from IPython.display import IFrame
崩壊の向き、量の考え方は関根の方法を基本とするが、崩壊量は流砂量に付加するのではなく、瞬時に崩壊が生じるものとした。
斐伊川下流部をモデルに設定した。初期水深を変えた3ケースの計算を行った。
河床勾配:1/670
河床材料:2mm
川幅:90m
延長:1800m
格子サイズ: 5m
境界条件
初期条件
IFrame("https://computational-sediment-hyd.github.io/a-rudimentary-knowledge-of-river-bed-variation/figSandbarSimulation/CASE1-300h.html",width=1000,height=350)
IFrame("https://computational-sediment-hyd.github.io/a-rudimentary-knowledge-of-river-bed-variation/figSandbarSimulation/CASE2-300h.html",width=1000,height=350)
IFrame("https://computational-sediment-hyd.github.io/a-rudimentary-knowledge-of-river-bed-variation/figSandbarSimulation/CASE3-300h.html",width=1000,height=350)
IFrame("https://computational-sediment-hyd.github.io/a-rudimentary-knowledge-of-river-bed-variation/figSandbarSimulation/CASE1-2000h.html",width=1000,height=350)
IFrame("https://computational-sediment-hyd.github.io/a-rudimentary-knowledge-of-river-bed-variation/figSandbarSimulation/CASE2-2000h.html",width=1000,height=350)
IFrame("https://computational-sediment-hyd.github.io/a-rudimentary-knowledge-of-river-bed-variation/figSandbarSimulation/CASE3-2000h.html",width=1000,height=350)
IFrame("https://computational-sediment-hyd.github.io/a-rudimentary-knowledge-of-river-bed-variation/figSandbarSimulation/CASE1.gif",width=1000,height=350)
IFrame("https://computational-sediment-hyd.github.io/a-rudimentary-knowledge-of-river-bed-variation/figSandbarSimulation/CASE2.gif",width=1000,height=350)
IFrame("https://computational-sediment-hyd.github.io/a-rudimentary-knowledge-of-river-bed-variation/figSandbarSimulation/CASE3.gif",width=1000,height=350)
import numpy as np
ib = 1/670
B = 90
h = np.array( [1.0, 0.6, 0.3] )
d = 2/1000
tau = h * ib / 1.65/ d
tau
array([0.45228403, 0.27137042, 0.13568521])
B*ib**0.2/h
array([24.492186, 40.82031 , 81.64062 ])
B/h
array([ 90., 150., 300.])
from scipy import special
x = (B/d)**(-0.45)*9.34*np.exp( 2.53*special.erf((np.log10(B/h) - 1.22)/0.594))
x * h
array([0.7705053 , 0.53485284, 0.28135338])