The Importance Of Freshwater Resources Environmental Sciences Essay
Fresh water has been considered one of the most important natural resources over the years. To know why it is important we first we need to know what is freshwater.
Freshwater is naturally occurring water found on the earth’s surface. It is a body of water that has a low concentration of salt which is usually less then 1%. 97% of the water found on Earth is saltwater which means of that only 3% is freshwater. 70%of this freshwater is in the form of ice; glaciers, ice caps and permanent snow. It used by people for agriculture, industry, recreation and tourism.There are different types of freshwater ecosystems; ponds and lakes, streams and river and wetlands.
There are two main types of freshwater, static water or lentic and flowing water or lotic. Lakes and ponds are stationary (lentic) whereas rivers and streams are flowing (lotic) bodies of water. Plants and animals from in this ecosystem can be important; plants provide oxygen through photosynthesis and for the animals. Animals are a source of food for humans within the given region.
Freshwater ecosystems have many uses to humans; dams are built to harness power from rivers to generate electricity. Rivers provide water for irrigation, industry, processing wastes and supplying food to organisms within the given region. It is also a water supply, water purification, assists in flood control and a major source of biodiversity.
But like all things there are many disadvantages that threaten freshwater ecosystems; pollution being the main one.
Pollution can be caused by organic matter as well as microbiological matter; Organic matter, for example human waste, is one of the prime causes of river pollution. It saturates the water and stops the normal functioning of the ecosystems; it also pollutes the water with pathogenic microorganisms.
Pesticides contaminate the water supplies as well as underground water by infiltration: they enter the earth’s atmosphere and is re-entered as rain. Animals are also affected by nitrates in fertilizers; nitrate pollution is caused by agriculture, can be toxic to the human body once too many nitrates are ingested. Phosphates in the fertilizers can change the biological balance of the freshwater region causing eutrophication.
These human and environmental forms of pollution causes excessive algal growth in freshwater ecosystem due to the nutrients contained in the fertilizers, animal manure, and waste-treatment plant effluent. When plants die and decompose, the dissolved oxygen is depleted, giving rise to the death of living organisms within the water.
It is difficult, expensive, and even it some cases impossible to remove pollutants once the water has been contaminated. The techniques used to remove these contaminants from groundwater are air stripping, granular activated carbon, and advanced oxidation. Air stripping involves a pump that removes the contaminated water, which is then heated to evaporate and remove the contaminant. The cleaned water is then re-injected into the ground. This is very time consuming and costly so it not desirable.
But pollution is not the only threat faced by this ecosystem such as;
The creation of dams are to improve human way of living by deriving power from water, and flood control however there have been negative effects on the freshwater ecosystem. Dams change the chemical, physical and biological processes of the ecosystem. They alter the free-flowing systems by the reduction of the river levels, block the flow of nutrients and change both the water temperature and oxygen levels. Dams block migration routes for fish and disrupts habitats. These changes can be considered advantageous or disadvantageous according to your point of view or needs.
When water is used by humans for recreation there are small withdrawals of water from the ecosystem that causes it to shrink and results in the degradation of habitats. Runoff from agricultural and urban areas hurts quality of water. The runoff is caused by the water flow that occurs when the soil is penetrated to its fullest and excess water from any water source that flows on land. Water resources, are renewable which means they are naturally recharge. Overexploitation occurs if a water resource is extracted at a rate that exceeds the recharge rate. A forest enhances the recharge of aquifers the depletion of these aquifers can lead to pollutants with contaminants.
The draining of wetlands for development depletes habitats. It removes their filtering abilities, which prevents the improvement of the water quality before it moves further downstream. It prevents the steady release of nutrient laden water. Wetlands are considered important because they utilize nutrients and convert them to sustainable food source for organisms.
Invasion of exotic species can harm native animals and plants as it can bring strange unwanted and harmful substances to species that are within the habitat.
There are many way in which these threats can be prevented or managed; one way is the Local Governments restricting the construct of dams. It is very beneficial to humans but is very destructive to the fresh water system, causing a limitation on an already limited supply.
Incentives and alternatives have to be provided to the agricultural community to encourage the use of less harmful substances to be used on crops instead of the use of pesticides to prevent the contamination of the water supply that can lead to the death and destruction of the natural habitat of the freshwater system.
Watershed protection reduces pollution and cuts the cost of drinking water treatment. Keeping that area free from development and agricultural runoff would be considered very efficient as a watershed is a high region of land where the different water sources are separated and the water from each region drains into surface or groundwater of the other and flows downwards to the other regions.
Establish protected wetlands areas. The local governments would have a part to play in wetland protection, because they have primary responsibility for local land use management. There should regulation of water withdrawal from human. This should be done by limiting the human use of the freshwater sources.
Overall freshwater resources are very beneficial to the regions they occupy but have to be protected as it is a limited natural resource that have been faced with negative impacts.