Table of Contents
General Descriptions of a Lake
The word “lake” has different origins as different countries were given different meanings to the term Lake. For instance, the word lake comes from the Middle English word “lake” which mean ‘lake, pond, waterway’, from Old English word “lacu” to mean that ‘pond, pool, stream’, from Proto-Germanic word “*lak” which mean ‘pond, ditch, slow moving stream’, from the Proto-Indo-European root “*leg’” meaning ‘to leak, drain’, from Cognates include Dutch word “laak” meaning ‘lake, pond, ditch’, from the Middle Low German word “lake” meaning that ‘water pooled in a river bed, puddle’, from German word “Lache” meaning ‘pool, puddle’, and Icelandic “lækur” to mean ‘a slow flowing stream’.
Black’s law dictionary defines the term Lake as “a large body of standing water in a depression of land or basin supplied from the drainage of an extended area: a natural depression in the surface of the earth containing a reasonable permanent body of water that is sustainably at rest.” A “lake can also be defined as a large body of water, usually fresh water, which is surrounded by land”. Lakes are internal water bodies and are not parts of ocean and are isolated from lagoons and the size of lakes can be larger and deeper than ponds.
Formation of Lakes
Lakes are commonly created at the time when natural depressions or basins in the land surface is occupied with water and they do not have a direct link with ocean and they may comprise of a fresh or salty water with various depth.” Lakes can be classified in many ways. For instance, based on their nature of formation, lakes can be classified as natural and man-made lakes. Those lakes that are formed by tectonic, volcanic, glacial, karst, fluvial, marine, and wind action are natural lakes whereas those lakes that are formed to fulfill different human needs such as power generating, fresh water, industrial water supply, navigation, fish farming and flood control etc. are man-made lakes. Further lakes can also be categorized on the basis of their water chemistry. Accordingly, based on the level of their salinity, lakes can be classified as freshwater, brackish and salty lakes. Similarly, on the basis of the level of nutrient content, lakes can also be categorized as Oligotrophic: lakes that have low level of nutrient content, Mesotrophic: lakes that have moderate nutrient content, and Eutrophic: those lakes that have highly rich in nutrient content.
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Types of Lakes
There are different types of lakes in the world. These include Crater lakes, Endorheic lakes, Oxbow lakes, Seasonal or Ephemeral or Intermittent lakes, Former lakes, Fjord lakes, Rift lakes or Sag pond, Underground lakes, Lava lakes, Shrunken lakes, Meromictic lakes, Artificial lakes, Glacial lakes, Sub-glacial lakes, Pre-glacial lakes and Eolic lakes.
“The Crater Lake is a lake formed in a volcanic crater after the volcano has been inactive for some time and lake water may be fresh or highly acidic and may contain various dissolved minerals. Endorheic Lake is a lake that has no significant outflow either through rivers or underground diffusion. On the other hand Oxbow lake is a lake that is characterized by a distinctive curved shape and is formed when a wide travel from a stream or a river is cut off. A Seasonal or Ephemeral lake is a lake that exists as a body of water during only part of the year. On the other hand, those prehistoric lakes which have permanently dried up through evaporation or human interference are known as former lakes and lakes in a glacially eroded valley that have been eroded below sea level are Fjord lakes.
The Rift lakes or sag lakes are lakes which are formed as a result of subsidence along a geological fault in the earth’s tectonic plates. The rift valley lakes in East Africa and Lake Baikal in Russia are a good examples. The underground lakes are those lakes which are formed under the surface of the earth’s crust and the lava lake is a pool molten lava contained in a volcanic crater or other depression. Eolic Lake is a lake which is formed in a depression created by the activity of the winds. The Meromictic Lakes are lakes which have layers of water which do not intermix. The deepest layer of water in such a lake does not contain any dissolved oxygen.”
Distribution of Lakes
According to different writers there are about fifty thousand natural and seven thousand five hundred manmade lakes all over the globe. Among these Lakes, the African continent comprises about six hundred seventy seven lakes and Ethiopia, which is the East African country contains about forty six lakes or 6.80%. Based on this, most of the world’s Lakes are found in Africa, North America and Asia. Accordingly, the African continent shares 30 %, the North America shares 25 % and the Asian continent on its part shares 20 % of lakes.
The African continent, on its large amount of inland water resource, is called as a home to the world’s largest natural and man-made lakes For instance, Lake Victoria is the largest natural fresh water lake in Africa and the second largest natural freshwater lake in the world. Lakes Tanganyika and Malawi are the World’s second and third deepest lakes respectively after Lake Baikal of Russia. Similarly, Lake Chad is the shallowest major lake and also the fourth-largest lake in Africa in terms of surface area and is also the largest wetland in the Sahel region and Lake Turkana is the largest desert lake in the world and is the largest closed basin lake in the East Africa. Concerning their formation, the African lakes have various origins of formation. Those lakes along the East African rift valley such as lakes Malawi, Albert, Tanganyika, and Turkana are formed by deep volcanic actions whereas lakes like Kivu in Rwanda were formed by volcanic action.
Ethiopia, which is the East African country, is endowed with both natural and man-made lakes and the majority of its lakes are natural and few are artificial. These natural lakes are commonly created due to the instability of the earth system. Moreover, the Ethiopian lakes are freshwater and only some lakes are saline and most of these lakes are found in the Ethiopian Rift Valley.
Ethiopia has eleven major river basins. The rift valley lake basin is one among these basins and it contains eight lakes such as Lake Ziway, Lake Langano, Lake Abiyata, Lake Shalla, Lake Hawassa, Lake Abaya, Lake Chamo, and Lake Beseka. The Ethiopian rift system covers from the Kenyan border up to the Red sea and it is divided in to four sub- systems. These are the main Ethiopian rift valley, the Chew Bahir, the Rudolf, and the Afar drainage system. The main Ethiopian rift system on its part holds three separate lake basins. These are the Ziway, Langano, Abiyata, and Shalla lake basin, the Awash basin and the Abaya- Chamo basin.
Why Lake Protection?
“Freshwater is an important natural resource that is necessary for the survival of all ecosystems. Freshwater or unpolluted water accounts only for 0.03 % of total availability or global scale. From the world total water supply about 332.5 million cubic miles of water, over 96 % is saline. And of the total freshwater, over 68 % is locked up in ice and glaciers. Another 30 % of freshwater is in ground. Fresh surface water resources, such as lakes and rivers only constitutes 93,100 cubic kilometers, which is about 1/150th or 1 % total water. Yet lakes and rivers are sources of most of the water consumed by the people.”
For example, people use it for different purposes such as irrigation, drinking and sanitation purposes all over the world. Lakes are also key natural resources with significant importance to humans. Lakes be whether natural or man-made, play a pivotal role in regulating the climate and making the environment conducive for life. Moreover, lakes also have a great importance in the development of economic, environmental and social aspects of a country. For instance, in Ethiopia, the majority of fish product that is used as source of food as well as an economic base for the surrounding community is from the Lakes Tana, Abaya, Chamo, Hawasa and Ziway. However, now a days, the expansion of agricultural activities, damming, diversions and pollutions, have threatened these irreplaceable resources in many parts of the globe. Therefore, “if once these precious resources are lost due to misuse practices and poor management systems, uncomfortable and challenging environment would complicate the life of humans and enhance poverty” .
The Concept and Significance of Wetlands
Wetlands are ecosystems. Their formation, process and characteristics are determined by water. They are “formed where the water table is at or near the surface of the land, or where the land is covered by shallow water”. Different scholars define the term wetland in different ways. However, the widely agreed definition is the one which is given by the ramsar convention and this broad definition accommodates the major types of wetlands that are found all over the world. Therefore, as of ramsar Convention, Wetlands are: “Areas of peat land, fen, marshes, or water whether temporary, permanent, artificial or natural, with water that is flowing or static, salt, brackish, fresh or marine water, which does not exceed six meters at low tide.”
Wetlands provide a variety of ecosystem services. People use them as a means of livelihood. They use them for farming, fishing, and livestock grazing purposes. Wetlands also serve as a suppliers of water, fuel and construction materials. Moreover, they have aesthetic, cultural, educational, spiritual and recreational values. The water available in the wetlands is also helpful for the growth of dense sedge vegetation. In addition, wet lands play a crucial role in filtering pollutants and regulating water flows by influencing ground water recharge, flood impacts, and water availability during the dry season. As wetlands are composed of various physical, biological and chemical components such as soils, water, plant and animal species, and nutrients, they also play a role in balancing the ecology and the socio-economic well-being services for living organisms and they are the most productive ecosystems and are the well beings of the biological diversity that provide the water and primary productivity upon which countless species of plants and animals depend for survival.
Wetlands are an important store houses of plant genetic species and they also accommodate a great population of birds, mammals, reptiles, amphibians, fish and invertebrate species. Moreover, Services such as groundwater recharge, ground water discharge, flood water control, sediment, and contaminate retention, food web support, shoreline stabilization and erosion control, storm protection, and regulation of climate condition are provided by wetlands.
Wetlands are, therefore, essential resources for human survival so that in the absence of a healthy wetland, there cannot be water and life. Though wetlands are the most productive and essential ecosystems, they are also the most threatened ecosystems due to the population increase and uninterrupted demand for further wetland resources to sustain their livelihood and conversion in to other land usage.
International Instruments Related with Natural Resources protection
The Stockholm Declaration
Considering the need for the common outlook and principles to inspire and guide the people of the world in the preservation and enhancement of the human environment, the United Nations was held a Conference on the Human Environment from the 5th to 16th June 1972 with the objective of passing the nature in clean and healthy conditions to the coming generations. This Declaration was the first international Declaration that dealt with the human environment and was taken as a remarkable foundation for the international community to formulate international environmental policy. The conference considered the need for the protection and improvement of the human environment as the human environment was a major issue which affected the well-being of peoples and the economic development throughout the world.
Among the 26 principles of the declaration, principle one states the “man’s fundamental right to freedom, equality, and adequate condition of life in an environment of a quality that permits a life and dignity and well-being, and he bears a solemn responsibility to protect and improve the environment for the present and future generation”. Further principle two of the Declaration also deals about “safeguarding of the earth’s natural resources such as air, water, land, flora and fauna and especially representative sample of natural ecosystems for the benefit of present and future generation through careful planning or management”.
The Convention on Biological Diversity 1992
The Convention on Biological Diversity was opened for signature on June 5, 1992 and entered in to force on December 1993. This convention is an international legally binding instrument and has three main objectives. These are conservation of biodiversity, sustainable use of biodiversity and the fair and equitable benefits arising from the use of resources. Its overall objective is encouraging actions which will lead to sustainable future so that was considered as the key international instrument for sustainable development. Further, in 2010 the parties to the Convention, were adopted a ten year (2011-2020) strategic plan to safeguard biodiversity and the benefits it provides to people.
Ethiopia is a party to this convention and is obliged to implement and fulfill all the commitments enshrined under the convention to conserve the biodiversity through sustainable utilization of its resources in a way that ensure equitable sharing of benefits.
The 1992 Rio – Declaration
The Rio-declaration on environment and development, was adopted by 178 member states at Rio-de- Janeiro of Brazil in 1992. The declaration was seen as a progressive act by all the nations that participated the negotiation and the declaration was established the concept of sustainable development at the international level and was discussed broadly on environmental problems and it consists of 27 principles. The declaration has placed human beings at the center to the concerns of sustainable development and has also entitled the human beings to the healthy and productive life in harmony with nature. 1) The declaration, under principle 4, has further imposed the issue of “environmental protection” by stating that the “environmental protection shall constitute an integral part of the development process and cannot be considered in isolation in achieving sustainable development.” The significance of environment for the current and future generation is also another issue that has been discussed strongly under the declaration. 3) To protect the environment, the “precaution approach” has been taken as key principle. 15) Moreover, the declaration has burdened the member states to put in place adequate legislative instruments to address environmental issues.
The Ramsar Convention
For centuries people had viewed wetlands as places to drain and converted to agricultural uses. As a result, in most parts of the world, disappearance of wetlands was the major problem and this had caused undesirable consequences such as loss of ground water reserves. Considering this issues, on February 3rd 1971, the representatives of 18 nations were put their signatures for the ramsar convention which is a remarkable treaty, in the little Iranian town of ramsar. The ramsar convention was the first modern instrument seeking to conserve natural resources at global level. The convention is concerned with the most threatened habitats- the wetlands such as lakes, ponds, rivers, marshes, bogs, swamps and flood plains. The convention has imposed a duty upon the contracting parties to utilize wisely their wetland resources. Article 3.1 of the convention states that the contracting states shall formulate and implement their planning so as to promote… as far as possible the wise use of wetland in their territory.
Regional Instruments Related to Natural Resources Conservation
The African Convention on the Conservation of Nature and Natural Resources
“The heads of state and Government of independent African states being fully Conscious of that the soil, water, flora and faunal resources constitute capital of vital importance to mankind, the danger which threaten to irreplaceable assets, accepting that the utilization of the natural resources must aim at satisfying the needs of man, the desire of undertaking individual and joint action for the conservation, utilization and development of these assets to establish and maintain their rational utilization for the present and future welfare of mankind” have assembled at Algiers, Algeria on 15th September 1968 and have signed the convention on conservation of nature and natural resources.”
Accordingly, the contracting parties to the convention were established the “African Convention on Conservation of Nature and Natural Resources.” The convention under its article 2 contains a fundamental principle and this principle states about the duty of the contracting states. It declares that “the contracting states shall undertake necessary measures to ensure the conservation, utilization and development of soil, water, flora and faunal resources in accordance with scientific principles and with regard to the best interests of the people.”
The convention under article 5 further elaborates that the “state is duty bound to establish policies for conservation, utilization and development of underground and surface water and has to take appropriate measures with due regard to: a) the study of water cycles and the investigation of each catchment area b) the co-ordination and planning of water resources development projects c) the administration and control of all water utilization and d) prevention and control of water pollution.”
