Asian Context

It is estimated that some 40 million sq.km. or 27 per cent of the total land area of the world lies above 1,000 masl. The break down of this elevated land surface is as follows: 24 million sq. km. at 1,000 - 2,000 m, 10 million sq. km. at 2,000 - 3,000 m, and six million sq. km. above 3,000m (Louis 1975). Another earlier source put the total area worldwide, defined as `mountain type', to be 50 million sq. km. (Trewartha et al. 1968). Accordingly, such areas account for 35 per cent of the world's total area. The mountain types defined by elevation range were hills (0-300m), low mountains (300 - 900m), and high mountains (above 900m). Eurasia dominates all other continents in terms of low and high mountains (Table 1). Arab geographers in the Middle Ages, in their imaginative way, regarded the Eurasian landmass as a desirable woman clothed in nothing but a long chain girdle about her ample waist. This girdle was of mountains studded with snowy peaks that stretched from the Pyrenees through the Alps, Balkans, Caucasus, and Elburz to the limits of the known world in the Hindu Kush and Himalayas. Most of the mountain areas of Eurasia are concentrated in the Asian sector.

Asia is unique among the continents in that it is mountain-hearted (Ginsberg 1958, p3). The vast complex of mountains and plateaus around Tibet forms the core of the Asian mountain system. This heartland is bounded on the south by the Himalayan arc, on the west by the Pamir, on the north by the Tien Shan, and on the east by a complex of ranges. The mountain core acts as the hub of a colossal wheel, the spokes of which are provided by some of the greatest rivers in the world. The ranges and plateaus of mainland Asia, extending west/south-west and east/north-east for nearly 8,000 kilometres, constitute the largest mass of highlands in the world. According to a list of 121 peaks exceeding 6,100m prepared by the National Geographic Society, those ranked from the first to 66th place and above 7,000m are all from Asia. Furthermore, the Nepal section of the Central Himalayan Range alone has over 1,300 peaks and pinnacles that exceed 6,000m in elevation (Gurung and Shrestha 1994). The Pamir knot acts as the pivotal node from whence the main ranges diverge into three directions: south-east, west, and north-east. In west and central Asia, the ranges merge into vast desert expanses. To the south and east, they descend to high relief hills and also extend as the spine of island chains. The prominent ranges included in this overview are listed by region (Annexes A-F). Various aspects of the Asian mountains are described according to the following six regions: viz., 1.)South Asia, 2) West Asia, 3) Central Asia, 4.) North-East Asia, 5) South-East Asia, and 6) Australasia.

A region or sub-region, of whatever hierarchy, assumes internal cohesion and external boundary. Therefore, in demaracating Asian mountains into regions, an explanation of the methodology is needed. The main bases for demarcation were conventionally recognised geographic ones such as (1) South Asia, south of the Pamir, (2) West Asia, beyond Afghanistan, (5) South-East Asia, and (6) Australasia. More problematic was recognition of the boundary between (3) Central Asia and (4) North-East Asia. An arbitrary approach was taken in this delimitation: political in the north and physiographic in the south. Thus, Mongolia was taken as the eastern extension of Central Asia in the north and ranges contiguous to the Tibetan plateau were considered to be Central Asian in the south. The other ranges of China were included in North-East Asia.

The recognition of discrete ranges within each region is based mainly on their contiguity internally and the existence of major rivers and land depressions externally. However, two exceptions should be considered. These are the sub-division of the Himalayas of South Asia into sections and the island individuality in South-East Asia. In the case of the former, recognition has been given to the conventional three sections of arid west, transitional central, and humid east (Table 2). In the latter case, each island chain is given a separate identity with the surrounding sea as their boundary. Regional treatment is in a clock-wise sweep, commencing from South Asia and ending with an outward loop towards Australasia. The sequence of regional description, therefore, is as follows: South Asia, West Asia, Central Asia, North-East Asia, South-East Asia, and Australasia.