NBI strategic water resources analysis Phase I findings

Transcription

1 NBI strategic water resources analysis Phase I findings Abdulkarim H Seid NBI Secretariat

2 The NBI Strategic Water Resources Analysis Key question: how to meet demands for water, food and energy upstream and downstream sustainably? Key tasks: Quantify current and projected/future water demands; Estimate water availability and variability under historical as well as climate change projections; Estimate water shortfall (if any); Explore concrete options for addressing current and future water demands Data sources: NBI countries: hydro-meteorological data, national water master plans; data on future water infrastructure projects; global data sources; Current status: first phase completed - Current(as of 2014) water availability, water demand and water use - Preliminary projection of water demand based on future 2 development projects, CC

3 Baseline: Objective Objective: Setup baseline model to characterize the rainfall-runoff process, establish the current water balance and utilization in the basin which will serve as an input to the subsequent stages of analyses Data Compilation : Review of existing analytic works and information Employing models, conducting simulation Answer basic questions Water balance : rivers and junctions, reservoirs and wetlands, at different scales of basins Estimation of required consumptive use of water for irrigated agriculture current level of abstraction Current capacity of Hydropower generation

4 Baseline Model Features Spatial scale : 180 sub- catchments in extent of Nile Basin Temporal scale: Daily and Monthly Tools: Nile-DSS, Mike Hydro, In-house developed scripts Processes Stream Flows that results in from rainfall-runoff process Abstraction, water use and losses Hydropower Generation Flow routing within reaches Dynamics of water for existing infrastructures such as reservoirs and dams Processes in wetlands and flood plains

5 Nile Basin DSS: Analytic Framework for Water Resources Planning Data/information management system Time Series analysis toolkit Basic GIS functionality Ensemble generator (for probabilistic analysis) Modeling System Water balance and allocation model Rainfall-runoff modeling tools Hydrodynamic modeling Crop water requirement Model linking/nesting tool Scenario Analyses and Decision making/analysis tools Scenario management (including indicator calculation) Multi-objective optimization Economic analysis tools Multi-criteria analysis tool 5

6 Baseline Model Architecture Hydrologic Model Daily Water Yielding Basins Catchment Runoff Water Spine Model Monthly ( ) Entire Nile Basin Irrigation Model Daily Full Extent Irrigation Demand Result Water balance Water use and deficit Hydropower generation and Deficit Indicators

7 Model segments The Nile Basin modeled in three sub-basin models Sub-basin models linked to run sequentially

8 Example of uncertainty due to model structure Wetlands and Flood plain Models (source big model uncertainty) Wetland: Loss + Delay Flood Plains : Delay, No Loss Spill to Wetland: Loss + Delay

9 Water Spine Model Simulation ( ) Current level of Water Use, Average Supply Results Hydropower Generation Deficit Dams and reservoir Storage, Levels, outflows Loss + Gains Wetlands and natural lakes Current level of Abstraction

10 Data availability and Source Stream flow data : Observed flow gauges records Open access GRDC Runoff Climatic data: Global Open access: Princeton, CRU; Water infrastructure: Reservoir, HP Irrigation data : Cropping patter, Area

11 1-Feb Jul Dec May Oct Mar Aug Jan Jun Nov Apr Sep Feb Jul Dec May Oct Mar Aug Jan Jun Nov Apr Sep Feb Jul Dec May Oct Mar Aug Jan Jun-1981 Flow (m3/sec) Results: Hydrology The Sudd Bahir el Jabel at Buffalo Cape Observed (m3/sec) Simulated 1/3 to Bahir el Zeraf Assumed Area-Elevation Calibrated Rating Curves

12 Results: Hydrology Lake Tana Cat Observed (MCM) Simulated(M CM) R2 Gilgel Abby Gumara Ribb Megech

13 Results: current condition

14 Results: Current water availability and use WN malakal BN at Diem Didndir Rehad u/s Atbara Annual Yield of Sub-basins (BCM) Estimated Water Demands, BCM/year Evaporation from Dams, M and I, Irrigation, Evaporation from Dams M and I Irrigation The Nile currently supplies water for approx. 5.4 Mill ha of irrigated land; actually cultivated area approx. 6.4 M ha. The total irrigation water demand basin-wide is approximately 83 BCM/yr; 14

15 Result: current water demand for Key Uses Country Location al (MCM) al (MCM) Sudan Blue Nile 168 White Nile 36 Main Nile Egypt Delta Greater Cairo Upper Egypt South Sudan Juba 4.3 Maridi 1.1 Upper White Nile 5.3 Western Uganda Jinja City 4.7 Kampla City 53.9 Soroti Town 1 Tororo Town 1.5 Other Demands Country Estimated Irrigation water demand [MCM] Burundi 28.9 DRC 0 Egypt Ethiopia 2018 Kenya 367 South Sudan 3 Rwanda 59 Sudan Tanzania 102 Uganda 260 Total Estimated Water Demands, BCM/year Evaporation from Dams, Rwanda Kigali city M and I, Kenya Kisumu City 6.8 Malaba Town Irrigation, Tanzania Musoma City 5.5 Mwanza City Evaporation from Dams M and I Irrigation 15

16 Result: Estimated current water withdrawal for irrigation 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Country Crop water Requirement[MCM] Irrigation Water Demand [MCM] Extracted water from River (MCM) Rwanda, 57.4 Kenya, Burundi, 28.7 Sudan, South Sudan, 3.2 Ethiopia, Extracted from GW or Reused (MCM) Actual Withdrawal [MCM] Tanzania, 63.4 DRC, 0.0 Unmet Demand [MCM] Burundi DRC Egypt Ethiopia Kenya South Sudan Rwanda Sudan Tanzania Uganda Total Overall Irrigation Water Demand Satisfaction rate Burundi DRC Egypt Ethiopia Kenya South Sudan Rwanda Sudan Tanzania Uganda Uganda, Egypt, Estimated water withdrawals for irrigation [MCM] 16

17 Result: Current hydropower production Current installed capacities of hp plants, (MW) DR Congo, 0.0 Burundi, 3.6 Uganda, Tanzania, 0.0 Egypt, Sudan, Total installed capacity = 5600 MW South Sudan, Rwanda 0.0, 0.0 Kenya, 83.0 Ethiopia, Hydro energy production by country (GWH/y) Uganda, 2822 Burundi, 31.5 Country E (GWH) Burundi 32 Egypt 9926 Ethiopia 4283 Kenya 224 Sudan 8239 Uganda 2822 Total Sudan, 8239 Egypt, 9926 Kenya, 224 Ethiopia, 4283 Total Hydro Energy per year GWH 17

18 Results: current hydraulic infrastructure Cumulative Storage (BCM) Dams with aggregate storage capacity of about 200 BCM provide water for hydropower, irrigation, flood control and Municipal and Industrial water supply Approx BCM water evaporates from all dams Approx. 25,000 GWH/y of hydro-energy generated. There is high degree of dependence on surface water resources Hydro energy production by country (GWH/y) Uganda, 2822 Burundi, Cummulative Storage Capacities of Dams Sudan, 8239 Egypt, Kenya, 224 Ethiopia, Year

19 Results: preliminary projections

20 Parameters for future scenarios Level of WR Infrastructure Expansion (Irr, Hp, Dams) All identified projects (full development; the reference) 75 % of identified projects 50 % of identified projects 25 % of identified projects CC Dry Climate Historical CC - Wet Improvements in irrigation efficiency Current level 50 % improvement for new dev. Up to 50 % Improvements for all

21 Result: projections Total basin dam storage capacity is expected to rise from the current 200 BCM to > 400 BCM; Hydropower capacity to increase from 5600 MW to > 26,000 MW. National planning documents show substantial growth in water resources infrastructure in the coming few decades Irrigated area is expected to increase from the current 5.4 Mill. ha to about 8.7 Million by ca. 2050; Projected installed capacities of hp plants, 2050; MW Burundi DR Congo Egypt Ethiopia Kenya Rwanda South Sudan Sudan Tanzania 0.00 Growth in Cumulative Storage Capacities of Dams (BCM) South Sudan, Distribution of future irrigation areas by country ('000 ha) Tanzania, 20 Uganda, 9.7 Rwanda, Kenya, Sudan, 2,911 Ethiopia, 1511 Burundi, 0 Dr Congo, 0 Egypt,

22 Result: Indicative growth irrigation water demand (% increase from 2014 value) Projected growth in total irrigation water demand, percent of current (2014) 170% 160% 150% 140% 130% 120% 110% 100% Substantial increase in irrigation water demand by 2050 and likely considerable shortfall

23 Summary Planned water resources developments are needed and expected to yield substantial benefits to the basin countries; However, if future water resources investments are not coordinated and optimized basin-wide, there are risks of incurring substantial shortfalls; the deficit is likely to grow to over 50 percent of historically available water supply Climate change scenarios analyzed indicate greater need for adaptive management to reduce vulnerability; A number of options have been identified by member countries for addressing the growing imbalance between supply and demand; 23

24 Conclusion Basin wide current aggregate water demand for irrigation is ca. 83 BCM = Approx. 80 percent of all water demands, (including M/I). Total current evaporation from NB dams ca BCM NB population growing rapidly to about ca. 1 Billion (UN medium variant) escalating demand for: food, energy and water supply Aggregate planned irrigation in NB to grow to ca. 8.7 M ha; Planned Dams in NB total storage capacities to > 200 BCM. 24

25 .... conclusion Projected Aggregate water demand could reach ca percent of current availability. If measures are not taken to manage the imbalance, there is risk that total water demand can outstrip available resources soon; Member countries have identified a number options with potential to address the imbalance. Second phase of analysis explores these options further!

26 Identified preliminary list of options (under investigation in Phase II) Water Supply Enhancement Conjunctive (groundwater surface water) use, Recycling and reuse of waste water Desalination; rain water harvesting; Increasing basin water yield (reduction of losses); Expanding water storage and cascading facilities, Expanding basin-wide rainfall effective use in agriculture. Demand side Management Improving water use efficiencies and water productivity;, Adoption of less water intensive uses in agriculture; Optimization of system wide water use, Basin System Management for Optimal water resources utilization 1. Optimize location of reservoirs 2. Coordinated reservoir operations 26

27 Strategic water resources analysis Main phases Phase I (Basin under unilateral development) Phase 2 (Strategic options for cooperative management & development) Jun 15 Dec 16 Dec 18(?) Establish baseline water Refine/expand water demand demand/use projections (M/I, livestock, e-flow..) Projection of water demand based Generate macro-economic on country plans (unilateral dev) Quantify basin water balance; future likely water shortage scenarios + Hydro-economic optimization for more efficient water allocation Identify options for addressing Develop dam cascade operation growing water demand sustainably rules (ENTRO) Projection of water availability Refine water supply projection (CC) under climate change Projection of water demand and Projection of water deficit under various options from Phase I water shortage under CC Explore options from phase I Explore water supply reliability Generate strategic options 27