| Source Regions of Yangtse River, Yellow River, Lantsang River refered to the headwaters region of the Yangtse River, Yellow River as well as Lantsang River. In the last years, People are very anxious about the environment of Yangtse River and Yellow River, that is to say, wanton flood disaster of Yangtse River while Yellow River's many sediments and multifarious break make threaten to human again and again. The vigorous situation of ecosystem safty of rivers makes us pay more attention to the flowing water's source—Source Regions of Yangtse River, Yellow River, Lantsang River.Around Source Regions, the natural environment is not only abnormally bad, but also the ecosystem is very weak. One side, once the ecosystem environment suffer break, causing reverse alternation, it will be difficult to make instauration and even can not completely recover. On the other side, as one of the four greatest pasturing area in China, the source region of rivers is not a problem of single eco-environment, what is more, we should realize it is necessary to solve the problem of people's starvation and economic and social development. Meanwhile, It involves water resource allotment of Yangtse River and Yellow river and ecosystem safety and so on. It is a key to settle a series of problem to study the ecosystem evolvement rule of source of rivers and the rule of regional variation.Combining systemic analytical method with basic theories about research on eco-environment evolvement, using historical-literature, terrain, climate, vegation as well as agr-pasture datum, this research summarized the total orderliness of eco-environment evolvement in Source Regions of Yangtse River, Yellow River, Lantsang River on the base of the past research, and discovered its regional variation rule. Main outcomes are as following:Its eco-environment evolvement does not comes from one single factor, but many factors which effect eco-environment in Source Regions of Yangtse River, Yellow River, Lantsang River. Each factor has its own character, connecting, effecting, soaking and fusing reciprocally, and have formed its unique rule together.Due to the difference of geo-environment, external forces which shape the terrain and landforms in source regions, are different strongly in type and intensity.The effects of glacier and wind erosion, wind remove are main factors in the upside source regions of Yangtse River, Yellow River, which showing a flat trend in the course of terrain and landforms. In the Source region of Lantsang River and Yushu county of Tongtianher River basin(one branch of Yangtse River), It is based on the effects of glacier and fluviation while the process of forming terrain and landforms shows a different trend.The exterior effect in the downside of Yellow River's source region is fluviation and wind, what is more, the landform is becoming complex, mountain, valley and hills distributing interleaving. According to the pinnacle frequency and the density of river, we can calculate the figured fragmentation of the terrain and landforms further proving the variation regions rule of the effects above.The range of temperature varies differently among regions and with time. Gonghe's annual average temperature had being risen more by 1.5616℃ during 1990-1999 than from 1959-1968, and the process of ascending in temperature was stable and varied little with uttermost difference 2.883℃;Tongren's average temperature rose by 0.8185℃,and difference 1.266℃ with little change; Yushu' temperature went up by 0.7458℃ with difference 2.642℃; Guoluo' temperature rosed by 0.6632℃ that is least, changing uneasy with difference 2.243℃. As this region is very low in temperature that annual average temperature is below 0℃, the relative change is remarkable upon the abolute change being little.The regional change of rainfall changed indefinitely. Maduo showed the climbing trend during 1959-1975, subsequently reducing 1976-1980 and 1981-1988, and representing descendent tide from 1998 to 1995 while rising evidently during 1995-19...
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