Japhet J. Kashaigili

Forest and Woodland Cover and Change in Coastal Tanzania and Kenya, 1990 to 2000

ABSTRACT Forest and woodland cover and change were calculated for the Zanzibar-Inhambane biogeographical region of Tanzania and Kenya from ∼1990 to ∼2000. A cover and change map was derived from high-resolution satellite imagery from Landsat and supplemental data from aerial overflights, field surveys, and local knowledge. Analyses showed that around 6820 km2 of coastal forest habitat remained in ∼2000 (2260 km2 in Kenya and 4560 km2 in Tanzania). In terms of change, a total of 424 km2 (6%) of forest was cleared between ∼1990 and ∼2000; 53 km2 in Kenya and 371 km2 in Tanzania. Rates of forest loss were 8 times higher in unprotected areas than in protected sites such as Forest Reserves and National Parks. Key Biodiversity Areas had forest loss rates 2.5 times faster than protected areas while Alliance for Zero Extinction sites had the slowest rates of forest loss for the region. These baseline forest cover and change estimates along with future updates can contribute to national and sub-national carbon emission baselines and assessments of species threat within the global Red List.

Deforestation and CO2 emissions in coastal Tanzania from 1990 to 2007

SUMMARY Conversion of forest to other land uses is a major contributor to climate change. The coastal forests of Tanzania have increasingly been recognized as being of global biodiversity importance, due to high rates of species endemism. Rates of forest loss are similar to those of other tropical regions, resulting in increasing levels of threat for the biological values within the remaining forest and potentially significant source of CO2 emissions. This study estimated the remaining cover and carbon stock of Tanzania’s coastal forests and the CO2 emissions due to forest loss between c. 1990 and c. 2007. Coastal Tanzania contained over 273 700 ha of forest in 2007. Deforestation rates in the area have slowed from 1.0 % yr −1 ,o r> 3735 ha yr −1 during the 1990s, to 0.4 % yr −1 ,o r> 1233 ha yr −1 during 2000‐2007. Despite lower deforestation rates in 2000‐2007, the percentage forest lost from within reserved areas has remained steady at 0.2 % yr −1 for both time periods. CO2 emissions from deforestation slowed from at least 0.63 Mt CO2 yr −1 in 1990‐2000 to at least 0.20 Mt CO2 yr −1 in 2000‐2007. Regional forest clearance in Tanzania is highly dynamic; while rates have slowed since 2000, forest habitat conversion has continued and there is no guarantee that future rates will remain low. A rigorous policy on reducing emissionsfromdeforestationanddegradation(REDD) should be implemented to avoid future increases in deforestation rates.

Freshwater management and climate change adaptation: Experiences from the Great Ruaha River catchment in Tanzania

Adaptation to anthropogenic climate change is becoming vital to freshwater ecosystems and resource management, but climate adaptation can be purposeful or unintentional. This paper presents lessons from an assessment of an autonomous adaptation in the Great Ruaha River catchment in Tanzania following WWF intervention. The project was designed to address challenges resulting from natural resource use and existing levels of climate variability by changing water resource management. The study applied participatory methods and an open-ended questionnaire to collect data. The study found key adaptation benefits, including reduced vulnerability to drought and strengthened local water user associations and other regional institutions. As a result of the project interventions from 2003 to 2009, rural livelihoods became more profitable and water-sustainable, and local livelihood strategies were diversified. Regional ecosystems improved as a result of restoring river flows in some rivers, conservation of riparian vegetation and halting tree felling for charcoal production. As a result of these changes the communities and ecosystems in the Great Ruaha River catchment should be more resilient to emerging climate change impacts, yet the need for further physical interventions and institutional reform is identified. The study concludes that strengthening local institutions and capacity building are fundamental to climate change adaptation and sustainable freshwater management.

Barriers to and opportunities for improving productivity and profitability of the Kiwere and Magozi irrigation schemes in Tanzania

Abstract Irrigation is a key strategy for food security and poverty alleviation among small farmers in Tanzania. However, the potential of irrigation to improve food security is limited by multiple barriers. This article discusses these barriers within the Kiwere and Magozi schemes. Results indicate that water supply barriers are caused by poor irrigation infrastructure and management. Lack of finance is also a critical barrier to increasing overall productivity. Finance affects farmers’ timely access to adequate supply of quality inputs and machinery and availability of transport to access inputs and profitable markets. There is evidence that these barriers have to be addressed holistically.

Environmental flow assessment as a tool for achieving environmental objectives of African water policy, with examples from East Africa

Africa has set ambitious targets for development of water resources over the coming decades. Africa Water Vision 2025 calls for a doubling of irrigated agriculture and a five-fold increase in water use for agriculture, industry, and hydropower. The ambitious development targets are framed in the context of integrated water resources management, which also seeks to simultaneously allocate sufficient water for environmental sustainability. Over the past two decades scientists have devised a number of practical and robust approaches to determine environmental water requirements in rivers and wetlands based on the objectives set in water planning. We review the most widely applied approaches to assess environmental flow requirements and consider their application in Africa through case studies in the transboundary Mara River basin of Kenya and Tanzania and the Great Ruaha River basin in Tanzania.

Irrigating Africa: policy barriers and opportunities for enhanced productivity of smallholder farmers

Abstract African governments have ambitious plans to expand irrigated agriculture, though existing smallholder schemes have largely failed to use land and water sustainably or become profitable. Six government-owned irrigation schemes in Mozambique, Tanzania and Zimbabwe were assessed to identify common policy barriers and opportunities for higher productivity among smallholder farmers. Issues like insecure land tenure systems, unclear institutional arrangements and poor access to markets have contributed to limited profitability. Reform of currently insecure land tenure, strengthening farmer organizations and reforming policies are recommended so that governments step back from scheme management and foster market linkages to enable more profitable irrigated agriculture.

Hydrological modelling to assist water management in the Usangu wetlands, Tanzania

Abstract The Usangu wetlands, containing the Ihefu swamp, are one of the most valuable inland wetlands in Tanzania. Over the last decade, outflow from the swamp has ceased for extended periods in the dry season. This has had severe consequences for downstream ecosystems, including the Ruaha National Park. Results from a simple hydrological model developed for the Ihefu swamp indicate that, between 1958 and 2004, dry season inflows declined by approximately 60% and the dry season area of the swamp decreased by approximately 40% (i.e. from 160 km2 to 93 km2). The model also shows that to maintain minimum downstream environmental flows requires a minimum inflow of 7 m3s‐1, which is approximately 65% greater than occurs currently. There is significant potential for improving water use efficiency. However, given the socio‐economic importance of current levels of water withdrawal, this inflow may be difficult to achieve. Consequently consideration needs to be given to other options, including upstream storage and water management within the wetland itself. This paper highlights that a simple model supplying relatively low‐confidence, but indicative, results can provide a useful basis for contemplating water management options.

Distribution of Heavy Metals in Lake Muhazi, Rwanda

The pollution of lakes is mainly conceived in terms of nutrient levels and eutrophication with the consequent development of algal blooms and fish kills. However, heavy metals are increasingly becoming prominent especially for water bodies closer to urban and mining areas. This study focuses on heavy metal pollution in lakes using a case study of Lake Muhazi in Rwanda. The study characterized the horizontal and vertical distribution of heavy metals in the Lake, with the research conducted from July to October 2007. The parameters studied are cadmium, chromium, copper, iron, lead, manganese, zinc, pH and temperature. The samples were collected at different depths in the Lake using a Van Dorn Bottle water sampler, and were analyzed using standard methods. The temperature and pH were measured in the field us- ing HACH field testing kits. The findings indicated that the mean concentration of Zn was 0.041±0.045 mg/L, Cd 0.026±0.029 mg/L, Pb 0.292±0.442 mg/L, Fe 0.756±0.734 mg/L, and Mn 0.340±0.336 mg/L. Chromium and copper were not detected in the water samples. The findings indicate that the concentrations of Cadmium, Iron and Lead far exceeded the recommended levels for aquatic life at all sampling points. The high levels of heavy metals are attributed to the ripar- ian landuse practices such as uncontrolled agriculture, urban runoff and mining activities around the Lake. It is recom- mended that a detailed study of the catchment be carried out to identify and isolate the main sources of heavy metals in the Lake so that appropriate control measures could be developed.

Heavy Metals Inflow into Lake Muhazi, Rwanda

Most tropical African lakes are facing pollution problems due to the rapid population growth and industrializa- tion in their riparian communities. Lake Muhazi in Rwanda is one of such lakes which has experienced a dramatic decrease in fish production since the eighties, with also reports of low water transparencies and high turbidities. The lakeshores are now being developed for ecotourism and this requires sound environmental management to make the planned activities viable. The purpose of this study was to assess heavy metal pollution in the tributary rivers of Lake Muhazi. The concentration of heavy metals in major tributaries was monitored for the period July to October 2007. The parameters studied are cadmium, chromium, copper, iron, lead, manganese, zinc, pH and temperature. Fourteen sampling stations on the Inflow Rivers and the spillway were monitored fortnightly. The samples collected for heavy metal analysis were preserved and stored in cooler boxes and analyzed in the laboratory using Standard Methods. Temperature and pH were measured in the field using HACH field testing kits. The concentration (mean ± standard deviation) of Zn was found to be 0.040±0.103 mg/L, Cd 0.031±0.007 mg/L, Pb 0.487±0.452 mg/L, Fe 7.53±13.34 mg/L, Mn 1.01±1.31 mg/L, chromium 0 mg/L and copper 0 mg/L. The concentrations of measured parameters deviate much from the recommended ones thus posing serious problems to aquatic life. It has also been shown that the high metal concentration levels in Lake Muhazi are related to landuse activities in the catchment. It is thus recommended that farming practices and erosion be controlled in the catchment to contain pollutant discharges into the lake. Lead is the main anthropogenic pollutant which has been found in the watershed of Lake Muhazi.

Climate change and the water–energy–food nexus: insights from policy and practice in Tanzania

ABSTRACT The threat of climate change is emerging at a time of rapid growth for many economies in sub-Saharan Africa (SSA). Dominant narratives comprising ambitious development plans are common and often based around sectors with strong inter-dependencies that are highly exposed to climate variability. Using document analysis and key informant interviews, this article examines how climate change is addressed in policy, how it is being mainstreamed into water, energy and agriculture sector policies and the extent to which cross-sectoral linkages enable coordinated action. These questions are addressed through a case study of Tanzania, highlighting broader lessons for other developing countries, particularly those in SSA facing similar challenges. The article finds that, while the agriculture and water sectors are increasingly integrating climate change into policies and plans in Tanzania, practical coordination on adaptation remains relatively superficial. Publication of the Tanzania National Adaptation Plan of Action (NAPA) in 2007 marked a step change in the integration of climate change in sectoral policies and plans; however, it may have reinforced a sectoral approach to climate change. Examining the policies for coherence highlights overlaps and complementarities which lend themselves to a coordinated approach. Institutional constraints (particularly structures and resources) restrict opportunities for inter-sectoral action and thus collaboration is confined to ad hoc projects with mixed success to date. The results highlight the need for institutional frameworks that recognize and address these constraints to enable development goals to be pursued in a more sustainable and climate-resilient manner. KEY POLICY INSIGHTS The NAPA has been successful at encouraging climate change mainstreaming into sectoral policies in Tanzania; however, the cross-sectoral collaboration crucial to implementing adaptation strategies remains limited due to institutional challenges such as power imbalances, budget constraints and an ingrained sectoral approach. Collaboration between nexus sectors in Tanzania is largely through ad hoc projects with limited progress on establishing deeper connections to enable collaboration as a process. Regular cross-sectoral planning meetings and consistent annual budgets could provide a platform to enhance cross-sectoral coordination. Plans to develop hydropower and agriculture are prevalent across sub-Saharan Africa. Insights from Tanzania highlight the importance of institutional and policy frameworks that enable cross-sectoral coordination.