i.¥.
.ON)
Water mansgement in Ontario
[Mt^MA
.JhAA
f//
Onlario
Water Resources
Corrifflissioiitr ^'v^
MAR 15 1971
J^m^r Resources
Bulletin 41
J2limatic series
SNOW SURVEY
REPORT
EAST AND MIDDLE
OAKVILLE CREEKS
DRAINAGE BASIN
19681969
IHD
1965
CANADA iy74
„.;::« DH I
Copyright Provisions and Restrictions on Copying:
This Ontario Ministry of the Environment work is protected by Crown copyright
(unless othenvise indicated), which is held by the Queen's Printer for Ontario. It
may be reproduced for noncommercial purposes if credit is given and Crown
copyright is acknowledged.
It may not be reproduced, in all or in part, for any commercial purpose except
under a licence from the Queen's Printer for Ontario.
For information on reproducing Government of Ontario works, please contact
ServiceOntario Publications at copyrisht(a),ontario.ca
WATER RESOURCES
BULLETIN 4 1
Climatic series
SNOW SURVEY REPORT
EAST AND MIDDLE
OAKVILLE CREEKS
DRAINAGE BASIN
1968—1969
By
L.A.Logan
ONTARIO WATER RESOURCES COMMISSION
DIVISION OF WATER RESOURCES
TORONTO
ONTARIO
1971
TABLE OF CONTENTS
ACKNOWLEDGEMENT
ABSTRACT ......
INTRODUCTION . . ,
OBJECTIVES ,,..:
BASIC CONCEPTS ...,.., ......
Assumptions ....... . .•.••.•. • • •
Statistical Procedures ........
FIELD INVESTIGATION . .
Snow Survey Network , , ,
Snow Samp ling EqiiipiDent .,,,....,.......,..«.
Data Collection .............. . ............ . .
SNOW COURSE EVALUATION .......
Single Index Ranking .,
Multiple Indices Ranking
SNOW DEPTH AND WATER EQUIVALENT .... , . .... . . . . , ,
Areal Variability
Empirical Relationship
PRECIPITATION (SNOW) STORAGE ESTIMATES ....,.,. ,
Arithmetic Method ..,,.,,..,,,,.,,.,,.,.,.,..
Thiessen Method , , , , , , ,
AreaElevation Method .................... . . ,
Isohyetal Method
CONCLUSIONS , . .
RECOMMENDATIONS
BIBLIOGRAPHY . .
APPENDICES DATA SIMIARIES AND RESULTS
OF ANALYSES
Appendix I .,,.....,,,,.,,,.,.,..,
Appendix II ....,.................,,,,,
Appendix III
Appendix IV ............................... • •
Page
i
11
1
4
5
6
12
12
13
15
17
18
19
21
21
24
30
30
31
32
33
35
38
39
42
43
56
67
71
ACKNOWLEDGEMENT
"Xtie snow survey prograni is being carried out
as part of the hydrologlc studies being undertaken
by the River Basin Research Branch of the Division of
Water Resources .
Mr. D, Puccini j Engineer, established the
snow survey network; collection of data and the
preparation of a preliminary draft snow survey report
was carried out by Mr. A. Sweetman, Engineer, with the
assistance of Mr. D. Donohue, Technician of the River
Basin Research Branch,
ABSTRACT
Snowcover Investlgatioii in the East and Middle
Oakvllle creeks drainage basin is one of several phases of
hydro logic studies being carried out by the Division of Water
Eesources , Ontario Water Resources Comnissionp as part of
Its International Hydrological Decade representative basin
program. The snow survey data collection program. Initiated
in the winter season of 19681969, forms part of a precursory
study for arriving at aeceptable hydrologic parameters for
use in evaluating general water balances in the basin. The
established sampling network facilitated the collection of
an adequate quantity of data, for use In estimating basin
snowpack index water equivalents and the extent of snow
cover in the specific areas . The gravimetric method of
sampling employed provides the measurements of snow depth,
core length and weight measurenient of equivalent depth of
melt water. Statistical evaluation of the data established
the accuracy and reliability of the sampling, the acceptable
quality of the data and the adequacy of the designed
network. Further reliability and consistency of the data
were ascertained through a simple linear regression, with
verification that under the prevalUng conditions of the
Investigation, the graviinetric technique was adequate
 11 
for providing sample estimates of the snowpack water
equivalents . The adequacy of the s^npllng network was
substantiated by the comparison of estimates of the basin
snowpack indices determined by different methods of data
evaluation.
 ill 
SNOW SURVEY REPORT
If
EAST AND MIDDLE OAK¥ILLE CREEKS DRAINAGE BASIN
19681969
INTRODUCTION
The Ontario Water Resoiirces Commission
Initiated the stody of winter precipitation and snow
cover in the East and Middle Oakvllle creeks International
Hydro logical Decade (I.H.D.) representative drainage
basin In the winter of 1968. The drainage basing located
in southern Ontario, covers an area of 76 square miles.
o
Its boundaries extend approximately between 79 45 'W and
80° O'W longitude and 43° 20 'N and 43° 38 'N latitude.
The topography has moderate slopes, with Increased surface
nndtilations in the most elevated areas. The elevation
ranges from 1,200 feet above sea level at the main stream
source to 600 feet above sea level at the lowest streamflow
gauging station. Approximately 28 per cent of the drainage
area is enclosed between elevation 800 feet and 1,200
feet above sea level. The vegetative covers are pre
dominantly crops and pastures, with sparse distribution
of improved and unimproved forested areas.
 1 
Snow accumulation and complete areal snow
cover are normal events in the basin for three to five
months of the year. From the condition of the snowpack
(accunulated snow) , a measure of the winter precipitation
amounts in the basin can be estimated.
Itn approach towards providing estimates of
the basin snowpack conditions at a given time is by
way of snow survey investigations . Snow surveys are
normally carried out by way of data collection from a
sampling network comprised of a number of snow courses «
The gravimetric method, which entails weight measure
ments of core samples from the snowpack, is one of
several sampling techniques employed for obtaining the
data necessary for evaluating the basin snowpack condition,
This sampling technique provides an estijnate of the
areal extent of the basin snow cover, an indication of
the trend of snow accumulation and depletion, and an
index of the basin runoff potential from snowmelt.
This report deals with preliminary analyses
for the evaluation of the data collected from the first
of a series of seasonal snow survey investigations ,
Subsequently, the data will be used in analyses of runoff
and water balances in the basin.
 2 
OBJECTIVES
The basic objectives which characterize the
snow survey Investigation may be summarized as follows;
1. To determine the point values of the
snowpack depth, water equivalent, core
length, and density for all the selected
snow courses In the drainage basin.
2. To determine the uniformity of snow cover
on each snow course and the adequacy of
representation of the basin snow cover
In the designated areas .
3. To evaluate the comparative reliability and
quality of the individual point measure
ments, as well as the relative reliability
of the data between the snow courses .
4. To determine and establish, by a practicable
and reliable method, satisfactory precipi
tation storage estimates or hydrologlc
Input Indices for the drainage basin for
the winter precipitation period.
 3 
BASIC CONCEPTS
The density of snow may be defined as the
ratio between the volinne of melt water from a given
sample of snow and the Initial volume of the sample (7)^.
For a given snowpack, the density Is known to vary widely
with time, to vary directly with depth and stratifica
tion of the pack, and to exhibit areal variability
within a region of snow accumulation (1, 4, 5, 9, 14),
The gravimetric method of sampling attempts
to provide direct estimates of an index of the water
stored in the snowpack. From a number of point measure
ments of snow depth and water equivalent (equivalent
depth of melt water, as determined from the weight of
the sample), an Integrated average of the snowpack water
equivalent and density may be determined (4, 5, 7),
By operating with the above mentioned basic
relationship between the snowpack indices (depth, water
equivalent and density) and with the support of a number
of apparent assumptions, the quality and reliability of
the data collected may be evaluated analytically.
* References in Bibliography
 4 
Assumptions
Snow deposition on a drainage basin is known
to be heterogeneous in distribution (5, 13) . It Is,
therefore, necessary to be aware of the llinttations of
the method of sampling employed. The successful use
of the gravimetric method in this investigation is
subject to a number of limitations . The main purpose '
for the summarized assumptions given below is to facilitate
meaningful and rational physical interpretations of the
analysed data. The following are assumed:
I, The selected sampling network provides a
sufficient nuraber of samples for reliable
estimates of the basin snowpack indices.
M:i The largescale effects of the regional
orographic factors (elevation, exposure,
rise and orientation) with respect to storm
experiences in the basin are general for
all locations .
1* The nature of snow deposition and distribu
tion at a selected site is influenced
entirely by the combined effects of the
local terrain parameters or environmental
factors, such as vegetation, ground slopes,
aspects and degree of protection from the wind .
 5 
4, The average density of the snowpack
detemlned from the simultaneous point
measurements of depth and water equivalent,
on a particular date, represents a constant
for the basin at that time period.
5 , The point measurements taken from the
snowpack on a particular survey represent
a statistical sample drawn at random from
a normal finite population.
Statistical Procedures
Statistical procedures can be used to
evaluate the accuracy and limitations of the point
measurements and the reliability and quality of the
data for use in obtaining basin snowpack index water
equivalents .
By accepting the assumption of normality and
randomness of a sample, bias introduced into the data
by selective sampling is neglected; hence, the sampling
errors and variations of a sample may be determined by
application of standard statistical equations (6, 8, 11)
of the forms:
 6 
1=1
N
nh
(Xi  X)
N1
... (1)
... (2)
S
• ■ • V"*/
^
... (4)
where: X  sample average;
X " 1 point measurement;
S » standard deviation;
N  number of observations;
C • coefficient of variation;
S~ « standard error of average;
1 «1, 2, 3,.,,N observations.
The errors associated with each sample average
may be determined and examined from confidence limits
specified by given probability levels. The confidence
Interval for the population average, ^ , for depth
or water equivalent^ may be determined from the general
expression:
 7 
where t^ ^c# is the value of the standard normal deviate
at the five per cent probability level for (N1) degrees
of freedom (6, 8, 11, 12) ,
By operating with the stated assumption that
the average density of the snowpack is a constant at a
specific time, tests for consistency and reliability
of the data can be carried out by an examination of
the statistical association between the measured depths
and water equivalents . These tests can be applied to
data collected on a particular date from a snowpack of
a given areal extent. The statistical association
between the two variables was derived from a developed
empirical function based on an assumed linear regression
(8, 11, 12) . Water equivalent, W, is the dependent
variable and depth, D, the applied independent variable.
By using the leastsquare technique with the added assump
tion that the origin of the line Is at the point of
averages (11, 12) , the derived function is of the form:
Wj, « A + bD ^
in which
# Standard table of 't 'distribution
 8 
N
y^ (M^  W) (D^  D)
b  1^1 ... (6a)
ir (Di  D)^
and
A  W  bD, ... (6b)
where W^ Is the predicted estimate of the water equlvalentt
b the regression coefficient (an estimate of the defined
constant density), A the intercept on the ordinate.
In the ease of the regression treatment, the leastsquare
derivation for the empirical function obviates the
assumption of a type of distribution or randomness of
the data.
The regression Is distributed with a residual
variance estimated by:
2 X (Wl  Wc)
e  —
^ N2
where S^ Is the standard error of estimate,
e
The corresponding variance associated with
the regression coefficient may be estimated by:
S^  ° . •.. (8)
Ji <°i  ^^'
where S^ Is the standard error of the regression
coefficient .
 9 
Due to practical knowledge of the nature of
the variables, the line of regression may be forced
through the origin, that Is, for D  0, W  0. Equation
(6b) gives an estimate of this condition for the popula
tion with estimated variance:
2 2
,S, ™ S
a e
1 +
N N
m2
S ^"i ■
D)
... (9)
mS
where S^ Is the standard error of the Intercept.
the practical significance of the regression
may be determined by the coefficient of determination:
2
r^  1  ^ . 25 < r^ 4 10 • .• (W)
where r is the coefficient of correlation and S^ is
the standard deviation of the water equivalent. Equation
2
(10) indicates that if the computed value of r Is greater
than or equal to .25 then the regression may be regardad
as practically significant (11, 12) .
A test of linearity of the regression, based
on the 'F' distribution. Is given by the general form:
2
. P(F(1, N2) >F) <.05, ... (11)
2/(N2)
 10 
5 2 2
where Sj^ == Sy  S is the variance accounted for by
the regression. Equation (11) Indicates that the
linear regression may be regarded as significant If
the computed Fvalue Is greater than or equal to the
corresponding Fvalue (F) determined from a standard
table of 'F' distribution (8, 11) for the defined
degrees of freedom (1, N2) at a given probability level
(P  .05).
The confidence interval on the population
regression coefficient,^ , may be obtained by replac
ing // f X, and Sy in equation (5) by^ , b, and S^,
respectively; similarly for the population intercept,
oC , the confidence interval may be obtained by replacing
//, X, and Sy by cC • A and S., respectively. The
value of the standard normal deviate remains at tQ Q5,
in this case for (N2) degrees of freedom.
 11 
FIELD INVESTIGATION
With the aid of a topographic map of tha basin,
a desirable number of snow courses were selected by
way of an elimination process through field surveys
and site investigations. Itie implementation of a
designed sampling program facilitated the collection of
a desirable quantity of data which were necessary for
the network evaluation. The sampling equipment employed
were the conventional tubetype snow samplers (2, 3,
7, 10).
Snow Survey Network
The survey network consists of eight snow
courses. The basic criteria for selecting these snow
courses were basin topography and vegetative cover.
The unique location of the drainage basin within a
larger geographic region and the relatively graded,
uniform topography supported the acceptance of the as
sumption of the largescale effect of the regional
orographic factors with respect to storm experiences
in the basin. Operating with the abovementioned
criteria and assiuiption, eight snow courses were select
ed throughout the range of topography and major types
 12 
of vegetation In the basin. The locations of the
selected sites are shown on Map 1 of Appendix I.
The selection of the individual sites for
each snow course was directed by accepted guidelines
(3, 5, 10), including conditions such as wellsheltered
area, welldrained site on clean litter or soil free
from stumps or debris, uncultivated, and a readily
accessible location. A standard snow course consists
of ten sampling points with spacing of 100 feet in a
straight line. Changes in local ground slopes and
limited property boundaries necessitated some modifica
tions in layout at a few sites . Figures 1 to 8 of
Appendix I are diagrannnatic sketches of the Individual
site layouts.
The network density was approximately one
snow course per 9 .5 square miles .
Snow Samp ling Equipment
TWO types of snowsamplers were employed,
the Mount Rose sampler and the MSC TypeI sampler.
Each sampler consists of a duralumin tube, with a saw
toothed cutter as an integral attachment at one end«
the toothed cutter allows for easy insertion of the
 13 
tube into the snowpack. Each tube has graduation in
inches on the outer surface which provides for depth
measurement to the nearest 0.1 inch. The unit length
of each Mount Rose sampler tube is 42 Inches with an
inside diameter of 1.485 inches. The length of the
MSC Type I sampler tube Is 43 inches with an inside
diameter of 2.785 Inches.
A tubular extensible spring balance was pro
vided with the samplers for obtaining a direct estimate
of the equivalent depth of melt water In each sampled
core by weighing. The balance has two separate scale
calibrations, one for each sampler. Unit calibrations,
weight ^ 1.0 ounce, for the Mount Rose sampler and
weight * 3.5 ounces for the MSC TypeI sampler, are
equivalent to a snowpack water equivalent of 1.0' inch.
The Mount Rose sampler was recommended for sampling in
a very deep powdery snowpack, while the MSC TypeI was
recommended for sampling in shallow and less powdery
snow (3 ) .
Other accessories were a wire cradle for
suspending the tube on the balance, a turning and driv
ing wrench for operating the sampler, spanner wrenches
for assembling tube units of the Mount Rose sampler,
cleaning tools and carrying cases.
 14 
Da t a Co 1 lee t ton
Prior to the expected winter precipitation
period, each selected snow course was prepared for
observation. Preparations involved checking and staking
the designed layout and clearing tall grasses and debris
from within a radius of five to ten feet of each staked
point .
It was planned to commence snow surveys
when snow had accumulated to an estimated depth of two
inches in the basin, but the first major snowfall
occurred in early January, 1969, with an accumulation
of greater than twelve inches . Snow surveys conmienced
immediately after this major storm event. Subsequent
surveys were done at least once every two weeks*
Point measurements obtained at each of the
ten sampling points on each snow course were: snowpack
depth, water equivalent and core length. Each core
sample was obtained by inserting the tube sampler into
the snowpack, held normal to the ground slope and driven
to the full extent of the snowpack depth. Table 1 of
Appendix I shows a compiled, sample, snow survey data
report sheet. Notes were made on the visual appearance
of average conditions of the snowpack (e.g. presence
or absence of crust and ice layers) and of the soil
 15 
condition beneath the snowpack (e.g. frozen or moist).
A sumoary of the data collected Is given In Table 2 of
Appendix I. These are averages of the respective ten
point observations, with the corresponding average snow
density on each snow course.
During the Initial survey, the Mount Rose
sampler was employed for stapling In the deep powdery
snow; the MSC TypeI sampler was employed during all
subsequent surveys . Observational errors were kept at
a minimum by strict adherence to the measurement pro
cedures. Special efforts were made to minimize the
wind effect on the spring balance during the weighing
operations .
 16 
SNOW COURSE EVALUATION
The snow courses were compared and evaluated
on the basis of the variability in accumulation. The
variations about the average snowpack indices were
determined statistically and used as measures of the
snow cover uniformity on the respective snow course.
A good to near excellent snow course would have the
least variation about each sample average snowpack index.
The standard deviation and coefficient of
variation were computed for each sample size by applying
the standard equations (1) to (3) on page 7. Tables 1,
2, 3 and 4 of Appendix II show the computed averages
and respective deviations for snow depth, water equivalent, •
core length, and density on each snow course. The
analysis was done for each survey for the period of
snowfall. The effects of the local terrain parameters
on snow deposition appeared to be more appreciable during
the accumulation period. It is believed that the terrain
parameters impart similar effects to precipitation experi
ences, snow as well as rain, in the basin. These effects on
snowfall are the more pronounced during the snow accumula
tion period. On the other hand during the major snowmelt
period, the expected differences in melt rates on
different areas of the basin would introduce variations
 17 
in the data not accounted for by the effect of terrain
parameters on snow deposition, Ihe data from this melt
period were therefore omitted from this analysis.
SingleIndex Ranking
Field experiences gained in sampling the snowpack
showed that the possible observational errors associated
with the measuring of the snowpack Indices were the least
for snow depth. Consequently, for practical purposes,
snow depths were regarded as the most accurately measured
values . This condition therefore qualifies depth as the
most suitable, single Index for use in comparing snow cover
variability within and between courses . The variability
was assessed by an examination of the series of coefficients
of variation of depth. Table 5 of Appendix 11 shows the
snow courses ranked according to the increasing order of
magnitude of the variation coefficients . The table was
derived by summing the rai^s of each snow course for the
four survey periods; the group totals were then reranked
to give the most uniform course (highest rank 1) and the
least uniform course (lowest rank 8) . An examination of
the results showed that snow course number 8 acquires the
highest rank and snow course number 4 acquires the lowest
rank, indicating that the snow cover was the most uniform
 18 
in depth on snow course number 8^ and least uniform in
depth on snow course number 4 for the specified accumula
tion period. This deduction compares reasonably with field
observations; that Is, snow course number B satisfied iiost
of the basic selection requirements for a good snow course,
whereas snow course number 4 was noticeably the least
sheltered. Snow courses number 2, 5, and 6 had comparable
uniform depth of snow cover, and courses number 1, 3, and
7 had fair to poor coverage.
Mult iple Indices Ranking
In order to test further the degree of vari
ability summarized by Table 5 of Appendix II, a multiple
^ranking procedure was carried out for all the snowpack
indices , Table 6 of Appandix II gives a summary of the
multiple ranking. The indices for water equivalent,
core length, and density were ranked similarly to depth
(Table 5 of Appendix II) , The grouped totals for each
index were sunaned and the grand totals were then reranked.
The result did not differ significantly from that of
the single index ranking. An examination of the results
showed that the depth of snow cover on snow course
number 4 was undoubtedly the least uniform. Using both
forms of ranking, the same snow courses can be divided
 19 
into two major groups* The first group, Bnavf courses
number 1 , 2 , 5 , 6 and 8 can be regarded as the more
representative of the basin cover. These courses were
located in the areas of ideal orientation and exposure
to all forms of precipitation. The second group,
snow courses nianber 3, 4, and 7 were less representative,
consisting of courses that were the least sheltered
and thereby were subjecting the snow cover to sub
stantial amounts of wind drift.
 20 
SMQW DEPTH AND WATER EQiriVALENT
For the purpose of a group evaluation of the
data, all of the point measurements from a particular
survey ware grouped in one sample analysis, excluding
data from courses with poor measurements (< 50 per cent
snow covered) • A simple computer program*, based on
equations (1) to (11) of pages 7 to 10, was utilized to
perform the statistical analysis. The results of the
analysis facilitated an examination for the areal varia
tions inherent in the snow cover distribution on the
drainage basin and the degrees of confidence and accuracy
placed on the data for use in obtaining overall averages
of the basin snowpack condition. The empirical relation^
ships determined were examined for their practical and
statistical significance as a basis for establishing
data reliability and coniistency.
Areal Variability
The sampling errors and variability of the
snowpack condition in the drainage basin were determined
from each group of data, analysed by equations (1) to
(4). Tables 1 and 2 of Appendix III summarize the results
* QUIKTIAN System  IBM Digital Computer
 21 
of the analyses ,
The coefflcleints of variation of depth (Table 1
of Appendix III) indicated a progressive Increase in
values from ,209 for the Initial survey, to .957 for
the survey on February 26, 1969, Similarly, for the
water equivalent, the coefficient of variation (Table 2
of Appendix III) ranges fron ,139 to 1,014 for the same
respeetive time period.
The extent to which a measure of confidence
could be placed on the data, with such large variations,
was determined from equation (5); that is, equation (5)
gives a measure of the eonfidence limit or Interval
asaociated with each estimate of the basin average depth
or water equivalent. For example, applied tO' Table 2
of Appendix III,,, the confidence interval on the popula
tion average water equivalent for' the Initial survey
pertod, would be given by 2.8 + *043 tg qc Inches and
for the final survey, would be given by 2.7 + .313 t^ qc
inches, where tg q^ ^ 1.99 for (N2) degrees of freedom.
For the case of the average snow depth (Table 1 of
Appendix III), the range of confidence interval on the
population .average would be 12,7 + .6 inches to 7.4 +
1,8 inches for the initial and final survey period,
 22 
respectively. A further examination of the results
showed that the errors associated with the respective
estimates of the snowpack averages for the basin were
less than 15 per cent at the 95 per cent confidence
level for the major snow accumulation period (January 2
to 15, 1969),
The general trend of a decrease in accuracy
of the estimates of the snowpack condition, shown in the
results, was attributed to the breakup of the pattern
of distribution of minor snow storms, to the dominant
effects of wind drifts on exposed accumulations and to
varying rates and stages of the snow metamorphosis on
the basin.
An attempt was made to examine the effect on
the accuracy pf the estimates of the snowpack condition
by a 50 per cent reduction in the sampling network.
Four snow courses, number 1, 2, 6, and 8, with the most
uniform snow cover were selected from Table 6 of Appendix
II. A similar statistical analysis, as outlined pre
viously (equations (1) to (4)), was carried out for this
group of data. Tables 3 and 4 of Appendix III show
the selected results. A cursory examination of the
results showed that the reduction of the number of snow
courses (guided by the ranked evaluation) gave an
 23 
Increase in the values of the estimate of the basin
average water equivalents and an appreciable reduction
In areal variation; however, a careful examination of
the results, as outlined In the previous paragraphs,
showed that the accuracy of the estimates (within 15
per cent at the 95 per cent confidence level) was con
fined to the same major snow accumulation period.
Empirical Relationship
Ihe computation of the average snowpack density
from a sample of measured depths and water equivalents
was based on a direct relationship between the two vari
ables; that is, an implicitly assumed linear regression
with the line forced through the origin was utilized
in the computations . As this implicit relationship was
accepted for use in computing average snowpack density
from the data of each snow course, it was extended to
the computation of the basin snowpack Integrated average
density, from the combined data from all courses, on a
particular survey. Subsequently, the knowledge of this
implicit and accepted relationship was utilized to
examine and evaluate the reliability of the point measure
ments and the quality and reliability of the grouped
data among the snow courses . If a set of data was
 24 
reliable and consistent in measurements , the empirical
relationship derived (equation (6)) would be reliable
and significant (equations (5) and (7) to (11)) »
The results of the regression analyses, based
on equations (6) to (11), carried out on the different
groups of data, are summarized in Tables 5 and 6 of
Appendix III. An exaraination of the results (Table 5
of Appendix III), showed that each coefficient of
determination was equal to or greater than the accepted
2
iralues of r ^ ,25; hence, the regressions were of
practieal significance. The computer Fvalues (equation
(11)) employed for the test of linearity of the regres
sions, showed that each Fvalue was highly slgnlf leant ,
indicating that the variations in the estimated water
equivalents could be explained nearly entirely by the regres
sion. With the appropriate application of equation (5),
explained on page 11, the confidence limit on the regression
.coefficients can be detemined; applied to the results
(Table 5 of Appendix III), the confidence interval on the
population regression coefficient can be shown to range
from .21 + ,040 to .33 + .030 from the second to the final
survey period, respectively. The initial survey gave the
most sensitive regression coefficient, of value ,07 + ,028,
These confidence limits gave a measure of the accuracy
 25 
of the slope of the regression lines.
From practical knowledge, the origin should
be a point on the line of regression; however, because
of errors in measurements, the intercept (equation (6b))
may not be equal to zero. The confidence limit on the
intercept gave a measure of the departure of the regres
sion line from the origin. These confidence intervals
of the intercepts (equation (5)), appropriately applied
to Table 5 of Appendix III, may be shown to range about
the origin, with values from .32 + .58 inch on January 15,
1969, to .19 + .28 inch on March 14, 1969. Alternative
ly, the confidence level on the Intercept may be determined
indirectly from computed tvalues; that is, the ratio
between the respective intercept. A, of a regression
A
and its standard error, S^. When t = /§. was computed
from Table 5 of Appendix III, it was seen that the results
from only the first and third survey period gave a
tvalue that was respectively greater than tQ qc * 1.99,
indicating that the Intercepts of the regression from
the other survey periods were not significant at the
95 per cent confidence level. In the case of the regres
sion coefficients, the corresponding tvalue (t  /Sw),
whan computed from Table 5 of Appendix III, was found to
 26 
be much greater than t^ «£ = 1.99 for all survey periods,
indicating, therefore, that the coefficients of regression
for the respective regressions were in each case very
significant*
By operating with the knowledge of the above
interpretations, regression analyses for the regression
line forced through the origin, 0(0,0), were carried
out for the same set of snow data , Table 7 of
appendix III summarises the results. The regression
coefficients were measures of the average densities of
the snowpack. The product of the raspective standard
error Ej^ and the value of tQ 05 gave a neasure of the
error associated with each coefficient at the 95 per cent
confidence level. If appropriately applied, the confidenoe
interval (equation (5)) on the population regression
coefficients (Table 7 of Appendix III) gave, for eKample,
values of .22 + ,032 and ,36 + .046 for the initial and
final survey period, respectively. Similarly, the tvalue,
when computed for the respective coefficients, was, in
each case, greater than tQ qj = 1.99; that is, the
coefficients were all significant.
Similar regression analyses, as outlined and
discussed for the total survey data, were performed on
 27 
the data from the four most uniform snow courses (number 1,
2, 6, and 8). The results of the analyses are suimnarlzed
in Tables 6 and 8 of Appendix III, The results followed
parallel deductions to those of Tables 5 and 7 of
Appendix III, but showed appreciable increases in the
ranges of the confidence intervals on the intercepts
about the origin, with values from ,82 + .98 inch on
January 27, 1969, to .82 + 1.72 inches on March 14, 1969,
(equation (5), appropriately applied to Table 6 of
Appendix III). Similarly, the t values, when computed.
Indicated that the value of the intercept was significant
only for the initial two survey parlods .
The general Indication was that the regression
equation (6) of page 8, with the regression line forced
through the origin, could be applied for the analysis of
the data, thereby supporting reliability and consistency
in the point measurements; that Is, based on the validity
of the implicit relationship between snow depth and water
equivalent, the compiled data were of acceptable quality
and accuracy for use in obtaining estimates of the basin
snowpack water equivalents. It appeared, however, that
a necessary requirement for practical application of the
regression 0(0,0) was an appreciable amount of snow
 28 
accunulaclon, plus a time lapse to allow £or destructive
and constructive snow metamorphosis (initial settling
of the pack, loss of shape of the original snow crystals
and increases in grain size).
 29 
PRECIPITATION (SNOW) STORAGE ESTIMATES
The estimation of the winter precipitation
storage In the snowpack was a necessary procedure for
obtaining the input Index required for use In the
hydrologlc calibration of the basin. The direct or
indirect measurement of the snow water equivalent pro
vides for estimating the water stored In the pack at a
specific time, or for the change in storage between
time periods*
An attempt was made to use different methods
of integrating the individual point measurements of the
snowpack into basin indices for a quantitative measure
of depth of water on the basin. The different methods
were applied mainly for the purpose of comparing the
estimates determined by weighted average methods to those
estimates determined by a simple arithmetic procedure.
Arithmetic Method
The statistical analysis of snow depth and
water equivalent data showed that the errors and
variabilities associated with the averages for the
basin during the initial periods of snow accimiulatlon
were acceptable. The snow courses were distributed
 30 
throughout the range of the basin elevation, thereby
supporting the expectation of satisfactory Indices of
basin snowpack condition, if estimated by simple
aritlnnetic averages . Table 3 of Appendix XV sionmarizes
the results, showing the precipitation storage in the
snowpack In terms of estimates of average water
equivalent or snow depth of given average density, for
several survey periods during the season.
All of the measured data from each snow course
per survey period were included In the computation,
Including estimates of data from courses with less than
50 per cent of snow cover.
Thlessen Method
The Thlessen method was accepted as applicable
for estimating the basin snowpack indices, because of
the assiunptlons with regard to largescale effects of
meteorological conditions on the basin and that the
effects of the local terrain parameters on roinor storm
distributions and snow cover variability on the basin
were to be neglected. Outlined on Map 1 of Appendix I
are the snow course locations and the polygonarea
distributions. Ihe areas enclosed by each polygon were
 31 
planimetered on a topographic map of scale 1 inch ■■ I mile.
The per cent areal distributions from Table 1 of
Appendix IV were applied to weight the data for the
respective snow courses to determine estijnates of the
winter precipitation storage. The results are summarized
in Table 4 of Appendix IV, in terms of the basin snowpack
indices for several survey periods , The estimates for
snow depth were less than the arithmetic average estimates,
but in general, there were no significant or appreciable
differences between the estimates of either method.
Area Elevation Method
The snow courses were placed Into zonal areas
based on 100foot rises in basin elevation from a lower
elevation of 600 feet. The area elevation distribution
was developed by planimeterlng the areas enclosed by
each elevation from a basin topographic map of scale
1 inch > 1 mile. It was assumed that the snow accumula
tion in a respective zonal area was approximately equal.
Table 2 of Appendix III shows the areaelevation and
zonal area distributions. The zonal area distribution
factors were applied to weight the average snowpack
indices on the respective snow course or group of snow
 32 
courses within the zonal area. Table 5 of Appendix III
shows a summary of the weighted averages of the basin
precipitation storage In the snowpack for several survey
periods , An examination of the results and a comparison
with the estimates of the previous methods showed that
there were no significant differences between the
different estimates .
Isohyetal Method
A series of Isohyetal maps were developed for
the basin snowpack depth for the survey periods, as shown
in Figures 1 to 6 of Appendix IV. Each map was developed
Independently from the snow course average values by
isollne Interpolation. Isohyet interval values used
were at least twice the standard error of the respective
average snow depth for the basin. By imposing this limit
on the isohyet intervals, the interpolation was restricted
to the same degree of errors associated with the sampling.
The respective empirical relationship for the regression
line forced through the origin (for the regression 0(0,0)),
between depth and water equivalent, with the associated
standard errors, is shown on each depth isohyetal map
for the periods of major snowfall (January 2 to
February 5, 1969).
 33 
these maps facilitate a qualitative or visual
Interpretation of areal distribution of snow cover In
the basin and the changes that occurred between surveys,
^ch map was analysed for arealsohyet distribution,
fhe area enclosed between the Isohyet Intervals was
planlmetered on a topographic map of scale .5 Inch ■
1 mile and used to weight the respective average Isohyet
value, to determine ultimately the basin Index weighted
average value. Table 6 of Appendix IV summarizes the
arealsohyet distribution of snow depth and the respective
basin Index. The results show no significant differences
from the basin Indices derived by the previous methods,
thereby indicating that the snow courses were adequately
distributed for use In estimating snow accumulation
throughout the basin.
 34 
CONCLUSIONg
Various observations, analysas and interpre
tations of the snow survey data contributed to the follow
ing smmiarized conclusions:
1. A substantial amount of seasonal snow
accumulation on the basin facllltatad the collection
of an adequate number of samples for a meaningful
analysis ,
2. Intraseason freeze and thaw cycles created
difficulties in obtaining ideal core samples, thereby
reducing the desirable accuracy of point measurements.
I. Evaluation of the data by statistical analysis
facilitated the identification of the snow courses with
poor or doubtful measurements . More uniform distribu
tion of snow cover and acceptable representation were
achieved from five snow course locations (snow courses
number 1, 2, 5, 6, and 8).
4. The major period of snow accumulation provided
adequate data for the determination of estimates of
winter precipitation amounts for a degree of accuracy
within 15 per cent at the 95 per cent confidence level.
3 . The quality of the data was ascertained
through a simple linear regression, which verified that
 35 
practical estimates of the snowpack water equivalent
could be derived from the measured snow depth of a
given average density. Although the computed regres
sions were good prediction equations, they were, however,
specific to the basin snowpack conditions of the winter
season of 19681969.
6. Reliable estimates of indices of the basin
snowpack condition could be derived from a 50 per cent
reduction in the evaluated sampling network.
ft. Determination of estimates of the precipi
tation storage in the basin snowpack, for specific time
periods, by several methods, showed no significant
difference between the respective estimates . This in
dicated that the areal distribution of the snow courses
throughout the basin was adequate and that their evaluation
was limited mainly by the quality of the data. The
arithmetic averages were desirable for easy computation
of large volumes of data. The areaelevation and
isohyetal method estimates were desirable for quantitative
interpretation of the snow cover areal distribution and
for the comparison of changes in the areal snow cover and
snowpack conditions between certain time intervals ,
8. The pattern of the basin snow cover distribu
tion and time trends in acciunulation and depletion
 36 
showed that the snowpack depth and water equivalent
increased with increased basin elevation. Major snow
stoms tended to be more unifom and proportionally
distributed on the basin. On the other hand, minor
snow storm distributions were affected by local terrain
parameters, thereby Increasing the areal variability
of snow cover on the basin.
 3? 
RECOMMENDATIONS
1. The existing density of the sampling network
should be maintained in order to ensure that the degree
of represent iveness of snow cover evaluated is sufficient
ly reproducible over a number of seasons .
2. Due to the poor quality of the data obtained
from snow course nimiber 4, an alternative location
should be Investigated.
3. Upon establishing an acceptable degree of
reproducibility in the snow cover on the basin from the
existing network, a sampling network of at least five
snow courses should be maintained. A minimimi of ten
sampling points per course should be maintained In order
to ensure representative statistical samples.
4. The frequency of the snow survey period should
be increased to once per week during the period of
significant freezethaw cycles.
 38 
BIBLIOGRAPHY
1. Adanis, W. and Roger son, R.  1968
"Snowfall and Snowcover at Knob Lake, Central
Labrador, Ungava.", Proceedings of the 25th
Annual Meeting of the Eastern Snow Confer encejp
pp. 110139.
2, Beaumont, R, and Work, R.  1963
"Snow Sampling Results with Differing Snow
Samplers", Proceedings of the 20th Annual
Meeting of the Eastern Snow Conference, pp. 185191
Canada Department of Transport,
Meteorological Branch
 1961  "A Guide to the Selection of Snow
Survey Courses", Clr . 3566, OBS305 .
* 1961  "The Mount Rose Sampler", Cir. 3572,
INS. 105.
«• 1964  "Instruction to Snow Surveyors", Cir*
4113, OBS329.
4. Chow, V.T.  1964
"Handbook of Hydrology", McGrawHill Book Co,
Inc . , New York .
U, S, Army Corps of Engineers  1959
"Snow Hydrology", OTSU.S. Department of Commerce,
PB. 151660.
6. Fisher, R.  1958
"Statistical Methods for Research Workers",
Hafner Publishing Co. Inc., New York.
 39 
?, Llfisley, R. et al,  1949
"Applied Hydrology", McGrawHill Book Co. Inc.,
New York.
8. Mode, E.  1961
"Elements of Statistics", PrenticeHall Inc.,
New Jersey.
Nicholas, L,  1963
"Snow Survey Record", Proceedings of the 20th
Annual Meeting of the Eastern Snow Conference,
pp. 198209.
10. Puccini, D.  1967
"Snow Survey Report  Wllmot Creek Basin", 1966'
1967, OWRC Preliminary Data Report No. 671.
11. Snedecor, G, and Cochran, W.  1968
"Statistical Methods", Iowa State University,
Press, Iowa,
12. Thorn, H,  1966
"Some Methods of Climatological Analysis",
WMONo. 199, TP, 103, Technical Note No. 81
13. Wilson, J.  1966
"Determination and Uses of Best Individual
Sampling Points On Individual Snow Courses",
Proceedings on the 34th Annual Meeting of the
Wee tern Snow Conference, pp. 8286.
 40 
14. Secratarlat of the Canadian National
Coimilttee for IHD  1966
"Guidelines for Research Basin Studies,"
ProGeedlngs of the 14ational Workshop
Seminar on Research Basin Studies,
Canadian National Conraittee for IHD,
• 41 
APPENDICES DATA SUhOlARIES AND
RESULTS OF ANALYSES
 42 
Appendix I
Page
Map 1
Snow Course Locatloni M
Figures 1 to 8
Diagrammatic Sketches of Snow 45 "
Course Layout: OSC1 to 8 52
Table 1
River Baslii Research Branch ^
Snow Survey Report
Table 2
Summary of Snow Survey Data Si,
 43 
/
/
r^
/\
\1* : ^^^
ONTARIO WATER RESOURCES COMMISSION
DIVISION OF AA7ER RESOURCES
INTERNATIONAL HYDROLOGICAL DECADE
EAST AND MIDDLE OAKVILLE CREEKS
DRAINAGE BASIN
SCALE 1:100,000
C 1
H ' rl lJ N I. ! 1
^^ ^^ Sub basin boundary jk Snow course
Drainage basin . PoNgon {Thiessen) a Strsamftow gauging
' " boundary boundan' ^ stalion
Map 1. Snow course loeations.
,25 mile to Federal gauge
Township! Oakville
Concesalon: VI
Lot 1
n.t.s ,
FiRure 1
Diagrammatic Sketch of Snow Course Layout: OSC1
SC  Snow Course
n.t.s. ^ not to scale
 45 
Township:
Oakville
Concession:
IX
Lot:
3
Figure 2
Dlagrmranatic Sketch of Snow Course Layout: OSC2
 46 
Township: Oakville
Concession: VII
Lot: 13
n.t: .s
Figure 3
Diagrammatic Sketch of Snow Course Layout: OSC3
 47 
Township: Esqueslng
Concession: V
Lot: 6
n.t .s
Figure 4
Diagrammatic Sketch of Snow Course Layout: OSC4
 48 
Tovmship; Esqueslng
Concession: X
Lot? 5
n.t ,s ,
Figure 5
Diagrammatic Sketch of Snow Course Layout; OSC5
 49 
n.t .s
Figure 6
Diagrammatic Sketch of Snow Course Layout: OSC6
 50 
Orchard
ti
Township* Esqueslng
Concession: VI
Lot: IS
Figure 7
Diagrammatic Sketch of Snow Course Layout: OSC7
 51 
Township: Esqueslng
Concession: V
Lot: 20
Figure 8
Diagrammatic Sketch of . Snow Course Layout: OSC8
 52 
Table 1
HIVER BASIN RESEARCH BRANCH
SNOW SURVEY REPORT
Basin : Oakville Creek S tat 1 on : OSC8
Date : February 5> 1969 Time : 3 : 00  3r30 Temp ;^ 17^
QbBerver; A. Sweetman & M. Long
1.
Sample
Number
2.
Snow
Depth
3.
Length
of Core
4.
Weight
of tube
5.
Weight of
tube & snow
6.
Water
Equivalent
7.
Density
1
14.7
12.7
4.3
8.3
4.0
.27
2
16.5
14.0
4.3
9.4
5.1
.31
3
14,0
11.0
4.3
7.7
3.4
.24
k
12.0
9.6
4.3
6.6
2.3
.19
5
16.1
14.4
4.3
8 .7
4.4
.27
6
19.3
15.3
4.3
8.3
4.0
.21
7
17.8
14.8
4.3
8.6
4.3
.24
8
17.8
17.8
4.3
10.3
6.0
,34
9
20.5
14.7
4,3
9.3
5.0
.24
10
21.0
15 .0
4.3
8.5
4.2
.20
TOTAL
169.7
139.3
43.0
85.7
42.7
2.51
MEAN ,
17.0
13.9
4.3
8.6
4.3
.25
Crust :
hard
Soil Conditions: frozen
Ice Layers
COMfffiNTS
 snow is on grass layer
 TiiiiPd.MSC Type I sampler.
 53 
Table 2
Summary of Snow Survey Data
Water
Snow
Snow Depth
Equtvalent
Course
Date
(inches)
Cinches )
Density
OSC1
2169
12.6
1*1
.22
15169
11.1
S Ji>S
.25
27169
4.9
IJ
.31
5269
3.9
0.4
.11
26269

0.1 e

14369
0.0
0.0
0.00
24369
0.0
0.0
0.00
OSC2
2169
12.2
2.5
.20
15169
17.3
3.9
.23
27169
9.1
3.2
.35
5269
10.4
2.7
.26
26269
5.5
1,5
.26
14369
0,9
0.3
.34
24369
0.0
0.0
0.00
OSC3
2169
11.5
2.5
.22
15169
10.4
2.2
.21
27169
5.3
1.6
.31
5269
4.9
1.0
.20
26269
1*7
0,4
.23
14.369
m
0.2 e

24369
0.0
0.0
0.00
OiC4
2169
11.9
2,9
.25
15169
14.5
3.8
.26
27169
6.7
2.4
.35
5269
5.5
1.8
.26
26269
3.1
0.9
.17
14369
3.7
1.4
.37
24369
0.0
0.0
0.00
 54 
Table 2 (cont'd)
Water
Snow
Snow Depth
Eqiilvalent
Course
Date
(Inches )
(Inches)
Density
OSC5
2169
10.8
2.7
.25
15169
12.7
3.0
.23
27169
7.0
2.1
.30
5269
5.1
1.4
.27
26269
2.0
0.4
.18
14369
0.8
0.2
.19
24369
0.0
0.0
0.00
OSC6
2169
11,0
2.8
.26
15169
15.3
4.3
.28
28169
9.8
3.4
.34
5269
9.6
3,4
.35
26269
i.4
2.0
.31
14369
7.5
3.1
.42
24369
0.0
0.0
0.00
OSC7
2169
13.8
2.9
,U
15169
13.0
2.8
.21
28169
8.9
2.2
.26
5269
7.2
1.4
.20
26269
4.6
1.0
,21
14369
3.5
1.3
.38
24369
0.0
0.0
0.00
OSC8
2169
18.2
3.0
.17
15169
20.^
3.9
.20
28169
13.9
3.3
.24
5269
17.0
4.3
.25
26269
16.4
4.1
.26
14369
14.9
4.9
.33
24369
0*0
0.0
0.00
e  estimated
 55 
Appendix II
Page
Table 1
Average, Standard Deviation and Coeffl Jf
clent of Variation of Snowpack Depth by Snow
Courses for the Period of Snow Accumulation
Table 2
Average, Standard Deviation and Coeffl 9
clent of Variation of Snowpack Water Equivalent
by Snow Courses for the Period of Snow Accumu
lation
Table 3
Average, Standard Deviation and Coefficient #E
of Variation of Snowpack Core Length By Snow
Courses for the Period of Snow Accumulation
Table 4
Average, Standard Deviation and Coefficient 63
of Variation of Snowpack Density by Snow
Courses for the Period of Snow Accumulation
Table 5
Ranked Snow Courses by Coefficient of ii
Variation, C^, of Snowpack Depth for the
Period of Snow Accumulation
Table 6
Summary of Ranked (Multiple) Snow Courses by 66
Coefficient of Variations of Snowpack Depth,
Water Equivalent, Core Length and Density
for the Period of Snow Accumulation
 56 
Table 1
Average I Standard Deviation and
Coefficient of Variation of Snoi^pack Depth By
Snow Courses for the Period of Snow Ac cumulation
Average
Standard
Cbef fie lent
Survey
Snow
Depth.
Deviation
of
Period
(Date)
Course
(OSC )
1
mm.
(In.)
12.6
Sd
(in.)
1.35
Variation
2.1.69
.108
2
12.2
1.82
.149
3
11.5
.81
.071
4
11.9
2.57
.216
5
10.8
.70
.065
6
11.0
1.14
.103
7
13.8
1.02
.074
8
18.2
1.74
.096
15,1.69
1
11.1
1.45
.131
1
17.3
2.67
.152
I
10.4
2.17
.209
*
14.5
4.34
.300
i
12,7
1.84
,145
i
15.3
2.68
.175
f
13.0
3.05
.234
:i
20.5
3.22
.158
27.1.69
1
4.9
1,67
.341
i
9.1
1.81
.199
I
5,3
1.41
.276
i
6.7
2.62
.392
i
7.D
1.81
.259
•
9.8
2.21
.226
r
8.9
1.69
.190
M
13.9
1.14
.082
 57 
Table 1 (cont'd)
Average
Standard
Coefficient
Survey
Snow
Depth,
Deviation,
of
Period
Course
D.
Sj),
Variation,
(Date)
(OSC )
1
(in.)
3.9
(in.)
%
5.2.69
1.11
.285
2
10.4
2,45
.236
i
4.9
1.86
.380
i
53
4.15
.755
sa
2.23
.436
i
^,6
2.29
.237
f
7.2
2.96
.413
ft
17.0
2.89
.169
 58 
Table 2
Average, Standard Deviation and
Coefficient of Variation of Snowpack Water Equivalent
By Snow Courses for the Period of Snow Accumulation
Average
^^ , , Coeffieient
Standard ^^
Survey
Period
Snow
Course
Water
Equivalent
Deviation variation
% r
(Date)
(OSC )
1
W (in.)
2.7
(in.)
W
2.1.69
.13
,048
2
2,5
.36
.144
1
2.S
.29
.116
4
2.9
,51
.175
1
2.7
.37
.137
1 «
2.8
.27
.097
1
2.9
.41
,141
i
3.0
.38
.127
15.1,69
1
2.8
.49
.175
2
3.9
,BB
.225
3
2.2
.62
,282
4
3.8
1.54
.405
5
3.0
.68
.227
6
4.3
.81
.188
7
2,8
.76
.271
a
3.9
1.14
.292
27.1.69
1
1.6
.61
.381
2
3.2
.76
.237
A
1.6
.59
.369
4
2.4
1.19
.495
1
2,1
.82
.390
i
3.4
1.20
.354
f
2,2
.67
.305
•
3.3
.87
.263
* 59 
Table 2 (cont'd)
Average
Water
Standard
Coefficient
Survey
Snow
Deviation
of
Period
Course
Equivalent
%
Variation
(Date)
(OSC )
W (in,)
(in.)
%
5.2.69
1
.4
.14
.350
1
2.7
1.14
.415
i
1.0
.50
.500
#
1.8
1.32
,745
1
3.4
.79
.565
1
3.4
.96
,283
t
1.4
.87
.620
i
4.3
l.Ol
.236
 60 
Table 3
Average p Standard Deviation and
Coefficient of Variation of Snowpack Core Length
By Snow Courses for the Period of Snow Aceumiilatlon
Coefficient
Survey
Snow
Average
Standard
Deviation
\ (in.)
of
Period
Course
Core Length
Variation
(Date)
(OSC )
1
L (in.)
8.9
Cl
2.1.69
.078
2
8.8
1.23
.140
J
7.6
.97
.128
♦
8.8
2.47
.281
s
8.3
1.08
.130
i .
9.3
1.16
.125
t
9.8
1.83
.187
i
10.3
1.66
.161
15.1.69
1
9.7
1.51
.156
t
14.1
3.01
.214
i
7.5
2.48
.331
4
12.9
5.30
.411
1
11.0
1.92
.175
i
14.1
2.45
.174
1
10.2
2.74
.268
i
14.4
3.54
.246
27.1.69
1
4.4
1.29
.294
1
8.3
1.76
.213
1
4,6 .
.89
.194
#
6.1
2.62
.430
'f
■ s
6.6
1.81
.275
i
9.4
2.21
.236
f
7 .4
1.32
.178
i
9.7
2.81
.290
 61 
Table 3 (cont'd)
Coefficient
Survey
Snow
Average
Standard
of
Period
Course
Core Length
Deviation
Variation
(Date)
(OSC )
1
L (in.)
3.7
Sl (in.)
.92
Cl
5.1.69
.248
2
9.4
2.36
.252
3
4.5
1.62
.360
4
5.2
3.90
.750
5
4.9
2.13
.435
6
9.2
2.44
.265
7
6.2
2.04
.329
*
8
13.9
2.32
.169
 62 
Table 4
Average j Standard Deviation and Coefficient
of Variation of Snowpack Density
by Snow Courses for the Period of Snow Accumulation
Survey
Period
Snow
Course
Average
Denis ty
Standard
Deviation
Coefficient
of Variation
(Date)
(OSC )
1
d (in.)
.22
Sd (in.)
.022
Cd
2.1.69
.100
2
.20
,017
.085
3
.22
.020
.091
4
.25
.014
.056
S
.25
.030
.120
6
.26
.014
.054
7
.21
.028
.134
8
.17
.026
.153
15.1.69
1
.25
.037
.148
2
.23
.032
.139
3
.21
.035
.167
».
4
.26
.036
,138
5
.23
.030
,131
6
.28
.014
.050
7
.21
.014
.067
8
.20
.056
.280
27.1.69
1
.31
.047
.151
a
.35
.056
.160
t
,31
.063
.204
A
.35
.041
.117
5
.30
.046
.153
6
.34
.057
.168
7
.26
.096
.370
i
.24
.061
.254
 63 
Table 4 (cont'd)
Survey
Snow
Average
Standard
Coefficient
Period
Coursi
e
Density
Deviation
of Variatioii
(Date)
(OSC
1
A
L
(111.)
.12
Sd '" ^
(in.)
.098
Cd
5.2.69
.815
2
.27
.081
.300
1
.20
.039
.195
4
.26
.119
.457
i
.27
.094
.347
.35
.059
.169
f
.20
.064
.320
*
•25
.023
.092
• 64 
Table 5
Ranked Snow Courses by Coefficient of
Variation, Cj^, of Snowpack Depth for the Period
of Snow Accumulation
ACCUMULATION PERIOD
 STATISTICAL PARAMETERS
.
DATE
2.1J
S9
15.1
.69
27.1.69
5.2
.69
Total
Group
Snow
Course
r
Rank
c
Rank
r
Rank
c
Rank
Rank
Rank
OSC
%
Oc)
^D
(k)
%
(k)
%
(k)
(Xk)
(K)
1
.108
6
.131
1
.341
7
.285
4
18
5%
2
.149
7
.152
3
.199
3
.236
2
15
2h
3
.071
2
.209
6
.276
6
.380
5
19
7
4
.216
8
.300
8
.392
8
.755
8
32
8
5
.065
1
.145
2
.259
5
,436
7
15
2h
6
103
5
.175
5
.226
4
.237
3
17
4
7
.074
3
.234
7
.190
2
.413
6
18
5h
8
.096
4
,158
4
.082
1
.169
1
10
1
Table 6
Summary of Ranked (Multiple) Snow Courses by
Coefficient of Variations of Snowpack Depth, Water Sjuivalent,
Core Length and Density for the Period of Snow Accumulation
'9i
Snow
Course
OSC
GROUP RANK K
Total
Group
Rank
(IK)
Multiple
Rank
(R)
Depth
Water
Equivalent
Core Length
Density
Ik
K
Tk
K
Ik
K
Ik
K
1
18
5%
11
2
11
1
21
6
14%
3
2
15
2%
15
4
15
3
16
3
12%
2
3
19
7
19
5
18
4%
20
5
21%
6
4
32
8
32
8
32
8
14
2
26
8
5
15
2%
22
7
19
eh
18
4
20
5
6
17
4
10
1
12
2
9
1
8
1
7
18
5%
21
6
19
6%
22
7
25
7
8
10
1
14
3
18
4^
24
8
16%
4
Appendix III
Table 1
Table 2
Table 3
Table 4
Table 5
Page
Standard Deviations and Variations 69
of Basin Snowpack Measured Depths by
Survey Periods
Standard Deviations and Variations 70
of Basin Snowpack Measured Water
Equivalents by Survey Periods
Standard Deviations and Variations of 71
Basin Snowpack Measured Depths for the
Most Uniform Snow Courses (OSC1, 2, 6
and 8) by Survey Periods
Standard Deviations and Variations of 72
Basin Snowpack Measured Water Equi
valents for the Most Uniform Snow
Courses (OSC1, 2, 6 and 8) by Survey
Periods
Statistical Association of Basin Snow 73
pack Measured Depths and Water
Equivalents by Survey Periods
 67 
Page
Table 6
Statistical Association of Basin Snow fi
pack Measured Depths and Water Equi
valents for the Most Unlfom Snow Courses
(OSC1, 2, 6 and 8) by Survey Periods
Table 7
Statistical Association of Basin Snow f
pack Measured Depths and Mater Equi
valents by Survey Periods for the
Regression 0(0,0)  (Wc = bD)
Table S
Statistical Association of Basin Snow fi
pack Measured Depths and Water Equi
valents for the Most Unifomi Snow
Courses (OSC1, 26, and 8) by Survey
Periods for Regression 0(0,0)
(W = bD)
c
 68 
Table 1
Standard Deviations and Variations of
Basin Snowpack Measured Depths by Survey Periods
Standard
Survey
Period
(Date)
Average
Depth,
B (in.)
12.7
Standard
Deviation,
Sd (in.)
2.64
Error of
Average
Depth,
$5 (in.)
.295
Coeffi
cient of
Variation,
2.1.69
.209
15.1.69
14.4
4.13
Ml
.288
27.1.69
8.1
3.29
.368
.404
5.2.69
8.0
4.77
.533
.599
3*26.2.69
5.7
5.43
.650
.957
*14.3.69
7.4
5.71
.903
,774
/ OSC1 excluded )
) or^c: 50% snow cover
* OSC1, 2, 3, and 5 excluded )
 69 
Table 2
Standard Deviations and Variations of
Basin Snowpack Measured Water Equivalents
by Survey Periods
Survey
Period
(Date)
Average
Water Equi
valent ,
W (in.)
2.1.69
2.8
15.1.69
3.3
27.1.69
2.5
5.2.69
2.1
#26.2.69
1.5
*14.3,69
2.7
Standard
Deviation,
Sw (in.)
Standard
Error of
Average
Water
Equivalent,
Sw (in.)
.043
Coeffi
cient of
Variation
Cw
m'
.139
1.12
.125
.335
1.08
.121
.434
1.51
.169
.735
1.49
.178
1.014
1.98
.313
.745
J* OSC1 excluded )
) or <r 501 snow cover
* OSC1, 2, 3 and 5 excluded)
 70 
Table 3
Standard Davlatldns and Variations of
Basin Snowpack Measured Depths for the Most Uniform
Snow Courses (OSC1, 2, 6 and 8) by Survey Periods
Standard
Survey
Period
(Date)
Average
Depth
B (in.)
13,4
Standard
Deviation,
S^ (in.)
3.13
Error of
Average
Depth,
S]5 (in.)
.494
Coeffi
cient of
Variation
^D
^ 2.1.69
.234
15.1.69
16,0
4.25
.672
.265
27.1.69
9.3
3.74
.591
.400
5.2.69
10.2
5.18
.818
.505
?t26.2.69
9.4
5.76
1,052
,610
*14.3.69
11,2
4.52
1.009
.404
f OSC1 eiccluded )
) or < 50% snow cover
* OSC1 and 2 excluded )
 71 
Table 4
Standard Deviations and Variations of
Basin Snoi^ack Measured Water Equivalents for the
Most Uniform Snow Courses (OSC1, 2, 6 and 8) by
Survey Periods
Survey
Period
(Date)
Average
Water
Equivalent
W (In.)
2.1.69
2.8
15.1.69
3.7
27.1.69
2,9
5.2.69
2.7
3*26.2.69
2.6
•14.3.69
4.0
Standard
Error of
Average
Coeffi
Standard
Water Equi
cient of
Deviation,
valent ,
Variation
Sy (in.)
.055
Cy
.35
.126
1.00
.156
.268
1.14
.181
.400
1.67
.265
.620
1.51
.276
.589
1.42
.316
.358
•ff OSC1 excluded )
) or
* OSC1 and 2 excluded) ,
50% snow cover
 72 
Table 5
Statistical Association of Basin Snowpack Measured
Depths and Water Equivalents by Survey Periods
l4
Survey
Period
(Date)
Average
Water
Equi
valent
W (in.)
Intercept
A (in.)
Regres
sion
Coeffi
cient, b
STANDARD ERROR OF
1
Coeffi
cient of
Determina
tion
r2
FValue
Estimate
Se (in.)
Intercept
Sa (In,)
Regres 
sion
Coeffi
cient
Sb
2.1.69
2.8
1.81
.07
.330
.li3
.014
.25
27.9
15.1.69
3.3
.31
.21
Jll
.290
.019
.58
117.8
2?. 1.69
2.5
.46
.25
.707
.212
.024
.57
105.2
5.2,69
2.1
,lf
.28
.686
.150
.016
.79
306.2
?t26.2.69
1.5
M
.26
.518
.090
.012
.88
503.4
*14.3.69
2.7
M
.33
.534
.139
.015
.93
496.8
# OSC1 excluded 
) or < 50% snow cover
* OSC1, 2, 3 and 5 excluded )
*
Table 6
Statistical Association of Basin Snowpack
Measured Depths and Water Equivalents for the
Most Ifeiform Snow Courses (OSC1, 2, 6 and 8) by Survey Periods
:
Average
Water
;
Regres
STANDARD ERROR OF
1
Coeffi
.:
Regres
sion
Survey
Period
(Date)
Equi
valent
W (in.)
Intercept
A (in.)
sion
Coeffi
cient, b
Estimate
Se (in.)
Intercept
Sa (in.)
Coeffi
cient
Sb
cient of
Determina
tion, r^
FValue
2.1.69
2.8
2.02
.06
.306
.245
.016
.23
12.4
15.1.69
3.7
1.46
.14
.812
.626
.031
.34
21.4
27.1.69
2.9
.82
.22
.810
.492
,035
.50
40.0
5.2.69
2.7
.19
.28
.830
.594
.026
.76
121.7
A26.2.69
2.5
.36
.23
.705
.536
.023
.78
104.9
*14.3.69
3.9
.82
.28
.651
,863
.033
.79
71.7
f OSC1 excluded )
) or < 50% snow cover
* OSC1 and 2 excluded )
Table 7
Statlitleal Association of
Basin Snowpack Measured Depths and Water Iquivalents
by Survey Periods for the Regression 0(0,0)
Survey
Period
(Date)
Average
Water
Equivalent
^ (in.)
2.1.69
2.8
15.1.69
3.3
27.1.69
2.5
5.2.69
2.1
#26.2.69
1.5
*14.3.69
2.7
(W  bD)
c
J
Regression
Coefficient,
b
Standard
Error of
Estimate,
Sg (in.)
.497
Standard
Error of
Reg, Coef.
^b
.22
.016
.23
.717
.021
.31
.728
. .029
.27
.693
.028
.26
.519
.024
.36
.547
.023
# OSC1 excluded )
) or < 50% snow cover
* OSC1, 2, 3 and 5 excluded )
 75 
Table 8
Statistical Association of
Basin Snowpack Measured Depths and Water Equivalents
for the Most Oniform Snow Courses
(OSC1, 2, 6 & 8) by
Survey Periods for Regression 0(0»0)
(%  bD)
Average Standard Standard
Survey Water Regression f ^J'^ ^^ f ^^^,°^
Period Equivalent Coefficient ftl^f ^e Reg. Coef
(Date) W (in.) b ^e ^^"'^ ^b
2.1.69 2,8 .21 ,558 .023
15.1.69 3,7 .23 .897 .035
27.1.69 2,9 .31 .867 .045
5.2.69 2*7 .27 .836 .042
#26.2.69 2.6 .28 .731 .038
*14.3.69 4.0 ,35 .725 .035
# OSC1 excluded )
) or <• 5 OX snow cover
* OSC1, 2, 3 and 5 excluded)
" 76 ^
Appendix IV
Table 1
Area! Distribution of Snow Courses
(Thies s en ' s Method )
Page
78
Table 2
Area Elevation and ZonalArea
Bistribution of Snow Courses
79
Table $
Arithiietic Averages of Basin Snow
pack Indices by Survey Periods
81
Table 4
Weighted Averages (by Thiessen's Method)
of Basin Snowpack Indices by Survey Periods
82
Table 5
Weighted Averages (by Area Elevation Method)
of Basin Snowpack Indices by Survey Periods
83
fable 6
AreaIsohyet Distribution and Basin Weighted
Average Snowjpack Depth by Survey Feriods
84
Figures 1 to 6
Isohyets of Snowpack Depth in Inches
(Survey Periods: 2.1.69 to 14.3.69)
m  m
 77 
Table 1
Areal Distribution of
Snow Courses (l^iessen's Method)
Snow
Course
OSC
Site
Elevation
 Feet
(a.s.l.)
i Sub Basin
2
Drainage Area in Mi
Areal
Cover 
. age
(Mi^)
Percent
Areal
Cover
age
(%)
01
02
03
04
1
600

.66

6.62
8.8
2
625


.02
.19
7.06
9.4
3
625


10.97
3.76
18.99
25.2
4
725
2.67
4.85
14.78

14.78
19.5
5
775


1.65
3.06
6.88
9.1
6
800


3.66
2.33
5.99
7.9
7
850
6,26
6.26
8.91

8.91
11.8
8
1,000
6.29
6.29
6.29

6.29
8.3
Total
Area
mn
15.22
17.40
46.94
9.34
75.52
100.0
Percent
Area (X)
20.2
23.0
62.0
12.3
100.00
Mi  square miles
a.s.l. > above sea level
 78 
Table 2
Area Elevation and ZpnalArea
Dlstrlbucion of Snow Courses
Area Below
Area
Zonal
Elevation
Enclosed
Area
Snow Course &
Elevation 
2
2
2
Distribution
Feet (a.s.l.)
(Mi )
(Ml )
(Mi )
Factor
1.05
600
1.05
8.91
625
9.96
12.85
(OSC1, 2 & 3)
650
22.81
7.66
675
30.47
5.06
700
36.53
36.53
.484
7.32
725
43.85
1.65
(OSC4, 5 & 6)
750
45.50
8.65
800
54.15
17.62
.233
8.78
850
62 .93
37
(OSC7)
900
63.90
9.75
.129
 79 
Table 2 (cont'd)
Elevation 
Area Below
Elevation
2
Area
Enclosed
2
Zonal
Area
2
Snow Cburse &
Distribution
Feet (a.s.l.)
(Mi )
(Ml )
(Mi )
Factor
!
1.25
950
65.15
2.37
1.000
67 .52
.05
(OSC8)
1,050
67 .57
3.34
1,100
70.91
1.46
1.150
72.37
3,15
1,200
75 .52
11.62
.154
Mi
square miles
 80 
Table 3
Arithmetic Averages of Basin Snowpack
Indices by Survey Periods
BASIN INDEX
Survey
Period
(Date)
 Average 
Depth, D
(in.)
Water Equivalent,
W (In.)
Density, ^
(in.)
2.1.69
12.7
2.8
mMMi
15.1.69
14.4
3.3
[
27.1.69
8.1
2.5
m \
5.2.69
8.i
2.1 \
M !
26.2.69
5.2
1.3
14.3.69
4.0
1.4
■
24.2.69
0.0
0.0
#ii
 81 
Table 4
Weighted Averages (by Thlessen's Method)
of Basin Snowpack Indices by Survey Periods
BASIN INDEX
Survey
Period
(Date)
 Weighted Average 
Depth, D
(In.)
Water Equivalent,
VI (in.)
Density, d
(in.)
2.1.69
12.5
2.7
.12 '
15.1.69
13.7
3.2
.23
27.1.69
7.5
2.3
.31
5.2.69
7.1
1.8
,23
26.2.69
4.2
■1
1.1
.21
14.3.69
33
1.2
.29
24.3.69
0.0
0.0
.00
 82 
Table 5
Weighted Averages (by Area Elevation Method)
of Basin Snowpack Indices by Survey Periods
BASIN INDEX
Survey
Period
(Date)
 Weighted Average 
Depth, D
(in.)
Water Equivalent,
W (In.)
Density, d
(in.)
2.1.69
13.0
2.7
.22
15.1.69
14.4
3.2
.23
27.1.69
8.2
2.4
,31
5.2.69
8.2
2.0
.23
26.2.69
5.3
1.4
.21
14.3,69
4.0
1.1
.27
24.3.69
0.0
0.0
.00
 83 
Table 6
AreaIsohyat Dlstrlbutlori and
In Weighted Average Snowpack Depth by
Survey Periods
<
;,,
AREA EMCLOSED
SNOW
DEPTH
Weighted
1 ;
Average
Survey
Average
(Accumula
Period
Isohyet
2
Isohyet
tive)
(Date)
(in.)
Mi
%
(In.)
(in.)
2.1.69
10.0
i
!
36.3
48.0
10.9
•(
12.0
14.0
23.1
30.6
13.0
5.8
7.7
15.0
,1
i
16.0
3.8
5.0
17.0
18.0
6.5
8.7
18.1
12.8
20.0
15.1.69
10.0
;
15.1
20.0
11.1
i
12.0
\
25.3
33.5
13.0
14.0
15.5
20.6
15.0
16.0
7.8
10.3
17,0
18.0
4.6
6.1
19.0
20.0
■
1 '■'
9.5
20.3
14.5
 84 
Table 6 (cont'd)
AREA ENCLOSED
SNOW DEPTH
Weighted
'
Average
Survey
Average
(Accumula
Period
Isohyet
Mi2
Isohyet
tive)
(Date)
(in.)
%
(in.)
(in.)
27.1.69
4.0
.
)
1
6.0
19.1
25.6
4.9
i
23.1
31.0
7.0
;
8,0
16.6
21.0
9.0
10.0
6.8
9.0
11.0
12.0
8.4
11.2
13.0
;
i
14.0
t
1.5
2.2
14.0
8.1
5.2.69
4.0
31.2
41.4
5.0
•
6.0
■
8.0
18.9
25.0
7.0
/
10.0
13.2
9.0
10.0
12.0
3.3
4.4
11.0
14.0
3.0
4.0
13.0
3.0
4.0
15.0
1
16.0
6.1
8.0
17.0
7.9
 85 
Table 6 (cont'd)
'
AREA
ENCLOSED
SNOW DEPTH
Weighted
ll
i
Average
Survey
Average
(Accumula
Period
Isohyet
2
Isohyet
tive)
(Date)
(in.)
Mi^
%
(in.)
(in.)
26.2.69
13.4
17.6
1.0
2.0
30.4
40.3
3.0
4.0
15.9
21.0
6.0
8.0
7.8
10.3
10.0
12.0
5.4
7.1
14.0
16.0
2.6
3.7
16.2
5.3
14.3.69
34.0
45.0
1.0
1
2.0
i
i
11.2
14.8
2.0
,1
4.0
14.1
18.6
6.0
8.0
ii
8.5
11.3
10.0
'
12.0
7.8
10.3
13.5
4.4
 86 
ONTARIO WATER RESOURCES COMMISSION
DIVISION OF WATFR RESOURCES
INTERNATIONAL HYDROLOGICAL DECADE
EAST AND MIDDLE OAKVILLE CREEKS
DRAINAGE BASIN
Figure 1 . Isohyets of snovvpaek depth in inches  Survey period 2.1 .69.
^^^..^rv>^
ONTARIO WATER RESOURCES COMMISSION
DIV SION or AATER RESOURCES
INTERNATIONAL HYDROLOGICAL DECADE
EAST AND MIDDLE OAKVILLE CREEKS
DRAINAGE BASIN
Wnil"
Figure 2. Isohyets of snowpack depth in inchas Survey period 15.1 ,6§.
Figure 3. Isohyets of snowpack depth in inches  Survey period 27.1 .69.
ONTARIO WATER RESOURCES COMMISSION
DIVISION OF WATER RESOURCES
INTERNATIONAL HYDROLOGICAL DECADE
EAST AND MIDDLE OAKVILLE CREEKS
DRAINAGE BASIN
Figyre 4. Isohyets of snowpack dspth in inches  Sorvey period 5.2.69.
79*43'
ONTARIO WATER RESOURCES COMMISSION
DIVISION OF WATER RESOURCES
INTERNATIONAL HYDROLOQICAL DECADE
EAST AND MIDDLE OAKVILLE CREEKS
DRAINAGE BASIN
2 Miles
Bnrlingtt
Dundas
HAMILTON
KEY MAP
Scale 1:1.000,000
_^ , ^ i^« — i::^ , L^ ^^ Hi— ' ^r ■ — ^
z a\
Figure 5. Isohyets of snowpack depth in inches  Survey period 26.2.69.
ONTARIO WATER RESOURCES COMMISSION
DIVISION OF WATER RESOURCES
INTERNATIONAL HYDROLOGICAL DECADE
EAST AND MIDDLE OAKVILLE CREEKS
DRAINAGE BASIN
] 2 Miles
Figure 6. Isohyets of snowpack depth in inches  Survey period 14.3.69.
*TtT3tDDDDDT15fl«