Drainage Basin: Elements

-

 Inputs, Outputs, Transfers, Storage...Woahhh


Characteristics of the Drainage Basin

  • Inputs: in the form of precipitation and snow
  • Outputs: this is where water is lost from the system, either through being carried to sea (by rivers) or through evapotranspiration. 

Within the system some water is:

  • Stored: In rivers, soil, vegetation.
  • Transferred: Infiltration, through-flow etc. 
Key:    INPUT
            STORAGE
            TRANSFERS
            OUTPUTS

Precipitation

This term refers to the act of water/moisture (in its solid or liquid form) falling from clouds in the sky. 

Examples include: Rain, hail and snow. 

Influencing Factors:

  • Presence of Vegetation 
  • Time of Year
  • Altitude 
  • Latitudinal Location

Evaporation

This is the process by which the suns energy converts water into water vapour.

Influencing Factors:
  • Atmospheric Conditions (temperature, humidity, hours of sunshine, wind speed)
  • Time of Year

Transpiration

This a biological process by which water is lost from a plant through the stomatas on the leaves. 

Influencing Factors: 
  • Type of vegetation
  • Vegetation density/coverage 
  • Availability of moisture 

Evapotranspiration (EVT)

This is the process by which water is loss from both water bodies and vegetation. 
  • Actual EVT: The exact amount of water being converted to water vapour
  • Potential EVT: The amount of water than can be (potentially) converted into water vapour

Interception

Refers to water that caught and stored by vegetation. Interception loss is the water that is retained on plant surfaces and never enters the system. 

Other terms to note:
  • Through-fall: Water falling between the gaps of leaves
  • Stem-flow: Water flowing along the stems of plants and trunks of trees
Influencing Factors:
  • Presence of Vegetation
  • Type of Vegetation
  • Volume of precipitation 

Infiltration

This is the downward movement of water from the surface, into the soil (subsurface). The maximum rate at which rain can be absorbed via the soil mm/hr is known as its infiltration capacity. 

Influencing Factors: 
  • Permeability 
  • Duration of precipitation 
  • Intensity of precipitation
  • Raindrop size
  • Angle of slope 
  • Vegetation Cover
Other terms to note:
Through flow: The lateral movement of water through the soil layer. 
Antecedent Precipitation: Water already present in the soil

Comments

Post a Comment

MOST POPULAR

Population Density and Distribution: INTRODUCTION

-
Image
No, population distribution and population density are not the same thing...here's the difference: Image: From Conde Nast Traveller India  What is Population Distribution?  Population Distribution is the way people are spread across a geographical area. Population distribution is usually uneven and over time, changes. Population distribution can be represented on a dot map .  What is Population Density? Population Density refers to the number of people that leave per square unit area. Population Density can be represented on a choropleth map.   Population Distribution Formula: On a global scale, population density and distribution patterns can be influenced by physical factors such as:  Relief Climate  Water Supply Vegetation  Soil On a smaller scale, namely local or regional, patterns of population distribution and density can be influenced by  Economic factors Social factors  Political factors 
Read more

River MORPHOLOGY

-
Image
 Yes, the shape of rivers is important in understanding aspects of hydrology. Lets look at it.  Image: From Seneca College Pressbooks What is Morphometry? Morpho - Shape Metry - Size  Morphometry refers to the shape , size and form of rivers in a drainage basin. This allows us to make objective comparisons on the similarities and differences of a drainage basin: Establish a stream hierarchy Law of stream order: the relationship between stream order and stream number Stream Ordering  First Order- initial tributaries (no prior connections)  Second Order- a stream joined by two first order streams  Third Order- a stream joined by two second order streams   Law of Stream Order  Two stream segments of an equal order, will create a segment of a higher order. However the order of a stream will remain the same if a lower order segment joins a higher order segment.  Bifurcation Ratio This is the relationship between the number of streams in one order to one that is of a higher order.  Signific
Read more