Future climate change and impacts on water resources in the Upper Blue Nile basin

This study aims to assess the impact of climate change on the water resources of the Upper Blue Nile basin using an integrated climate and hydrological model. The impact of climate change on water resources is being assessed using the regional climate model (RCM) under the representative concentration pathway (RCP4.5 and RCP8.5) scenarios and the Soil and Water Assessment Tool (SWAT) hydrological model. Future climate scenarios have been developed for the 2030s (2021–2040) and the 2050s (2041–2060). The study found that the projected rainfall shows a decreasing trend and is not statistically significant, while the temperature shows an increasing trend and is statistically significant. Due to the sharp rise in temperature, the annual evapotranspiration increased by about 10.4%. This and the declining trend of rainfall will reduce streamflow up to 54%, surface runoff up to 31%, and water yield up to 31%. Climate change causes seasonal and annual fluctuations in the water balance components. However, the projected seasonal changes are much greater than the annual changes. Therefore, the results of this study will be useful to basin planners, policymakers, and water resources managers in developing adaptation strategies to offset the adverse effects of climate change in the Upper Blue Nile basin.

OPTIMAL OPERATION OF MULTIPURPOSE RESERVOIRS IN SERIES: ROSEIRES AND SENNAR CASE STUDY

The Roseires-Sennar Dams System (RSDS) at lower part of Blue Nile River play a vital role in water supply to the irrigation schemes in Sudan. The existing rule curves for this system belong to 1925 and 1966 for Sennar and Roseires reservoirs, respectively. Introduction of new irrigation schemes, approved climate change impacts on Blue Nile River flow and upstream developments in Ethiopia as well as the heightening of the Roseires Dam from elevation 480 to 490 m.a.s.l have shown the RSDS is losing its efficiency in terms of fully supplying the water demands. The literature addresses the simulation of Roseires and Sennar dams, and tries to find the best coordinated rule curves through a limited number of operation rules to find optimal operating rules for reservoirs that minimize the impacts of new developments, water demand growth and climate change on water supply to various demands on Blue Nile River. Such decisions are locally optimal in best condition since they do not consider the storage and carry-over capability of reservoirs that can transfer the non-optimal (locally optimal) decisions to other time steps of planning horizon and creat shortages in other time steps. Therefore, aim of this research is to find optimal coordinating operation rules for Roseires and Sennar dams that through a non-linear multi-period optimization model that considers the conditions of climate change, flow regime and water demand as scenarios. Model is validated by comparison with observed reservoir operation during November 1999 till May 2000. Eighteen scenarios that cover the normal, dry and very dry flow regimes, along with three suggested crop patterns and climate change impact are analyzed. Results shows in normal conditions of flow, crop pattern 2 is the most recommended with more than 11 Billion USD marginal profit and fully supplying the water demand and 1530 GWh energy generation per annum. The coordinated rule curves have a totally different pattern of emptying and filling compared with existing ones. Rule curves change from one flow regime to another, which proves how change in conditions of the system has influence on optimal operation rules. Comparison of marginal profits with crop pattern 2 shows in three inflow conditions of normal, dry and very dry years multi-period optimization model could keep the marginal profits above 11 Billion USD, let’s say, 11,050, 11,056 and 11,042 Billion USD, respectively, which shows the robustness of model in dealing with all conditions and keeping the marginal profits not affected. However, the Roseires rule curves are different in these three condition, while Sennar rules curves are almost the same. Without climate change impact, model can manage to supply the water demands fully in all flow conditions. However, water supply reliability is affected by climate change with all crop patterns. Roseires-Sennar Dams system in a normal year under climate change can produce 10,688 Billion USD marginal profit and 1371 GWh per year energy. It shows that model could manage the system performance so that climate change decrease the marginal profit by 3.27%, while inflow is reduced by 25% and water demands and evaporation increased by 19%. Energy generation under climate change has decreased by 10.5%, which is the most affected sector. Crop pattern 2 and 3 are not suitable for climate change conditions since up to 65% deficit in water supply can happen if very dry year realizing with climate change. In very dry conditions crop pattern 1 is more suitable to be practiced.

Impact of policies, strategies and agricultural institutions on food security and poverty status of vegetable farmers along the blue nile banks, Gezira State, Sudan (2017)

Having clear picture on food security status and its major determinants helps policy makers and planners to introduce new policies that enhance food security. The study was aimed to evaluate the impact of policies, strategies and institution on food security and poverty status of the vegetables farmers in Gezira State with reference to the Blue Nile farmers. To achieve these objectives stratified random sampling technique was used to select the respondents from five localities lays along Blue Nile, so 150 farming households were interviewed. Food security Policy and strategy were collected by the mean of questionnaire targeting key line institutions. Poverty indices were calculated using expenditure as welfare indicator,Gini coefficient was applied. The results showed that the majority 75% of the respondents were above expenditure poverty line (7196)SDG. Moreover, the results showed that the poverty gap index was equal to five percent. Kamlin, Medani, East Gezira reported the higher expenditure distance from the poverty line (6 percent). The severity of poverty in the state is estimated to be two percent, likewise the severity of poverty in East Gezira was found to have a higher percentage (three percent). According to Gini coefficient the income distribution estimated at 0.46 while that for expenditure distribution is estimated at 0.31, these results showed a higher degree of inequality. The results showed that the poorest 20% of the population earned 0.06% of the total income while the richest 20% earned 45% of the total income. About 50.7% from the respondents use borrowing from others as one of their coping strategies. About 78%of policy makers said that there was organized team from all institutions dealing with food security and nutrition issue, all policy makers in the state said there was strategy concerning the food security and nutrition issues. The study recommended that the cash transfer needed to lift the poor out of poverty that each poor person needs five percent of the value of the poverty line.

Value Chain Analysis of Eucalyptus Wood Products in the Blue Nile Highlands of Northwestern Ethiopia

Eucalyptus wood products contribute significantly to the income of smallholder growers in many parts of Ethiopia. This has incentivized smallholders to convert arable lands to Eucalyptus plantation. Given the limited attention and availability of empirical evidence, this study examined the Eucalyptus wood products value chain in terms of the actors engaged, the type and importance of channels, margins analysis and the overall value chain governance in the main Eucalyptus growing areas of the Blue Nile highlands of Northwestern Ethiopia in 2019/2020. Sources of data were randomly selected 388 Eucalyptus grower households and 166 Eucalyptus wood traders, complemented by an interview with key informants, group discussions and direct observations. The results reveal that a total of 2,051,114.75 m3 of Eucalyptus wood was produced in the study area and Eucalyptus plantations are expanding over crop lands at a rate of 102.35 ha a year on average. Many actors involved handle a large volume of wood in eight main channels with a high disparity in the shares of the margins. We found that Eucalyptus is the main source of cash earning, contributing about 45.76% to the total annual income of smallholder growers. Little policy attention, a lack of sectoral integration, missing infrastructure and an absence of modern wood processing factories are among the key challenges impeding the performance of the wood sector value chain. There are however existing opportunities for the development of the wood sector value chain such as favorable growing conditions and the spectacular growing demand for wood products. The study provides valuable insights about the wood sector value chain and actions towards ensuring sustainable value chains and the commercialization of the sector.