See posted comments (0) Post a Comment Lake Kyoga

Uganda

Lake Kyoga is a shallow lake with a surface area of 4000 km2. Half a million people live on its shores as well as on some on the large masses of vegetation called sudds seen floating in the lake (see especially the 1986 image). These communities rely heavily on the lake for their livelihoods. However, in the early 2000s life on the Lake was disrupted following a rapid change in the water level as a result of El Nino rains in 1997 and 1998. The high water caused some of the sudds, along with dislodged papyrus beds and water hyacinth mats to block the lakes outlet. The satellite images from 1974, 1986 and 2002 show the floating sudds on the lake. By 2002 many of these sudds had moved west blocking the outlet to the Nile River, leading to flooding in places surrounding the lake. The floods displaced people, destroyed infrastructure and disrupted livelihoods. Two channels were opened by Uganda’s Directorate of Water Development (DWD) in 2001-2002 and later on a team from Egypt had to dredge to allow water flow downstream. View detailed information

See posted comments (0) Post a Comment Nairobi

Kenya

Following its founding in 1902 it took roughly 40 years for Nairobi to exceed a population of 100 000 people. By independence, 20 years later it had reached around 350 000 people. Rapidly increasing population has been ongoing ever since, surpassing one million in the 1980s, two million in the 1990s and now approaching three million residents. While the annual rate of growth has at times exceeded 10 per cent it has more recently decreased to below four per cent per year — still very high by global standards. Nairobi is projected to top 3.8 million by 2015. The dramatic growth in area of intense urban settlement can be seen between the 1966 image and the 2007-2008 image mosaic. Much of Nairobi’s urban footprint is unplanned settlement driven by rapid population growth and urban poverty among other things. Sprawling informal settlements handicap the city’s delivery of social services and negatively impact the quality of life. View detailed information

See posted comments (0) Post a Comment Mount Elgon

Uganda

Mount Elgon, on Uganda’s eastern border, is a long extinct volcano supporting a variety of habitats, including dense tropical hardwood and bamboo forests, as well as an assortment of grassland and riverine ecosystems. Roughly 2000 square kilometers on the Ugandan side of the mountain are managed as protected areas; the largest of these being Mount Elgon National Park – established in 1992. Some of the densest population in the country makes its home along the park’s borders on the steep foot-slopes of the mountain. Most of these communities rely on pastoralism and subsistence agriculture; and with a growing population there is a strong demand for farmland and grazing land. The Ugandan Government and several non-governmental agencies along with the local communities, strive to balance the livelihoods of the local people with the need to protect the important natural areas of Mt Elgon – upon which those livelihoods ultimately rely. The resettlement of local people in 1983, in an area previously managed as forest can be seen clearly seen in these images from 1973 and 2005. This resettlement proved to be quite problematic for local people and the government. Since the mid 1980s, management of this area has taken a community based resource management approach, with improved participation and empowerment of the local comminutes. Nevertheless, continued growth of the area’s population makes striking a balance between protecting the mountain’s natural resources and meeting the needs of the local communities ever more challenging. View detailed information

See posted comments (0) Post a Comment Mau Forest Complex

Kenya

In spite of its national importance, many areas of the Mau Forest Complex have been deforested or degraded, with much of the damage occurring since the 1980s. Degazettement of forest reserves and continuous widespread encroachment have led to the destruction of over 100 000 ha of forest since the late 2000s, representing roughly one-quarter of the Mau Complex’s area. This series of satellite images documents 35 years of incremental destruction of forest area, punctuated by dramatic excisions. The Mau Forest Complex contains the catchment areas for many of Kenya’s most important rivers. The loss of forest can impact the quality and volume of water for these important rivers. Extreme land-cover changes such as these can have serious consequences both within the forest and downstream in the form of water shortages, health risks, desertification, habitat destruction, sedimentation, erosion, and even alteration of the micro-climate. This rate of forest loss is unsustainable and threatens the security and future development of Kenya. View detailed information

See posted comments (0) Post a Comment Loita Plains

Kenya

The Loita Plains, northeast of world famous Masai Mara National Reserve, are an important part of the larger Serengeti-Mara Ecosystem. They are core breeding and calving grounds and wet-season grazing land for the wildebeest, whose annual migration is the primary tourism feature of the Masai Mara Reserve. The natural landscape here is tall grass savanna with some scattered acacia and dwarf shrubs. The primary human inhabitants of the Loita Plains are the Maasai, who have traditionally been nomadic pastoralists. Responding to the limited, unpredictable and seasonal rains on these grasslands the Masai like the wildebeest, traditionally migrated through the year to where the grasses provided adequate food for their cattle. Over the past several decades, changes in land use in the Narok District have caused changes in ways of life for both the Masai and the Wildebeest. While most Masai in both Tanzania and in Kenya have taken up cultivation in recent decades, land tenure restrictions in Tanzania have tended to prevent widespread development of mechanized cultivation. In Kenya however, large mechanized wheat farms in the area surrounding Masai Mari expanded roughly 1 000 per cent between 1975 and 1995, most of them on the Loita Plains. This has reduced the available natural grasslands in this important wildebeest habitat. The Masai Mara is perhaps the most famous of Kenya’s tourist attractions and the annual migration of the wildebeest and other large mammals is one of the Mara’s most compelling features. Management of competing land uses for this vast grassland will require a careful balance if its value is to be preserved for future generations. View detailed information

See posted comments (0) Post a Comment Lake Wamala

Uganda

Seventy kilometers to the west of Kampala is Lake Wamala. After being stocked in 1956 the lake was a productive fishery in the 1960s and early 1970s, providing a major source of fresh fish for the city of Kampala as well the local residents surrounding the lake. However, the lake was seriously overfished and the fishery had largely collapsed by the mid 1970s. The shallow lake’s levels have fluctuated with changes in precipitation through the recent decades. In the 1980s its surface covered roughly 250 sq km. During the 1990s its surface shrank to roughly half that size. It has more recently recovered much of its surface area, however Lake Wamala’s future management remains a concern for those who live in its vicinity. View detailed information

See posted comments (0) Post a Comment Lake Naivasha

Kenya

Unlike other lakes in Kenya’s Eastern Rift Valley, Lake Naivasha is a freshwater lake, receiving most of its inflow from the Aberdare Mountains to its east. It is a valuable freshwater resource for human uses and for a diverse population of water birds and large mammals, including hippopotamuses. The lake supports a range of economic activities including commercial flower growing, fishing, and a geothermal power plant. In recent years, pressure on the Lake has increased as population and human activities have intensified throughout its catchment. Several of these changes can be seen in the differences between the 1973 and 2008 satellite images. The footprints of Naivasha town and Karagita have grown considerably to well above 600 000, reflecting the increased population throughout the catchment. Many commercial greenhouse flower farms have been built since the early 1980s. These are visible surrounding the lake as bright white and light blue squares of greenhouse roofs. Designated a Ramsar Wetland of International Importance, efforts are being made to sustainably manage the lake. Nevertheless, water abstraction for agriculture; watershed deforestation; diversion of inflow from Malewa and Gilgil Rivers; nutrient, sediment, and chemical runoff into the lake; and invasive species are just some of the many concerns bearing on Naivasha’s future. View detailed information

See posted comments (0) Post a Comment Kampala

Uganda

Due primarily to high rural to urban migration, Kampala’s population has grown at an average rate of 5.6 percent annually since the 1960s; expanding its urban footprint to a sprawling 197 square kilometers. Over 1.2 million people now live in the capital city. This stunning growth can be seen in the remarkable contrast between these 1974 and 2008 satellite images. The growing population has led unplanned settlement and inadequate infrastructure for many of the City’s residents. In addition, areas of forest in and around the capital have been lost to increasing demand for charcoal. Many of the wetlands in the Kampala area have been lost to industrial and residential development. This has had a negative impact on water quality within Kampala as well as the water of Murchison Bay which has experienced periodic infestations of water hyacinth and massive algae blooms which turn the water of the bay green. View Detailed information

See posted comments (0) Post a Comment Dadaab Refugee Camp

Kenya

Ifo, Dagahaley, and Hagadera refugee camps are located in Dadaab town in the North Eastern Province of Kenya, near the border with Somalia. The camps date back to 1991 when civil wars erupted on a large scale in Somalia. The conflicts, along with prolonged drought, forced more than 400 000 people from Somalia to flee to Kenya and another 500 000 to other neighboring countries. The 1987 image shows a fairly intact landscape dominated by shrub vegetation characteristic of the semiarid area. In the 2000 image, the Ifo, Dagahaley, and Hagadera refugee camps stand out distinctly, revealing the presence of over 100 000 refugees and the impact of a high concentration of people on the environment. Shrublands have been reduced largely to bare spots with sparse and stunted shrubs and grasses, while riverine vegetation has also suff ered loss and degradation. View Detailed information

See posted comments (0) Post a Comment Budongo Forest Reserve

Uganda

A study in the Budongo Forest/Murchison Falls National Park landscape shows that there has been both woody cover decrease and increase. In areas where there has been continuous burning, woody cover species have changed from those that are less resistant to fire to those that are more resistant. The burning was mainly carried out by the local communities bordering the forest. In the northern portion of Budongo, an increase in policing of the forest area and the presence of a park entry gate has resulted in an observable decrease in burning. Signs of fire are evident in such landscapes as dark reddish purple scars. Fire scars were evident on the 1973 image of northern Budongo. There are almost no fire scars on the 2008 image. The areas where there has been a higher control of burning are the areas which have seen an increase in woody cover. View detailed information

See posted comments (0) Post a Comment Okavango Delta and Lake Ngami

Botswana

The vast stretches of grassland, wetland, and open water of the Okavango Delta are home to a variety of wildlife and vegetation as well as several native tribes. Although the Okavango ecosystem is considered one of the wonders of the world and attracts tourists from all over the globe, it faces several significant threats. Proposed upstream water projects are among these threats. The Okavango River originates in the highlands of east-central Angola and brings the flood waters and sediment necessary to maintain the dynamic flooding of the delta. Upstream dams could trap much of this sediment, causing the river View detailed information

See posted comments (0) Post a Comment Kangerdlugssuaq Glacier

Kangerdlugssuaq, the largest outlet glacier on Greenland’s east coast, is one of 12 fast flowing outlet glaciers that discharge ice into the surrounding oceans. Its rate of flow more than doubled between 2000 and 2005 reaching a speed of 14 km per year or 1.6 meters per hour. It has since slowed. During this same period mean summer temperature at coastal weather stations along southeastern Greenland increased 1.1° C. While the mechanisms controlling the rate of flow are complex and not fully understood, there is a general consensus that warming temperatures are driving the increased rates of discharge. The fronts of glaciers throughout southeast Greenland also receded rapidly during this same time period; an average retreat of 24 m/yr increasing to an average of 175 m/yr. Kangerdlugssuaq Glacier, which had been retreating 25 to 100 meters per year in the period between 1992 and 2000, retreated more than 4 km between April 2004 and April 2005. The loss of the Greenland Ice sheet is a major factor in projecting the sea level rise which might result from global warming. Loss of the entire sheet would raise global sea level an estimated 7 meters. If melting were the only mechanism through which Greenland was losing ice mass, this could take 1000s of years. The acceleration of Greenland’s glaciers raises concerns that the global sea level may rise more rapidly under global warming scenarios than had previously been estimated. View detailed information

See posted comments (0) Post a Comment Mendenhall Glacier

Mendenhall Glacier flows 22 kilometers from an elevation of nearly 1,600 meters in the Coast Mountain Range, to just above sea level at its terminus roughly 5 kilometers northeast of Juneau, Alaska. It has been receding since the 1700s when the “Little Ice Age” ended, retreating approximately 3 kilometers in the past century. Most of this retreat occurred in the mid-1940s and the late 1990s. The majority of the global community now accepts fluctuations in glaciers, particularly changes in their volume, to be reliable indications of a global trend of warmer air temperatures. While the retreating tongues of glaciers are less directly linked to climate change than overall volume, they are much more readily observed and allow the study of glaciers which would otherwise be out of the reach of most research projects. It is believed that the current climate conditions will not be reflected in most glacier tongues for years and will eventually amount to a kilometer or more of additional retreat. If climate conditions continue to follow current trends many glaciers will disappear completely. The satellite images from 1986 and 2007 show the continuing retreat of Mendenhall Glacier. Similar changes are taking place in many of the glaciers in southeastern Alaska. A 2002 study estimated the contribution of melting Alaska glaciers to sea level rise between the 1950s and 1990s to be twice that of the melting of Greenland’s ice sheet during the same time period. View detailed information

See posted comments (2) Post a Comment Great Man-made River Project, Al Kufra

Libyan Arab Jamahiriya

In the 1950s, oil exploration in Libyan Arab Jamahiriya turned up another resource beneath the scorching sands: the Nubian Sandstone Aquifer System. Radiocarbon analysis showed that some of the water in the aquifer system was 40 000 years old. Tapping the aquifers was chosen as the most cost-effective option for meeting the country's water needs. In 1993, Phase I of the Great Man-made River (GMMR) Project brought water from eastern well-fields at Sarir and Tazerbo to Benghazi (not shown). In 1996, Phase II brought water from well-fields at Jebel Hassouna to Tripoli (not shown). Phase III is still under construction. The project's largest reservoir, known as the Grand Omar Mukhtar, is located at Suluq (2006 image, yellow arrows). When fully operational, the GMMR will pump 3.6 million cubic metres of the Nubian Aquifer water per day. Water from the aquifer is used to support extensive centre-pivot irrigation agriculture at Al Kufra (see 1972 and 2001 images above). At current extraction rates the Nubian Sandstone Aquifer System is not likely to be depleted for a thousand years. Nevertheless, it is shared among four African nations: Libyan Arab Jamahiriya, Chad, Sudan, and Egypt. The concern of environmentalists is that eventually people will drain the aquifer faster than nature can renew it. The International Atomic Energy Agency is trying to bring the four countries together to plan rational shared use of the water. View detailed information

See posted comments (0) Post a Comment São Tomé

Sao Tome and Principe

São Tomé is the capital city of the island that shares its name. Located in the island's Agua Grande district, the population of São Tomé increased from a mere 8 431 in 1940 to 51 886 in 2001. The satellite image shows how settlements, especially along roads, have expanded inland from the city. While much of the island still retained its natural vegetation in 2007, vegetation loss is obvious near the capital city and surrounding settlements, where forests have been converted to croplands. Substantial oil reserves have recently been discovered off the island of São Tomé, which will most likely fuel increased development. View detailed information

See posted comments (0) Post a Comment Anjouan Island

Comoros

Comoros’ population quadrupled between 1950 and 2000. On Anjouan Island, where population density is 446 people per square kilometre, agricultural land is in short supply and many areas of steep terrain not suitable for agriculture have nevertheless been cultivated. Traditional agriculture leaves many trees in the fields, which help control soil erosion. However, pressure for food production is leading to more open field agriculture and some monoculture farming on the island of Anjouan. These more intense methods of agriculture encourage soil erosion. The top image above shows Anjouan’s fragmented forest. The reddish yellow areas on the simulated 3-D images show agricultural lands on Anjouan’s slopes. As a whole, Comoros lost about 60 per cent of its forest cover between 1950 and 1985. View detailed information

See posted comments (1) Post a Comment Coral Reefs of Mauritius

Mauritius

Over the past 50 years, the population of Mauritius has nearly doubled, to 1.2 million. It currently has the highest population density of any African country, 652 people per km2. Mauritius has also seen a dramatic growth in its economy, which has increased demands on its environment. Coral reefs almost surround Mauritius. Coral reefs are complex ecosystems, rich in biodiversity yet only able to survive in very clear, warm and nutrient-poor ocean waters. In these satellite images, coral reefs (yellow arrows) form a fringe along the island's shores and create shallow lagoons that are extremely important to the fishing and tourist industries. The island's population density as well as agricultural runoff, untreated sewage, changes in freshwater runoff, tourist activity, and global warming all threaten the health of the reefs. View detail information

See posted comments (0) Post a Comment Balanta Rice Farming

Guinea-Bissau

Rice is a major crop and staple food in Guinea-Bissau. The production of paddy, or "wetland," rice started in the late 17th and early 18th centuries, when the Balanta (the country's largest ethnic group) started organising men and women for agricultural production. Rice paddies have replaced many of the mangroves along the Gêba and Mansôa Rivers to the north of the capital, Bissau (2007 image). These rice paddies are built by cutting a path through the mangroves and piling up mud to form a dike that will keep back the tide. The mangroves, cut off from the ocean, quickly die. The ground is then burned to clear remaining undergrowth. After the paddies are constructed, their walls trap rain water, in which rice will grow. The 2007 image (above right) shows several dark green belts of mangrove forests adjacent to the Gêba and Mansôa Rivers. Intensive rice farming is indicated by the light-grey areas bordering these mangroves. This pattern is observed around Bissau, as well as the smaller towns of Cufar, Mansôa, Bissassema de Cima, and Nã Balanta. The 2005 high-resolution image (above left) shows the intensity of rice cultivation in an area near Cufar (from yellow box, above right). Inundated rice paddies (whitish rectangles) and rice fields (light- to dark-green rectangles) surround the meandering river. Only isolated patches of mangroves (deep-green) remain along much of the river. View detailed information

See posted comments (1) Post a Comment Swaziland Sugar Plantations

Swaziland

Sugar cane production has become Swaziland's biggest industry as large-scale producers have been joined by hundreds of small-scale farmers. Much of this growth can be attributed to government promotion of sugar cane farming. While this growth has come at the expense of natural flora and fauna, it has brought significant benefits for the eastern province of Lubombo. Sugar cane plantations are found primarily in northeastern Swaziland where temperatures are optimal. However, this region is also characterized by erratic rainfall with periods of drought; precipitation provides only 25 per cent of the water sugar cane crops need. To meet the sugar cane industry's remaining water requirements, several dams have been constructed along major rivers, including the Sand River and Mnjoli Dams. These satellite images, from 1979 and 2006, show the dams and how the area devoted to sugar cane plantations has increased over time. Sugar cane exports bring in roughly US$1 500 million annually to Swaziland. Lubombo Province, in particular, relies heavily on income from sugar cane as well as social services that the industry provides, including medical care, education, housing, and access to clean water. Yet fluctuating sugar prices have prompted the Swazi government to promote the production of other crops. Such a transition, however, is far easier for small-scale farmers than for large-scale producers with extensive plantations. View detailed information

See posted comments (0) Post a Comment Souss-Massa Valley

Morocco

The Souss-Massa Valley is located in southwestern Morocco. Rainfall in the valley is only about 200 mm per year, which is not enough to support most types of agriculture. In 1968, Morocco's King initiated a plan to irrigate one million hectares. In 1972, the Youssef Ben Tachfine Dam (photo below) was built on the Massa River, creating a reservoir that supported a substantial growth in agriculture in the valley and allowed development of a modern agricultural area of 18 000 hectares, primarily dedicated to vegetable and citrus cultivation. Irrigated agriculture in the valley also uses groundwater; however, groundwater withdrawal has exceeded the natural rate of recharge. Since the 1970s groundwater resources have declined, forcing farmers to drill much deeper wells to reach water. In the 1970s, greenhouse agriculture was introduced to the area. It requires 80 per cent less water per kg of crop than unprotected agriculture. The 1988 satellite image shows a few greenhouses (light blue squares) scattered throughout the valley. The 2003 image shows the expansion that has occurred in greenhouse agriculture, with greenhouses (white squares) covering a substantial portion of the valley's agricultural land. The Souss-Massa Valley is Morocco's leading region for greenhouse agriculture, covering 14 530 hectares in 2004. Vegetables are the primary crops, with tomatoes covering more than half the greenhouse area. View detailed information