Endangered Heritage Sites
For a few years, many global heritage sites have been designated in danger, and some of them are out of danger now while others are still in danger. This project is aimed for visualization of endangered heritage sites in the world according to several features, such as the geographic locations and categories of sites. Based on this visualization, viewers are able to get insights about three topics.
· Relationship between causes of threats and categories of sites
· Trend between endangered sites and time
· Link between currently endangered sites and their geographic locations
This visualization represents the data with two attribute types - quantitative and categorical type - using various visual variables. It is composed of six kinds of idioms - line chart, word cloud, categorical map, Sankey diagram, and (stacked) bar chart - and the appearance of each idiom can be changed by interactions with other idioms. This helps viewers focus on the data needed as well as understand the overall relationships.
|Index||Data||Attribute Type||Visual Variables|
|①||· Counts of endangerments
· Year of sites declared in danger
|②||· Categories of threats||Categorical||· Shape|
|· Counts of threats||Quantitative||· Value
|③ ⑥||· Categories of sites
· Categories of time declared in danger (current or past)
|· Counts of designation||Quantitative||· Length|
· Categories of time declared in danger
|⑤||· Periods for sites to be declared in danger||Quantitative||· Size|
|· Categories of time declared in danger (current or past)||Categorical||· Hue
|⑦||· Categories of time declared in danger (current or past)||Categorical||· Hue
|· Region||· Hue
|· Hectares in endangered sites||Quantitative||· Length|
Relationship between causes of threats and categories of sites
As for threats causes, in general the main reason is Management and Institutional Factors. To be specific, in Natural sites, Other Human Activity is the major factor, and Biological Resource Use/Modification is followed while Management and Institutional Factors is the main cause in Cultural sites, and Buildings And Development is followed. When one of categories is chosen in the stacked bar chart, word cloud shows the different features.
Trend between endangered sites and time
According to the time period of designation, most presently endangered sites, especially in the Natural category, have longer period than previously imperiled places. As for regions, Africa, especially in currently threatened sites, has longer period than others. Latin America and the Caribbean, on the other hand, has shorter period than others. If viewers pick the category of sites from the stacked bar chart or a region from the bar chart, they can compare the period from Sankey diagram.
Regarding times series of the number of endangered sites, the Natural category tends to be constant after 2000 whereas the Cultural category is fluctuating and has strikes in 2003 and 2012. The number of presently threatened sites is also fluctuating whilst that of previously imperiled sites is slightly decreasing after the strike in 1992. Additionally, Arab States, and Asia and the Pacific shows decreasing trend while Africa represents increasing tendency after 2010. If one of the categories in the stacked bar chart or one of regions in the bar chart is selected, the line chart provides time series.
Link between currently endangered sites and their geographic locations
The number of currently endangered sites is more than that of previously threatened sites. The area (hectares) and the number of sites in Africa are the largest in presently endangered regions while in formerly imperiled regions, Latin America and the Caribbean is the largest area and Asia, and Europe and North America has the largest number of sites. The largest areas - presently endangered sites in Africa and formerly imperiled places in Latin America and the Caribbean - include more inland area than others. The number of currently threatened places is higher than that of previously endangered sites in Africa, Arab States, and Latin America and the Caribbean while in Asia and the Pacific, and Europe and North America, the number of presently imperiled places is lower than that of formerly threatened sites.
There are some differences in the features depending on the category of sites. As for Cultural sites, Arab States is the largest area in presently endangered region overwhelmingly whereas the areas of formerly threatened sites in Asia and the Pacific are the largest. In the Natural category, on the other hand, currently endangered sites have the largest area in Africa whereas Latin America and the Caribbean is the largest area in previously imperiled sites. These insights can be derived when viewers select one of the category of sites from the stacked bar chart or choose one of regions from the bar chart.