Shrinking of Half of the World's Freshwater Lake Reserves

It is estimated that the lake water has decreased by more than 600 billion liters or half of its maximum capacity so that it becomes a serious threat to human survival throughout the world.

The following article was translated using both Microsoft Azure Open AI and Google Translation AI.

AFP/ JOSH EDELSON

Vehicles are seen driving along Interstate 5 over much of the dry Shasta Lake in Lakehead, California, United States, on Sunday (16/10/2022). The extreme drought caused by the climate crisis has mandated California residents to conserve their water usage.

As much as 87 percent of fresh water in the world is supplied from lakes. Ironically, during the period 1992-2020 the volume of fresh water in lakes around the world fell by 53 percent. The great lakes are drying up due to the climate crisis and water overuse.

Globally, the area of lakes throughout the world only covers three percent of the Earth's surface. Despite its limited area, the total human population living in lake basins amounts to at least 2 billion people. This is closely related to the strategic function of lakes, namely as a source of drinking water, irrigation systems, electricity generation, as well as providing habitats for animals and plants.

However, this strategic role is now faced with an increasingly alarming natural condition. The volume of the lake water fluctuates drastically and tends to show a trend of decreasing volume. It is estimated that the lake water will shrink by more than 600 billion liters or half of its maximum capacity. This is certainly a serious threat to the survival of humans throughout the world.

The phenomenon of decreasing volume was obtained from the analysis conducted by several researchers and published on May 19, 2023, under the title "Satellites reveal widespread decline in global lake water storage". The research was conducted by observing 1,972 lakes worldwide using satellite imagery, climate data, and hydrological modeling.

The shrinking volume of lake water occurs in all regions globally. However, the largest volume decline in the world occurred on the western side of North America, the eastern side of Latin America, the eastern side of Africa, the Middle East, Central and South Asia, and East Asia. The factor that most influences the phenomenon is climate change. Apart from that, it is also accompanied by uncontrolled water consumption patterns and sedimentation in the lake body which causes siltation.

Read also: Global Reservoir Volume Shrinking

The climatic factor is the main cause of the drying up of lakes in the world. Global warming encourages high evaporation or evapotransporation. This was exacerbated by the phenomenon of heat waves that appeared in a number of areas. The research results also show that the dry water sources are not only in the body of the lake, but also in the river system that supplies the lake.

The following factor is the excessive use of fresh water for domestic and industrial purposes. Global consumption of fresh water has been steadily increasing since the 1900s. Based on data from Our World in Data, as of 2014, fresh water consumption reached approximately 4 trillion cubic meters. One source of fresh water comes from lakes.

Another third factor is sedimentation from hilly areas that have river channels to the lake. Excessive sedimentation is a result of poor land management, causing soil materials to erode and flow into the lake. Land use changes and soil drying due to the climate crisis also weaken the soil structure, increasing sedimentation.

Dry lake

The increasingly dry reserves of lake water over the past three decades are a serious warning for the world community. Adequate amounts of high-quality fresh water reserves are a necessity to ensure the sustainability of human and other living beings' lives. Therefore, a greater effort is needed to prevent the future deterioration of lake conditions.

The United Nations Environment Programme (UNEP) has emphasized the importance of preserving the sustainability of lakes in all countries around the world. One concrete step taken is the issuance of a Sustainable Lake Management document. The document instructs that it be implemented in integration with national and regional development plans in a country.

The lake preservation step is very important because if the lake shrinks and dries up it will cause enormous losses, both in terms of the environment and economic valuation. Research on the drying up of lakes in the world saves enormous losses to ecology and socio-economic communities. Drying of the lake will cause a loss of biodiversity because around 140,000 species of the total biodiversity of flora and fauna depend on freshwater habitats in the lake.

Read also: Emergency Threat of World Water Crisis

AFP/ JOSH EDELSON

The Pit River Bridge spans over Lake Shasta, which has experienced a significant decrease in water levels in Lakehead, California, United States, on Sunday (17/10/2022). The extreme drought caused by the climate crisis has resulted in significant decreases in water levels and even droughts in lakes in the western region.

The lake ecosystem also provides food for billions of people around the world, including as a valuable source of income. Freshwater fishing in lakes is capable of producing millions of tons of fish to meet human protein needs. Lakes also have aesthetic and recreational value that can provide income from the service sector for local communities.

In the context of global carbon emission reduction, lakes also play an important role in storing the world's carbon reserves with a proportion of 20-30 percent. The drying up of lakes around the world is certainly a major problem for efforts to curb the pace of the climate crisis.

The phenomenon of the global drying up of lakes also occurs in Indonesia. According to research by Fangfang Yao et al. (2023), Indonesia has 840 lakes that have been identified with a total area of 7,103 square kilometers. In addition, it also has a number of ponds, craters, or reservoirs which amount to 735 points.

The large lakes in Indonesia are concentrated on the island of Sumatra, with a national proportion of around 20 percent. Other areas that have many lakes are Kalimantan and Papua. If totaled, the volume of water that can be accommodated by all lakes nationally is estimated to reach 500 billion cubic meters. Unfortunately, hundreds of those lakes face various problems.

For example, like Lake Semayang and Lake Melintang in East Kalimantan. Both of these lakes show shallowing so that the volume of water decreases. In fact, once there was only 1 meter of water depth in the middle of the lake, causing damage to the ecosystem and economic losses (Kompas/12/2/2020).

Another lake, Lake Toba, also faces similar problems. Its water level dramatically decreased in early 2021, approaching its minimum limit. The rate of Lake Toba's water level decline is around 1 centimeter per day. The main cause is the damage to the lake's surrounding ecosystem, which affects the supply of fresh water.

The fate of Lake Tempe in South Sulawesi is also equally sad. The lake volume is continuously decreasing, even though its existence is vital for freshwater fish cultivation and irrigation of agricultural land. In addition to unpredictable weather, sedimentation or siltation is also the main cause of the shrinkage of Lake Tempe. One of its impacts felt by the community is the drastic decrease in fish production up to 75 percent compared to the 1970s.

Strategic role

Ecologically, lakes have the ability to naturally store rainwater to reduce the risk of flooding and drought. In addition to having an ecological function, lakes are also able to meet water needs for agriculture, fisheries and domestic household needs in a sustainable manner. That is, conserving the lake also means maintaining the sustainability of water resources for life.

In the document of the 2020 Integrated and Sustainable Lake Management Recommendation by the National Water Resources Council, there are more than ten strategic roles of the lake for the community's livelihood. These roles are divided into two groups, direct and indirect roles. Seven direct strategic roles of the lake include providing household water supply, generating electricity, providing irrigation water for agriculture, and fulfilling industrial needs.

Also read: The Water Level of Lake Toba Has Dropped Drastically, Weather Modifications Are Done

NIKSON SINAGA

The Agency for the Assessment and Application of Technology conducted a weather modification technology by sowing cosat flares into the clouds to increase rainfall in the Lake Toba catchment area, North Sumatra, Wednesday (7/4/2021). Lake Toba's water level continues to drop to 903.17 meters above sea level and makes many piers unusable. Sigura-gura and Tangga hydroelectric power plants must reduce power if the TMA is below 902.40 MDPL.

In addition, it also serves as a means of recreation and tourism, freshwater for fishing activities in the lake, and supports the preservation of local culture around the lake. One of the strategically large lakes is Lake Toba in North Sumatra. Currently, Lake Toba is the center of economic development through tourism and culture.

Furthermore, the indirect role of lakes is to provide a place for education and research on freshwater ecology (lakes) as well as facilitate water transportation activities for the community. The presence of lakes is also very important as a container and absorption of water for flood control. For the ecological system, lakes become a means of realizing biodiversity.

Legally, the government has a number of regulations regarding the sustainable preservation of lakes. Among them are regulations on lake conservation which are included in Law Number 17 of 2019 concerning Water Resources, which includes the protection of water sources, water quality management, and water pollution control. Furthermore, the Indonesian government has issued Presidential Regulation Number 60 of 2021 on the National Priority Lake Rescue.

There are a total of 15 nationally prioritized lakes spread from Sumatra to Papua. Their designation is based on the environmental degradation conditions, their economic and scientific value, and their inclusion in development planning documents. Efforts to save lakes in Indonesia are strengthened through inventorying the points that have been challenging thus far.

There are at least three main challenges faced. First, how to integrate lake management and lake boundaries with terrestrial ecosystem management. In addition to managing the surrounding lake areas, the key to saving the lake must also begin with the conservation of rivers that supply lake water. Ecosystem damage to rivers will affect lake water quality.

Second, managing the damage of the river basin that supplies a lot of sediment to the lake area. The accumulation of sediment will cause eutrophication and the shallowing of the lake which damages freshwater habitats. Third, realizing participatory management carried out by the local community and government.

Cumulatively, there are over 1,250 lakes scattered throughout Indonesia, ranging from small to large sizes. These thousands of lakes contain about 500 billion cubic meters of freshwater reserves that are crucial for the sustainability of ecosystems, economic activities, and cultural continuity. The strategic role of lakes for humanity cannot be underestimated, especially during the current global climate anomaly that causes a decrease in water volume in lakes. By protecting and restoring lakes, it can become one of the important solutions in minimizing the impact of climate change. In addition, by preserving lakes, it also contributes to ecosystem restoration, maintaining freshwater reserves, and maintaining the sustainability of human life and the environment as a whole.