JO-ERH-KAI MARSH

Pinyin Zoig Zhaoze, large marsh lying mostly in north-central Szechwan sheng (province), China. It lies on the Tsinghai-Tibet plateau and extends across the border of Szechwan into southeastern Tsinghai province. It occupies 1,000 square miles (2,600 square km) of the southwestern part of the Tibetan Highlands at an elevation of 11,800 feet (3,600 m) above sea level. The marsh, formed by abundant rain and snow, lies in a region of restricted drainage with a long frost period (fewer than 20 frost-free days annually). It is bordered on the northeast by the Min Mountains and on the west by the A-ni-ma-ch'ing Mountains; the Huang Ho (river) runs through the western part of the marsh from south to north. Beneath its uneven surface lies a layer of peat generally 710 feet (23 m) thick but increasing to as much as 2023 feet (67 m) deep in some places. Crossed by the Chinese Communists during the Long March (193435), the marsh was then a wilderness area. In the 1970s ditches were dug, parts of the marsh drained, and cattle, sheep, and horses pastured on the reclaimed grasslands.