摘要
冰雪融水是冰川泥石流的一种主要激发动力。冰雪融水沿程(s)流量Qs=q0(S 2-s2 2S)。其沟谷纵剖面形态模式近似为抛物线型:h H=(s S)N。冰雪融水泥石流流域水文地貌系统的熵可用沟谷纵剖面形态指数N来表征:信息熵P=ln[(N+2) 2]-N (N+2),超熵δXP=N3(N2-4)(N+2) [32(6-N)]。冰雪融水沟谷纵剖面演化的最小能耗模式表现为沿程流速平均值 u与N值成正比: u∝(N)。f(N)为流速函数,f(N)={2 3-2 [(N+1)(N+3)]}1 2;冰雪融水泥石流沟的各地貌发育阶段开始时的 u值之比为:泥石流发展阶段(N=0 62)1 0;泥石流旺盛阶段(N=1 23)1 182;泥石流衰减阶段(N=2 0)1 280;流域稳定阶段(N=3 71)1 361。以藏东南典型冰雪融水泥石流沟谷为例,检验了上述沟谷纵剖面之形态与演化模式。
Melt\|water of glacier and snow deposit is a main excitation source of glacier debris flow.A discharge(Q)of icesnow meltwater along stream length(s) is Q=q(S/2-s2/2S).Shape model of the icesnow meltwater valley longitudinal profile is a parabola pattern formula similarly:h/H=(s/S)N (the N is forming index of the longitudinal profile).It is evolution direction of the valley longitudinal profile that shape of the longitudinal profile develops to a concave parabola pattern from a convex one and value of the N increases.Information entropy (P) and superentropy(δXP) of hydrologymorphology system of the debris flow basin are function of the N:P=ln[(N+2)/2]-N/(N+2),δXP=N3(N2-4)(N+2)/[32(6-N)].It is model of minimum energy dissipation on evolution of the valley longitudinal profile,that relation formula between average value ()of velocity along the valley and the N is:=594(Q0H)1/2S-1/2{2/3-2/[(N+1)(N+3)]}1/2.The f(N) is a increase function of velocity and f(N)={2/3-2/[(N+1)(N+3)]}1/2.In start of every morphological stages related with development of icesnow meltwater debris flow in the valley,proportions of the value are 1\^0(developing stage of the debris flow,N=062),1182(the exuberant stage,N=123),1280(the declined stage,N=20)and 1361(a stable stage of the basin,N=371).As examples with model icesnow meltwater debris flow valleys of southeast Tibet,above models of shape and evolution on the valley longitudinal profile are tested.
出处
《中国地质灾害与防治学报》
CSCD
2003年第4期19-25,共7页
The Chinese Journal of Geological Hazard and Control
基金
中国科学院知识创新工程资助项目(KZCX2 306)
关键词
冰雪融水泥石流
沟谷纵剖面形态指数
流域系统的熵
最小能耗模式
沿程流速均值
ice-snow melt-water debris flow
forming index of valley longitudinal profile
entropy of basin system
model of minimum energy dissipation
average value of velocity along valley
Palongzangbu River
model of evolution
