METHODS AND THEIR RELATIONSHIPS IN STUDIES OFREGIME RELATIONS
河相关系研究的各种方法及其间关系

On the basis of a systematic analysis and comparison of the methods and their relation-ships in the studies of regime relation, the main difference and their essential relations are dis-cussed. The principal conclusions are: (1) The regime relations obtained from statistical method and dimensional method are reasonable only for the regions where data are collected for developing these relations, and thus the methods themselves can not give the physical meanings of these relations. The results obtained from the above two methods can be well described by the form of Eq. 5 in this paper. (2)The introduction of the stability theory and the extremity hypotheses will conduce to approaching the fourth closed equation in regime theory and supply for clear physical mean-ings. On the other hand, both methods are sensitive to variations of other combining equations and are difficult to be proved if these methods are reasonable from mathematics.The only standard for judging the feasibility of these methods is that weather the results from them agree wich the measured data. (3)If only the final results from the above methods are considered, all the fourth regime relations can be summarized approximately in the form of Eq.5 when the discharge Q is eli-minated. Therefore, the Eq. 5 has a similar physical meaning to Eq. 9 from the hypotheses of extremity. (4) The parameter t, in Eq. 5 is the real barrier in the studies of regime relation, the de-termination of it depends on the level of understandings on the scouring-resistant characteris-tics of the river flume boundaries.