Análisis de los centros de interés según las variables seleccionadas

The Zambezi River Basin’s human popu- lation continues to grow at an average rate of about 2.36 percent per annum (SADC/SARDC and others 2012). Con-

31

SADC/SARDC and others, Zambezi River Basin Atlas of the Changing Environment, 2012

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Table 2.4 WWater Availability in the Zambezi River Basin

Country Total annual 1995 population 1995 Per capita 2000 2000 Per 2025 2025 renewable fresh (000) water availability population capita water Population Per capita water available (cu m) UN medium availability UN medium water (cu km/yr) projection (000) (cu m) projection availability (000) (cu m Angola Botswana Malawi Mozambique Namibia Tanzania Zambia Zimbabwe

WATERSTRESS Availability less than 1700 cu m/capita/year WATERSCARCITY Availability less than 1000 cu m/capita/year

Namibia values are high due to the Orange and Okavango river allocations but faces distribution challenges

Note that despite improvements in monitoring technology, estimates of water availability are approximations, and the average annual figures mask large seasonal, inter-annual and long-term variations. Geographical variations are also a factor, for example in Namibia and Malawi.

Hirji, R., Johnson, P., Maro, P. & Matiza-Chiuta, T. (Eds), Defining and Mainstreaming Environmental Sustainability in Water Resources Management in Southern Africa, 2002; Tumbare, M.J. The Management of the Zambezi River Basin and Kariba Dam, 2010

184 14.7 18.7 216 45.5 89 116 20 11 558 1 459 9 374 15 400 1 590 28 400 9 100 11 526 15 920 10 075 1 995 14 026 28 616 3 134 12 747 1 735 13 302 1 651 10 160 17 245 1 817 32 422 10 755 13 485 13 832 8 904 1 840 12 525 25 041 2 745 8 275 1 483 25 940 2 270 18 695 26 730 2 460 56 090 18 285 17 395 7 093 6 476 920 8 080 18 496 1 587 6 345 1 030

Table 2.5 Comparison of Zambezi River Basin Water Sector Status with other Benchmarks/Indicators

Sector Zambezi River Basin status SADC status World averages Industrialized countries Water abstraction 102 cu m/capita/year 170 cu m/capita/year 570 cu m/capita/year 1 330 cu m/capita/year Surface water storage 140% of ARWR stored 14% of ARWR stored 25% of ARWR stored 70% to 90% ARWR stored Irrigated land 13% irrigated of

available irrigable land 7% irrigated of 20% irrigated of 70% irrigated of available irrigable land available irrigable land available irrigable land

Water supply 77% of the ZRB 61% of the 87% of the World 100% of the

population (2008) SADC population population (2006) population has access has access to an has access to an has access to an to an adequate and safe adequate and safe adequate and adequate and safe water supply

water supply safe water supply water supply

Sanitation 60% of the ZRB 39% of the SADC 62% of the World 100% of the

population (2008) population has access population (2006) population has access has access to an to an adequate has access to an to an adequate adequate sanitation sanitation service adequate sanitation sanitation service

service service

ARWR Annual Renewable Water Resources

Hirji, R., Johnson, P., Maro, P. & Matiza-Chiuta, T. (Eds), Defining and Mainstreaming Environmental Sustainability in Water Resources Management in Southern Africa, 2002; Tumbare, M.J. The Management of the Zambezi River Basin and Kariba Dam, 2010

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Box 2.1 WWATER SECURITY

A country’s water security results from a combination of its inherent vulnerability and the way in which it responds to and manages that vulnerability.

Water vulnerability consists of three factors:

Water Availability

The basic amount of long-term water available to a country from surface and ground- water inflows and rainfall compared to the demand for water is a fundamental determi- nant of water security.

Water Variability

The extent to which the water is available when and where it is needed also heavily influ- ences the water security of a country. Countries that are neither water scarce nor water stressed may still be vulnerable because of a mismatch between the location of the water and the location of the demand. Highly fluctuating seasonal demands or a highly variable climate can also create vulnerability.

Water Dependence

The structure of a country’s economy and the dependence of its sectoral output on water will influence its security. More industrially developed countries generally have sectors that are less dependent on water than less-developed countries. Their productive output is less dominated by water-dependent sectors, such as agriculture, and there are multiple sources of energy for the industrial sector apart from hydropower.

Management response consists of two factors:

Water Infrastructure

Water storage helps to buffer against temporal variability; inter-basin transfers can buffer against spatial variability; levees and embankments protect against flooding; and pans, dams and boreholes provide access to water during drought in arid and semi-arid zones.

Management Environment

The way in which a country’s water resources are managed in the face of limited endow- ments and high variability can greatly influence its water security. Investment in forecast- ing and monitoring capabilities; laws and regulations that provide equitable access to water; involvement of stakeholders in water management; pricing policies that encourage water conservation and re-use; pursuit of conjunctive management of surface and groundwater; and treaties that promote regional water sharing all enhance efficient and equitable use of a country’s water resources.

sequently, the need for water will increase with the requisite increase in infrastruc- ture development. This will become more complex as countries utilize the most economically viable sources first and as these get exhausted, and then the more expensive sources have to be utilized. These sources might be from trans- boundary or inter-basin sources. In short, the competition for water by users will be- come fiercer as the water resource be- comes scarcer (Tumbare 2010).

Table 2.6 and Figure 2.3 show the current water use patterns in Zambezi ri- parian states for three sectors of Agricul- ture, Domestic and Industry.

Table 2.7 shows the area under ir- rigation in Zambezi Basin countries and its share in arable land and perma- nent crops. For Botswana, although the area under irrigation increased from one thousand hectares in 2001 to about two thousand in 2006, it still remained the lowest as compared to the area

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Figure 2.2 Comparison of Zambezi River Basin Water Sector Status with Other Benchmarks/Indicators

under irrigation in other riparian states. In 2008, Zimbabwe had the largest area of land under irrigation although its percentage share in arable land and permanent crops (4.5) was lower than that of Zambia (6.5).

Hydropower generation is one of the most important in stream uses of water in the basin and the region as a whole because most countries rely heav- ily on hydroelectricity for domestic and industrial use as well as for pumping water and other agricultural uses. Al- though hydropower generation is nor- mally considered non-abstractive, there are evaporation losses associated with storage and in some cases, diversion of water for hydropower generation away

from other uses such as tourism and the environment exemplified by the diver- sion of water on the Zambian side of the Zambezi River at Victoria Falls for hydropower generation at the Victoria Falls North Bank Power Station.

Competing uses of water arise from the demands of competing users, whether in the public or private sector, domestic or commercial use. Some of the major challenges for water sector stake- holders in the Zambezi River Basin are: • water scarcity as demand exceeds

supply due to natural causes, popu- lation growth, increased mining ac- tivities, emerging demands for bio-fuels, growing economies or dis- tribution of the water resources;

35 Figure 2.3 Water Use By Economic Sector

Aquastat, FAO Information System on Water and Agriculture, 2008

Table 2.6 Current Water Use Patterns By Sector

for Zambezi Riparian States

Country Current volume per capita (cu m/capita/year) Total Domestic Industrial Agriculture Angola 27 6 5 16 Botswana 83 29 18 35 Malawi 96 14 5 77 Mozambique 35 4 1 30 Namibia 139 46 5 87 Tanzania 58 3 1 54 Zambia 173 29 13 131 Zimbabwe 203 19 9 174 Average 101 18 7 76

World Bank, Strategic Role of Water in SADC Economies, 2004

Table 2.7 Irrigated Land in the Zambezi Basin and Share in Arable Land and Permanent Crops

IRRIGATED LAND SHARE IN ARABLE LAND AND PERMANENT CROPS

000 Ha % Country 1999-2001 2003-2005 2006 2007 2008 1999-2001 2003-2005 2006 2007 2008 Angola 80 80 80 80 80 2.4 2.2 2.2 2.2 2.2 Botswana 1 1 2 2 2 0.4 0.5 0.8 0.8 0.8 Malawi 51.7 56 56 59 59 1.8 1.8 1.8 1.9 1.6 Mozambique 115 118 118 118 118 2.7 2.5 2.4 2.5 2.5 Namibia 7.3 8 8 8 8 0.9 1.0 1.0 1.0 1.0 Tanzania 163 184 184 184 184 1.6 1.7 1.7 1.7 1.7 Zambia 133.3 156 156 156 156 6.0 6.9 6.3 6.4 6.5 Zimbabwe 174 174 174 174 174 5.2 5.0 4.7 4.7 4.5

• lack of access to adequate safe water and sanitation facilities due to finan- cial and infrastructure constraints; • water quality deterioration arising

from large volumes of effluent from urban, mining, industrial and agro use;

• fragmentation of water resources management policies and practices at national, river basin or regional levels.

Impact of Climate Change

While climate change and variability re- search is ongoing, both globally and lo- cally, researchers generally agree that average temperatures in the Zambezi River Basin are rising and that the

northeast of the SADC region will be- come wetter while the southwest will become drier. Table 2.8 gives a summary of the main indicators.