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Perspectives on EO for the SDGs
  The Role of Geospatial Information and Earth Observations in the SDGs: A Policy Perspective  
  Earth Observation for Ecosystem Accounting  
  Forging Close Collaboration Between EO Scientists and Official Statisticians – An Australian Case Study  
  Monitoring the 2030 Agenda in Mexico: Institutional Coordination and the Integration of Information  
  Perspectives from a Custodian Agency for Agriculture, Forestry and Fisheries  
  The ‘Urban’ SDG and the Role for Satellite Earth Observations  
  EO4SDG: Earth Observations in Service of the 2030 Agenda for Sustainable Development  
  Pan-European Space Data Providers and Industry Working in Support of the SDGs  
  The Rise of Data Philanthropy and Open Data in Support of the 2030 Agenda  
  Building a Demand-Driven Approach to the Data Revolution for Sustainable Development  
  Environmental Information from Satellites in Support of Development Aid  
spacer Earth Observation for Ecosystem Accounting

Ecosystem accounting is a new and emerging area of statistics that can inform the 2030 Agenda for Sustainable Development. The System of Environmental-Economic Accounting (SEEA) Central Framework, adopted as a statistical standard in 2012, measures how the economy uses the environment as input in the production process through the extraction of natural resources, how it impacts the environment through the release of emissions to water and air as well as solid waste. The SEEA Central Framework is complemented by the SEEA Experimental Ecosystem Accounting (SEEA EEA), which measures the functioning of ecosystems in relation to human activities.

This article provides examples of how the integration of EO data with statistical data in an internationally agreed statistical framework underpinned by an agreed system of classifications for land cover, land use and ecosystem types ensures coherent, consistent and comparable measures. This in turn has an impact on the derived indicators, including the SDG Indicators, which are accurate and comparable over time and across countries. In particular, it provides examples on compiling ecosystem extent, carbon and water accounts.


2.1 Introduction

The SEEA EEA, ecosystem accounting in short, presents the basic accounting framework to measure the extent and condition of ecosystems and the flows of ecosystem services to the economy and, broadly, to humanity. Together, the SEEA Central Framework and the SEEA EEA provide a coherent and integrated approach to the assessment of the economy-environment nexus, thus providing an important framework in support of sustainable development analysis and policies.

Ecosystem accounting is unique in the spatial or geospatial reference it provides to the accounts. It has been made possible by the ease of access and use and increased accuracy of a range of spatially explicit data sources, such as EO data, in the form of satellite and aerial images, among others. The EO data combined with the accounting structure facilitates the integration of environmental information with economic statistics to depict the contributions of the ecosystems and the impacts of economic activities on the ecosystems. They give an indication of the extent and condition of – and services provided by – ecosystems, contributing to the decision-making on ecosystem management, including the allocation of resources to preserve or improve their status. Ecosystem accounting can be undertaken at any scale – country, region, province, river basin, protected area and so on. However, the link with the economic accounts can only be done at scales where economic information is available.

2.2 Ecosystem Extent Accounts

Ecosystem extent accounts organise information on the extent or area of the different types of ecosystems that exist within a country or region. Land cover data, classified according to the SEEA Central Framework standard classification and complemented by additional characteristics such as land use, elevation and ecosystem services provided, helps to further classify the land according to ecosystem types. Land cover accounts are directly linked to several SDG Indicators, including Indicator 15.3.1 on land degradation, Indicator 6.6.1. on freshwater ecosystems, or Indicators 11.3 and 11.7 on land use. Ecosystem extent accounts supporting these Indicators are usually compiled by using EO data combined with statistical observations and ground truthing. Examples in Brazil and Nepal of land cover and use accounts are provided below. Additional examples are provided by Mexico in their article in this Handbook. The ecosystem extent account in Mexico is used in support of providing information for the monitoring of SDG Indicators 15.1.1 and 15.3.1.

Example 1: Land-cover and land-use changes in Brazil

The Brazilian Institute of Geography and Statistics (IBGE) has carried out a project using EO techniques to detect changes in land-cover and land-use. These changes are represented through the change in proportion of cover and use classes measured in time and space. Tracking these changes over time provides an analysis of the changes in the extent of ecosystem assets, changes in landscapes and the impact of such changes on the provision of ecosystem services.

The work involved the acquisition, conversion, enhancement, segmentation and classification of MODIS (Moderate Resolution Imaging Spectrodiameter) images with 250m resolution, from the TERRA and AQUA satellites. Subsequently, matrix editing to correct possible imperfections required the use of other sources of information, such as thematic maps and statistical data, as well as input of data on deforested areas and data from the agricultural census.

This work produced three land-cover and land-use maps for the three periods analysed (2000–2010, 2010–2012 and 2012–2014) and class changes by overlying these maps. The class changes allow tracking and analysing changes of overall classes or transition between specific classes. Figure 2 shows the land-cover/land-use map of the State of Rondonia in Brazil for 2010 and 2014.





Figure 2: Land-cover/land-use in the State of Rondonia, Brazil.
Source: Brazilian Institute of Geography and Statistics (IBGE), 2017


Example 2: Land cover in Nepal

Nepal is landlocked and challenged by many environmental concerns that are directly related to its topography, including deforestation, natural disasters, climate change and urbanisation. With the technical assistance of the Economic and Social Commission for Asia and the Pacific (UNESCAP), the Central Bureau of Statistics (CBS) has developed land and forest accounts based on the SEEA for 1990, 2000 and 2010 in order to understand and manage the environmental impacts. The existing land-cover maps were produced by the International Centre for Integrated Mountain Development (ICIMOD) by locally correcting Landsat satellite imagery from 1990, 2000 and 2010. Efforts are currently under way to address some discrepancies that were identified between the maps and the official total land area of the country. These discrepancies could be caused by the EO maps being collected during different times of the year, thus making the representation of the regression of glaciers unreliable, and the use of different concepts and classifications when the various maps were produced. An interdepartmental working group was established with the objective of adopting common concepts and classifications on land-cover/land-use and developing an agreed single map at the country level.

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Figure 3: Land-cover map of Nepal.
Source: Uddin et al. 2014


2.3 Water accounts

The SEEA EEA includes thematic accounts for water, carbon and biodiversity. Thematic accounts are compiled across different ecosystem types to support assessments for specific management purposes including land management and planning, and water resource management.

Ecosystem services related directly to water include the provisioning of water, in terms of volume of water used for different purposes (e.g., drinking, irrigation, cooling, hydropower generation, etc.); water regulation (e.g., filtering pollutants or regulating water flow); and cultural services such as for recreation (e.g., swimming, boating). This information is of crucial importance for the monitoring of SDG 6 on water availability and sustainable management of water. The example in the Netherlands shows how water accounts can support the monitoring of Target 6.4.

Example 3: Monitoring of Target 6.4 in the Netherlands

Indicators in relation to SDG Target 6.4 focus on water use efficiency (6.4.1) and water scarcity (6.4.2). Data for these two Indicators can be obtained from different sources, among them statistical sources, model-based data and EO data. In particular, the estimation of actual evapotranspiration (AET) is quite important for the measurement of water-related SDG Indicators, including measuring water use in agriculture and the availability of water. AET is defined as the sum of evaporation and plant transpiration from Earth’s surface to the atmosphere and it can be calculated using algorithms that use EO data as a source.

In order to assess AET, a range of remote-sensing data is freely available (e.g., MODIS, Landsat, Proba-V and Sentinel-2), and several AET databases have been developed, such as MOD16 (NASA) and the Land Surface Analysis Satellite Applications Facility (LSA SAF). Statistics Netherlands has partnered with eLEAF, an EO analysis company, to produce an AET map for the Netherlands in order to obtain spatial and temporal resolution that is superior to data sources in the public domain. The resulting map is shown in Figure 4.




Figure 4: Actual evapotranspiration (in mm) for the Netherlands at a 250m resolution.
Source: Graveland et al., 2016


2.4 Carbon accounts

In the SEEA EEA, the scope of carbon accounting encompasses measurement of carbon stocks and flows for all parts of the carbon cycle and carbon pools. The measurement of stocks and flows of carbon can support discussion of many policy-relevant issues, including the analysis of greenhouse gas emissions, use of energy and extent of deforestation. As such, carbon accounting supports the measurement of several of the SDG Indicators, including Indicator 15.3.1 that specifies carbon stocks as one of the aspects of degradation of land. Carbon accounts can be compiled using existing land-cover maps, but also directly using EO data by using the Normalized Difference Vegetation Index (NDVI) or other techniques.

Recent methodological developments in remote-sensing techniques allow measurement of carbon stocks as well as changes in carbon stocks directly with adequate accuracy (see Figure 5). Such approaches may be important when alternative data sources and ground truthing is sparse.




Figure 5: Biomass and carbon monitoring using EO data.
Source: SarVision, 2012


2.5 Conclusion

The examples above demonstrate that EO data are an important source in the construction of ecosystem accounting. The availability of EO data and its alignment with the requirements of environmental-economic accounting would further improve the access and use of EO data and would also improve the quality of ecosystem accounts. The growing partnership among the various communities of statisticians, Earth observation and geospatial specialists, scientists and economists will further improve the development of standards and in turn the usability, quality and policy relevance of data.

There is also scope for joint development of tools and standards, such as classifications and open source software tools to assist countries with the capture, processing and integration of data. The use of EO data for land-cover accounts would benefit from common land classifications agreed by various communities. In this context, the statistical community has on its research agenda the finalisation of the proposed preliminary classification of land-cover as well as the development of a system of classifications including land-cover, ecosystem types and ecosystem services, taking into consideration existing approaches and availability of source data, especially that from EO. This work is being undertaken as part of the international revision process of the SEEA EEA that has been recently launched with the objective of adopting international agreed concepts, classifications and methodologies for ecosystem accounting. The involvement of the EO community in this work is not only welcome but needed.
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spacer spacer System of Environmental-Economic Accounting Experimental Ecosystem Accounting (SEEA EEA).

The main goal of SEEA is to establish the link between the environment and the economy in a consistent, comparable and coherent manner. The SEEA EEA starts from the perspective of ecosystems and links ecosystems to economic and other human activity. In particular, it brings the spatial dimension into environmental accounting and the need to link statistical accounts to geospatial information and Earth observation.

The SEEA EEA is underpinned by a set of accounts and tools, as shown below. The main accounts of extent, condition, and ecosystem services are complemented by thematic accounts of land, water, carbon and biodiversity, altogether supported by tools, such as classifications, spatial units, scaling and biophysical modelling.

SEEA EEA Accounts, Tools and Linkages



Figure 1 from: ‘Technical Recommendations in support of the System of Environmental-Economic Accounting 2012 – Experimental Ecosystem Accounting’. The white cover publication was published in December 2017. (https://seea.un.org/sites/seea.un.org/files/technical_
recommendations_in_support_of_the_seea_eea_final_white_cover.pdf
)

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spacer spacer Article Contributors

Alessandra Alfieri, Bram Edens and Marko Javorsek (UN Statistics Division)

The paper reflects the views of the authors and not those of the United Nations.

Further Information

https://seea.un.org/ecosystem-accounting

Brazil example: Brazilian Institute of Geography and Statistics (IBGE). Land-cover and land-use changes in Brazil, 2000-2010-2012. Rio de Janeiro, 2015. Prepared in cooperation with Wadih Neto and Fernando Dias from IBGE.

Nepal example: Uddin, K., et al., 2014. Development of 2010 national land cover database for the Nepal, Journal of Environmental Management, Volume 148, 15 January 2015, Pages 82-90. http://dx.doi.org/10.1016/j.jenvman.2014.07.047 Prepared by Michael Bordt, ESCAP.

Graveland, Cor, and others. Sustainable Development Goals for water - SDG 6.4 - Three step approach for monitoring. Statistics Netherlands: Memo, 2016. Available from: http://www.cbs.nl/-/media/_pdf/2016/51/sdgs-6-4-monitoring%20nl-ladder%20approach.pdf

D. H. Hoekman, M. A. M. Vissers and N. Wielaard, “PALSAR Wide-Area Mapping of Borneo: Methodology and Map Validation,” in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol. 3, no. 4, pp. 605-617, Dec. 2010. http://library.wur.nl/WebQuery/wurpubs/407385

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