Browsing by Author "Kashaigili, J.J"
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Item Assessing the Impacts of Land Use and Land Cover Changes on Hydrology of the Mbarali River Sub-Catchment. The Case of Upper Great Ruaha Sub-Basin, Tanzania.(Scientific Research Publishing Inc., 2018) Mutayoba, E; Kashaigili, J.J; Kahimba, F.C; Mbungu, W; Chilagane, N.AIntensification of agricultural land use and population growth from 1990-2017 has caused changes in land cover and land use of the Mbarali River sub-catchment which is located in the Upper Great Ruaha Sub basin, Tanzania. This has affected the magnitude of the surface runoff, total water yield and the groundwater flow. This study assesses the impacts of the land cover and land use changes on the stream flows and hydrological water balance components (surface runoff, water yield, percolation and actual evapotranspiration). The land use and land cover (LULC) maps for three window period snapshots, 1990, 2006 and 2017 were created from Landsat TM and OLI_TIRS with the help of QGIS version 2.6. Supervised classification was used to generate LULC maps using the Maximum Likelihood Algorithm and Kappa statistics for assessment of accuracy. SWAT was set up and run to simulate stream flows and hydrological water balance components. The assessment of the impacts of land use and land cover changes on stream flows and hydrological water balance component was performed by comparing hydrological parameters simulated by SWAT using land use scenarios of 2006 and 2017 against the baseline land use scenario of 1990. Accuracy of LULC classification was good with Kappa statistics ranging between 0.9 and 0.99. There was a drastic increase in areal coverage of cultivated land, for periods 1990-2006 (5.84%) and 2006-2017 (12.05%) compared to other LULC. During 2006 and 2017 surface runoff increased by 4% and 9% respectively; however, water yield increased by only 0.5% compared to 1990 baseline period. This was attributed to increased proportion of cultivated land in the sub-catchment which has a high curve number (59.60) that indicates a higher runoff response and low infiltration rate.Item Assessment of forest cover change under different forest tenure regimes in Ngitili management systems in Meatu district, Tanzania(Tanzania Journal of Forestry and Nature Conservation, 2022) Manyanda, B.J; Kashaigili, J.JDeforestation and forest degradation are tied to a complex array of socioeconomic and political factors. Quantifying the amount of amount of forest is key to ensure that appropriate management practices and policies are in place to combat deforestation and forest degradation. Despite the fact that forestland tenure changes from private and communal to state ownership occurred in Ngitili management systems in Meatu district Tanzania, little has been done to evaluate its impacts on forest cover. The objective of this study was to assess the forest cover changes under different tenure regimes in Ngitili management system. Landsat imagery of 1986 and 2000 were used in this study and data were analyzed using QGIS software. Results show that open land, grassland, bushland and open forest were the dominant forest classes under private and communal tenure regime while semi closed forest dominated most of the Ngitili area under the state tenure regime. The study concludes by supporting the alternative hypothesis that, forest land tenure changes have significant impacts on forest cover. The study recommends that, a study is needed to assess the impact of devolution which occurred in 2002 on forest cover change.Item Assessment of the Impacts of Climate Change on Hydrological Characteristics of the Mbarali River Sub Catchment Using High Resolution Climate Simulations from CORDEX Regional Climate Models(Canadian Center of Science and Education, 2018) Mutayoba, E; Kashaigili, J.J; Kahimba, F.C; Mbungu, W; Chilagane, N.AThis study assesses the impacts of climate change on water resources over Mbarali River sub-catchment using high resolution climate simulations from the Coordinated Regional Climate Downscaling Experiment Regional Climate Models (CORDEX_RCMs). Daily rainfall, minimum and maximum temperatures for historical climate (1971-2000) and for the future climate projection (2011-2100) under two Representative Concentration Pathways RCP 8.5 and RCP 4.5 were used as input into the Soil and Water Assessment Tool (SWAT) hydrological model to simulate stream flows and water balance components for the Mbarali River sub-catchment. The impacts of climate change on hydrological conditions over Mbarali river catchment were assessed by comparing the mean values of stream flows and water balance components during the present (2011-2040), mid (2041-2070) and end (2071-2100) centuries with their respective mean values in the baseline (1971-2000) climate condition. The results of the study indicate that, in the future, under both RCP 4.5 and RCP 8.5 emission scenarios, the four main components that determine change in catchment water balance (rainfall, ground water recharge, evaporation and surface runoff) over Mbarali river catchment are projected to increase. While the stream flows are projected to decline in the future by 13.33% under RCP 4.5 and 13.67% under RCP 8.5 emission scenarios, it is important to note that simulated surface runoff under RCP8.5 emission scenario is higher than that which is obtained under the RCP4.5 emission scenario.Item The effect of agricultural intensification on ecosystem Services around Ihemi cluster(Tanzania Journal of Forestry and Nature Conservation, 2021) Sirima, A; Kashaigili, J.J; Kamau, F.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 clusterItem Evaluation of groundwater recharge dynamics using the wetspass model in the Usangu Plains, Tanzania(TAJAS, 2022) Sahinkuye, T; Silungwe, F.R; Tarimo, K.P.R.A; Kashaigili, J.JA comprehensive understanding of groundwater recharge dynamics is of great importance in enhancing the sustainable management of the groundwater resources and the sound planning of their utilization. This study aimed at evaluating the groundwater recharge dynamics in the Usangu Plains (20,810 km 2 ) by the help of a hydrological GIS-based model named WetSpass. The Water and Energy Transfer between Soil, Plants, and Atmosphere under quasi-Steady State (WetSpass) model used land use/landcover, soil texture, topography, slope, groundwater table and hydrometeorology data to simulate the temporal (yearly and seasonal) averages and spatial differences of groundwater recharge, surface runoff and actual evapotranspiration. The findings of this study showed that 17.8% of the mean annual rainfall contribute to the groundwater storage while 66.1% and 16.1% are lost through evapotranspiration and surface runoff, respectively. The high rates of evapotranspiration occurred in the wet season and in the seasonal/permanent wetlands and water body. Also, the maximum amount of surface runoff took place during the rainy season and in the built-up and in bare land vegetation types given the impervious state of their ground surfaces. About 25% (1.025km 3 /year) of the annual recharge was found to be the groundwater that can be safely extracted for domestic and economic purposes. Compared to the water lost through evapotranspiration and surface runoff, the simulated portion of groundwater recharge is noticeably low. Consequently, it could be wise to initiate the rainwater harvesting technologies and artificial groundwater recharge strategies particularly in the zones with moderate and low recharge rates to boost the groundwater storage as its users cannot cease to increase.Item Wildlife poaching practices in Tanzania’s Ruaha landscape(Tanzania Journal of Forestry and Nature Conservation, 2022) Mrosso, H.T.; Kicheleri, R.P; Kashaigili, J.J; Munishi, P.K.T; Kadigi, R.M; Mgeni, C.P; Kimaro, M.HThroughout the world, millions of wild species and products are illegally collected, used, traded and exported. Tanzania's Ruaha landscape is considered a critical area for biodiversity, as well as an area where poaching exists. Despite the area being rich in abundance and diversity of wildlife, in- depth analysis of wildlife species hunted most and the methods used by poachers is lacking. This study assessed the most hunted wildlife species, extracted products and uses, and associations between wildlife products, hunting methods, and ethnic groups. Data was collected by utilizing the snowball technique after 123 poachers were given a semi-structured questionnaire in villages near the Ruaha National Park. Among the most hunted species are did-dik, impala, kudu, lion, buffalo, and elephants. Bushmeat, skin, claws, ivory, and fat were the most harvested wildlife products. 60 % of wildlife products used for food and source of income, and the methods used for illegal hunting were domestic dogs, spears, snares, and torches. The findings are critical for understanding the link between the most poached species, products, and methods used in relation to ethnic groups in the Ruaha landscape. Increased anti-poaching patrols and wildlife conservation awareness could help reduce the dependence of local communities on wildlife products.