Disappointing NSDI National Clearinghouse Survey

Many countries are working on a National Spatial Data Infrastructure (NSDI) to create an efficient environment for accessing spatial data. One of the main components is the national clearinghouse. The authors conducted a web survey to trace current developments, status, suitability and spatial distribution of clearinghouse implementation around the world.

A spatial data clearinghouse may be defined as an electronic facility for searching, viewing, transferring, ordering, advertising and/or disseminating spatial data from numerous sources via the internet and, when appropriate, providing complementary services. A clearinghouse usually consists of a number of servers containing information (metadata) about available digital data.

Web Survey
To assess the status of national spatial data clearinghouses around the world a web survey was carried out in April 2005 as part of a longitudinal web survey conducted systematically and periodically since 2000. The survey consists of two steps: firstly, inventory of all existing national clearinghouses on the internet by extensive browsing, reading related literature and contacting experts and webmasters. Secondly, there is categorisation of each of the clearinghouses by measuring characteristics selected on the basis of the following criteria: ease of measurement, objective character and clear presentation of history, content, use and management. The selected characteristics are summarised in the second column of Table 1. The reader is referred to the literature listed at the end of this article under ‘Further Reading’ for more detailed treatment of the above characteristics.

Main Results
Since 1994 the number of countries with national clearinghouses has been steadily increasing. To date, 83 countries have an implemented version posted on the Web, 25 countries have projects for implementation and 85 countries have no initiative. The reasons for the latter include lack of appropriate network architecture and specialised data managers. National clearinghouse implementation is an international activity. However, numbers vary considerably between regions. On the continents of Europe and America more than 60% of countries have established a national clearinghouse, whereas in Africa this is less than 20%. The many project initiatives in Africa are promising.
Table 1 also shows the current status of ‘quantitative’ characteristics. Since distribution of some clearinghouse characteristics is highly skewed, the median, which is less sensitive to extremes than the average, provides a better measure. The furthest right-hand column of Table 1 presents distribution of ‘qualitative’ characteristics, showing that current clearinghouses are generally not very well managed and used and are not very rich in content. Diversity among current clearinghouses in use, content, technology and management is high; this may be due to the unique historical, institutional, economic, legal, technical, cultural and environmental setting of each clearinghouse-related area. Downward trends in management, use and content for the period 2000 to 2002 continue in 2005.
In management this results mainly from decreasing numbers of data suppliers and datasets and the frequency of Web updates, and is related to poor management on the part of data providers and, particularly, clearinghouse managers. The decline in use is another concern; this mainly refers to the decreasing number of monthly visitors, suppliers and Web references. With respect to content, both the quality and the quantity of data are diminishing. This proceeds from a decrease in the number of datasets and the non-up-to-date nature of datasets produced. Dissatisfaction on the part of the spatial data community with the functional capability of clearinghouses may be one cause of downward trends. Another may be the piecemeal funding of the majority of clearinghouses, which results in no suitable framework being built to facilitate the management of information assets.

Suitability Index
To arrive at an indication of suitability of national clearinghouses for accessing and sharing spatial data/services, some two hundred MSc students (of thirty differing nationalities) from Wageningen University were asked to determine main criteria and weight their importance. For more detailed treatment of criteria and weighting the reader is referred to the literature listed in ‘Further reading’. According to these criteria the national clearinghouses of USA, Canada, Australia, Germany, Malaysia, Indonesia and Japan provide the most suitable facilities. Remarkable, moreover, is the high degree of diversity in suitability. Comparing current indices with those of December 2002, the suitability of 38 clearinghouses fell, whilst the suitability of 25 clearinghouses increased and four remained unchanged. This confirms the concern expressed earlier, that overall suitability increased slightly as a result of technological improvements whilst management, use and content declined.

Further Reading

• Crompvoets, J. and A. Bregt, 2003, World status of National Spatial Data Clearinghouses. URISA Journal [Special Issue on Public Participation GIS], 15, APA I, 43-50.
  
• Crompvoets, J., A. Rajabifard, A. Bregt, I. Williamson, 2004, Assessing the worldwide developments of national spatial data clearinghouses. International Journal of Geographical Information Science, Taylor & Francis, vol. 18, no. 7, October-november 2004, 665-689.