PowerPoint Presentation
ERT 246 Hydrology and Water Resources1HYDROGRAPH ANALYSISRiver
gauging produces discharge (flow) data of a cross-sectional area of
an outlet point of a watershedContinuous recording of discharge
data with respect to time will produce a discharge-time (Q-t)
relationship of the watershedHydrographA record and graphical
representation of discharge (Q) as a function of time (t) at a
specific location, for example, the discharge at a point in a river
or the discharge from a pumping wellDischarge of a river are
fluctuated (up and down) due to the rainfall condition. How river
response to rainfall.The shape of hydrograph is depending on the
shape of the watershed & the rainfall pattern
1ERT 246 Hydrology and Water Resources2Effect of Watershed shape
on Hydrograph shapeABCBACQtDifferent shape would produce different
Tc2ERT 246 Hydrology and Water Resources3Natural HydrographA
natural hydrograph: An observed Q-t relationship of a watershed due
to rainfall eventA rainfall event produces a single hydrographA
natural hydrograph has important characteristics:Rising point
(abrupt) (a)Rising limb (b)Peak flow (c)Falling limb (d)Inflection
point (e)
Time (hr)Q(m3/s)bcead3ERT 246 Hydrology and Water Resources4Main
Component of HydrographDirect flow (quick flow, effective flow)
(Qe)That part of the flood hydrograph that represents the fastest
response to rainfall and that is distinct from the base flow. Base
flow (slow flow) (Qb)That part of the stream discharge that is not
attributable to direct runoff from rainfall or melting snow, it is
usually sustained by groundwater. Basin lag (tL) The time
difference between the centroids of rainfall excess and its
corresponding peak surface runoff produced in the watershed
t(jam)Q(m3/s)i(mm/j) Effective Rainfall, PeIndek QptL Inflection
point QeQbQbBaseflow line4ERT 246 Hydrology and Water
Resources5Base flow separation techniqueNatural hydrograph consists
of two main components, i.e. Direct flow, Qe (quick flow) &
Base flow (slow flow) (Qb).The quantity of Qe is important to know
because it represents the volume flood and fresh water supply
produced by individual rainfallTherefore it is important to
separate the base flow from the total flowVarious
techniques.Empirical formula: N = b A 0.2A = area (km2)b = constant
= 0.8, depending on watershed characteristicsN = time lag after Qp
(day) Constant-discharge methodConstant-slopeMaster Depletion
CurveDigital filter for continuous hydrograph t(jam)Q(m3/s)QpTitik
infleksiN5Master depletion curve method
use when the most accurate model of hydrograph recessions is
needed combine data from several recessions to make general
recession model from this an equation of the form can be derived,
which gives discharge at any time after discharge is measured
ERT 246 Hydrology and Water Resources6
Eg: Total volume of Effective Runoff = Total Surface area under
the curveERT 246 Hydrology and Water Resources8IIIIIIIVVVIERT 246
Hydrology and Water Resources9Baseflow Separation
lineQuick/fast/direct flowSlow/base flowTotal Volume of direct flow
= Total surface area = Qe * dt = 33 m3/s * 3600 s ERT 246 Hydrology
and Water Resources10Unit Hydrograph (UH)Hydrograph of one unit
surface runoffUnit hydrographThe discharge at a point, expressed as
a function of time, due to a unit of effective rainfall that is
applied uniformly over the contributing area during a specified
period of time (D). Hydrograph resulted from one unit of effective
rainfall spread uniformly over the watershed for a given
durationAssumptions:Effective rainfall is directly proportional to
direct runoff2 Unit Effective rainfall will produce 2 unit
hidrographSuperposition:2 effective rainfall successively produce 2
successive UH with time lag TWhy need to establish Unit
Hydrograph?
10ERT 246 Hydrology and Water Resources11Establishing UH from
Natural HydrographObtain a natural hydrograph from a known
effective rainfall (D) and duration (T)Separate its base flowObtain
the ordinate of the direct runoffCompute the total volume (depth)of
the direct runoffCompute the ordinate of UH by dividing the
ordinate of direct runoff to that the total depth of direct
runoffPlot UH having 3 important parameters, Peak flow(Qp), Time to
peak (Tp), base time (Tb)
11ERT 246 Hydrology and Water Resources12Eg: Unit
HydrographColumn (1) and (2) is the coordinateof a natural
Hydrograph generatedby 2 hour effective rainfall of 100
Hawatershed. Establish its Unit Hydrograph.
t (hr)Qt (m3/s)Qb(m3/s)Qe(m3/s)UH
(m3/s/cm)05500.0016510.0829540.34314590.764155100.84510550.4268530.2576510.0885500.0033
m3/s12ERT 246 Hydrology and Water Resources13Eg: Unit
HydrographEffective rainfall duration, T=2hrSeparate its baseflow
(column 3)Obtain ordinate of the effective hydrograph (Column
4)Compute total depth of runoff (11.88 cm or 11.88 unit)Compute the
ordinate of UH by dividing the ordinate of direct runoff to that
the total depth of direct runoffPlot UH having 3 important
parameters, Peak flow(Qp), base time (Tb)
13ERT 246 Hydrology and Water Resources14Changing the duration
of UHS-Curve methodThe established T-UH is not always applicable
because of different duration of effective rainfallS-Curve: method
of deriving a UH for a desired duration from one of another
durationEg: 2Hr - UH to 3 Hr-UHProcedures: An S-curve is
constructed from a series of UH of several T by the simple process
of successive displacement by T and summing up the ordinatesWhy
need to change the duration of UH?
14ERT 246 Hydrology and Water Resources15Eg: S-Curve
methodConvert the 2Hr-UH in the previous example (page 10) to
3Hr-UH, using S-Curve methodSteps (refer to Table pg.13):Obtain the
ordinate of the original 2Hr-UH (column 2)Lagged the 2Hr-UH
ordinate for 2 hours several times (column 3, 4, 5, 6, )Summing-up
all the ordinate (column 2+3+4+..) to form S-curve ordinate (Column
6)The plots of the lagged ordinates and S-curve is shown in
Figure.
S-Curve15ERT 246 Hydrology and Water Resources16Eg: S-Curve
method (cont.)
(1) (2) (3) (4) (5) (6) 16ERT 246 Hydrology and Water
Resources17Eg: S-Curve method (cont.)Steps (Cont.) (Refer Table on
the right)Obtain ordinate S-Curve (column 2)Lagged ordinate S-curve
3 Hrs (column 3)Subtract ordinate S-curve to 3Hr lagged Curve
(Column 4=column 2- column 3)Obtain a new UH-3Hr by multiplying
column 4 with 2/3 (column 5) Plot the UH-2 Hr and UH-3Hr in one
graph to see the different
(2)(3) (4) (5)
17ERT 246 Hydrology and Water Resources182Hr-UH to 3Hr-UH
2Hr-UHQp=1.39Tb=7Hrs
3Hr-UHQp=1.12Tb=8.5 hrs2Hr-UH3Hr-UH18ERT 246 Hydrology and Water
Resources19Obtaining natural hydrograph from multiple rainfall from
UHHaving UH, natural hydrograph from multiple rainfall (many
rainfall) can be obtainedEg. Using 1Hr-UH, obtain natural
hydrograph generated by 4 rainfall events as shown below
19ERT 246 Hydrology and Water Resources20multiple rainfall from
UH
20ERT 246 Hydrology and Water Resources21
2.54.5 01.021ERT 246 Hydrology and Water Resources22Synthetic
Unit HydrographA make-up (artificial) UH based on empirical
relationship of key UH parametersNot all watersheds has their own
UHMany watersheds are ungauged (no flow data)Many methods: Snyder,
SCS, Epsey5 important key parameters: Qp (peak flow), Tp (time to
peak), Tb (base time), D (duration of rainfall)
QpTpDTb22ERT 246 Hydrology and Water Resources23a.Tempoh
mencapai Qp, tp
tp= Ct (L*Lca)0.3Ct = pekali empirikal (bergantung kepada
kawasan tadahan) 0.2 2.2L = panjang sungai (km)Lca= panjang sungai
dari titik tumpuan ke pusat graviti kawasan tadahanc.g.LcaERT 246
Hydrology and Water Resources24b.Tempoh hujan berkesan, trtr =
tp/5.5c.Kadar alir puncak, QpQp = Cp A/tpCp = pekali empirikal =
2.0 6.5A = keluasan tadahan (km2)tp = tempuh puncakd.Tempoh aliran
dasar (base time), TbTb = 3 + 3 (Tp/24) hari atau Tb = 5 TpERT 246
Hydrology and Water Resources25Synthetic Unit Hydrograph (Snyder
Method)Qp = (640 Cp A )/Tp (cfs)Tp = Ct (L Lc)0.3 (hr) A =
watershed area (mile2)Tb = 3 + Tp/8 (days)Cp = storage coefficient
(0.4-0.8)Ct = watershed coefficient (1.8-2.2)Lc = length along
channel to watershed centroid (miles)L = length of main stream
(miles)
25Problem SetERT 246 Hydrology and Water
Resources26Time0306090120150180210240270300330360390Runoff
(m3/s)01.22.81.71.41.21.10.910.740.610.500.280.170The 30-min Unit
Hydrograph for a 2.25 km2 catchment is given by:Determine the
S-hydrographCalculate the 40-min unit hydrographVerify that the
40-min unit hydrograph correspond to a 1-cm rainfall
excessChart60000000.099206349211110.09920634920.396825396802220.39682539681.19047619050.09920634923331.28968253971.38888888890.39682539680441.78571428570.79365079371.19047619050.0992063492552.08333333330.39682539681.38888888890.3968253968062.182539682500.79365079371.19047619050.099206349272.083333333380.39682539681.38888888890.396825396802.1825396825900.79365079371.19047619050.09920634922.083333333310100.39682539681.38888888890.39682539682.1825396825
Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd- 2Hr lag4th
2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time (Hrs)Q (m3/s)
Sheet1t (j)012345678932.53.559107531.5t
(Hr)03300Time(Hr)Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd-
2Hr lag4th 2-Hr lagS-Curve Ordinate
(1)+(2)+(3)+1330000.000.0023.530.50.099206349210.100.1035320.396825396820.400.000.4049361.190476190531.190.101.29510371.388888888941.390.400.001.7967340.793650793750.791.190.102.0875320.396825396860.401.390.400.002.188330070.000.791.190.102.089330080.401.390.400.002.187740090.000.791.190.102.0821.5100.401.390.402.185.04t
(Hr)031323.5354951067758393
Sheet1
Time (Hr)Q (m3/s)
Sheet2
Time (Hr)Q (m3/s/cm)
Sheet3
Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd- 2Hr lag4th
2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time (Hrs)Q (m3/s)
Sheet1t (j)012345678932.53.559107531.5t
(Hr)03300Time(Hr)Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd-
2Hr lag4th 2-Hr lagS-Curve Ordinate
(1)+(2)+(3)+1330000.000.0023.530.50.099206349210.100.1035320.396825396820.400.000.4049361.190476190531.190.101.29510371.388888888941.390.400.001.7967340.793650793750.791.190.102.0875320.396825396860.401.390.400.002.188330070.000.791.190.102.089330080.401.390.400.002.187740090.000.791.190.102.0821.5100.401.390.402.185.04t
(Hr)031323.5354951067758393
Sheet1
Time (Hr)Q (m3/s)
Sheet2000.09920634920.39682539681.19047619051.38888888890.79365079370.396825396800
Time (Hr)Q (m3/s/cm)
Sheet3
Sheet1t (j)012345678932.53.559107531.5t
(Hr)03300Time(Hr)Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd-
2Hr lag4th 2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time(Hr)S-Curve
OrdinateLagged 3Hr SCurve OrdinateS-Curve Ordinate - Lagged 3HrsNew
UH-3HrOriginal Ordinate UH-2HrNew
UH-3Hr1330000.000.0000.000.000.000.00023.530.50.099206349210.100.1010.100.100.070.100.066137566135320.396825396820.400.000.4020.400.400.260.400.264550264649361.190476190531.190.101.2931.290.001.290.861.190.8597883598510371.388888888941.390.400.001.7941.790.101.691.121.391.124338624367340.793650793750.791.190.102.0852.080.401.691.120.791.124338624375320.396825396860.401.390.400.002.1862.181.290.890.600.400.59523809528330070.000.791.190.102.0872.081.790.300.200.000.19841269849330080.401.390.400.002.1882.182.080.100.070.06613756617740090.000.791.190.102.0892.082.18-0.10-0.07-0.066137566121.5100.401.390.402.18102.182.080.100.070.06613756615.04t
(Hr)031323.5354951067758393
Sheet1
Time (Hr)Q (m3/s)
Sheet2
Time (Hr)Q (m3/s/cm)
Sheet3
Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd- 2Hr lag4th
2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time (Hrs)Q (m3/s)
Chart8000.09920634920.06613756610.39682539680.26455026461.19047619050.85978835981.38888888891.12433862430.79365079371.12433862430.39682539680.595238095200.198412698480.06613756619-0.0661375661100.0661375661
Time (Hr)Q (m3/s)
Sheet1t (j)012345678932.53.559107531.5t
(Hr)03300Time(Hr)Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd-
2Hr lag4th 2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time(Hr)S-Curve
OrdinateLagged 3Hr SCurve OrdinateS-Curve Ordinate - Lagged 3HrsNew
UH-3HrOriginal Ordinate UH-2HrNew
UH-3Hr1330000.000.0000.000.000.0000.00023.530.50.099206349210.100.1010.100.100.0710.100.066137566135320.396825396820.400.000.4020.400.400.2620.400.264550264649361.190476190531.190.101.2931.290.001.290.8631.190.8597883598510371.388888888941.390.400.001.7941.790.101.691.1241.391.124338624367340.793650793750.791.190.102.0852.080.401.691.1250.791.124338624375320.396825396860.401.390.400.002.1862.181.290.890.6060.400.59523809528330070.000.791.190.102.0872.081.790.300.2070.000.19841269849330080.401.390.400.002.1882.182.080.100.0780.06613756617740090.000.791.190.102.0892.082.18-0.10-0.079-0.066137566121.5100.401.390.402.18102.182.080.100.07100.06613756615.04t
(Hr)031323.5354951067758393
Sheet1
Time (Hr)Q (m3/s)
Sheet2
Time (Hr)Q (m3/s/cm)
Sheet3
Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd- 2Hr lag4th
2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time (Hrs)Q (m3/s)
Time (Hr)Q (m3/s)
Sheet1t (j)012345678932.53.559107531.5t
(Hr)03300Time(Hr)Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd-
2Hr lag4th 2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time(Hr)S-Curve
OrdinateLagged 3Hr SCurve OrdinateS-Curve Ordinate - Lagged 3HrsNew
UH-3HrOriginal Ordinate UH-2HrNew
UH-3Hr1330000.000.0000.000.000.0000.00023.530.50.099206349210.100.1010.100.100.0710.100.0661375661Time
(hr)Ordinate
1Hr-UH35320.396825396820.400.000.4020.400.400.2620.400.26455026460049361.190476190531.190.101.2931.290.001.290.8631.190.8597883598150510371.388888888941.390.400.001.7941.790.101.691.1241.391.1243386243216067340.793650793750.791.190.102.0852.080.401.691.1250.791.1243386243322575320.396825396860.401.390.400.002.1862.181.290.890.6060.400.595238095241858330070.000.791.190.102.0872.081.790.300.2070.000.198412698451259330080.401.390.400.002.1882.182.080.100.0780.06613756616807740090.000.791.190.102.0892.082.18-0.10-0.079-0.066137566174521.5100.401.390.402.18102.182.080.100.07100.06613756618205.0490t
(Hr)031323.5354951067758393
Sheet1
Time (Hr)Q (m3/s)
Sheet2
Time (Hr)Q (m3/s/cm)
Sheet3
Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd- 2Hr lag4th
2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time (Hrs)Q (m3/s)
Time (Hr)Q (m3/s)
Time (hr)Q (m3/s)
Sheet1t (j)012345678932.53.559107531.5t
(Hr)03300Time(Hr)Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd-
2Hr lag4th 2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time(Hr)S-Curve
OrdinateLagged 3Hr SCurve OrdinateS-Curve Ordinate - Lagged 3HrsNew
UH-3HrOriginal Ordinate UH-2HrNew
UH-3Hr1330000.000.0000.000.000.0000.00023.530.50.099206349210.100.1010.100.100.0710.100.0661375661Time
(hr)Ordinate 1Hr-UHTime (hr)Rainfall
(cm)35320.396825396820.400.000.4020.400.400.2620.400.264550264600049361.190476190531.190.101.2931.290.001.290.8631.190.859788359815012.5510371.388888888941.390.400.001.7941.790.101.691.1241.391.1243386243216024.567340.793650793750.791.190.102.0852.080.401.691.1250.791.124338624332253075320.396825396860.401.390.400.002.1862.181.290.890.6060.400.59523809524185418330070.000.791.190.102.0872.081.790.300.2070.000.198412698451259330080.401.390.400.002.1882.182.080.100.0780.06613756616807740090.000.791.190.102.0892.082.18-0.10-0.079-0.066137566174521.5100.401.390.402.18102.182.080.100.07100.06613756618205.0490t
(Hr)031323.5354951067758393
Sheet1
Time (Hr)Q (m3/s)
Sheet2
Time (Hr)Q (m3/s/cm)
Sheet3
Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd- 2Hr lag4th
2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time (Hrs)Q (m3/s)
Time (Hr)Q (m3/s)
Time (hr)Q (m3/s)
Sheet1t (j)012345678932.53.559107531.5t
(Hr)03300Time(Hr)Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd-
2Hr lag4th 2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time(Hr)S-Curve
OrdinateLagged 3Hr SCurve OrdinateS-Curve Ordinate - Lagged 3HrsNew
UH-3HrOriginal Ordinate UH-2HrNew
UH-3Hr1330000.000.0000.000.000.0000.00023.530.50.099206349210.100.1010.100.100.0710.100.0661375661Time
(hr)Ordinate 1Hr-UHTime (hr)Rainfall (cm)Time (hr)Ordinate
1Hr-UH2.5*UH4.5*UH0*UH1*UHTotal
(Natural)35320.396825396820.400.000.4020.400.400.2620.400.264550264600000049361.190476190531.190.101.2931.290.001.290.8631.190.859788359815012.515000510371.388888888941.390.400.001.7941.790.101.691.1241.391.1243386243216024.52160125012567340.793650793750.791.190.102.0852.080.401.691.1250.791.12433862433225303225400225062575320.396825396860.401.390.400.002.1862.181.290.890.6060.400.59523809524185414185562.5720001282.58330070.000.791.190.102.0872.081.790.300.2070.000.198412698451255125462.51012.505015259330080.401.390.400.002.1882.182.080.100.0780.0661375661680680312.5832.5016013057740090.000.791.190.102.0892.082.18-0.10-0.079-0.0661375661745745200562.50225987.521.5100.401.390.402.18102.182.080.100.07100.0661375661820820112.53600185657.55.04909050202.50125377.51009008017011004545t
(Hr)Ordinate U12020200313001323.5354951067758393
Sheet1333.559107533
Time (Hr)Q (m3/s)
Sheet2000.09920634920.39682539681.19047619051.38888888890.79365079370.396825396800
Time (Hr)Q (m3/s/cm)
Sheet30000000.099206349211110.09920634920.396825396802220.39682539681.19047619050.09920634923331.28968253971.38888888890.39682539680441.78571428570.79365079371.19047619050.0992063492552.08333333330.39682539681.38888888890.3968253968062.182539682500.79365079371.19047619050.099206349272.083333333380.39682539681.38888888890.396825396802.1825396825900.79365079371.19047619050.09920634922.083333333310100.39682539681.38888888890.39682539682.1825396825
Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd- 2Hr lag4th
2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time (Hrs)Q (m3/s)
000.09920634920.06613756610.39682539680.26455026461.19047619050.85978835981.38888888891.12433862430.79365079371.12433862430.39682539680.595238095200.198412698480.06613756619-0.0661375661100.0661375661
Time (Hr)Q (m3/s)
0501602251851258045200
Time (hr)Q (m3/s)
Chart11000000111012502212540022503625562.5720001282.5462.51012.50501525312.5832.501601305200562.50225987.5112.53600185657.550202.50125377.50900801701100454512120202013131300
2.5*UH4.5*UH0*UH1*UHTotal (Natural)Time (hr)Q (m3/s)
Sheet1t (j)012345678932.53.559107531.5t
(Hr)03300Time(Hr)Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd-
2Hr lag4th 2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time(Hr)S-Curve
OrdinateLagged 3Hr SCurve OrdinateS-Curve Ordinate - Lagged 3HrsNew
UH-3HrOriginal Ordinate UH-2HrNew
UH-3Hr1330000.000.0000.000.000.0000.00023.530.50.099206349210.100.1010.100.100.0710.100.0661375661Time
(hr)Ordinate 1Hr-UHTime (hr)Rainfall (cm)Time (hr)Ordinate
1Hr-UH2.5*UH4.5*UH0*UH1*UHTotal
(Natural)35320.396825396820.400.000.4020.400.400.2620.400.264550264600000049361.190476190531.190.101.2931.290.001.290.8631.190.859788359815012.515000510371.388888888941.390.400.001.7941.790.101.691.1241.391.1243386243216024.52160125012567340.793650793750.791.190.102.0852.080.401.691.1250.791.12433862433225303225400225062575320.396825396860.401.390.400.002.1862.181.290.890.6060.400.59523809524185414185562.5720001282.58330070.000.791.190.102.0872.081.790.300.2070.000.198412698451255125462.51012.505015259330080.401.390.400.002.1882.182.080.100.0780.0661375661680680312.5832.5016013057740090.000.791.190.102.0892.082.18-0.10-0.079-0.0661375661745745200562.50225987.521.5100.401.390.402.18102.182.080.100.07100.0661375661820820112.53600185657.55.04909050202.50125377.51009008017011004545t
(Hr)Ordinate U12020200313001323.5354951067758393
Sheet1
Time (Hr)Q (m3/s)
Sheet2
Time (Hr)Q (m3/s/cm)
Sheet3
Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd- 2Hr lag4th
2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time (Hrs)Q (m3/s)
Time (Hr)Q (m3/s)
Time (hr)Q (m3/s)
2.5*UH4.5*UH0*UH1*UHTotal (Natural)Time (hr)Q (m3/s)
Chart130501602251851258045200
Time (hr)Q (m3/s)
Sheet1t (j)012345678932.53.559107531.5t
(Hr)03300Time(Hr)Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd-
2Hr lag4th 2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time(Hr)S-Curve
OrdinateLagged 3Hr SCurve OrdinateS-Curve Ordinate - Lagged 3HrsNew
UH-3HrOriginal Ordinate UH-2HrNew
UH-3Hr1330000.000.0000.000.000.0000.00023.530.50.099206349210.100.1010.100.100.0710.100.0661375661Time
(hr)Ordinate 1Hr-UHTime (hr)Rainfall (cm)Time (hr)Ordinate
1Hr-UH2.5*UH4.5*UH0*UH1*UHTotal
(Natural)35320.396825396820.400.000.4020.400.400.2620.400.264550264600000049361.190476190531.190.101.2931.290.001.290.8631.190.859788359815012.515000510371.388888888941.390.400.001.7941.790.101.691.1241.391.1243386243216024.52160125012567340.793650793750.791.190.102.0852.080.401.691.1250.791.12433862433225303225400225062575320.396825396860.401.390.400.002.1862.181.290.890.6060.400.59523809524185414185562.5720001282.58330070.000.791.190.102.0872.081.790.300.2070.000.198412698451255125462.51012.505015259330080.401.390.400.002.1882.182.080.100.0780.0661375661680680312.5832.5016013057740090.000.791.190.102.0892.082.18-0.10-0.079-0.0661375661745745200562.50225987.521.5100.401.390.402.18102.182.080.100.07100.0661375661820820112.53600185657.55.04909050202.50125377.51009008017011004545t
(Hr)Ordinate U12020200313001323.5354951067758393
Sheet1
Time (Hr)Q (m3/s)
Sheet2
Time (Hr)Q (m3/s/cm)
Sheet3
Original Ordinate UH-2Hr1st 2Hr lag2nd-2Hr lag3rd- 2Hr lag4th
2-Hr lagS-Curve Ordinate (1)+(2)+(3)+Time (Hrs)Q (m3/s)
Time (Hr)Q (m3/s)
Time (hr)Q (m3/s)
2.5*UH4.5*UH0*UH1*UHTotal (Natural)Time (hr)Q (m3/s)