| The paper emphasizes on analyzing and researching on the eco-geological Environment evolution process and trend of Lijiang in Yunnan, from the point of global systematic science, with guidance of theories and methods of related subjects such as geology, geography, landscape ecology, sociology and so on, with comprehensive utilization of research methods alternated with physical science and social science such as field research, GIS, analysis of mathematical models, comparison of document analysis, etc. It mainly includes the contents as follows:1. From the point of global systematic science and environment geology, it discusses the rise of eco-geology and main research contents, and analyzes the meaning of eco-geological environment. It analyzes the features of Lijiang eco-geological environment system, evolution process and dynamical mechanism of human - earth - life coupling system in aspects of geological structure, climate, water resources, vegetation and land resources, social economic subsystem and so on.2. It illustrates the influence and effect of Qinghai-Tibet Plateau uplift to Lijiang eco-geological environment. It showed on the Lashihu lacustrine sediment records that climate and environment change of Lijiang has experienced for 5 steps: Step I (2000～1480a) was bias to warm-dry climate; Step II(1480～890aBP) was with cold-humid climate ; Step III (890～450aBP) was with warm-dry climate which occurred obvious cold-humid fluctuation; Step IV (450～130aBP) was with cold-humid climate; Step V (since 130aBP) was developed to warm-dry climate which occurred cold-humid fluctuation. Magnetic susceptibility index is rising obviously in general, it reflects that the environmental respond of human activities nearby Lashihai drainage area had been strengthened since 2000a. From the quaternary period, the alternation of Lijiang climate and vegetation showed a combination climate of cold-humid and warm-dry, which represents the regional features of climate evolution of southwest monsoon region. It discusses the forming process of Jinshajiang River and the formation mechanism of First bend of the Yangtze River and Tiger leaping Gorge.3. It emphasizes on discussion of effect of eco-geological environmental evolution in the modern ages of Lijiang under the influence of geology structural moving - climate change -human activities. Domestic pollution of Dayan Town had resulted in deepening pollution of Lijiang Basin underwater and Yanggong River. With increasing of water consumption for industry, living and eco-landscape, the existing water resources of the basin is able to satisfy the recent and medium-term development of Lijiang city, but it has lower guarantee for the long-term development. Changes of warm and dry climates, overpumping groundwater and degeneration of ecological environment of water resources has resulted in the unstable groundwater regime, the broadening amplitude of high-and-low flow of Heilongtan spring group, and the strong dependence of water transferring from Lashihai. The shortage of quality and quantity of the old town scenic water will affect the development of the world heritage. Since the 1950's, glaciers of Mt. Yulong has a significant respond of the global climate changing, which represented the features as increasing of glacier ablation, retreat of ice tongue position, decreasing of glacier area, rising snow-lines etc. Hillside geological disasters (collapses, landslide and mud-rock flows), hazard like special soil and earthquake have become the key factors to restrict the social sustainable development of mountainous region in northwest of Yunnan. The consumption of forest resources in low position of Lijiang has become the main reason of decreasing of forest resources. According to the LUCC research between the year 2001 to 2004 of Lijiang, woodland and unused lands occupies considerable proportion at present in Lijiang, the continuous increasing of woodland and decreasing of unused land are the distinguished changing characteristics. It studies the fracture activities nearby the hydropower development junction of Tiger leaping gorge and forecasts the possibility of inducing earthquakes of 2.3 scales to 4.7 scales with the construction of Tiger leaping gorge dam. With the utilization of influence index of industrial structure on natural environment (IIISNE), it studies the change of industrial structure and the influence of ecological environment between the years 1992 to 2006 of Lijiang district, the model of regional economy development of Lijiang city is sustainable generally since the year 1992.4. With adoption of comparison method of literature review and history, it qualitative analyzes the effects of warm and dry climate changing and worsening influence of human activities to the social economy development of Lijian. Enhancing the eco-geological environment construction of Lijiang is a key issue for the future development of Lijian, and protection of Lijian basin underwater resources and reinforcing the eco-geological environment layout and planning of Lijian are important measures to realize the sustainable development of the world heritage Lijian.5. With utilization of methods as field investigation, literature review, model analysis, comparison of history and so on, it discusses the evolution trend of eco-geological environment of Lijiang in the future 50a. The temperature of Lijiang will be increased by 1.6℃till 2050, human activities becomes the main factor of temperature increasing. The fluctuation of precipitation is obvious, increasing first and decreasing afterwards, it will have a trend of accelerated decreasing after 2030 and it will be decreased by about 10% in 2050. Annual runoff of mountains will be decreased over 4% in 2010, and in 2050 the annual runoff will be decreased by 10% and annual probability of low water will be increased. Lijiang district will experience its booming precipitation period in about 2030, which will be increased by 9% to 18%, and causes that the annual runoff will be increased by about 35% to 40% and the annual probability of abundant water will be increased. The Max. peak discharge will happen in about 2030. The warm-dry climate results that the glacier melt of Mt. Yulong will experience the situation of increasing first and decreasing afterwards in about 2020 to 2050. With adoption of DRASTIC method to evaluate the underwater of Lijiang basin, it shows that the underwater of Lijiang basin has a high vulnerability and it is easy to get polluted of karst water and pore water in margin basin. The deepening of water pollution and shortage of quality and quantity of scenic water affect the safety of water of Lijaing city, and it puts forward that karst water spring in the margin basin, paretic water and artesian water in the gravel layer accumulated in glacio-aqueous of the middle basin can be used as an emergency underwater resources for Lijiang city.Material balance model of glacier changing of Mt. Yulong is made according to the monitoring data of Mt. Yulong climate. When the temperature is continuously increased, the increased precipitation is mainly liquid precipitation in the monsoonal temperate-glacier region. If the temperature will be increased by 1.6℃in 2050, the precipitation of existing snow-line of glacier Baishui No. 1 (4800m above sealevel) for the whole summer almost cannot replenish the glacier, the annual solid precipitation will be only 433mm, the annual melted quantity of glacier Baishui No.1 will be increased to 2692mm, the relative material balance of glacier will reach to -1430mm water equivalent, ELA will rise to 166mm, the glacier area will be decreased to about 22% of the existing area.It comprehensively analyses the evolution trend of disasters of Lijiang mountainous region in the future. Three aspects like fluctuation of climate, change of earthquake activities, mode and intensity of human activities and so on are the main factors to restrict the special and temporal change of the growing of mountainous hazards. At present, the trend of mountainous hazards deterioration of Lijiang is very difficult to be reversed eflfectively in a short time, the years about 2005, 2020 and 2030 will be the active years of hazards, and from the year 2000, mountainous hazards will enter into another ascent stage of fluctuating cycle of about 12a.The economy loss which possibly caused by the mountainous hazards in the future 50 years will be about 6 to 8 times more than the average Ievel of 1980's to 1990's.During 10 years between the begaining of 1990's to the end of 1990's, the change of land cover type of Lijian is mainly represented as the decreasing of forest area and the transferring from forest to meadow. In the changing direction of vegetation type, it is mainly changed from natural cover type to the human disturbance cover type. There is an obvious trend of transferring forest cover type to bush cover type and pure forest to mixed forest.
|
PDF Full Text Request