Question

write short note on tropical rectangular pattern​

Answer 1

Answer:

Answer

The term `drainage' describes the river system of an area. The streams within a drainage basin (the area drained by a single river system) form certain patterns which are given below:

(i) Dendritic pattern: The dendritic drainage pattern develops where the river channel follows the slope of the terrain. The stream with its tributaries resembles the branches of a tree, thus the name dendritic.

(ii) Trellis: This drainage pattern develops when a river is joined by its tributaries at approximately right angles. This drainage pattern also develops where hard and soft rocks exist parallel to each other.

(iii) Rectangular: This drainage pattern develops on a strongly jointed rocky terrain.

(iv) Radial Pattern: This drainage pattern develops when streams flow in different directions from a central peak or a dome like structure.

Answer 2

PATTERNS OF BIODIVERSITY -

Biodiversity is not uniform throughout the world but varies with latitude and altitude.

Favourable environmental conditions favour speciation and make it possible for a larger number of species to exist there, i.e., biodiversity is more in such areas than the others.

Latitudinal Gradients

Species diversity decreased from equator towards poles.

The tropics harbor more species than temperate and polar regions.

For example, Colombia (near equator) has 1400 species of birds whereas New York(41 N) has 105 species, Greenland(71 N) has 56 species and India(equator region) has 1200 species.

Species-Area Relationship

Alexander Von Humboldt has observed that within a region, species richness gets increased when explored area is increased, but only up to a limit.

The relationship between species richness and area for a number of taxa like angiospermic plants, fresh water fishes and birds is found to be a rectangular hyperbola.