Why is it important to check the consistency of rainfall data?
Precipitation puts water in the watershed. Precipitation measurements help determine water availability for evaporation and streamflow, and the risk of forest fires, landslides, and soil erosion.
What is purpose of mass curve?
A plotting of the cumulative values of a variable as a function of time. This is applied especially to mass curves of rainfall in storm studies, to departures of various weather elements from normal, and to streamflow data for reservoir studies.
What is meant by double-mass curve?
The theory of the double-mass curve is based on the fact that a plot of the two cumulative quantities during the same period exhibits a straight line so long as the proportionality between the two remains unchanged, and the slope of the line represents the proportionality.
How do you double mass?
Let be the data points then the procedure for double mass analysis is as follows;
- Divide the data into distinct categories of equal slope ( ).
- Obtain correction factor for category as;
- Multiply category with to get corrected data.
- After correction, repeat this process till all data points have the same slope.
What is the use of double mass curve in hydrology?
Abstract: The double- mass curve is used to check the consistency of many kinds of hydrologic data by comparing date for a single station with that of a pattern composed of the data from several other stations in the area. The double-mass curve can be used to adjust inconsistent precipitation data.
What is the causes of the inconsistency of rainfall data?
Inconsistency would arise in the rainfall data at a raingauge station if conditions relevant to recording of rainfall at the station undergoes significant change during the period of record. It would be felt from the time a significant change took place.
What is mass curve analysis?
The mass curve technique, proposed by Rippl in 1883 to determine storage capacity of a reservoir, is a graphical technique. To determine minimum required storage, the mass curve of inflow and the mass curve of demand are accumulated separately.
How do you determine the consistency of rainfall data?
The consistency of a rainfall record is tested with double-mass analysis. This method compares the cumulative annual (or alternatively, seasonal) values of station X with those of a reference station. The reference station is usually the mean of several neighboring stations.
What is double-mass curve of rainfall?
Double mass curve: The accumulated rainfall of station is plotted as ordinate and the accumulated rainfall of the average of surrounding rain gauges is plotted as abscissa to obtain a curve known as a double mass curve. The double-mass curve can be used to adjust inconsistent precipitation data.
What is the difference between mass curve and Hyetograph?
The mass curve depicts cumulative rainfall over time, but the hyetograph depicts rainfall intensity over time intervals. Rainfall at a single location is referred to as point precipitation.
What happens if we double mass?
If the mass of one of the objects is doubled, then the force of gravity between them is doubled. If the mass of one of the objects is tripled, then the force of gravity between them is tripled. If the mass of both of the objects is doubled, then the force of gravity between them is quadrupled; and so on.
What happens when you double the mass?
If you double the force, you double the acceleration, but if you double the mass, you cut the acceleration in half.
Why is it important to determine the runoff coefficient?
Why is It Important? It is important for flood control channel construction and for possible flood zone hazard delineation. A high runoff coefficient (C) value may indicate flash flooding areas during storms as water moves fast overland on its way to a river channel or a valley floor.
What are the methods of estimating missing rainfall data?
The following methods are most commonly used for estimating the missing records.
- Simple Arithmetic Method.
- Normal Ratio Method.
- Modified normal ratio method.
- Inverse distance method.
- Linear programming method.
Where is the mass curve method used?
This method is also known as the Rippl mass curve method after the developer of this method. This is a simple method commonly used to estimate the required storage capacity of a reservoir in the project planning stage. The method uses the most critical period of recorded flow to compute storage.
How do you do a mass curve analysis?
Hydrology Topic 2-3-4 Precipitation Data Analysis / Missing Rainfall …
What is difference between hydrograph and hyetograph?
2. Hydrograph shoes variation of discharge with the time at particular point office stream it also shows the time distribution of total runoff at the point of measurement. The area under hyetograph gives the total rainfall occurred in that period. 3.
How does a hyetograph work?
HYETOGRAPH A hyetograph is a graphical representation of the relationship between the rainfall intensity and time. It is the plot of the rainfall intensity drawn on the ordinate axis against time on the abscissa axis.
What would happen to the acceleration if the mass is doubled?
The acceleration is equal to the net force divided by the mass. If the net force acting on an object doubles, its acceleration is doubled. If the mass is doubled, then acceleration will be halved.
What happens to velocity when mass is doubled?
If you increase either mass or velocity, the momentum of the object increases proportionally. If you double the mass or velocity you double the momentum.
How does doubling the mass affect gravitational energy?
If the mass of both of the objects is doubled, then the force of gravity between them is quadrupled; and so on. Since gravitational force is inversely proportional to the square of the separation distance between the two interacting objects, more separation distance will result in weaker gravitational forces.
What are the factors affecting runoff?
Temperature, wind speed, and humidity are the major meteorological factors, which affect runoff. Temperature, wind speed and humidity affect evaporation and transpiration rates, thus soil moisture regime and infiltration rate, and finally runoff volume.
What does a high runoff coefficient mean?
A high runoff coefficient (C) value may indicate flash flooding areas during storms as water moves fast overland on its way to a river channel or a valley floor. How is It Measured? It is measured by determining the soil type, gradient, permeability and land use.
What causes missing rainfall data?
Environmental data, particularly, rainfall data are highly vulnerable to be missed, which is due to several reasons, such as malfunction instrument, incorrect measurements, and relocation of stations.