Remote Sensing Tutorial Page 6-13a
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Off the southeast coast of Africa is the fourth largest island in the world, now known as the Malagasy Republic but once called Madagascar. This Landsat scene shows some of its northwestern lands, drained by the Mahajamba/Sofia rivers to the north and the Ikopa/Betsiboka river further south (after they join, they form a distinctive inland multichannel drainage pattern). The dark red marks a forest that survive the general land clearing, leaving much of the landscape as a savannah.

Malagasy in a Landsat image.

The Horn of Africa is occupied by part of Ethiopia, Djibouti, Somalia, and Eritrea. In the Landsat mosaic below, the Red Sea meets the Gulf of Aden at what is known geologically as a triple point (meeting of three plates), producing the Afar Triangle. Fault zones underlie each of the three arms. The land portion becomes the Rift Zone. The dark areas on the African side (the Arabian side has the country of Yemen) are young basaltic flows that inundate tens of thousands of square kilometers.

The Afar Triangle, a Landsat mosaic.

Among the largest cities in Africa is Addis Ababa, the capital of Ethiopia:

Addis Ababa; ASTER image.

One of the dominant and most historic rivers on Earth is the Nile - 6695 km (4185 miles) long (its White Nile Branch). Here is a map showing its extent and the countries it affects.

Map tracing the Nile's course.

Living almost exclusively along the Nile, Egyptian and Sudanese civilizations flourished in the narrow floodplains and irrigated bank lands for at least 5 millenia. The main tributary to the Nile is called the Blue Nile, which starts from Lake Tana in Ethiopia. The White Nile's source was unknown until the 19th century when a British explorer finally traced it to Africa's largest inland body of water, Lake Victoria, one of a group in several central African countries:

Lake Victoria and others in central Africa; astronaut photo.

Lake Victoria.

Sudan is one of the largest countries in Africa. Here is a color mosaic of Sudan and neighbors:

Color mosaic of Sudan; Geology.com product.

As the Nile runs towards its source in central Africa, it passes through the Republic of Sudan and splits near Khartoum into the White Nile, seen here, and the Blue Nile to the east.

MODIS image of the Blue and White Nile branches as they join at Khartoum.

Khartoum is one of the larger African cities - more than a million people - made famous in the 1885 defense against Arab tribesmen led by British General Charles Gordon (who was killed). Here is a view from the International Space Station, showing that, like the Amazon-Rio Negro rivers seen earlier in this Section, the two streams differ in the silt loads they contain.

Khartoum, in the Sudan, at the juncture of the White and Blue Nile branches (the colors here suggest the origin of their names).

The clay-surfaced land, with occasional dunes (bottom), can be tilled to support crops, if properly watered. Water drawn from the Blue Nile, derived from the Sennar Dam as part of the Gezira Scheme, provides abundant irrigation for very distinctive, elongated farms whose main crop is cotton, the prime export from the Sudan. The soils are sufficiently depleted of some nutrients to require crop rotation (usually to millet) during alternate years:

The Nile as it passes through Sudan, south of Egypt, provides enough water carried eastward along canals to supply many cotton farms (note their rectangular shapes) in an irrigated collective.

This intriguing Landsat image below shows the White Nile as it flows through southern Sudan. The dark tones are organic soils developed on ancient rocks. Savannah grasses, acacia, and riverine vegetation account for the reds in this false color rendition.

The White Nile in southern Sudan

One of the most striking space views of Africa is the Nile Delta built as the great Nile River splits into the Rosetta Nile (left) and the Domietta Nile (right) while emptying into the southeastern Mediterranean Sea. The roughly triangular appearance struck ancient mappers as looking like the Greek letter D, as viewed from the north, hence the term "delta" has been applied to similar river mouth depositional landforms worldwide. The delta, with its system of canals spreading from the main stream pair, is so well irrigated that it is given almost totally to farming of, principally, cotton along with corn and other foodstuffs. Flooding used to supply water replenishment but this has largely ceased since the building of the Aswan Dam well to the south. The largest city in Africa, Cairo, with well over 6 million residents, is the bluish patch near the bottom apex of the delta. Most of Egypt is like the light colored areas to the west and east, sand-covered land unsuited to any production of edibles. Coastal sand dunes have blocked off lagoons, with salt marshes.

Sections of two successive Landsat images joined together to show the full extent of the famous Nile Delta; Cairo is a small blue area near its bottom; the Nile downstream flows through vast deserts.

Let us put the Nile Delta more in context with its surroundings. Here is a Landsat mosaic covering much of Egypt that gives a better idea of the desert sands and bedrock beyond the Nile.:

Part of Egypt from the Nile Delta to the beginning of the Upper Nile.

Cairo is a widely dispersed city located at the inland apex of the Nile Delta:

GoogleEarth/Quickbird image of Cairo, Egypt.

The two full delta images do not have the resolution needed to pick out the Suez Canal, built under the direction of the famed Ferdinand de Lesseps in the 19th Century. Here it is as it reaches the Mediterranean.

False color image of the Suez Canal.

A feel for how barren most of Egypt and northern Sudan are is gained from this astronaut photo looking eastward taken during the Apollo 9 mission:

The Nile, the Egyptian desert (foreground) and the Nubian Highlands beyond the Nile; the Red Sea, and the Arabian Highlands, photographed from Apollo 9.

Upriver in Egypt is the Aswan Dam, built by the Egyptians as a means for generating electricity. Here it is in this astronaut photo:

The Aswan Dam.

Built during the presidency of Gamal Nasser (the lake behind it is named after him), the Aswan Dam is controversial. It was constructed by the Soviets, which proved troubling to the NATO nations. But, of greater concern was the environmental impact on the cultivated lands along the Nile. So far, careful control of released water has minimized any damage.

Cairo and Alexandria are old cities, tracing their settlement along or near the Mediterranean to pre-Christian times. Another in this category is Carthage, a Phoenician city (in present day Libya) which was the center of efforts to challenge the growing Roman empire during this period. Here is a photo of the present-day Carthage as taken by an astronaut from the International Space Station.

Carthage, as seen from the ISS.

We are now ready to cross over the Nile into the Middle East. The next image is a mosaic showing the "hot spot" of the Middle East, Israel and neighboring countries, a land of seemingly never ending strife and hostility but also with Jerusalem as the site of ancient holy places associated with three great religions. The Sea of Galilee and the Dead Sea (south) both lie astride the great Dead Sea fault, a strike-slip fracture akin to the San Andreas fault; here too is the boundary of two tectonic plates. Lebanon (with Beirut), part of Syria (with Damascus and the Golan Heights), Jordan, and a sliver of the Sinai Peninsula all appear in this image.

 Landsat mosaic of the Holy Land (Israel) and parts of Lebanon, Syria, and Jordan; the Dead Sea fault is conspicuous.

It is informative to compare this mosaic with an oblique photo looking west as taken by astronaut Shannon Lucid from the space station MIR. While the latter presents a different perspective, it does not bring out the scene richness that the computer-processed Landsat mosaic offers. Note on the left the boundary between Israel and Egypt's Sinai; land use practice through irrigated farming by the Israelis accounts for this.

View from MIR of the Mid-East countries of Jordan, Israel, and the Sinai Desert of Egypt

A closer look at this Mideast center of history and current trouble spot is offered in this Terra MODIS view (below), with some of the geographic features in Israel, the West Bank (Palestine) and neighboring countries identified by annotation. The green area at the bottom of the Dead Sea is a manmade evaporation basin in which salt is extracted from the saline waters piped in from this body of water which is largely below sea level.

Israel and parts of adjacent countries, as imaged by Terra's MODIS.

The Holy City of Jerusalem appears as a darker "blotch" in the Terra image. An ASTER image shows a close-up of Jerusalem (this image indicates the the areal extent of Jerusalem is not that large):

Jerusalem, Israel, as imaged by ASTER.

This is an aerial oblique view of the inner part of greater Jerusalem:

Part of Jerusalem, from the air.

The golden domed building is the Dome of the Rock, a holy Moslem shrine that lies within the Old City (walled). It is visible as a yellow dot just left of center in the ASTER image.The sacred ground of the Old City has been subdivided into four sectors: Armenian; Christian; Jewish; Moslem. Some of East (Moslem) and West (mainly Jewish) Jerusalem is in this scene but modern Jerusalem extends well beyond.

The Dome of the Rock dominates this high resolution IKONOS image of the Old City:

IKONOS image centered on the Dome of the Rock muslim shrine in the Old City of Jerusalem.

Beirut, the capital of the small country of Lebanon, has been in the news in recent years, most frequently in 2006 (see Overview). Here is a photo taken by an astronaut onboard the International Space Station that show much of this city and some surroundings:

Astronaut photo of Beirut, Lebanon.

In 1975, the writer (NMS) flew into Beirut as part of his around the world trip after particating as a NASA/State Department emissary to help lead Remote Sensing Symposia in four countries (Thailand, Malaysia, Singapore; Indonesia). The flight passed low over the downtown buildings, some of which appear in the first image below. The TWA flight began in Bangkok, stopped in New Dehli and Karachi, passed near Iran, then over Iraq and Syria, into Lebanon as it went over the mountain range seen in the second image as snow-capped peaks.

Buildings in central Beirut.

Beirut, looking eastward from the Mediterranean.

At the Beirut airport, I was allowed to get off the plane, but could only walk 20 feet from the disembarcation stairs. A soldier with a rifle slung over his shoulders ordered me to proceed no further (enountered the same situation in Karachi). The plane then took off over Turkey to Istanbul, where I deplaned for a 2-day stay.

The next image is another Landsat scene of an area to the east of Israel. The mouth of the fabled Tigris and Euphrates Rivers empties through a delta into the Persian Gulf in southeastern Iraq. Those rivers meet into a single channel, the al Arab, in the swamplands in the upper left of the image. Crops along the river include wheat, millet, sorghum, cotton, rice, and dates. The Rivers Karun (top center) and Jarrahi (right center) are both in western Iran. The lower left corner is a barren desert, with sand dunes, which includes part of Kuwait, over which the Gulf War in 1991 was fought between a coalition of nations and the Iraqi invaders (see page 13-4c). Several black plumes of smoke emanate from the burning of gases released from oil fields. Kuwait lies atop one of the richest concentrations of oil and gas in the world.

Landsat MSS scene showing the mouths of the Tigris-Euphrates river system as it flows through southern Iraq. A delta forms at the top of the Persian Gulf. A small part of Iran lies to the right; a bit of Saudi Arabia and most of Kuwait (note the black smoke plumes from oil wells) are to the lower left.

Much of the Arabian Peninsula - actually a huge, wide land mass bounded by the Red Sea and Persian Gulf and thus not strictly a peninsula in geographic terms - is covered by barren desert with vast sand seas as evident in this mosaic.

Mosaic of Saudi-Arabia; the fuzzy area near the bottom is desert sand.

But, as seen in this mosaic Saudi Arabia's western side is composed of the Arabian Shield, a great mass of crystalline rocks (mostly metamorphic) that were once part of eastern Africa until separated by plate tectonic rifting in the Tertiary Period. The highest part in this scene is a dissected scarp that runs from along the west edge. The scarp in places is almost 1.6 km (1 mile) high, and erosion in this area leads to mountain-like prominences.. The plateau to its northeast includes dark volcanic rocks (younger basalts). In the coastal plains against the Red Sea is a mix of natural vegetation and localized farmlands. (See page 17-3 for a Landsat mosaic that shows a much larger part of the Arabian Shield.)

Landsat MSS image showing a segment of Saudi Arabia along the Red Sea, with mountains consisting of crystalline and some sedimentary rocks making up part of the Arabian Shield.

Most of Saudi Arabia is barren desert in the classic sense, namely, millions of acres of sand hundreds of meters thick, with surfaces showing a variety of dune types. The Empty Quarter of southern Saudi Arabia is host to the Ar Rab Al Khali basin and desert fill. Several types of dunes are expressed in this Landsat image:

The Rab al Khali desert, with dunes.

We saw an image of Riyahd, Saudi Arabia's capital, on page 4-4. Famed throughout the Islamic world is the coastal city of Mecca, with its holy shrines including the al Haram Mosque which devout Muslims must visit at least once in their lifetimes.

Mecca.

The al Haram Mosque at night; as many as 800000 worshipers can gather there.

In the far courtyard one sees the Ka'ba, a large marble structure containing the Black Stone, worshiped by Mohammed's followers as having fallen from Heaven (it is actually a dark meteorite). This IKONOS image shows the Mosque and the rectangular structure, around which the people circulate.

The al Haram Mosque in Mecca.

Along the east side of the Arabian Peninsula, bounded by the Persian Gulf, are several small countries - Kuwait, Qatar, the United Arab Emirates, and Oman. These have benefited greatly from revenues of mid-Eastern oil production. The sheiks who rule them have wisely invested these monies in developing extraordinary cities that have become population centers supported by water from wells and from desalinization of ocean waters. The citizens have the highest per capita income in the world. This results from oil money (which will start to run out around 2020. The intention is to use the oil profits to make these cities financial centers and top rate tourist attractions. Because of the growing importance of these centers, we will devote some space to their appearance from space and on the ground. First, a map of the region of special interest:

Map of several states along the Persian Gulf.

As seen from space:

Space image centering on the United Arab Emirates.

Dubai, in this satellite view:

The city of Dubai.

The downtown part of Dubai, a seen from the ground:

Downtown Dubai.

The tallest and most luxurious hotel in the world is the Burj-al-Arab. Begun in the early 1990s it opened just before the Millenium 2000 New Years Eve. It is shaped after an arabian sail(ing) ship. Its construction involved one engineering and artistic feat after another. You can read about this marvel at this. Wikepedia website

The Burj-al-Arab hotel.

Currently under construction is the Burj Dubai, which at 780 meters (2684 ft) to its antenna will be the tallest building in the world.

The Burj Dubai.

A complex of 5 apartment building skyscrapers is known as the Dubai Towers. It will soon be under construction.

The Dubai Towers.

Nearby Abu Dhabi is keeping pace with Dubai. First a view from space, then an aerial oblique photo.

SPOT image of Abu Dhabi.

Aerial view of Abu Dhabi.

The Abu Dhabi Arts Center is an architectural wonder, rivalling the Sydney (Australia) Opera House.

The Abu Dhabi Arts Center.

Not to be outdown, Doha, the capital of Qatar, is also building many skyscrapers. Here is an apartment complex under construction

Apartments in Doha, Qatar.

Doha, as seen from space:

Doha from space.

While more properly placed in southern Asia, the country of Iran is often thought of as part of the Middle East since it is politically tied to the Muslim communities such as Syria and Saudi Arabia. Here is a mosaic of the entire country:

Satellite mosaic of Iran.

The capital, Tehran, is shown in this Landsat-1 image as a dark area just off the image center:

Landsat image of part of Iran, with Tehran near the center and the Elburz Mountains to its north.

This is a higher resolution satellite image of Tehran. Beneath it is a 2 meter resolution IKONOS image of a small section of the city known for its parks:

Closer look at Tehran, up against the Elburz Mtns.

A suburban part of Tehran, with high rises.

Very much in the news in recent years is the defiance (to the UN) of Iran regarding its nuclear programs. The Iranians claim the Nantanz uranium-enrichment plant outside Tehran (and others) is being used to prepare for electricity generation. The U.S. warns the world that high grade uranium produced therein could be used to make nuclear weapons. Here is a satellite view of the facility:

The Nantanz nuclear plant in Tehran.

Although Iran is both an ancient and an advanced nation within south Asia, most of its land is barren and sparsely settled. Here is a region about 300 km (200 miles) southeast of Tehran known as the Great Kavir. Kavirs are similar to playas in the southwest U.S. The evident geologic folds are not high mountains but low hills within a surface that has been beveled by peneplanation.

The Great Kavir.

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Primary Author: Nicholas M. Short, Sr.