地壳构造运动对河型转化影响的实验研究

AN EXPERIMENTAL STUDY OF RIVER PATTERN CHANGES INFLUENCED BY TECTONIC MOVEMENT

本文通过室内模拟试验,探讨了由于地壳构造运动以及由此而导致输沙特性变化所引起的不同河型转化和发育的规律。利用试验测量资料进行多元逐步回归分析,分别得到了地壳沉降与地壳抬升时计算河型转化判据的判别函数。应用数量化理论对试验资料进行综合分析,建立了因地壳构造运动影响而形成的五种河型的判别空间,并由此分析了地壳构造运动对河型转化影响的一般规律。

Based on two groups of model experiments, crustal uplift and crustal subsidence, this paper deals with the laws of river pattern Changes caused by tectonic movement as well as with changes of the sediment character. we have got three basic patterns; straight, meandering and branched in the experiments, among which the branched pattern can be classified into three types. anabranched, multibranched and braided.Crustal subsidence results in lowering the flow energy and accumulating the sediment. According to regression analysis in several elements of the experimatal data, the discriminating function which decides the river pattern has been gained. it is the meandering pattern; if 1.6<△<2.5, it is the anabranched; if 2.5<△<3.3; it is the multibranched; and if 3.3<△, it is the braided. Crustal uplift brings about increase of the unit stream power .In accordance with the calculations of the experimatal data, we have., transverse profiles get narrower and deeper; φ>1.34, they become wider and shallower.By using quantitative measurement data and qualitative analysis data for the computation of discriminatory analysis, we obtain a space of distinguish, in which all the samples of experimental measurement can be divided into five classes. It is more satisfactory.The results of criterion indicate that each sample shows the nature and variability of the river pattern, Besides, it is inferred that these experiments demonstrate the general tendency of the changes of river patterns influenced by tectonic movement.