Modeling Incision History of the Gorge of

the Nile with Remote Sensing and GIS Analysis

Mohamed G. AbdelsalamGeological Sciences and Engineering

Missouri S&T

GEO/GE 248 – Fundamentals of GISNovember 3, 2009

What I would like to convince you with

• There has to be a drastic Late Miocene – Pliocene increase in sediments flux carried by the Blue Nile from the Ethiopian Plateau in order to build the fertile floodplains and delta of the Egyptian Nile in ~800,000 years. This was the result of accelerated incision driven by ~6 and ~3 Ma pulsed uplift of the Ethiopian Plateau. Increased sediments flux can not be associated with enhanced atmospheric shift (higher precipitation) because Africa was undergoing aridification at that time

Approach

The Nile System The Ethiopian Nile and sediments removal The Egyptian Nile, its floodplains and delta Nile System sediments budget dilemma (Why steady

incision doesn’t make sense) Accelerated, uplift-driven incision leading to increased

sediments removal from the Ethiopian Plateau Semi-quantitative uplift estimates from the geological record

(Making the case for post-Afar Mantle Plume uplift) Quantitative GIS modeling (Making the case for accelerated incision) Paleo-climatological and paleo-anthropological circumstantial

“evidence” (Making the case against increased precipitation)

Acknowledgements

NSF, Evolution of the Gorge of the Nile in Ethiopia from ASTER and SRTM Remote Sensing Data and Field Studies, September 2003 – October 2005

NSF, Reconstructing the Geological History of the Egyptian Nile, April 2008 – March 2011 (with Steve Gao, Kelly Liu and Estella Atekwana)

NSF, Modeling Drainage Incision on the Ethiopian Plateau, September 2009 - August 2012 (with Hong Sheng)

Geological Survey of Ethiopia, Addis Ababa, Ethiopia Addis Ababa University, Addis Ababa, Ethiopia Sohag University, Sohag, Egypt Alexandria University, Damanhur, Egypt Nahid Gani, Solomon Gera, Ahmed Youssef, Elamin Ismail

The Nile System

Africa

USA

The Nile System

~85 bcm of water/y

~25 bcm of water/y

~60 bcm of water/y

• ~6500 km long• The Nile basin countries include Burundi, Congo, Egypt, Eritrea, Ethiopia, Kenya, Rwanda, Sudan, Tanzania, Uganda

Said (1993) divided the Nile System into five regions:(1) Egyptian Nile (2) Cataract Nile (3) Central Sudan Nile (4) Sudd Nile (5) Lake Plateau Nile

Gani and Abdelsalam (2006 - JAES) suggested adding a sixth region:

(6) Ethiopian Nile

1

2

3

4

5EquatorialAfrica

Ethiopia

Khartoum

Aswan

Sudan

MediterraneanSea

Nubian Swell

WB

N

The Nile System