Sub-Saharan African G-WADI

Transcription

1 Sub-Saharan African G-WADI Regional chapter of the Global network on Water and Development Information for Arid Lands Prof. Cheikh B. Gaye

2 G-WADI Workshop April 2010 Dakar, Senegal 35 participants from 12 countries

3 G-WADI/Africa: Strategy Build on the existing expertise and know how (involvement of three sub-regional centres (AGRHYMET, ICPAC, SADC-DMC) Stakeholder mapping needs to identify key stakeholders and their intervention areas within arid and semi-arid zones in SSA Work in synergy with the other UNESCO-IHP networks in SSA such as FRIEND, ISARM, GRAPHIC and the network of HELP basins.

4 G-WADI/Africa: Expectations Agreement by African delegates to the formation of a G- WADI network for the SSA region which compliments those on other continents. Support for this from International partners. To explore the scope of regional scientific projects relating to arid and semi-arid regions of SS Africa and the impacts they have had or are having on development and policy. To determine the research inputs and requirements of policymakers in dealing with water security in water scarce areas of SS Africa

5 G-WADI/Africa: Expectations How to make scientific data and knowledge about this region more accessible and see how scientific solutions could be better taken up or promoted. Identify existing gaps and needs in capacity development related to research, curricula development and also institutional capacity relating to water resources (sensu lato) in relation to arid and semi arid regions of SS Africa.

6 G-WADI/Africa: Expectations Promoting improved scientific exchange relating to water management and for developing a G-WADI network in arid and semi-arid areas of SS Africa To strengthen the ties between French and English partners in SS Africa through the formation of the G- WADI network. Promoting improved scientific exchange relating to water management and for developing a G-WADI network in arid and semi-arid areas of SSA

7 G-WADI/Africa: Network structure A secretariat to be hosted by an institution (sub-regional institution) A steering committee composed with representatives of key African centres and individual experts Key themes each one led by an expert or institution

8 G-WADI/Africa: Potential themes Water augmentation techniques including rain water harvesting and aquifer recharge Soil-water management techniques Monitoring tools including early warning and drought monitor Experimental basins and modeling Data, particularly rainfall data

9 G-WADI/Africa: Follow up activities Mapping of stakeholders with their profile regarding activities related to arid and semi-arid areas. The organizational structure of the network including TORs and suggestion on the members (hosting institution for the secretariat, members for the steering committee, proposition of themes and leading agency for each theme,..)

10 Architecture of a website to be hosted by the subregional institution hosting the secretariat of the network (or at UNESCO s HQ or regional office) Detailed activities for the network for the next two years. Strategy for fund raising for the implementation of some of the identified activities.

11 G-WADI/Africa: Suggested Plans for future A G-WADI activity on Science to Policy will be set up, led from Africa and extended to other regions

12 Formal creation of G-WADI Sub Saharan Africa After extensive discussions on the relevance of the G-WADI network in Sub- Saharan Africa, the participants agreed to formally establish a G-WADI network in Sub-Saharan Africa. Paris - 9th December 2010

13 Transfer of Princeton University Drought monitoring to Africa Workshop in Niamey (Niger) Feb 2011 Workshop in Nairobi (Kenya) June 2011 Contribution to the special issue of SCAR journal (2013) Workshop on satellite and ground-based data merging Niamey (July 2013) Workshop on Drought monitor Niamey 2013

14 Opening ceremony of the G-WADI drought monitoring workshop in Niamey, Niger AFRICAN DROUGHT MONITOR

15 Training: practical sessions

16 The drought monitoring web site

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19 Evaluation des performances du modèle hydrologique VIC Ce rapport fait suit à l atelier qui s est tenu à Niamey (Niger) du 30 janvier au 03 février Centre Régional AGRHYMET du transfert d un outil hydrologique sur le suivi de la sécheresse développé par l Université de Princeton

20 Pluies journalières estimées par satellites et observées (période ) /01/ /01/ /01/ /01/ /01/ /01/ /01/ /01/ /01/ /01/ /01/1980 Pluie_VIC Pluie_Obs

21 Pluies journalières estimées par satellites et observées (en 1970) /01/ /02/ /03/ /04/ /05/ /06/ /07/ /08/ /09/ /10/ /11/ /12/1984 Pluie_VIC Pluie_Obs

22 Pluies journalières estimées par satellites et observées (en 1984) /04/ /04/ /05/ /05/ /06/ /06/ /07/ /07/ /08/ /08/ /09/ /09/ /09/ /10/ /10/ /11/ /11/1970 Pluie_VIC Pluie_Obs

23 Débits mensuels observés et calculés Debits (m3/s) mai-70 mai-72 mai-74 mai-76 mai-78 mai-80 mai-82 mai-84 mai-86 mai-88 mai-90 mai-92 mai-94 mai-96 mai-98 mai-00 mai-02 mai-04 mai-06 mai-08 Obs Modele_VIC

24 en année humide (1994) et en année sèche (1984) Debits (m3/s) janv-84 mars-84 mai-84 juil-84 sept-84 nov-84 Debits (m3/s) janv-94 mars-94 mai-94 Obs juil-94 sept-94 nov-94 Modele_VIC Obs Modele_VIC

25 Corrélation entre débits mensuels calculés et observés 900 Modele_VIC (m3/s) y = x R 2 = Obs (m3/s)

26 Débits observés et calculés en année humide ( ) et en année sèche ( ) Debits (m3/s) /05/70 01/07/70 01/09/70 01/11/70 01/01/71 01/03/71 01/05/71 01/07/71 01/09/71 01/11/71 Debits (m3/s) /01/83 01/03/83 01/05/83 01/07/83 01/09/83 01/11/83 01/01/84 01/03/84 01/05/84 01/07/84 01/09/84 01/11/84 Obs Modele_VIC Obs Modele_VIC

27 CONCLUSION Au vu des résultats obtenus on peut tirer les conclusions suivantes : Les estimations de pluie par satellite sont acceptables et peuvent constituées une alternative en cas de lacune de données observées ; Le modèle VIC est assez robuste pour la simulation des écoulements ; le modèle reproduit d une manière satisfaisante la forme des hydrogrammes observés. Les débits de pointes calculés sont bien situés dans le temps mais parfois sous-estimés ou surestimés; Donc, on doit fortement encourager le processus de transfert de l outil au CRA mais aussi voir comment le faire tourner avec les données observées.