布哈河河口三角洲1970~2010年间面积变化研究

The Area Change of Buha River Estuary Delta during the Period of 1970-2010

通过对布哈河河口三角洲1970~2010年间的5期MSS、TM、ETM遥感影像进行分析,发现其地貌形态发生了明显的变化,并对影响其变化的原因进行了探讨。结果表明:1)布哈河河口三角洲从1970到2000年呈扩张趋势,面积扩张达67.97 km^2,湖岸线扩张也十分明显,仅在1989~2000年间平均推进量达0.56 km;2)布哈河河口三角洲在2000到2010年呈萎缩趋势,面积萎缩了9.85 km^2,湖岸线萎缩了0.44 km;3)造成三角洲形态变化是有诸多因素的,其主导因素为青海湖水位变动,其次是受到其它诸如河流输沙、人为干扰等因素的影响,这些影响的贡献度尚不明确,有待进一步探讨。布哈河作为青海湖国家级自然保护区的最大补给河流,对青海湖的生态、气候环境有很大程度的影响,研究其河口三角洲的地貌变化具有重要意义。

It has been more and more common that using CIS spatial analysis method to study the status and trend of the change in topographic feature of delta and lake and so on.We got the obvious changes have taken place in the delta＇ s morphological of Buha River estuary,and discussed the reasons of delta＇ s morphological of Buha River estuary according to the analysis of the five periods of MSS,TM/ETM remote sensing images of Buha River estuary during 1970-2010.The results shows.-1.there are explicit changes in Buha River estuary＇ s morphology during 1970-2010,and the area of Buha River estuary is increasing,which enlargement is 67.97 km.Shorelines expansion is also very obvious,only during 1989-2000 the average advance amount reached to 0.56 km;2.the area of Buha River estuary is declining from 2000 to 2010,shranked by 9.85 km,and lake shoreline shrank by 0.44 km;3.The research show that there are multiple causes of this morphology changes.The change of Qinghai lake water level is main reason;and it also influenced by other factors such as river sedimcut load and the disturbance of human activities,the contribution of these effects remains to be further discussed.Qinghai lake is a national nature reserve,Bird island is a national 4 A level tourist scenic spot,thus it is greatly significant to study morphological changes in bird island.Buha River as the maximum supply rivers for the Qinghai Lake National Nature Reserve,with a great influence on the Qinghai Lake＇s ecology and climate,so to study its estuary delta has important significance.