Illustrations of research development in the Niger river basin at PIK IRD / PIK meeting Samuel Fournet Monday 1th of October2014

Illustrations of research development in the Niger river basin at PIK Outline PIK collaborative project involvements in the Niger river basin Brief case study characteristics: Niger river, Upper Niger, Inner Delta Research outcomes SWIM model settings (reservoir, inundaton module) River basin planning, climate change settings Water economic trade-offs assessment for the Upper Niger basin Experimental hydrological forecast system Potential future research applications Land use change scenario settings Regional food security assessment

Potsdam Institute for Climate Impact Research founded in 1992 200 scientific staff + 100 guests Fundings: institutionnal 8.6 M. € additionnal 7.4 M. € Research Domain II 110 employees, 42 third funded projects Fred Stefan Samuel Valentin Hattermann Liersch Fournet Aich Research domains: I. Earth System Analysis II. Climate Impacts & Vulnerabilities III. Sustainable Solutions IV. Transdisciplinary Concepts & Methods Studying relevant effects of climate and global change on environmental and societal structures. Global aspects of land use, trade offs, freshwater, bioenergy, development with global and regional focus. How sensitive are specific sectors (in selected regions) to climate and global change

Former and current research project involvement Enhancing the role of wetlands in integrated water resources management for twinned river basins in EU, Africa and South America in support of EU Water Initiatives Africa at meso-scale: Adaptive and integrated tools and strategies on natural resources management Quantifying projected impacts under 2°C warming Early warning and forecasting systems to predict climate related drought vulnerability and risks in Africa

Collaboration with Wetlands International Sahelian Sub-Regional Office in Mali opened in 1998 Collaborative research projects experiences Long term partnership in the Upper Niger River Basin with Niger Basin Authority with national partners (government structures, national NGOs, Local Authorities, and local populations) national research institutions (IER and CNRST) as well as foreign research institutions (Altenburg & Wymenga, Institute for Environmental Studies, IVM) Chris Baker Head of Programme Water Resources Bakary Kone Director Mali Office

I. Case study introduction Niger river 3rd longest river in Africa watercourse 4200km 9th biggest fluvial system area 2.1M.km2 ~ 25% located in Mali 9 countries Benin, Burkina Faso, Cameroon, Chad, Ivory Coast, Guinea, Mali, Niger and Nigeria Major cities Tembakounda, Bamako, Timbuktu, Niamey, Lokoja, Onitsha 4 climate zones Humid tropical zone Tropical zone with dry seasons Sahelian zone Desert zone 30 to 50% water losses at the outlet Climate zones note Desert Zone Africa’s desert climates receive little precipitation and in the case of the Sahara, daytime temperatures can be extremely high. At Faya-Largeau, Chad, the daily maximum temperature for June averages 42 degrees Celsius (WMO n.d.). With little cloud cover, humidity or coastal influence in the Sahara, the average daily temperature range is as much as 15 to 20 degrees Celsius. Average annual precipitation is scant, exceeding 100 mm only in a few areas and tending to be below 25 mm for much of the Sahara. Sahelian Zone Only about 250 to 500 mm of rain falls in the Sahelian climate zone. With considerable seasonal and inter-annual variation in rainfall, the potential for rain-fed agriculture is very low. Average annual temperatures in areas adjacent to the Sahara and in the Horn of Africa range from 26 to 29 degrees Celsius, with somewhat cooler temperatures in elevated areas. Before the spring rains, daily maximum temperatures often reach 40 degrees Celsius. Tropical Zone With Dry Seasons To the north and south of the humid tropical climate zone are zones of tropical climate, characterised by long dry seasons, where precipitation and temperature are more seasonal. Here, dry seasons last more than six months and tend to increase in length with distance from the equator. Annual average precipitation is generally 600 to 1 200 mm with pronounced inter-annual variation. Both annual and daily temperatures vary more here than in the climate zones closer to the equator (Stock 2004). Humid Tropical Zone The humid tropical zone exhibits peaks in precipitation and a short dry season. Some areas in this zone experience two rainfall maxima; the first occurs as weather systems associated with ITCZ migrate toward higher latitudes, while a second occurs as those weather systems move back toward the equator and toward the lower latitudes (Stock 2004). The average annual rainfall generally ranges between 1 100 mm and 1 800 mm in this zone (FAO 2001). Temperatures are relatively high, but with somewhat more seasonal variation than temperatures in the equatorial zone (Goudie 1996). UNEP. 2010 , Africa Water Atlas Zwarts et al., 2005, Niger the lifeline, Wetlands International

I. 1. Case study introduction Upstream river basin management The Upper Niger 2,43 M. inhabitants Covers the Guinean part of the basin and stretchs to Selingué dam included. Crucial for the generation of water ressources with the Fouta Djallon mountains Regulation and storage infrastructure with Selingué and the future Fomi and Diaraguéla dams The zone of the Offices 1.44 M. inhabitants Intensive irrigated rice production with Office du Niger (Markala dam), Office de Ségou and Office de Baguinéda with a high potential to extend agricultural area Bamako and the hydropower dam of Sotuba High potential for navigation The Bani catchment 0.53 M inhabitants Reservoir of Talo and Djenné (planned extension) High potential of rural development of more than 100.000 ha (agriculture, fishing and livestock) Projects of minor dams in Baoulé, Gbado and Bagoué Total area 376,000 km2 129,000km2 for Bani Peak discharge Wet year 1,000 – 10,000 m3/s 1954-55 Dry year 200 – 2000 m3/s 1984-85 Source: NBA, PADD, 2010

I. 2. Case study introduction Inner Niger Delta 3,27 M inhabitants Large wetland inundation plain (40.000 km²) in the Sahelian climate zone Drastic seasonal and inter-annual variation in discharge (30 to 50 hm3/y), flood extent (5 to 25.000 km²) Flood peak delay ~2 months 30 to 50% water losses Zone crucial for fishing, livestock, agriculture in free submersion and the biodiversity High vulnerability from upstream management Talo Djenné Sélingué Markala Source: http://earthobservatory.nasa.gov/ Zwarts et al., 2005, Niger the lifeline, Wetlands International

II. 1. SWIM: Niger river modelling setup Past climate application ECMWF reanalysis ERA40 from 1960-2001 at daily time step 0.5° resolution Bias corrected with Global Precipitation Climatology Centre (GPCC v4) and Climate Research Unit (CRU TS2.1) Source; Weedon et al., 2010 , Watch tech report 22 Aich and Fournet 2013 in Dewfora D4.6, PIK

II. 1. SWIM: Niger river modelling setup Topography, Land-use, Soil, Sub-basins Shuttle Radar Topographical Mission SRTM Version 4, 90m resolution Reclassified Global Land Cover GLC 2000 Hydrotope Hydrological Response Unit FAO Digital Soil Map of the World Harmonized World Soil Database Number of sub-basins: 1923 Sub-basin average area: 1150km²  Source; Fournet 2013 in Dewfora D3.5, PIK

II. 1. SWIM Soil and Water Integrated Model Development of Inundation module Pre-processing in the delta floodplain: upstream of each sub-basin´s outlets, inundated area and the water volume accumulated and trapped in ponds are identified into sequential layers Processes Flooding Routing, backwater Evaporation (water surface) Percolation Release Parameters > Flooding: flow-threshold > Flood release (linear) 1 2 5 Source: Liersch et al., 2011, SWAT conference

II. 1. SWIM calibration-validation Discharge Global Runoff Data Centre (GRDC), RESSAC project, Wetlands Internaitonal 7 steps of calibration-validation from upstream to outlets (16 out of 25 available gauges) Upstream individual gauge parameter was kept next step only if it brings additionnal skill downtream

II. 2. Scenarios Irrigation extent and efficiencies scenarios Settings of built (Sélingué, Talo) and planned (Fomi, Djenné, Diaraguéla) reservoirs and the current and future extension of the six main irrigation area as well as restricted minimal flows were setup in line with the development plan of the Niger Basin Authority A minor and bigger extension as well as 3 irrigation efficiencies were added for the Office du Niger using last updated engineering master plan. BAU A NBA Extension but BAU for ON B NBA Extension but minor extension for ON C NBA extension D NBA extension but land allocation extension for ON E1 BAU E2 Improve Tertiary channels E3 Improve Tertiary and Secondary channels

II. 2. Scenarios River basin planning scenario The final river basin management scenario matrix combine dam, irrigation extension and efficiencies plans. It was defined with local stakeholder representatives from the Inner Niger Delta region.

II. 2. Scenarios Climate change scenarios: ISIMIP + CORDEX Change of monthly discharge at Koulikouro between the period 2070‐2099 and the base period for Rcp8.5 Change of annual discharge at Koulikouro projected with SWIM driven by 18 climate models (5 ISIMIP, 3 MENA Cordex, 3 MENA Cordex bias‐corrected, 7 Africa Cordex)

II. 3. Water economic trade-offs assessment Tree decision matrix frame

II. 3. Water economic trade-offs assessment Tree decision matrix indexes From simplistic trade-offs (National policies) Unsupplied irrigated water volume (%) vs. Change of dischagre entering the delta (%) To detailed characteristics (Dam and Irrigation scheme managers)

II. 3. Water economic trade-offs assessment Identify realistic trade-offs pathways

II. 4. Experimental hydrological forecast and early warning systems ECMWF Integrated Forecast System 4 0.5 degree resolution ENS Monthly SEAS Seasonnal Lead time in days 0-32 * 215 Number of ensemble members 5 15 Starting date used per year 52 (1 per week) 4 (1st of MJJA) Hindcast period tested 1993-2010 1981-2010 Initial conditions in days ** 1063 515 * 0 to 15 = medium range ** with WFD-EI, WFD-E4 and EI WFD= Watch Forcing Data; E4= ERA-40; EI=ERA-Interim

III. Potential future research applications 1 III. Potential future research applications 1. Land use change scenarios 1960 2005 2050 RCP85

Wetland ecosystem food services III. Potential future research applications 2. Regional food security vulnerability assessment Source of improvement: modelling resolution of the floodplain for wetland ecosystem services assessment losses estimation between production and demand processes water economic trade-offs assessment between UNB and IND Wetland ecosystem food services Food demand Fish catches Crop production: rice Fodder production: livestock, milk, meat, leather Dietary requirement Demographic projection

Thank you for your attention !

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