Table 1. Official statistics on current development trends in Tanzania. In the two last columns, we have interpreted the implications of these trends for Makanya catchment. Sources: The World Bank (2007), UNDP (2007), IPCC (Boko et al. 2007, Christensen et al. 2007, Easterling et al. 2007), and the United Republic of Tanzania (2001, 2002, 2005a, 2005b, 2006). Regional-, district-, and local-level data also come from FAO (2008), Same District Council (2006), and Enfors and Gordon (2007).

Indicator National-level statistics Current implications for Makanya Implications for Makanya 2030: direct projection of current trends
Economic Development Annual GDP growth On average 6.3% between 2000–2006, projected to increase to 7.9% by 2009 Investments in infrastructure and secondary education
Per capita income US$350 in 2006 Below national average, US$150 in 2002
Human welfare Poverty (% of population below the basic needs poverty line) 31% in 2005, projected to be 27% in 2010 About 11 000 people in Makanya 7000–9000 people, depending on population growth
Prevalence of malnourishment 44% in 2002–2004 Food shortages during 2005–2006 drought
Adult literacy rate 59% in 1985–1994, 69% in 1995–2005 >80% in Kilimanjaro region Increasing
Demography Annual predicted population growth rate 2.4% 2005–2015
(urban growth rate at 4.6%)
35 000 people, the regional population growth is about 1.6% annually With 1.6% growth, the population will be 52 000, with 2.4% it will be 63 000
Urban population (% of total population) 24.2% in 2005, projected to 28.9% in 2015 Young people are moving to towns Potentially changing demographic structure, dominated by older people and children
Climate change Temperature Increases of 2.5–3.5°C likely during the 21st century
Rainfall levels Increases up to 15% expected during the 21st century (projections consistent across most IPCC scenarios) 562 mm/year, with large variations
Extreme events Rainfall intensity likely increasing, having a clear negative impact on agricultural productivity Dry-spell frequency steadily increasing from 1950s. After 1980, four out of five “Masika” seasons have a dry spell of 21 days or longer >four–five seasons with severe dry spells
Agricultural development Yields Potential maize yield reductions of up to 20% during the 21st century due to temperature changes alone 1.14 ton/ha on average, but drought-induced harvest losses common 0.9–1 ton/ha providing no improvements, may be declining more if trend of increasing dry-spell frequency continues
Available farmland per capita Average farm size 2.3 ha per household, of which 80% is in use 2.5 ha per household (0.5 ha per capita), including fallow land 0.28–0.34 ha per capita depending on population growth, taking agricultural land expansion into account it would be 0.33–0.39 ha
% of population living from small-scale farming Between 70%–80 %, decreasing Estimated to be higher than 80% Decreasing
Average annual change in forested area -1.0% (1990–2005) Bushland covers 37% of the catchment Decrease to 28% of the catchment
Agricultural policy Focus on transformation of subsistence to commercial farming Support for vegetable-growing projects and food- processing projects -