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Earth Observation / Geospatial Tools

Short overview​

General Description​

GIS or geographic information systems are “an integrated system of components” (Maantay et al. 2009). It provides information about the real world that has been abstracted and simplified into a digital database which includes spatial and nonspatial features. In conjunction with the needed software and computer hardware, and “coupled with the expert judgment of the GIS user or analyst”, it produces solutions to spatial problems (Maantay et al. 2009).

Remote sensing (RS) is a process of detecting and monitoring the physical characteristics of an object or area by measuring the electromagnetic energy reflected and emitted radiation at a distance. Typically, this is done from a satellite or aircraft, for instance to track large forest fires from space, or urban growth over years (De Jong and van der Meer 2006, USGS 2024).

GIS and remote sensing can be integrated, including for real-time monitoring and assessments, such as environmental parameters in urban ecosystems (Oppong et al. 2023).

Potential for Climate Change Adaptation​

GIS integrated with RS, by definition, are technologies for collecting, compiling and analysing data at different scales and resolutions. They can be applied on various topics that contribute to increasing the climate resilience of cities. Therefore, these resources have broad potential to support CCA, especially for climate risk assessments, as well as monitoring and evaluation. Examples include land use/land cover mapping and groundwater potential assessments for climate-smart irrigation (Akpoti et al. 2023), or for modelling impacts on food security (Garajeh et al. 2023).

Potential for Disaster Risk Management​

GIS and remote sensing techniques can be effective in reducing the risks of disasters and helps in the identification of hazards zone and causes (Gikunda 2021). GIS and RS have become an important tool in disaster risk management and environmental management, for example to model shoreline evolution for coastal risk management (Cenci et al. 2017) . A GIS consists of integrated computer hardware and software that store, manage, analyse, edit, output, and visualize geographic data. Therefore, any thematic layer can be incorporated into a GIS as long as it contains position data on the Earth's surface. Consequently, the GIS has the same analysis potential for each application in climate hazard. Therefore, the focus of the applications for different climate risks will be on the potential contributions of RS. Finally, it should be noted that any editing, processing or analysis of RS data necessarily requires GIS software.

Application in different Climate Hazards​

Flooding​

During rainy seasons, many places get flooded, and immediate action is needed to rescue the vulnerable group. On-site observation of the affected area may be possible as all the land has water, and therefore an alternative method is required. The remote sensing technique fits best in such a situation; since it is sky-based, it may take an image on the earth and hence initiate rescue missions (Gikunda 2021). The results of remote sensing image processing can be visualized and integrated with other databases within the GIS software, such as topography, drainage, streets, sidewalks, etc.

Sea Level Rise​

Satellite observations dedicated to quantify global sea level rise are invaluable for climate monitoring and climate model data assimilation. By harmonising Earth observation data of the numerous satellite platforms that have orbited our planet since the early 1970s we can detect and monitor global sea level rise and even forecast natural changes. Using Near- and Short-Wave Infrared observations, water can be delineated from land (Wolters 2017). The results of remote sensing image processing can be visualized and integrated with other databases within the GIS software, such as topography, coastline, vegetation, beaches, roads, etc.

Landslide​

An area with a potential landslide hazard usually has some evidence of previous occurrences. An examination of stream traces frequently shows deflections of the bed course due to landslides. Typical features that signify the occurrence of landslides include, chaotic blocks of bedrock whose only source appears to be upslope, crescentic scarps or scars whose horns point downward on a normal-looking slope, abnormal bulges with disturbed vegetation at the base of the slope, large intact beds of competent sedimentary or other layered rock displaced down dip with no obvious tectonic relationship and mudflow tongues stretching outward from the base of an obviously eroded scar of relatively unconsolidated material (OAS 1990). The results of remote sensing image processing can be visualized and integrated with other databases within the GIS software, such as topography, slope, vegetation, land use, soil type, etc.

Water Scarcity / Drought​

The rise in the earth’s temperature may result in drought and other high temperature-related defects. However, sensors may be used to predict the temperature rise. Since they are sky-based, they are able to measure the temperature of the reflected radiation from the earth’s surface; the information obtained may be compared with the previous ones. In case of an increase in temperature, a warning is passed to the vulnerable group, and relevant activities are taken to reverse the temperature rise (Gikunda 2021). The results of remote sensing image processing can be visualized and integrated with other databases within the GIS software, such as vegetation types, land use, weather stations, etc.

Strong Winds / Storms​

Remote sensing, an essential tool in modern meteorology, has considerably increased the accuracy and predictability of weather forecasts. With the use of satellites and advanced instruments, we can now observe and measure various meteorological parameters and, consequently, predict strong winds and the formation of storms, cyclones and hurricanes, paving the way for anticipating measures to evacuate the population in places with a high risk of this type of phenomenon. The results of remote sensing image processing can be visualized and integrated with other databases within the GIS software, such as land use and land cover, weather stations, shelter points, buildings, escape routes, etc.

Forest / Bush Fires​

Forest fire is a type of disaster that may result in a great loss if not controlled. Thus, proper protection needs to be laid down to avoid fire attacks. Remote sensors are used as a warning tool for early warning systems and provide information on the areas affected by the fire. The early warning enables people to have suitable plans to extinguish the fire and thus hindering its spread (Gikunda 2021). The results of remote sensing image processing can be visualized and integrated with other databases within the GIS software, such as land use and land cover, buildings, escape routes, types of vegetation, water bodies, fire departments, hospitals, etc.

Extreme Temperatures​

By monitoring atmospheric conditions, remote sensing contributes significantly to weather forecasting or characterizing the climate based on past data. Satellites can track cloud patterns, wind direction and atmospheric pressure, facilitating accurate forecasts of weather events. This is particularly useful in predicting storms, heavy rain, heat waves, extreme cold and other weather-related disasters. The results of remote sensing image processing can be visualized and integrated with other databases within the GIS software, such as land use and land cover, water bodies, hospitals, weather stations, rivers, shelters, etc

Saltwater Penetration​

There are no satellite images capable of recording any activity underground. However, if saline water intrusion causes changes to the soil surface or vegetation cover, it is possible to study this environmental risk using remote sensing. In other words, orbital data can contribute to mapping salt water penetration through terrestrial targets related to this phenomenon. However, GIS can contribute by storing, visualizing and integrating databases related to this phenomenon, such as coastlines, tidal ranges, river flows, in situ measuring stations, water salinity, etc.

Application in DRM / CCA measures​

Nature-based Solutions​

Climate change influences the vulnerability of urban populations worldwide. To improve their adaptive capacity, the implementation of nature-based solutions (NBS) in urban areas has been identified as an appropriate action, giving urban planning and development an important role towards climate change adaptation/mitigation and risk management and resilience. However, the importance of extensively applying NBS is still underestimated, especially regarding its potential to induce significantly positive environmental and socioeconomic impacts across cities. Concerning environmental impacts, monitoring and evaluation is an important step of NBS management, where remote sensing and GIS can contribute. RS is known for providing valuable disaggregated data to assess the modifications caused by NBS implementation in terms of land cover, whereas the potential of RS to uncover the role of NBS in urban metabolism modifications (e.g., energy, water, and carbon fluxes and balances) remains underexplored. The RS and GIS have shown potential in the monitoring and evaluation of NBS implementation in cities, indicating that satellite observations combined with data from complementary sources may provide an evidence-based approach in terms of NBS adaptive management (Chrysoulakis et al. 2021).

Integrated Coastal Zone Protection​

Coastal zones are often at high risk of disasters like cyclones, tsunamis, and sea-level rise. Remote sensing can monitor these areas for early signs of danger and help plan protective measures. It can also assess the impact of these disasters, guiding recovery efforts (SpitalPost 2023). The results of remote sensing image processing can be visualized and integrated with other databases within the GIS software, such as land use and land cover, hospitals, weather stations, shelters, fire stations, evacuation routes, etc.

Stormwater Management​

Satellite images are used to acquire land use information of the developed urban area. GIS software is used to derive hydrologic parameters from the processed satellite data. The parameters thus derived are incorporated in the GIS spatial database. Storm water management planning requires an accurate assessment of the current land use/land cover. In rapidly growing communities, this assessment must be frequently updated. Remote sensing is a new approach for rapidly documenting watershed characteristics for storm water management planning (Srinivas et al. 2010). The results of remote sensing image processing can be visualized and integrated with other databases within the GIS software, such as land use and land cover, hospitals, weather stations, shelters, fire stations, evacuation routes, drainage, etc.

Waste Management​

The use of RS techniques, such as satellite imagery and aerial photography, has enabled accurate mapping of waste generation and disposal sites, while GIS has enabled spatial analysis for waste collection route optimization, landfill site selection, and waste-to-energy projects. Additionally, GIS and RS have contributed to waste composition analysis, landfill stability assessment, and environmental impact evaluation. Waste management practices have been significantly enhanced through the combination of RS and GIS technologies (Sakshi et al. 2023).

Relevance within the Project Cycle​

Earth observation and geospatial tools can be helpful throughout all phases of project implementation.

Project Preparation:

Earth observation / satellite data can be very valuable to set up and plan a project. It can be particularly useful to define exact project locations, determine baseline indicators, relevant context factors and risks, and support the identification of control groups as needed. Data retrieved can support discussions and project definition with partners and clients. RS is mostly useful for physical data, while GIS allows for merging population and other social with physical data.

Project Implementation:

Data from RS/GIS can support the determination of needed interventions in a given location, and support monitoring throughout the construction/implementation process. GIS can be useful for integrating and visualizing data from different sources.

Verification and Project Progress:

RS can support project monitoring by regularly reviewing progress and impacts of physical interventions. GIS can be useful to visualize and further analyse progress.

Final Project Review:

With the help of RS project outcomes and impacts can be compared against the baseline. Visualization can be done in form of GIS maps that remain with the local team and can be used for future use.

Ex-Post Evaluation:

RS/GIS can help to compare outcomes and impacts on maps, and serve as important data sources for mapping goal achievements.

Technology Requirements​

To exploit the full potential of GIS and/or RS, certain technical, data and knowledge conditions must be met:

  • Infrastructure: The needed physical Infrastructure for RS or GIS includes a) the storage system, usually cloud storage platforms, and b) computer resources, namely workstations with high-performance computing. For RS, additionally the networks of sensors and devices (weather stations, smartphones, drones, orbital sensors, etc.) is needed for data collection. The exact demands depend very much on the monitoring type (e.g. real-time, daily, weekly, etc.),
  • Software: Specialized RS software is needed for processing satellite data, which can be commercial or open source. Similarly, GIS software has excellent commercial and open-source options.
  • Data access: Many space agencies offer open data from orbital sensors at various spatial and spectral resolutions. However, the availability of coverage is low, which can be compensated for by commercial sensors, but this increases the cost of deployment. In addition, effective regulations that facilitate access to spatial data might be required.
  • Expertise: Staff needs to have the expertise, usually this would include a geotechnical specialist (such as a geographer, cartographer, engineer, meteorologist, geologist, oceanographer, physicist, etc), data scientists, and IT support
  • Support: Finally, a complex GIS and/or RS intervention (assessment, monitoring, etc.) would require political will, including commitment for long-term maintenance.

It is however also possible to engage in GIS without having to meet all these requirements, through open source applications (Mobasheri et al. 2020) such as participatory open street mapping (Toma-Danila et al. 2020, Yeboah et al. 2021) or engaging youth in mapping water, energy and food availability in data-scarce vulnerable communities (Monteiro de Carvalho et al. 2022).

Human rights risks: In countries with human rights issues or in conflict settings, project location data containing exact GPS coordinates could be used against the population or vulnerable parts thereof, such as minorities. This information could be misused for targeting them via discriminatory policies, (state) terror attacks, and so on. The funding of a specific infrastructure or location by an international donor could increase such a risk. Careful attention to data protection and data security (below) is required so as not to risk harming individuals or groups.

Intellectual property rights for using the GIS information must be secured, thereby avoiding liability for infringement on such rights, whether intended or not. Such infringements could include failure to control access to geo-data or tools, resulting in the illegal use of the data or tools by others. Users must familiarize themselves with the terms of use of the respective GIS tool.

If commercial services, such as Google Maps and Google Earth, for example, are employed, any use has to comply with their general Terms of Services and their Additional Terms of Services for Maps and/or Satellite Services. Those terms prohibit certain conduct, including copying the content or “mass downloading” content (even content from projects that was mass-uploaded before).

Data Protection: Combining descriptive data with precise location data is the cornerstone of many types of spatial analyses. But when locations are easily linked to identities of individuals, households or farms, there is potential for violating personal privacy. Avoid the inadvertent collection of personal data. Only strictly relevant personal data should be collected and processed in line with the recommendations in the Fact Sheet Earth Observation via Satellites. If initial data minimization is impossible, personal data must be anonymized (e.g., by redaction or pixelation).

Data security requirements can also arise from applicable data protection regulations (local and/or GDPR) or the above-mentioned human rights risks, which stipulate basic security requirements for storing and processing of exact GPS coordinates. Entities may be required under those rules and/or conditions to ensure the ongoing confidentiality, integrity, availability, and resilience of storing and processing systems and services (technical and organizational measures). More information on legal aspects can be found here: RMMV Guidebook Section 2.3

See also Geospatial tools and GIS

Summary Assessment​

Overall Effectiveness​

It is a fact that in the last decade there has been a rapid increase in the availability of geospatial data and portable sensors, as well as improvements in sensor technology and therefore in detection capabilities, especially regarding miniaturization and cost reduction. In addition, spaceborne sensors produce images at typically zero to little cost and can be used for large-scale monitoring of natural disaster or extremes phenomenon. Likewise, GIS has become a go-to tool over the past years, including open-source applications. Thus, there is technology available to guarantee the effective execution of a given RS or GIS project.

The application of public participation GIS tools can further enable public participation and thereby improve urban planning outcomes (Nurminen et al. 2024).

Overall Efficiency​

Efficiency will depend on the level of integration with other technologies (traffic cameras, social networks, smartphones, drones, weather stations, remote sensing, etc.) Each integration with these devices increases the cost of implementation, as well as requiring more specialists on the team. The application of remote sensing with GIS makes it possible to monitor natural phenomena such as extreme temperatures, forest fires, flooding, etc. Therefore, efficiency depends on the size of the study area, level of operability, type of natural event monitored and financial resources.

Key Challenges and Limitations​

GIS requires specialists in geo-technologies, and this can be a limiting factor in hiring people with this profile. Remote sensing data can be affected by atmospheric conditions, such as clouds, haze, and aerosols, which can distort or obscure images. The impact of atmospheric conditions can limit the accuracy and usefulness of remote sensing data. Remote sensing technology is constantly evolving, requiring updates and changes to equipment and software, which can be costly and time-consuming. The accuracy of remote sensing data can be affected by calibration issues, such as the sensor’s drift, which can lead to errors in the data. The calibration issues can limit the reliability and usefulness of remote sensing data in some applications. Remote sensing can be limited by spatial and temporal resolutions, which can affect the level of detail and frequency of data collected, respectively.

Very high-resolution or frequently taken satellite imagery of the same locations may make the identification of individual household patterns possible, thus creating privacy and other human-rights-related risks. For more comprehensive information on human rights-related challenges and limitations, see the Principles for Digital Development, the Global Digital Compact, as well as Mejias and Couldry (2024).

Recommendations to optimize the Use of the Digital Tool​

Before starting a project, it is recommended to understand and agree on the specific project purposes to allow for assessing the need to develop specific GIS algorithms in a programming language (e.g. Python). This will allow for faster data processing and analysis in line with all project phases. The spatial data structure in the GIS environment needs to be defined by the whole team to avoid rework or unnecessary format conversion processes.

With respect to RS, atmospheric conditions can be overcome by radar sensors which, being an active sensor, can emit waves that pass-through clouds and reach the earth's surface, resulting in the mapping of intended targets. See also Earth Observation via Satellites

Finally, in terms of limited spatial and temporal resolutions, land use coverage can be done using airborne remote sensing, such as drones. UAVs offer some independence from atmospheric adversities (cloud cover, for example) and allow mapping with greater spatial resolution. See also Drones / UAV

In order to identify and mitigate technology-related human rights risks within KfW-financed projects, we recommend to use the KfW Human Rights Check for Financial Development Cooperation during project preparation and implementation. See also Geospatial tools and GIS

Project Examples / Use Cases​

  • Blaschke et al. (2011) published an article demonstrating the integration of geospatial technologies (GIS software) to understand urban systems. The authors state that remote sensing technology provides a key data source for mapping such environments but is not sufficient for fully understanding them. In this article we provide a condensed urban perspective of critical geospatial technologies and techniques: (i) remote sensing; (ii) geographic information systems; (iii) object-based image analysis; and (iv) sensor webs and recommend a holistic integration of these technologies within the language of open geospatial consortium (OGC) standards in-order to more fully understand urban systems.
  • Sagl et al. (2015) critically discuss the challenge of integrating contextual information, in particular spatiotemporal contextual information, with human and technical sensor information, which we approach from a geospatial perspective. They start by highlighting the significance of context in general and spatiotemporal context in particular and introduce a smart city model of interactions between humans, the environment, and technology, with context at the common interface. They found many technologies and applications using in situ and mobile technical sensors within the context of smart cities, and surprisingly limited use of remote sensing approaches. This article seeks to improve our understanding of technical and human geo-sensing capabilities, and to demonstrate that the use of such sensors can facilitate the integration of different types of contextual information, thus providing an additional, namely the geo-spatial perspective on the future development of smart cities.

Linkages to other Tool Types​

  • Artificial Intelligence (AI): Earth observation tools make intensive use of AI models and methods. For instance, convolutional neural networks (CNN), a DL model, is extensively used when analysing satellite imagery. Furthermore, earth observation tools can function as data inputs for AI systems, supporting urban analytics processes and data-driven decision making.
  • Data Sources: When only being used for data production, earth observation tools can be integrated into Big Data systems through harmonization with pre-existing information. Due to the nature of earth observation data being space and time-specific, the frequency and coverage of data is key to obtaining more representative and relevant datasets. Moreover, the data can be shared as Open Data, increasing its utility and accessibility.
  • Digital Twins: BIM or Digital Twins, and GIS or Remote Sensing can be merged to visually map the physical infrastructure and the integration of geospatial data, such as land use and topography. See also Building Information Modelling.
  • Communication and Collaboration Tools: As with other technologies, Earth observation tools are supported by Communication channels and tools for dissemination, joint work and decision-making. For example, remote sensing data on phenomena such as heating islands or carbon emissions can be communicated effectively to citizens and stakeholders in real-time. Knowledge on the use of GIS and RS can be obtained through e-learning. See also Collaboration and E-learning tools.
  • Mobile tools: Mobile devices can collect geospatial data and inform geospatial models. The portability of mobile tools enables users to cover remote areas. The integration of data from earth observation tools with that collected from mobile devices allows to formulate maps and understand the spatial distribution of data, especially in relation to the built environment. See also Crowdsourcing Tools.
  • (Remote) Management Information Systems (R/MIS): Spatial data is key for the use of MIS in disaster risk management. It allows for geo-localized visualizations of data, which helps in operation during crisis or mapping vulnerabilities. Remote sensing can also be relevant to provide relevant spatial data to the system. See also Management Maintenance Systems (MMS) and (Remote) Management Information Systems.
  • Internet of Things (IoT): Earth observation tools and the IoT can work as complementary data collection systems. IoT collects granular real-time events, while earth observation tools capture broader-scale data, although less frequently. Furthermore, IoT might be able to support model calibration whenever geospatial models are being trained. See also Sensors / SmartMeters (Internet of Things)

Licence​

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License (CC BY-NC-SA 4.0).

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