【摘要】 [目的]对青海湖流域近24a的土壤保持量进行评估,揭示其时空变化规律,为定量评估青海湖流域土壤保持功能和区域土壤保持的重要性提供理论支撑。[方法]利用通用土壤流失方程(USLE)和GIS技术,评估和揭示1987—2010年青海湖流域土壤保持量的时空动态变化。[结果]近24a来青海湖流域土壤保持量平均为4.68×108 t/a;单位面积土壤保持量高值区分布在青海湖流域主要河流的河源区及中部地区,低值区主要集中分布在青海湖周围、河谷以及青海湖流域西北部地区。在各生态系统中,高寒草甸的土壤保持量最大,平均为2.68×108 t/a。近24a来青海湖流域土壤保持量呈先增加后减小的变化趋势,并在2005年达到最大,相比于1987年,2010年其土壤保持总量共计增加了2.17×108 t,其中,高寒草甸的土壤保持量增加最多,增加了1.20×108 t。[结论]近24a来,青海湖流域土壤保持功能在不断增强,土壤侵蚀程度不断减弱,表明青海湖流域的生态环境在不断改善。更多还原

【Abstract】 [Objective]Soil conservation plays an important role in preventing soil erosion.We choose Qinghai Lake basin as the research area to examine and assess the temporal-spatial variation pattern of soil conservation quantity.[Methods]Universal soil loss equation(USLE)and GIS technology were used to illustrate the variation of soil conservation quantity from 1987 to 2010.[Results]The soil conservation quantities in Qinghai Lake basin were at an average of 4.68×108 t/a in the past 24 years.The high conservative areas of soil conservation capacity per unit area were at the upper and middle reaches of main river in Qinghai Lake basin,and the areas with low conservation level was around the Qinghai Lake and at the northwestern of Qinghai Lake basin.Among different regional ecosystems,the amount of soil conservation in the alpine meadow was the maximum,with an average of 2.68×108 t/a.Total quantities of soil conservation in Qinghai Lake basin showed an increase-decrease trend from 1987 to 2010,and it reached the largest in 2005.Compared with the one in 1987,soil conservation quantities in Qinghai Lake basin increased to 2.17×108 t by the end of 2010.The increment of soil conservation quantities in alpine meadow was the largest,about 1.2×108 t.[Conclusion]In the past 24 years,soil conservation capability of Qinghai Lake basin increased and soil erosion slowed down,the ecological environment of Qinghai Lake basin got better and better.更多还原