1 / 9

Drainage Basin(1)

Drainage Basin(1). What is drainage basin? - An area of land drained by a river and its tributaries (river system). - Its boundary is marked by a watershed (highland surrounding the lowland). Drainage Basin(2). Drainage basin as an open system:

monty
Download Presentation

Drainage Basin(1)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Drainage Basin(1) • What is drainage basin? - An area of land drained by a river and its tributaries (river system). - Its boundary is marked by a watershed (highland surrounding the lowland).

  2. Drainage Basin(2) • Drainage basin as an open system: 1. Flows of energy and matter in and out in the drainage basin. 2. Major components: a. Inputs: - climatic inputs: precipitation and temp. - geological input: rocks - relief input - vegetation cover

  3. Drainage Basin(3) 2. b. Processes and storage of energy and matter: - Denudation (weathering, mass wasting, transportation, erosion and deposition) - Storage of matter (water, load) and energy in river channels - Transfer of matter and energy through a number of processes (infiltration, percolation, base flow, seepage, etc.)

  4. Drainage Basin(4) 2. c. Outputs: - River discharge entering the sea or returning to the atmosphere - Sediments finally deposited in the sea - River landforms along the course

  5. Drainage Basin(5) 2. d. Linkages to other subsystems: - Weathering subsystem - Slope subsystem - Channel subsystem

  6. Drainage Basin(6) • Analysis of drainage network: quantity approach a. Stream order: - Within a drainage basin, a constant geometrical relationship exists between the occurrence of one stream order in the hierarchy and the number of streams in the next highest order. - The number of stream decreases with the stream order. - A drainage basin is described in terms of the highest order stream within.

  7. Drainage Basin(7) 3. b. Stream density : - the average length of stream channel per unit area of drainage basin, i.e. km/ sq. km. - Stream density = channel length Area

  8. Drainage Basin(8) 4. Factors controlling drainage density: a. Climatic factors: - precipitation: annual amount, distribution, variability - temperature affects evaporation b. Geological factors: permeability of rocks c. Soil : permeability of soil d. Topography e. Vegetation cover: infiltration of rainfall f. Human activities: urbanization, farming, transportation

  9. Drainage Basin(9) 5. Bifurcation ratio: a. It shows the relationship between the number of streams of one order of magnitude with those of the next higher order. b. Bifurcation ratio = No. of first order streams No. of second order streams

More Related