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How has the Aswan High Dam affected sediment delivery to the Nile delta?

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continental shelf The broad, gentle pitch of the continental shelf gives way to the relatively steep continental slope. The more gradual transition to the abyssal plain is a sediment-filled region called the continental rise. The continental shelf, slope, and rise are collectively called the continental margin.

The construction of the Aswan High Dam has fundamentally altered the sediment dynamics of the Nile River. By providing complete control over the river's annual flooding, the dam impounds the vast majority of the silt that was historically transported downstream.1

Previously, the Nile flood deposited approximately 40 million tons of nutrient-rich silt annually across the delta and riverside agricultural lands. Because this load is now trapped within Lake Nasser, the sediment delivery to the Nile delta has been drastically reduced. This loss has had significant environmental and geological consequences, including:12

Coastal Erosion: The reduction in sediment supply has led to increased coastal erosion along the delta.2
Ecological Impact: The offshore fish population near the delta has declined significantly due to the loss of nutrient-laden silt.2
Soil Salinity: The overall reduction in flow and sediment has contributed to saltwater intrusion from the Mediterranean Sea, resulting in the deposition of salt in delta soils.2