近40年来海南省三大河下游水体的含沙量特征及影响因素

利用海南省水文局提供的1960—2000年水文资料,对近40年来海南省三大河下游水体的含沙量特征及影响因素进行了分析。结果表明,南渡江、昌化江和万泉河下游水体4—11月份的含沙量一般都较大,而1、2、3、12月份的含沙量都很小,夏秋两季的含沙量明显高于冬春两季,这也跟三大河下游地区的不同月份和季节性平均降雨量分布规律基本相一致,说明降雨在一定程度上决定着三大河流域的土壤侵蚀状况。从年平均含沙量来看,昌化江的含沙量整体明显高于南渡江和万泉河,这可能是昌化江流域原始森林的破坏引起水土流失等自然灾害向下游输送泥沙的结果。

Characteristics and impact factors of sediment concentration in lower reaches of three great rivers of Hainan province in the recent 40 years

The characteristics and impact factors of sediment concentration in lower reaches of three great rivers were researched in this paper based on the hydrological data from 1960 to 2000.The results indicated that the sediment concentration of lower reaches in Nandu river,Changhua river and Wanquan river is much from April to November and is less in January,February,March and De-cember.Moreover,it is obviously higher in summer and autumn than in winter and spring,and similar to distribution rules of the monthly and the seasonal average rainfall in lower reaches of the three rivers,indicating that soil erosion in the watersheds of the three rivers depends largely on rainfall.In addition,the sediment concentration in Changhua river is obviously higher than that of Nandu river and Wanquan river,and it is suggested that one of the main causes of serious soil erosion of Changhua river watershed might be the destruction of primeval forest.