关键词: “三江源”地区, 生态问题, 对策及建议

Abstract: The Headstreams of the Three Rivers,the Yellow River,Changjiang River and Lan-cangjiang River,are of great ecological significance to Qinghai-Tibet Plateau.They range from31°39'N to36°16'N and89°24'E to102°23'E with elevation s of the headstream regions varying from3450m to6621m.In Qinghai province the headstreams cover an area of0.318million km 2 ,accounting for50.3%of the province total.The largest marshland of China is located here,and these regions are regarded as"China's water tower".There inhabit large quantities of rare wild animals,such as yaks,Tibetan wild donkeys,Tibetan antelopes,and dark-necked cranes etc.On the whole,some 271kinds of wild animals and about 1000species of plants are identi-fied in the headstream regions.In recent two decades,due to global climate change and human activities,the ecosystems of these regions are degrading.The acreage of water and soil erosion reaches34462km 2 ;the areas suffering from rat-caused damages accumulated to6.58million ha,accounting for11%of the whole region;and the desertified area increases to2.53million ha.Some of the glaciers here are shrinking,and the shrinking rate of the glaciers where the Dangqu river originates reach es be-tween8.25m/a and9.9m/a.The lakes here are diminishing with quick water level descending,and the descending level in Zhaling Lake and Eling Lake are over2m.The critical problems urge the authors to seek approaches of ecological alleviation in the three rivers' headstream regions.Thus,the following countermeasures are put forward:to work out scientific plan as quickly as possible to establish natural reserves in the headstream regions;to properly settle the immigrants from responsive regions;to establish scientific research bases for developing and spreading new-high applicable technologies to speed up the environmental re-construction;to lead to restoration of grassland eco-system by eliminating rat-caused damages;and to set up ecological compensative mechanism among areas of upper,middle and lower reaches of a watershed to promote environmental reconstruction.The ultimate intention of this paper is to contribute to ensure the social development towards an ecological sustainability in the three drainage basins.

Key words: headstreams of the Three Rivers, ecological crisis, countermeasures