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Pros and Cons of the Aswan Dam

Due to the lack of awareness of environmental protection when the Aswan Dam was designed, the completion of the dam played a huge role in promoting Egypt’s economy and at the same time caused certain damage to the ecological environment.

1. The dam project has caused a continuous decline in the soil fertility of the arable land along the river basin. Before the completion of the dam, agriculture in the lower reaches of the Nile River benefited from the seasonal changes in the river water. The flooded river water covered a large amount of fertile sand on the cultivated land every year when the rainy season came, periodically replenishing the soil with fertility and moisture. However, after the completion of the dam, although water diversion irrigation can ensure that crops are not threatened by drought. However, because the sediment is blocked in the upstream of the reservoir area, the land in the downstream irrigation area cannot receive nutrients. Therefore, the fertility of the land continues to decline, resulting in a reduction in agricultural production.

2. Soil salinization appeared along the banks of the Nile after the construction of the dam. Since the river is no longer flooding, there is no longer a large amount of river water in the rainy season to take away the salt in the soil, and the continuous irrigation makes the groundwater level rise, bringing the salt in the deep soil to the surface, plus the salt and water in the irrigation water. High levels of various chemical residues lead to soil salinization.

3. The water quality of the Nile River in the reservoir area and downstream of the reservoir is deteriorating, and the health of residents who use the river water as their living water source is endangered. After the completion of the dam, the water quality and physical properties of the reservoir have obviously deteriorated compared with the original Nile water. The large amount of evaporation of water in the reservoir area is an important reason for the change of water quality.

Another reason is that the decline of land fertility forces farmers to use a large amount of chemical fertilizers, and the residual part of chemical fertilizers flows back to the Nile River with irrigation water, which increases the nitrogen and phosphorus content of the river water, leading to eutrophication of the river water, and the growth of phytoplankton in the downstream river water. The average density increased from 160 mg/L to 250 mg/L.

In addition, soil salinization has greatly increased the salt and chemical residues in the soil. Even if the groundwater is polluted, it has also increased the salinity of the Nile water. These changes not only have a significant impact on the survival of organisms in the river and the irrigation of cultivated land in the basin, but also poison the drinking water of the residents in the lower reaches of the Nile.

4. The change of the nature of the river water causes aquatic plants and algae to spread everywhere, not only evaporating a lot of river water, but also blocking the river irrigation canals and so on. As the flow of river water is regulated, the turbidity of river water decreases and the water quality changes, resulting in a large number of aquatic plants multiplying. These aquatic plants not only spread over irrigation channels, but also invaded the main waterway.

They obstruct the efficient operation of irrigation channels and require frequent mechanical or chemical cleaning. so. It also increases the maintenance cost of the irrigation system. At the same time, aquatic plants also transpire a large amount of water. According to the estimate of the Egyptian Ministry of Irrigation, the amount of water lost due to the transpiration of aquatic weeds reaches 40% of the irrigated water every year.

5. The river bed in the lower reaches of the Nile has been severely eroded, and the coastline at the mouth of the Nile has receded. After the completion of the dam, the sediment content of the lower reaches of the Nile River dropped sharply, the suspended solids in the water dropped from 1600ppm to 50ppm, and the turbidity dropped from 30-300 mg/L to 15-40 mg/L. The reduced amount of sediment in the river water has led to erosion of the lower Nile river bed.

In the 12 years since the dam was built, the riverbed has eroded an average of 2 centimeters per year from Aswan to Cairo. The course of the Nile is expected to continue to change. It will probably take more than a century to form a new stable river channel. The decrease in sediment content in the lower reaches of the river, coupled with the Mediterranean circulation that washed away the sediment deposited in the estuary, caused the coastline of the Nile Delta to continue to retreat. A former Egyptian soldier said that the lighthouse where he once stood guard has now sunk into the sea, 1-2 kilometers away from the current coast.

6. The artificial lake of Nasser built due to the dam is magnificent, but it seriously threatens the historic temples on the shore, and many of them sink into the lake. The United Nations Educational, Scientific and Cultural Organization (UNESCO) has launched a series of rescue operations for this purpose. Although some historic sites have been rescued, there are still very precious cultural heritages that have been destroyed.