## 5 Analysis of Results
### Most Active Geographical Regions  
As might be expected, Asia (China, India and Korea), North America (USA and Canada) and Europe (Poland, Lithuania, Italy, Spain Czech Republic and France) are the continents dominating the top countries of corresponding authors, reflecting the large amount of infrastructure and/or development in these regions, Figure 3. In this Figure each horizontal bar is divided into green and red sections indicating the proportion of papers from the country for which there are co-authors from other countries (red) or the proportion of those in which all co-authors were from the same country (green). Most of the documents were multi-authored, with an average of 2.8 authors per document and only 63 (i.e., 13%) were single authored documents. This is consistent with the MCDA analysis reported in the paper being a single part of a much larger project with many contributors. The national distribution of authors shows quite a variation shown by the colours in Figure 3. For instance, some papers from China, Canada, Poland, Lithuania, Spain, and Iran have multinational mixes of co-authors while the co-authors of papers from some other countries (USA, India, Czech Republic, and Turkey) tend to be from the same country. Some countries, such as Lithuania (population 2.7 Million) and Italy (population 60 Million) have a considerably higher number of contributions when considered as a proportion of their population (e.g., Lithuania 8.9 articles per Million population, and Italy 0.33 articles per Million) when compared to much larger countries, e.g., China (0.04) or India (0.015). In between these extremes is the USA (0.15). Figure 2: MCDA documents related to civil engineering—publication rates (per annum) over time. The list of top 20 keywords, Table 2, contains only two typical multi-criteria methods (analytic hierarchy process (AHP) or its variations and TOPSIS). As might be expected from the search criteria, the keywords list is dominated by words associated with application areas (civil engineering; construction (including construction industry), water resources, sustainable development; environmental impact; climate change; and risk assessment). These are the areas where applications of MCDM are more likely to be reported. They have some key elements in common in that all three involve some element of design and of resource allocation. In addition, these areas have a high degree of complexity with large numbers of components or sub-processes to be managed and thus a very large number of possible configurations requiring some automated procedure to seek optimal solutions. Note that Engineering education is included in the list and this category includes a paper on MCDA education for sustainability [40]. Only four terms that could be considered as decision criteria are listed in the top 25, i.e., sustainable development (24 papers), environment (impact) (12 papers) risk (16 papers) and safety (11 papers). This is not surprising as sustainability, safety and concern for the environment are typically recognized as ethical responsibilities of engineers and incorporated into codes of ethics, e.g., for the ASCE ([[https://www.asce.org/code-of-ethics/](https://www.asce.org/code-of-ethics/)]([https://www.asce.org/code-of-ethics/](https://www.asce.org/code-of-ethics/))) (accessed on 24 March 2021) or for Engineers Ireland ([[https://www.engineeringersireland.ie/Professionals/News-Insights/Resource-centre/Regulations-and-governance/Code-of-ethics](https://www.engineeringersireland.ie/Professionals/News-Insights/Resource-centre/Regulations-and-governance/Code-of-ethics)]([https://www.engineeringersireland.ie/Professionals/News-Insights/Resource-centre/Regulations-and-governance/Code-of-ethics](https://www.engineeringersireland.ie/Professionals/News-Insights/Resource-centre/Regulations-and-governance/Code-of-ethics))) (accessed on 24 March 2021).