Research On Vegetation Ecohydrological In Buha Riverbasin Of Qinghai Lake

Qinghai Lake is China’s largest inland saltwater lake, in the face of the water into the lake,the water level decline and other issues, the need to further study the process of runoff and the corresponding vegetation eco hydrological mechanism of the basin into the lake. Qinghai Lake Basin is an alpine region, response to climate change is very sensitive to achieve and maintain the stability of the Qinghai Lake basin ecological, summarize the Buha River Basin of Qinghai Lake,the largest rivers into the lake vegetation eco hydrological rules. From the macro scale, through different periods of remote sensing image solution translation and comparison, reveal climate change under the natural areas of vegetation succession law; analysis generated by natural vegetation succession eco hydrological response rules; the use of hydrological model, according Buha River runoff data, simulation and verification of vegetation changes in the hydrology of the vegetation response of.By Tian Jun, Gangcha, Chaka weather long series of temperature and precipitation data analysis on the variation characteristics of Buha River Basin climate. Shows that nearly 50 years,basin temperatures were significantly higher, at an elevation of more Gaosheng temperature more obvious, the winter heating significantly higher than other seasons. Using Mann Kendall trend analysis and accumulative anomaly curve of each period of warming trend was used to analyze the change and warming since 1986 to 1997 in a decade or so, the fluctuation period, then in 1997 was the mutation process, consistent with the overall trend of the Qinghai Tibet Plateau Based showed its own regional characteristics of temperature increasing. Precipitation showed an increasing trend, but not as obvious as the temperature. The higher the altitude, the more obvious the increase of precipitation, the increase of summer precipitation is more obvious than other seasons.According to the temperature and the variation characteristics of precipitation and watershed in the 1980 s began into temperature and humidity increasing period. In the 1990 s into the relatively warm dry period, before this century 10 years cardioversion is warm and humid period.Through the 1980 s and 2014 land use types and transfer matrix analysis showed that, present situation of watershed land use types mainly to the natural ecological landscape; 30 years of watershed land use types increase occurred mainly in the high, medium and low three different coverage of grassland, reducing the amount of main performance of the unused land. In the total change, nearly half of the changes in the number of absolute value, and the other half of the space position shift. Low coverage grassland and did not use the net change mainly, and high coverage grassland with high coverage grassland were to make change mainly; from the angle of new analysis of land use category conversion information relative to the first land utilization type area,high coverage grassland to woodland, grass cover to high coverage of grasses and low coverage of grasses to farmland has higher conversion intensity, not to use only to the low coverage of grasses have tendency of transformation, but its strength is low. 30 years, the space transition analysis showed that basin, Northwestern 3900 meters above the source belonged to the depopulated by elevated temperature precipitation increases the effects of global climate change, source area of vegetation increased response significantly. And at an altitude of 3900 meters below the area, the increase in vegetation cover type distribution is more dispersed, the overall impact of natural factors on climate change. The type of coverage reduction is more concentrated in the vicinity ofTianjun County, which shows that more people are affected by grazing and other human disturbance.Buha River Basin, under different landform type water supply type is the main factor to determine the changes in vegetation, altitude region and low altitude area by the water supply way is more, vegetation height higher than the other landform. Secondly, wind direction has a great influence on the evapotranspiration in the study area. The vegetation coverage is lower than the windward slope high wind slope vegetation coverage, vegetation coverage is higher than that of sunny shady vegetation coverage.To evaluate the relationship between vegetation change and runoff correctly is of great significance to the whole river basin of Qinghai Lake. The application of SWAT in the high cold and high altitude area has been affirmed. The sensitivity analysis is limited to the change of vegetation types, the impact of climate change, this study has not introduced. From the sensitivity analysis, we can see that the impact of vegetation changes on the underlying surface is not significant.