3.1.1 Change of heritage quantity over time
From the change in the annual increment of world cultural heritage sites over time (Fig. 2), the count has the characteristics of a phased distribution, and previous studies have similar conclusions [1]. In 42 years, approximately 3/4 of the years, world cultural heritage sites' annual increase was between 10 and 30. The number of new cultural heritage sites increased significantly less in 1989 and 2002, and the peak number appeared in 1997 and 2000.
There is an obvious corresponding relationship between the number of new inscription heritage sites and global or regional political, economic or policy events over time. For example, the drastic changes in Eastern Europe in approximately 1988 and the restructuring of the global order corresponded to the low annual increment in 1989. Additionally, the promulgation of the “Keynes Resolution” in 2000 resulted in a significant decrease in the annual increment from 2000 to 2002 and the subsequent microwave dynamic development stage. The "No more than one heritage declaration per year by the Contracting Parties with existing projects" regulation in the Keynes Resolution and the "Up to two World Heritage sites to be declared by the Contracting Parties each year" in the amendment to the Keynes Resolution in 2004 have played important roles.
On the whole (Fig. 2), global political and policy factors have had great and long-term impacts on the annual increment of new heritage sites. When economic factors fluctuate, the impact on the annual increment of heritage is small and short-term.
3.1.2 Spatial-temporal distribution of world cultural heritage at regional and national scales
The World Heritage list is divided into five regions: Asia and the Pacific, Europe and North America, Africa, Latin America and the Caribbean, and Arab regions. Among them, the Arab region is listed separately. Europe and North America are merged, and Latin America and the Caribbean are merged into one region, reflecting the consistency of regional cultural identity, political alliances, and economic development.
According to the distribution of the annual increment of WC in different regions (Fig. 3), there are 18 and 10 years without any increases in the African and the Arab regions, respectively. There were increases concentrated in 1992–2001 in Europe and North America, Latin America and the Caribbean, and the Asia and the Pacific region. Newly added amounts are concentrated after 2003, accounting for half of the total number of regions. The imbalance of the number of newly added heritage sites among the above regions over time reflects the differences in the degree of attention given by the different regions to world cultural heritage and the regional influence of World Heritage policies.
From the impact coefficient of the annual increment of world cultural heritage sites in each region from 1978 to 2019 and the total number of new world cultural heritage sites in that year (Fig. 4), Europe and North America are the dominant regions with the highest heritage representation degree (R2 is 0.824). The calculation results of other regions' influence coefficients are not significant (R2 is less than 0.5), indicating that the heritage representation degree of other regions is relatively weak.
To further analyse the impact of heritage policy on the annual number of new heritage sites, the period model of heritage policy impact is selected to compare and analyse the changes in the influence of different regions before and after the implementation of heritage policy to reflect the effect of heritage policy implementation on each region. Concerning the regional impact of the Global Strategy (proposed in 1994) and the Keynes Resolution (promulgated in 2000), three periods are selected to calculate the regional impact coefficients: 1978–1994 (17 years), 1978–2000 (23 years) and 1978–2019 (42 years).
From the impact coefficient of each region in the three periods mentioned above, the implementation of the Global Strategy in 1994 did not change world cultural heritage status in Europe and North America, which was the global heritage issue of most concern. After implementing the Global Strategy, the heritage display degree of Asia and the Pacific Region increased slightly, and R2 increased from 0.564 to 0.653. After implementing the Keynes Resolution, Asia and the Pacific region showed a slight decrease in R2 in the Pacific region, decreasing from 0.653 (weakly significant) before the implementation of the Keynes Resolution, to 0.307 (insignificant). The resolution significantly weakened heritage visibility in Asia and the Pacific but had little impact on Europe and North America.
Table 3. The influence coefficient of the world cultural heritage site numbers
in different regions and the world during three periods
|
Africa
|
Arab States
|
Asia and the Pacific
|
Europe and North America
|
Latin America and the Caribbean
|
Period 1(1978–1994)
|
0.025
|
0.237
|
0.564
|
0.707
|
0.336
|
Period 2(1978–2000)
|
0.034
|
0.033
|
0.653
|
0.838
|
0.491
|
Period 3(1978–2019)
|
0.011
|
0.065
|
0.307
|
0.824
|
0.397
|
From the perspective of the change in heritage before and after the implementation of the policy (Table 3), the implementation of the two policies is more favourable for Europe and North America and Latin America and the Caribbean in terms of world cultural heritage declarations, but negatively impacts Asia and the Pacific.
According to the statistics of the frequency and peak value of the number of newly added heritage sites in each country from 1978 to 2019 (42 years), it can be seen that the number of newly added heritage sites in the top 10 of the same year appears. The countries with high superiority in world cultural heritage declarations can be divided into three tiers: Germany ranked first with 28 instances; the second tier was France, Italy, Spain, India and China; and the third tier was Japan, Iran, Brazil and Mexico. The countries in most of Africa, the Arabian Peninsula, Central Asia, Southeast Asia, Eastern Europe and Northern Europe had low superiority in world cultural heritage declarations.
From the perspective of the peak number of world cultural heritage sites added over the years (Fig. 5), the countries with high peak values are concentrated in Europe and the Mediterranean. There are also large differences in the superiority of world cultural heritage declarations among countries in the region. For example, the highest peak value was in Italy, which had 10, while many Eastern European countries had only one peak value.