ years using NDVI with Landsat data.

A study called Aerial photography for assessing vegetation change: A Review of applications and the relevance of findings for Australian vegetation history by Fensham and Fairfax published in 2022 in the Australian Journal of Botany and on the CSIRO page is accessible here.

Relevant publications

Rainwater harvesting in semi-arid to arid climate - in development

Published on 03 Nov 2023

Rainwater harvesting Standardized Precipitation Index (SPI)CHIRPS Normalized Difference Vegetation Index (NDVI)Precipitation Precipitation monitoring Kenya

Map with y axis being latitude and x axis being longitude indicatingdecadal precipitation in Kenya

Rainwater harvesting in semi-arid to arid climate - in development

Published on 03 Nov 2023 , by

Lilian Nguracha Balanga

Founder of Women .conserve at Samburu women

Isabel Zetina

Student

María José Molina-Montero

Geographer at FAB-LAB at Inter-American Institute for Cooperation on Agriculture

Hannah Ritchie

PhD Researcher at Cranfield University

Kenya Space Agency

Inter-American Institute for Cooperation on Agriculture

Addressed challenge(s)

Samburu tribe lacks access to safe drinking water - Dry spells due to water scarcity

Collaborating actors (stakeholders, professionals, young professionals or Indigenous voices)

Kenya Space Agency

Inter-American Institute for Cooperation on Agriculture

Lilian Nguracha Balanga

Founder of Women .conserve at Samburu women

Isabel Zetina

Student

María José Molina-Montero

Geographer at FAB-LAB at Inter-American Institute for Cooperation on Agriculture

Hannah Ritchie

PhD Researcher at Cranfield University

Suggested solution

Why is the approach suggested

Not as time-consuming as a borehole drilling
Cheaper
January is a very dry month in Kenya: time to build reserves
In July, it should be ready for the harvesting

Requirements

Standardized Precipitation Index (SPI)
Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS)
Normalized Difference Vegetation Index (NDVI)

Outline of the Solution

Map available rainfall with CHIRPS with Kenya Space Agency data
Determine if enough water can be stored during the rainy season to last the dry season
Combine with meteorological data (SPI values)
NDVI to get stationality of the water cycle

Figure 1: Decadal Precipitation in Kenya

Decadal rainfall data — Figure 2: Dekadal rainfall in mm from July 2020 to July 2023

Relevant publications

Surface water extent river course - in development

Published on 30 Nov 2023

Land use Land Cover Data Normalized Difference Vegetation Index (NDVI)Digital Elevation Model (DEM)Geographic Information System (GIS)Hydrography New Zealand

HAND of the investigated region showing flooded araeas and drainage lines

Surface water extent river course - in development

Published on 30 Nov 2023 , by

Padmi Ranasinghe

PhD Student at University of Texas at Arlington

Cadence Kaumoana

Chair, Te Huia & Rangiwherowhero Trust

National Water and Sanitation Agency of Brazil

University of Natural Resources and Life Sciences Vienna

Addressed challenge(s)

Lacking historic knowledge on vegetation cover and surface water extent / river course

Collaborating actors (stakeholders, professionals, young professionals or Indigenous voices)

National Water and Sanitation Agency of Brazil

University of Natural Resources and Life Sciences Vienna

Padmi Ranasinghe

PhD Student at University of Texas at Arlington

Cadence Kaumoana

Chair, Te Huia & Rangiwherowhero Trust

Suggested solution

The solution approach begins with identifying the region's main rivers and understanding their hydrology using mapping and geoprocessing tools. After understanding the hydrography of the area and mapping the surface water extent river course through the building a hydrographic dataset, multiple image sources are used to map the historical land use and land cover surrounding the river.

1. Resources needed

Software

QGIS https://www.qgis.org/en/site
TerraHidro 5 - Console applications https://www.dpi.inpe.br/terrahidro/doku.php
PostgreSQL https://www.postgresql.org
PostGIS Spatial Database System https://postgis.net/
PgHydro extension for PostgreSQL/PostGIS http://pghydro.org/
PgHydro Plugin for QGIS https://plugins.qgis.org/plugins/PghydroTools/

Data

Forest And Buildings removed Copernicus DEM

Publications

see reference in the bibliography below.

2. Steps to the solution & status

Overivew

Plot the Region of Interest (completed)
Identify the region's main rivers and understand their hydrology (completed);
Identify the region's potential flood areas using H.A.N.D.;
Build a hydrography dataset (completed);
Identify multiple image sources for land cover analysis (completed);
Map the historical land use and land cover surrounding the river (in progress);

Step-by-step

1. Plot the Region of Interest (completed)

Download and install QGIS to plot the KML files of the region of interest

Figure 1: Example KML plot of the strip of land of the Maori communtiy who submitted the challenge

2. Identify the region's main rivers and understand their hydrology (completed)

Download the FABDEM data for the Region of Interest.
FABDEM (Forest And Buildings removed Copernicus DEM) is a global elevation map that removes building and tree height biases from the Copernicus GLO 30 Digital Elevation Model (DEM) (https://data.bris.ac.uk/data/dataset/25wfy0f9ukoge2gs7a5mqpq2j7).

Figure 2: A FEABDEM Digital Elevation Model of the Ngutunui region, New Zealand.
Download and Install TerraHidro 5 - Console applications (https://www.dpi.inpe.br/terrahidro/doku.php) to extract the hydrograph products derived from the FABDEM to understand the hydrography setup of the area (Flow direction, flow accumulation and drainage lines and areas, H.A.N.D.).

Figure 3: Flow direction in the Ngutunui region, New Zealand
Figure 4: Flow accumultation in the Ngutunui region, New Zealand

Figure 5: Sintetic draingage lines and areas Ngutunui region, New Zealand

3. Identify the region's potential flood areas using H.A.N.D.

Building on Nobre et. al (2011) in which the HAND terrain model that "normalizes topography according to the local relative heights found along the drainage network, and in this way, presents the topology of the relative soil gravitational potentials, or local draining potentials" is introduced by the authors.

Height Above the Neaerest Drainage (HAND)in the Ngutunui reiong, — Figure 6: Height Above the Neaerest Drainage (HAND) in the Ngutunui region showng the areas for potential flooding in darker blue. In the current map this is in the bottom right quarter of the image.

4. Build a hydrography dataset (completed)

Download and instal PostgreSQL/PostGIS Spatial Database System (https://www.postgresql.org/) (https://postgis.net/), PgHydro extension for PostgreSQL/PostGIS (http://pghydro.org/) and PgHydro Plugin for QGIS;(https://plugins.qgis.org/plugins/PghydroTools/).
Build the Hydrograph Dataset;(https://www.youtube.com/channel/UCgkCUQ-i72bBY41a1bhVWyw) using the Drainage Lines and Drainage Areas extracted from FABDEM;
Information like drainage area, upstream area, drainage line length and distance to sea information are now available.

Figure 7: Hydrography dataset of the Ngutunui region in New Zealand

5. Identify multiple image sources for landing cover analysis (completed);

To collect historic and high-resolution up-to-date imagery over the area, UNOOSA contacted the Land and Information New Zealand Data Service, which provided both historical aerial imagery and LIDAR data sources.
Historic data for the relevant land patch can be accessed via the Retrolens New Zealand Service (https://retrolens.co.nz/Map/#/1784971.9859981549/5783474.532151884/1786387.2653498782/5784857.564632303/2193/12).
Up-to-date aerial photos of the area can be accessed here at the New Zealand Data Service. Tile 503 and 603 are the ones of interest (https://data.linz.govt.nz/layer/112048-waikato-03m-rural-aerial-photos-index-tiles-2021-2023/history/).
Relevant Landsat data are available from 1989. For the study area, Landsat 7 data is available from 2 July 1999, and Landsat 4 from 2 February 1989;
Google Earth Engine Apps - Global Forest Change (https://google.earthengine.app/view/forest-change)

6. Map the historical land use and land cover surrounding the river (in progress);

Relevant publications

Normalized Difference Vegetation Index (NDVI)

Related Content

Article

Using space-based technologies to predict mosquito-borne disease outbreaks

Interview with Sarhan Zerouali

Interview with Sarhan Zerouali

Launch of Zimbabwe's first Satellite ZIMSAT - 1

Capacity Building and Training Material

Digital Earth Africa: Agriculture and Food Security

Digital Earth Africa learning platform

Space-based Solution

Water suitability map (Samburu County, Kenya) - in development

Water suitability map (Samburu County, Kenya) - in development

Lilian Nguracha Balanga

Claire Muhungi

Isabel Zetina

Samburu tribe lacks access to safe drinking water - Dry spells due to water scarcity

Lilian Nguracha Balanga

Claire Muhungi

Isabel Zetina

Background information on the geology of Kenya

Resources used for addressing the challenge

Software

Data sources

Publications used for methodology and background research

Steps outlining the solution

Location of water sources

Groundwater resources

Next steps to be taken with external actors

Other solutions based on space technology and geophysics

Electromagnetic and seismic solutions

Vegetation classification for land of Maori communtiy - in development

Vegetation classification for land of Maori communtiy - in development

Padmi Ranasinghe

Cadence Kaumoana

Lacking historic knowledge on vegetation cover and surface water extent / river course

Padmi Ranasinghe

Cadence Kaumoana

Required Software

1. Data collection

2. Mapping the historical land use and land cover surrounding the river (in progress)

Other methods - Conducting a community survey

Further information on vegetation identification

Rainwater harvesting in semi-arid to arid climate - in development

Rainwater harvesting in semi-arid to arid climate - in development

Lilian Nguracha Balanga

Isabel Zetina

María José Molina-Montero

Hannah Ritchie

Samburu tribe lacks access to safe drinking water - Dry spells due to water scarcity

Lilian Nguracha Balanga

Isabel Zetina

María José Molina-Montero

Hannah Ritchie

Why is the approach suggested

Requirements

Outline of the Solution

Surface water extent river course - in development

Surface water extent river course - in development

Padmi Ranasinghe

Cadence Kaumoana

Lacking historic knowledge on vegetation cover and surface water extent / river course

Padmi Ranasinghe

Cadence Kaumoana

1. Resources needed

Software

Data

Publications

2. Steps to the solution & status

Overivew

Step-by-step

1. Plot the Region of Interest (completed)

2. Identify the region's main rivers and understand their hydrology (completed)

3. Identify the region's potential flood areas using H.A.N.D.

4. Build a hydrography dataset (completed)

5. Identify multiple image sources for landing cover analysis (completed);

6. Map the historical land use and land cover surrounding the river (in progress);