Due to their large surface area, they lose a lot of water to evaporation. If this happened, it wouldn’t take long for the common water supply to become unsanitary under these conditions. The polluted water supply would kill aquatic life, further reducing the available food supply.

Freshwater is vital for life, supporting ecosystems and human civilizations. We use freshwater in many aspects of daily life including food production, power generation, manufacturing, and sanitation. Access to freshwater will be a defining issue for future generations.

Rivers, streams, springs, swamps, lakes and deepwater aquifers are all sources of the fresh water we need to survive. Besides being essential to humans for drinking and growing food , water is vital for recreation and for daily activities like brushing our teeth and washing our clothes. Simply put, water is life.

Only about three percent of Earth’s water is freshwater. Of that, only about 1.2 percent can be used as drinking water; the rest is locked up in glaciers, ice caps, and permafrost, or buried deep in the ground.

Energy, food and health – all indispensable to human development – rely on the water services provided by natural ecosystems. Freshwater ecosystems, such as wetlands and rivers, also provide crucial regulating services, such as water purification, flood mitigation and the treatment of human and industrial wastes.

Major threats to freshwater fishes and other freshwater biodiversity, include: habitat modification, fragmentation, and destruction; invasive species; overfishing; environmental pollution; forestry practise; and climate change.

Protection of Rivers & Lakes

1. Prevention of pollution by interception and decentralised treatment of wastewater entering rivers and lakes.
2. Management of solid waste around the water bodies and catchment areas.
3. Enhancement of waterfront and catchment areas, such as storm water management, institution of buffer zones and silt traps.

Humans use rivers for irrigation in agriculture, for drinking water, for transportation, to produce electricity through hydroelectric dams, and for leisure activities like swimming and boating.

The air we breathe: The ocean produces over half of the world’s oxygen and absorbs 50 times more carbon dioxide than our atmosphere. Climate regulation: Covering 70 percent of the Earth’s surface, the ocean transports heat from the equator to the poles, regulating our climate and weather patterns.

Pollution and Dumping Human pollution also significantly affects the oceans. In addition, oil spills such as the one resulting from the Deepwater Horizon fire in 2010 can contaminate large stretches of the ocean, wiping out entire populations of fish and other species, and affecting the regional ecosystem for decades.

Humans can have a major impact on freshwater systems through water overuse. Reducing the amount of water in lakes and other reservoirs puts pressure on aquatic populations, reducing the amount of living space available, and in some cases, it dries up streams and ponds entirely.

Lakes and ponds are inland bodies of standing or slowly moving water. Although lakes and ponds cover only 2 percent of the world’s land surface, they contain most of the world’s fresh water. Individual lakes and ponds range in area from a few square meters to thousands of square kilometers.

The Great Lakes suffer from three main sources of pollution: Heavy industry, manufacturing, and agriculture. This does not account for all of the pollution, but are a majority of the blame. Chemical pollution, Plastic pollution, and Nutrient pollution have been devastating to The Great Lakes.

Human effects can also result from activities within the watershed that indirectly affect streams by altering the movement of water, sediment, and contaminants into the channel. Deforestation, cropping, grazing, land drainage, and urbanization are among the land uses that indirectly alter stream processes.

Effects of human activities on the Waterval River, Vaal River catchment, South Africa.

The source of a river is usually found in high places such as hills or mountains. A river can have more than one source. Some rivers begin where a natural spring releases water from underground. The source of the River Thames is a spring.

Humans disrupt the drainage basin cycle by accelerating processes, (deforestation, changing land use) and creating new water storage reservoirs or by abstracting water. It is mainly human changes to: rivers and drainage. the character of the ground surface (its shape, texture and covering)

there are 4 types of drainage patterns on the basis of their flowing pattern-dendritic, trellis, radial and rectangular.

Characteristics of the drainage basin

• Drainage basin – the area of land drained by a river.
• Catchment area – the area within the drainage basin.
• Watershed – the edge of highland surrounding a drainage basin which marks the boundary between two drainage basins.
• Source – the beginning or start of a river.

Physical characteristics

• Basin size. This influences the lag time – a large drainage basin will mean that water takes a long time to travel through tributaries or the ground to reach the channel.
• Basin shape.
• Elevation and slope.
• Rock type.
• Soil type.
• Drainage density.
• Rainfall type.
• Rainfall intensity.