A hydrograph is a graph showing stage, discharge, velocity, or other properties of water flow with respect to time. When the stage is plotted against time, the graph is a stage hydrograph (which is the form of a stream gage record). When the discharge is shown against time, the graph is a discharge hydrograph.
What is the unit of discharge in hydrographs?
Discharge & Hydrographs. The discharge of a river (or stream) is the volume of water that flows past a point in the river’s course per second. The volume is measured in cubic metres (m3) and it’s per second so the units of discharge are cubic metres a second or m3s-1.
What is a hydrograph?
What is a Hydrograph? Stream discharge hydrograph. Enlarge graph. Hydrographs are charts that display the change of a hydrologic variable over time. Here are several examples from the US Geological Survey's gaging station on the Tioga River near Mansfield, Pennsylvania.
What is a stream stage hydrograph?
Stream stage hydrograph. Enlarge graph. A stream stage hydrograph shows how the height of the water above a reference datum has changed over time. Because the discharge of a stream is related to its stage, stage hydrographs and discharge hydrographs have very similar shapes.
What is the relationship between discharge and conductance hydrographs?
If you study this specific conductance hydrograph and compare it to the discharge hydrograph, you should conclude that the concentration of dissolved ions is inversely proportional to the discharge of the stream.
What is discharge in geography?
The discharge of a river is the volume of water which flows through it in a given time. It is usually measured in cubic meters per second. Calculation: Cross-sectional area of channel (m2) X Velocity of the river / water (m/s) *This gives discharge as the volume (m3/s) or cumecs.
What are the types of hydrographs?
Types of hydrographs include:Storm hydrographs.Flood hydrographs.Annual hydrographs a.k.a. regimes.Direct Runoff Hydrograph.Effective Runoff Hydrograph.Raster Hydrograph.Storage opportunities in the drainage network (e.g., lakes, reservoirs, wetlands, channel and bank storage capacity)
What is discharge and runoff?
Thus, the terms discharge, streamflow, and runoff represent water with the solids dissolved in it and the sediment mixed with it. Of these terms, discharge is the most comprehensive. The discharge of drainage basins is distinguished as follows: Yield. Total water runout or crop; includes runoff plus underflow.
What are the uses of hydrographs?
A hydrograph may be used to show how the water flow in a drainage basin (particularly river runoff) responds to a period of rain. This type of hydrograph is known as a storm or flood hydrograph and it is generally drawn with two vertical axes.
What factors affect hydrographs?
Factors Affecting a Storm HydrographThe Drainage Basin. The shape of a hydrograph is altered by a few different things. ... Soil & Rock Type. ... Weather & Climate. ... Vegetation Cover. ... Human Activity.
What are the component of hydrographs?
There are three main components to the hydrograph—rising limb, peak, and falling limb. The falling limb is often referred to as the recession curve, which provides information on the configuration of the karst conduits within an aquifer system, as well as its transmissivity and volume.
What is the difference between flow and discharge?
The amount of fluid passing a section of a stream in unit time is called the discharge. If v is the mean velocity and A is the cross sectional area, the discharge Q is defined by Q = Av which is known as volume flow rate. Discharge is also expressed as mass flow rate and weight flow rate.
What is called runoff?
Runoff is nothing more than water "running off" the land surface. Just as the water you wash your car with runs off down the driveway as you work, the rain that Mother Nature covers the landscape with runs off downhill, too (due to gravity). Runoff is an important component of the natural water cycle.
What is unit of discharge?
Discharge = V x D x W If length is measured in feet and time in seconds, Discharge has units of feet3/sec or cubic feet per second (cfs). Depth times Width gives the cross-sectional area. The shape of the channel is important because of the reduction in velocity due to friction along the channel margins.
What is unit of hydrograph?
5). A unit hydrograph is a hydrograph for a specific time period of rainfall excess (runoff) and uniform distribution and whose volume of runoff is equal to one inch of water over the entire watershed. Unit rainfall duration refers to the time period of rainfall producing runoff (rainfall excess).
What is characteristics of hydrograph?
A hydrograph is a curve describing the variation of discharge with time as a result of a storm. The main features are the rising and falling limbs, the peak and the base duration.
What is hydrograph and its significance?
A hydrograph is a graph or plot that shows the rate of water flow in relation to time, given a specific point or cross section. These graphs are often used to evaluate stormwater runoff on a particular site considering a. development project.
What are the types of runoff?
There are three major types of runoff depending on the source: surface flow, interflow, and base flow.
What is true hydrographs?
Hydrograph: It is a continuous plot of instantaneous discharge (runoff) v/s time. It results from a combination of physiographic and meteorological conditions in a watershed and represents the integrated effects of climate, hydrologic losses, surface runoff, interflow, and groundwater flow.
What are the three basic properties of unit hydrograph theory?
(i) Flood hydrograph can be calculated with the help of very short record of data. (ii) In addition to peak flow unit hydrograph also gives total volume of runoff and its time distribution. (iii) The unit hydrograph procedure can be computerised easily to facilitate calculations.
What are the characteristics of hydrograph?
A hydrograph is a curve describing the variation of discharge with time as a result of a storm. The main features are the rising and falling limbs, the peak and the base duration.
What is a hydrograph?
Hydrographs are charts that display the change of a hydrologic variable over time. Here are several examples from the US Geological Survey's gaging station on the Tioga River near Mansfield, Pennsylvania. Although these examples are from a stream, hydrographs can also be made for lakes, water wells, springs and other bodies of water.
How does a hydrograph show water temperature?
This water temperature hydrograph shows a daily cycle of temperature from solar heating. When the morning sun begins heating the land, stream, and atmosphere, the water temperature begins to increase. This temperature increase continues through the day and reaches a maximum near sunset. Temperatures drop through the night, and the cycle begins again the next morning. In this hydrograph, notice how the daily temperature cycle was interrupted on August 30th. The cold precipitation/runoff lowered the water temperature and eliminated the daily temperature rise.
What causes the pH of the Tioga River?
The pH of the Tioga River at this location is generally below 7.0. This low pH is caused by acid mine drainage entering the river at several locations upstream. The sharp increase in pH on August 30 was caused by the large amount of precipitation/runoff (probably with pH of about 7.0) entering the stream.
Can hydrographs be made for lakes?
Although these examples are from a stream, hydrographs can also be made for lakes, water wells, springs and other bodies of water.
What are the components of a hydrograph?
Following are the components of the hydrograph: 1. Rising Limb: It shows the increase in discharge from the catchment area in response to the rainfall. 2. Falling limb or Recession Limb: The falling limb is the extension of the graph from the peak flow rate. 3. Peak Discharge:
What is synthetic hydrograph?
A synthetic unit hydrograph retains all the features of the unit hydrograph but does not require rainfall-runoff data. It is derived from model and experience, and it is used to simulate basin diffusion by assessing the basin lag based on a specific method.
What is unit hydrograph?
unit hydrograph is a natural or synthetic hydrograph representing one inch of runoff', uniformly from the watershed during a specified time. In other words, the area under the graph is actually a volume of one inch of runoff.
What is dam breach hydrograph?
dam breach hydrograph represents the sudden release of water from the impoundment due to a breach, followed by the draining of the reservoir. The volume represented by the hydrograph is the storage volume of the reservoir released during the breach. Factors affecting the shape of the breach hydrograph include: size and shape of breach, depth of water at the dam, volume of stored water, surface area of reservoir, and shape (especially length) of reservoir. A breach hydrograph can be natural (recorded) or synthetic (a simulation). Figure 4 shows a breach hydrograph from the instantaneous failure of a dam.
What is dimensionless unit hydrograph?
dimensionless unit hydrograph is a generic combination of many natural unit hydrographs. The ordinate and abscissa scales are ratios of the discharge with respect to the peak discharge and the time relative to the time ,to peak, respectively (Figure 2).
What is a hydrograph?
A hydrograph shows two graphs - a bar chart showing rainfall, usually from a storm and a line graph showing discharge from before, during and after the rain storm shown in the bar graph. Basically, a hydrograph shows you the ways in which a river is affected by a storm.
What is hydrograph in geography?
A hydrograph shows how a river is affected by a storm. This helps to understand discharge patterns of a particular drainage basin and helps to predict flooding and plan flood prevention measures. Part of. Geography. Hydrosphere.
Why is there a delay in the flow of a river?
There is a delay because it takes time for the water to find its way to the river. This is called lag time. The normal (base) flow of the river starts to rise when run-off, ground and soil water reaches the river. This is shown on the hydrograph as the rising limb.
