Use of Weather and Climate Information in Decisions on Conservation of Water Resources in Kilombero River Catchment, Tanzania

The authors thankfully acknowledge the financial support from Uncertainty Reduction in Models for Understanding Development Applications (UMFULA) Project under the Future Climate for Africa (FCFA). Special thanks go to Declan Conway (London School of Economics and Political Science) who contributed invaluable inputs to the publication. Abstract This study assessed the use of climate information in decisions on the conservation of water resources and determined influencing factors in Kilombero River Catchment in Tanzania. A cross-sectional research design was employed. Purposive sampling was used to select Kilombero, Ulanga and Malinyi districts and Lumemo, Nakafulu and Biro villages while simple random sampling was used to select respondents. A total of 120 household respondents were interviewed in the three villages. In addition, 7 Key Informants’ Interviews (KIIs) involving officers from Kilombero Game Controlled Area (KGCA) and Rufiji Basin Water Board (RBWB) and 3 Focus Group Discussions (FGDs) with the villagers were conducted. Quantitative data were analyzed using Statistical Package for Social Science (SPSS) and STATA computer programs while qualitative information was analyzed using content analysis. Results show nearly half of respondents of weather and climate information in decisions to conserve water resources. Although ten decisions were identified in the area, weather and climate information was highly used in deciding conservation measures (X2=5.992, p<0.05), construction of small pans or bore holes for water storage (X2=6.580, <0.05) and reducing the number of livestock (X2=5.889, p<0.05). Four variables which had significant and positive correlation with conservation of water resources were identified. Foremost among them is extension visits (ß=0.079; p<0.01) which implied access and frequency of extension visits influence use of weather and climate information in making decisions. It is concluded that communities in the area use weather and climate information in decisions which conserve water resources.  Policy makers are advised to emphasize factors which had positive significant correlation with conservation of water resources. Keywords: Climate Information Use, Water Conservation Decisions. DOI: 10.7176/JEES/10-4-06 Publication date: April 30th 202

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

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

THE EFFECT OF AGRICULTURAL INTENSIFICATION ON ECOSYSTEM SERVICES AROUND IHEMI CLUSTER

As the world population continue to increase, the demand for food also increases which necessitate the need for agricultural intensification. Agricultural intensification affects large parts of terrestrial area, therefore, assessment of its contribution to the decrease of ecosystem services is critical for successful conservation in the future. A study was conducted in five districts of Iringa and Njombe Regions, part of Ihemi cluster, to assess the effects of agricultural intensification on ecosystem services.  A total of 607 household surveys and 19 Focus Groups discussions were conducted. Descriptive and cross tabulation were used for quantitative analysis while content analysis was used for qualitative data. Findings reveal that there are several benefits communities get from the ecosystem that play a great role on their livelihood. Across all villages, firewood is preferred due to its affordability and availability. Other ecosystems goods such as traditional medicine and mushrooms are hardly available due to clearing of land for agricultural activities, as well as settlement expansion.  Community activities, such as valley bottom farming was mentioned as a practice that jeopardize the long-term sustainability of ecosystem resources within the Cluster. Agricultural intensification by investors was also mentioned as a sources of ecosystem depletion. Sustainable agricultural intensification, if adopted, might be one among the solutions to serve the ecosystem around the cluster

Ecosystem health and sustainable agricultural development in Ihemi cluster

Agricultural landscape provide a range of ecosystem services apart from producing crops. However, the inter-linkage of the ecosystem services and agricultural activities is poorly understood. For over 50 years, agriculture has been conducted without considering the natural ecological processes that safeguard agricultural production in the long run. To ensure that agricultural systems are sustainable, we have to make sure that the crucial ecosystem functions in the natural landscape are protected. Agricultural intensification, dramatic land use changes, application of agrochemicals and intensification of resource utilization are among the factors contributing towards biodiversity loss. The process of agricultural intensification is associated with an increase in labour inputs, increase use of natural and artificial fertilizer, use of improved seeds, change in technologies, change in agricultural mechanization & frequency of cultivation, changes to the landscape such as irrigation or soil conservation measures. The agricultural inputs, for instance, have altered the key-hydrological processes of rivers, lakes, floodplains and groundwater-fed wetlands, damaging their ecosystems and services that they provide. Agricultural intensification affects large parts of terrestrial area, therefore, assessment of its contribution to biodiversity loss is critical for successful conservation in the future. Irrigation, clearance of natural vegetation, and the construction of water storage facilities have all altered the timing and natural variability of water flows, damaging ground water recharge and wetland areas. It is claimed that agriculture in the Southern Agricultural Growth Corridor of Tanzania (SAGCOT) is developed in harmony with the natura

The role of superficial geology in controlling groundwater recharge in the weathered crystalline basement of semi-arid Tanzania

Study region Little Kinyasungwe River Catchment, central semi-arid Tanzania. Study focus The structure and hydraulic properties of superficial geology can play a crucial role in controlling groundwater recharge in drylands. However, the pathways by which groundwater recharge occurs and their sensitivity to environmental change remain poorly resolved. Geophysical surveys using Electrical Resistivity Tomography (ERT) were conducted in the study region and used to delineate shallow subsurface stratigraphy in conjunction with borehole logs. Based on these results, a series of local-scale conceptual hydrogeological models was produced and collated to generate a 3D conceptual model of groundwater recharge to the wellfield. New hydrological insights for the region We propose that configurations of superficial geology control groundwater recharge in dryland settings as follows: 1) superficial sand deposits act as collectors and stores that slowly feed recharge into zones of active faulting; 2) these fault zones provide permeable pathways enabling greater recharge to occur; 3) ‘windows’ within layers of smectitic clay that underlie ephemeral streams may provide pathways for focused recharge via transmission losses; and 4) overbank flooding during high intensity precipitation events increases the probability of activating such permeable pathways. These conceptual models provide a physical basis to improve numerical models of groundwater recharge in drylands, and a conceptual framework to evaluate strategies (e.g., Managed Aquifer Recharge) to artificially enhance the availability of groundwater resources in these regions

Effects of land use/ cover changes on flow regime of the Usangu wetland and the Great Ruaha River in Tanzania

The Usangu wetland (Ihefu) is a wetland of great importance for its biodiversity and acts as regulator for downstream flows for the Great Ruaha River through the Ruaha National Park. While recognizing the importance of this wetland, little is known about the effects of land use and cover changes on the wetland itself and the flow regime of the Great Ruaha River in the downstream. Recognizing that, a study was conducted using remote sensing and GIS techniques to inventory land use/cover changes in the watershed over the years. Hydrological data were analyzed to reveal the alterations and trends at three periods (pre-1974, 1974-1975 and post 1985) from 1958 to 2004. It was revealed that there was a steady increase in cultivated area, from 121.2 km2 to 874.3 km2 between 1973 and 2000 while the woodland area decreased significantly over years. The minimum dry season area of the wetland declined significantly, with more changes occurring between 1984 and 2000 at 67% reduction. The river was found to be sensitive to land use/ cover changes and highly variable on an intra annual (seasonal) and inter-annual (year to year) basis. There was a slight shift in the peaking for the post-1985 period with high flows attained earlier in February instead of April. The Q50 flow progressively declined from 19.23m3s-1 in the pre-1974 to 16.51 m3s-1 and 9.04 m3s-1 for 1974-1975 and post-1985 period respectively. The Q95 (low flow) declined from 2.84 m3s-1 to 0.11 m3s-1 and 0.0 m3s-1 for pre-1974, 1974-1975 and post-1985 period respectively. The study concludes that the modification of the land use and cover has resulted into changes in time distribution of runoff within the catchment. The study highlights the effects of land use /cover changes on ecosystems and water resources for an informed decision on proper catchment planning and management

Effects of land use/ cover changes on flow regime of the Usangu wetland and the Great Ruaha River in Tanzania

The Usangu wetland (Ihefu) is a wetland of great importance for its biodiversity and acts as regulator for downstream flows for the Great Ruaha River through the Ruaha National Park. While recognizing the importance of this wetland, little is known about the effects of land use and cover changes on the wetland itself and the flow regime of the Great Ruaha River in the downstream. Recognizing that, a study was conducted using remote sensing and GIS techniques to inventory land use/cover changes in the watershed over the years. Hydrological data were analyzed to reveal the alterations and trends at three periods (pre-1974, 1974-1975 and post 1985) from 1958 to 2004. It was revealed that there was a steady increase in cultivated area, from 121.2 km2 to 874.3 km2 between 1973 and 2000 while the woodland area decreased significantly over years. The minimum dry season area of the wetland declined significantly, with more changes occurring between 1984 and 2000 at 67% reduction. The river was found to be sensitive to land use/ cover changes and highly variable on an intra annual (seasonal) and inter-annual (year to year) basis. There was a slight shift in the peaking for the post-1985 period with high flows attained earlier in February instead of April. The Q50 flow progressively declined from 19.23m3s-1 in the pre-1974 to 16.51 m3s-1 and 9.04 m3s-1 for 1974-1975 and post-1985 period respectively. The Q95 (low flow) declined from 2.84 m3s-1 to 0.11 m3s-1 and 0.0 m3s-1 for pre-1974, 1974-1975 and post-1985 period respectively. The study concludes that the modification of the land use and cover has resulted into changes in time distribution of runoff within the catchment. The study highlights the effects of land use /cover changes on ecosystems and water resources for an informed decision on proper catchment planning and management

Failure of the Mtera-Kidatu reservoir system in the Early 1990s

Four possible causes for the failure of the Mtera-Kidatu Reservoir System within the Rufiji River Basin in Tanzania in the early 1990s were investigated. These were sudden decrease in inflows, sudden increase in losses, sudden increase in hydropower generation, and unnecessary spills; or a combination of these, and it was found out that unaccounted for and unnecessary spillage was the main cause. This paper proposes that consideration of the flows that are generated within the intervening catchment (i.e. catchment between Mtera and Kidatu) and the operational policy that maximum power is produced at Kidatu most of the time must be the core in the management of the reservoir system. If this was the case in the past then the Mtera Reservoir should not have gone dry in the 1991-1994 period. The validity of this assertion was tested with the TALSIM 2.0 model and an efficiency of 95% was achieved, indicating a very good correlation with the investigative techniques employed in this study

Evaluation of water productivity for maize under drip irrigation

A drip system operating under deficit irrigation was used to evaluate water productivity (WP) of TMV-1 maize variety in Morogoro, Tanzania. A block was divided into four sub-blocks; and each randomly assigned with deficit treatment (T1, T2, T3 and T4 as 60%, 40%, 20% and 0% irrigation water deficits, respectively). Three replications were used producing randomized block design. Each sub block biomass, grain yield and harvest index were determined. Biomass development and grain yield were significantly (0.1<P<0.05) influenced by water deficit. Both increased with increasing irrigation water to full irrigation. WP were different (P=0.1), with T2 having the highest value (2.2 kg/m3)