Rills in olistostromal melange in the Bologna Appenines )
description
Transcript of Rills in olistostromal melange in the Bologna Appenines )
Rills in olistostromal melange in the Bologna Appenines)
Rainfall rate(intensity)mm/hr
Time (days)
Time (days)
Stream discharge(m3/sec)
Rainfall rate(intensity)mm/hr
Time (days)
Time (days)
Stream discharge(m3/sec)
Hydrograph:peak
Rainfall rate(intensity)mm/hr
Time (days)
Time (days)
Stream discharge(m3/sec)
Hydrograph:peak
Recession limb – period of falling stream flow after rainfall ceases
Rainfall rate(intensity)mm/hr
Time (days)
Time (days)
Stream discharge(m3/sec)
Hydrograph:peak
Base flow = low flow btwn storms, and their equivalent during storms
Rainfall rate(intensity)mm/hr
Time (days)
Time (days)
Stream discharge(m3/sec)
Hydrograph:peak
Base flow = low flow btwn storms, and their equivalent during storms
Storm runoff = runoff above projection of pre-storm flow
Rainfall rate(intensity)mm/hr
Time (days)
Time (days)
Stream discharge(m3/sec)
Hydrograph:
Base flow = low flow btwn storms, and their equivalent during storms
Lag to peak = Time from peak rainfall to peak stream flow
Storm runoff = runoff above projection of pre-storm flow
Response times altered by land use!
Build a parking lot ?
Irrigate a field ?
HOF
Sat. overland flow
Runoff coefficient – ratio of
total storm runoff (runoff above projection of pre-storm flow)
total storm rainfall
= Sum (rainfall) / Sum (runoff)
Qt = discharge at time t
Qp = peak discharge
Qt = Qp Kt
K = recession constant (small K = fast recession)
Qp : HOF > SOF > SSSF
Lag to peak: HOF < SOF < SSSF
K: HOF < SOF < SSSF
Darcy’s Law (groundwater discharge)
Porosity: measure of total pore space (not necessarily interconnected)
Permeability: volume fraction of interconnected pores Aquifer: permeable rocks and sediments that store
groundwaterWater table: upper surface of saturated zone in an
aquiferDarcy’s Law: groundwater discharge (Q) per cross
sectional area (A) of an aquifer is proportional to the hydraulic gradient (slope of water table surface)
To the board…
To the board…