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近年来,世界上许多重大河流的泥沙量发生了显著变化,其原因是土地利用发生变化、修建水库和人类对其流域的其它影响。许多河流的泥沙量下降,而另外一些河流上升。这种变化对系统的自然机能及人类对河流系统的利用都有着重要意义。本文研究了湄公河泥沙量近年的变化迹象。可利用的数据在取样频率和覆盖周期上都有许多局限性,但它们经过处理,仍为研究20世纪60年代初至2002年期间该河流的泥沙量变化提供了基础。尽管有证据表明一些监测站的泥沙量升高,但总体趋势并没有重大变化的迹象,并且系统通过泥沙积存达到了缓冲。到2002年为止,在中国源头修建的大坝看来对泥沙量没有影响,尽管当更大的大坝被批准时,湄公河的泥沙量有望下降。
In recent years, significant changes have occurred in the amount of sediment in many of the world’s major rivers due to land-use changes, the construction of reservoirs and other human impacts on their watersheds. Many rivers reduce the amount of sediment, while others rise. This change is of great importance to the natural function of the system and to human use of the river system. This paper studies the changes of sediment in the Mekong River in recent years. Available data have many limitations in terms of sampling frequency and coverage period, but they are still processed to provide the basis for the study of changes in sediment load in the river from the early 1960s to the mid-2002s. Although there is evidence of an increase in the amount of sediment at some stations, the overall trend shows no sign of major changes and the system has been cushioned by sediment accumulation. As of 2002, the dam built at China’s source seems to have no effect on the amount of sediment, although the amount of sediment in the Mekong is expected to decline as larger dams are approved.