FRESH SURFACE WATER

Lake• Is an inland body of water, small

to moderately large, with its surface water exposed to the atmosphere.

• Existence of a depression / basin without an outlet at the bottom and depressed water table are considered in lake formation.

Factors in Lake Formation

Diastrophism

Glacial action

Volcanic action

Importance of Lakes

• Provide Cheap transportation

• Serves as water reservoir

• Provide water for generating electricity

• Source of livinghood- fishing

• Form of recreation

Types of Lakes

Kettle Lake

•Melting glaciers leave behind ice blocks and debris. Melted ice fills depressions between the debris to form kettle lakes.

Tarn

•Circular mountain lake is known as a tarn.• These lakes form in hollow worn by glacial erosion or blocked by ice debris.

Volcanic Lake

• is the craters of ancient volcanoes fill up with water and produce lakes.

Oxbow Lake• Is a curved lake appears when a river cuts off a meander loop.• The lake eventually fills with sediments and vegetation.

Stream• is a body of running water moving under the influence of gravity to lower levels in a narrow clearly defined natural channel.

Swamp• is a basin that becomes partly or completely filled with fresh and decayed vegetation sediment in water.• It becomes lakes during rainy season and swamps during dry months.

• The regions where swamps are common..

(1) Glaciated Region (2) Coastal Region and (3) Flood plains and delta’s of

rivers

River• is natural stream of water of fairly large size flowing in a definite course. It is a large, natural freshwater surface stream having a permanent or seasonal flow and moving downwards the sea, lake or another river in a definite channel.

Melt Water• is a river may begin its life in a glaciated part of the world. Melting ice and snow from a glacier feed mountain streams.

•OVERLAND FLOW is rainwater running downhill gathers into small streams called TRIBUTARIES, which join to form river.

WaterFalls • a perpendicular or nearly perpendicular

descent of water in a stream. • a stream of water descending suddenly

from higher to a lower level. A river flows swiftly near its source cutting through soft rocks more easily than hard.• A sheer face of hard rock is exposed

where water plunges, undercutting the rock below.

Cascade Falls has small water volume

Cataract has large water volume