International Commission on Irrigation & Drainage Commission Interationale des Irrigation et du Drainage

Multilingual Technical Dictionary (MTD)
<<    Browsing page 1 of 4    >>
Term No.Term Name/Term DescriptionAction
6
Accuracy of the mean
The closeness of agreement between the true value and the mean result obtained by applying the experimental procedure to a very large number of times. The smaller the systematic part of the experimental errors which affect the results, the more accurate is the procedure......
Similar Terms
105
Arithematic mean
The arithmetic mean of a set of values. Generally denoted by a bar, thus :
Similar Terms
107
Consecutive average, Moving average, or Consecutive mean
The mean of a small group of consecutive values, especially annual means, assigned to the middle time-term of the group in the process of smoothing, e.g. 5-year mean......
Similar Terms
109
Geometric mean
If the set of n values are all multiplied together and the nth root is taken, the results are known as the geometric mean (G), viz. G = (x1 . x2 ... x n-1 . xn)1/n .....
Similar Terms
110
Harmonic mean
The reciprocal of the arithmetic mean of the reciprocals of each observation.
Similar Terms
113
Weighted average, or Weighted mean
An average of quantities that attaches a series of weights to it in order to make proper allowance for their relative importance. A value obtained by multiplying each of a series of values by its assigned weight and dividing the sum of those products by the sum of the weights. For example, a weighted arithmetic mean of x1, x2 ... xn with weights w1.....
Similar Terms
114
Root mean square
The square root of the arithmetic mean of the squares of each observation and is given by
Similar Terms
117
Average deviation, or Mean deviation
A measure of dispersion derived from the average deviation of observations from some central value, such deviations being absolute, i.e. without reference to algebric sign......
Similar Terms
124
Positional measures of dispersion, or Quartiles
Measures defined by a certain position on the scale of cumulative frequency; any two of such positional measures, or quartiles, give an idea of the variability......
Similar Terms
129
Mean square
In general, the mean square of a set of values is the arithmetic mean of the squares of their differences from some given value, namely their second moment about that value......
Similar Terms
134
Standardized averages, or Standardized means
A method of allowing or `adjusting` the effects of other variables, or for differences in the composition of the groups that are to be compared, by using a standard set of weights to combine the means of sub-groups into a single mean. Used mainly for the construction of index numbers......
Similar Terms
208
Mean square error of estimate
The square root of the arithmetic mean of the squared deviations between the estimates for different samples and the population parameter under estimation......
Similar Terms
278
Mean consecutive
The mean of a small group of consecutive values, especially annual means, assigned to the middle time-term of the group, in the process of `smoothing`......
Similar Terms
364
Speed, or Velocity
img:equations//362_368_e.jpg
Similar Terms
417
Angular velocity
img:equations//415_417_e.jpg
Similar Terms
418
Velocity
img:equations//418_421_e.jpg
Similar Terms
548
Velocity
img:equations//547-548_e.jpg
Similar Terms
759
Mean annual precipitation
The average over a period of years of the annual amounts of precipitation.
Similar Terms
760
Weighted mean monthly precipitation
The weighted mean precipitation for each month for a large area derived from the study of the isohyetal map of the area.
Similar Terms
847
Mean annual runoff
The value of the annual volume of water discharged by the stream drainage of the areausing  sufficiently long record to obtain a fair mean......
Similar Terms
848
Mean monthly runoff
Arithmetic mean of all the individual monthly mean discharges for a named month in a period of record.
Similar Terms
884
Mean annual evaporation
The average depth of evaporation over period of enough years to give an approximate constant value.
Similar Terms
1099
Effective velocity (of groundwater), Actual velocity (of groundwater), True velocity (of groundwater), or Field velocity (of groundwater)
The velocity measured by the volume of groundwater passing per unit time through unit cross sectional area divided by the effective porosity of the water transmitting material......
Similar Terms
1100
Apparent velocity (of groundwater)
The apparent distance moved in unit time by groundwater. It is determined by V = Q/F where F is the cross sectional area perpendicular to the streamlines and Q the volume of water passing through this cross section in unit time......
Similar Terms
1101
Average velocity (of groundwater)
The volume of groundwater passing through a unit cross-sectional area in unit time divided by the porosity of the water transmitting material......
Similar Terms
<<    Browsing page 1 of 4    >>