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Glacier volume change forecasts Glacier volume change forecasts
Oerlemans et al. (1998) conducted modelling experiments for a sample of 12 glaciers and ice caps, to determine volume changes under a range of temperature and precipitation forcings (Fig. 3). The range of glacier response is very wide, so a key issue is fnding ways to upscale the results of modelling this tiny sample of glaciers to large regions. Figure 2 shows the results of two alternative weighting procedures. Although the absolute values o...
06 Dec 2010 - by Riccardo Pravettoni
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Southern Asia natural disasters between 1975 and 2004 Southern Asia natural disasters between 1975 and 2004
Overview of natural disasters in Asia between 1975 and 2004. Floods account for a very signifcant proportion of the disasters observed.
06 Dec 2010 - by Riccardo Pravettoni
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Glacier cumulative mass balance Glacier cumulative mass balance
Compilation of available data (Fig. 1) shows that most mountain glaciers are losing mass, and that the overall rate of mass loss has increased in the last decade. For the last decade the highest mass loss per unit area has been observed in the European Alps, Patagonia, Alaska, and north-western USA/south-western Canada (Kaser et al., 2006, Lemke et al., 2007, Arendt et al., 2009).
06 Dec 2010 - by Riccardo Pravettoni
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Regional flood vulnerability Regional flood vulnerability
Since Asia comprises a large portion of the World’s popula- tion, and more than 40% of all the foods in the world occur in Asia, a large number of people are affected by disasters (Fig. 14). More than 40% of the people killed by natural di- sasters are killed in Asia (Fig. 15). In the ten-year period from 1999–2008, 402 foods were recorded in Africa, 342 in the Americas, 259 in Europe and 649 in Asia. In the same time period close to 1 bill...
06 Dec 2010 - by Riccardo Pravettoni
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Seasonal patterns of precipitation and runoff Seasonal patterns of precipitation and runoff
The infuence of glaciers on seasonal distribution of river fow is strongly dependent on annual temperature and precipitation cycles, and the proportion of the catchment occupied by glacier ice. Figure 4 compares precipitation and river fow data for heavily and lightly glacierized catchments in the European Alps and Peru. In the European Alps, runoff is greater than precipitation in summer in both heavily and lightly glacierized catchments. This...
06 Dec 2010 - by Riccardo Pravettoni
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Qanat Qanat
A qanat is a water management system used to secure reliable water supply to human settlements or irrigation in semi-arid and arid regions. Probably originating in Persia, the qanat system has been adopted and developed further in large parts of Asia and Europe. Its widespread use is refected in the many names for the system and similar systems; kariz/kahan (Persian), khettara (Morocco), galeria (Spain), falaj (United Arab Emirates and Oman), ...
06 Dec 2010 - by Riccardo Pravettoni
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Glacier recession and expansion in Hindu Kush-Himalayas and Central Asia Glacier recession and expansion in Hindu Kush-Himalayas and Central Asia
Averaged over their entire areas, within the period 1960– 2003 glaciers in Patagonia and Alaska have thinned by ap- proximately 35 m and 25 m, respectively, whereas high mountain glaciers in Asia have thinned by over 10 m. Data for Patagonia and Alaska are computed from glacier surface elevations for dozens of glaciers. In many other high moun- tain environments such as the Himalayas and the high Andes, where data are limited due to bo...
06 Dec 2010 - by Riccardo Pravettoni
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Victims and affected people in Pakistan flood, August 2010 Victims and affected people in Pakistan flood, August 2010
Seasonal fooding can occur along all the major watersheds in the Himalayan region (Figure 11–14). The largest problems occur in food prone areas with high population densities. This includes parts of northeast India, south-central Nepal, central and southern Pakistan, large parts of Bangladesh and lower reaches of the large rivers in China. In India around 40 million people are affected by fooding annually and the damage has been estimated...
15 Feb 2010 - by Riccardo Pravettoni
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Salzach river discharge, Austrian Alps Salzach river discharge, Austrian Alps
Simulated contributions of glacier melt (frn/ice melt) to annual total runoff were calculated between 1 and 4%. In the period 1999–2000, when the glacier mass balance of Goldbergkees and Stubacher Sonnblickkees have been observed to be zero or slightly above zero, the annual contribution of glacier melt was calculated as 1% (Fig. 7). The highest monthly contribution in 2000 was 4% for the month of August, and the highest daily glacier melt was 12...
06 Dec 2010 - by Riccardo Pravettoni
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Glacier shrinkage in hypothetical river basins Glacier shrinkage in hypothetical river basins
Downstream variation in the impact of glacier recession is illustrated in Figure 5, which shows modelled river fows for idealized catchments under climates representative of the western and eastern Himalaya and a 0.06º C per year warming scenario. In the upper parts of the river basins, where glaciers occupy 95% of the catchment area, the impact of glacier shrinkage is large. River discharges increase until mid-century, after which they de...
06 Dec 2010 - by Riccardo Pravettoni
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Recent flood events in the Hindu Kush-Himalaya region Recent flood events in the Hindu Kush-Himalaya region
Since Asia comprises a large portion of the World’s popula- tion, and more than 40% of all the foods in the world occur in Asia, a large number of people are affected by disasters (Fig. 14). More than 40% of the people killed by natural di- sasters are killed in Asia (Fig. 15). In the ten-year period from 1999–2008, 402 foods were recorded in Africa, 342 in the Americas, 259 in Europe and 649 in Asia. In the same time period close to 1 bill...
03 Feb 2010 - by Riccardo Pravettoni
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Sources of water for domestic use in Port Harcourt Sources of water for domestic use in Port Harcourt
The main source of water in Port Harcourt is boreholes, which account to about 50 per cent of the water sources for domestic use. Many of these boreholes are shallow, making them prone to pollution, and increasing the risk of water-borne diseases.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Slum population in urban Africa Slum population in urban Africa
One of the major challenges of urbanisation in Africa is the rapid expansion of areas of informal settlements. These slum areas tend to lack infrastructure such as pipe-borne water and sewerage, and services such as garbage collection and waste management are often non-existent.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Access to sanitation in urban Africa Access to sanitation in urban Africa
The number of people in Africa with access to improved sanitation, defined as “one that hygienically separates human excreta from human contact” (WHO/UNICEF 2010), has increased over the last two decades. Still, because of the rapid urbanisation, the proportion of the urban population with access to improved sanitation is on the decrease.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Urban growth rate in Africa Urban growth rate in Africa
Africa’s urban centres are currently growing at an annual rate that is the fastest compared to other regions. The urban expansion is expected to continue, with cities like Abuja and Ouagadougou expecting very high growth in the next decade, while Cairo, Africa’s largest city, is projected to see a comparatively lower growth rate.
27 Feb 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Population distribution in Africa Population distribution in Africa
In 1990 there were only 24 cities in Africa with more than one million inhabitants. Today this number has increased to 48 cities, of which Cairo and Lagos are the largest with more than ten million inhabitants each.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Water supply and demand in Nairobi Water supply and demand in Nairobi
The bulk of water supply for Nairobi comes from Thika, Sasumua and Ruiru Dams, as well as the Kikuyu Springs. Over time water supply for the city has failed to meet demand. The current estimated water demand for Nairobi is 650 000 m3/day compared to the production of 482 940 m3/day (WRMA 2010). The difference between production and demand has been widening over time due to population growth, inadequacy of the carrying capacity of the distributio...
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Access to water in urban Africa Access to water in urban Africa
Improved water sources, defined as “one that is protected from outside contamination” (WHO/UNICEF 2010), is essential for ensuring the health of Africa’s urban dwellers. Although an increasing number of people have access to improved water, rapid urban population growth in the African region has equally increased the number of people without proper access.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Urban population trends, Kenya and Nairobi Urban population trends, Kenya and Nairobi
As the total urban population of Kenya continues to grow, the capital of Nairobi still harbours the largest share of the country’s urban population. Between 1948 and 2009, Nairobi’s share of the country’s urban population increased from 5.2 per cent to 32.4 per cent and in 2009 the city had an estimated 3.1 million inhabitants.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Access to sanitation in Yaoundè Access to sanitation in Yaoundè
Proper disposal of sewage is essential for urban water quality, and in Yaoundè the treatment of wastewater, excreta, and sewage can be classified into two categories – individual wastewater systems (septic tanks and latrines) and collective wastewater systems (sewer and treatment plants). About half of the residents of Yaoundè are connected to the sewer system, while the rest depend on either septic tanks, latrines, or a combination of the two.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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