Desertification and Migrations in Western Mediterranean: Environmental effects of the inverse flow of people and capital

Transcription

1 Desertification and Migrations in Western Mediterranean: Environmental effects of the inverse flow of people and capital Juan Puigdefabregas EEZA(CSIC), Almeria, Spain Teresa Mendizábal CIEMAT, Almeria, Spain

2 N-S flows gradients and flows in Western Mediterranean Fr It Pt Es Mo Al Tn Source: Earth Trends Environmental Information

3 A growing N-S socio-economic gradient net migration % values GDP during relative per capita the to interval 1970 (x1000) remittances received (Million US $) Total Net population migration GDP Remittances growth in growth, West un constant W-Mediterranean received US $ countries countries year years years intervals France Italy France France Portugal Italy Italy Portugal Morocco Spain Portugal Spain Algeria Morocco Spain Morocco Tunisia Algeria Morocco Algeria Tunisia Algeria Tunisia

4 Two groups of case studies Fr It Pt Es Mo Al Todgha Almeria-Dalias Tn Fatnassa-Mareth

5 Source of information for oasis studies IMAROM (Migration, agricultural transformation and natural resource exploitation in the oases of Morocco and Tunisia)» IC18-CT-0134 (EC, DGXII, INCO-DC) University of Amsterdam (The Netherlands). Coordinator Mohammed V University (Rabat, Morocco) Mohammed I University (Oujda, Morocco) Institut des Regions Arides (Medenine, Tunisia) Estacion Experimental de Zonas Aridas-CSIC (Almeria, Spain)

6 Case studies: Almeria-Dalias NASA: Feb 2004 Area = 330 km 2 P = 200 mm y km

7 Case studies: Almeria-Dalias Time evolution of greenhouse area in Almeria Source: Cajamar Mediterraneo Economico, 2002 Greenhouse area (ha) Time evolution of net migration in Almeria years Source: Updated from Anuario de la agricultura almeriense Net migration per time interval (x1000) year intervals

8 Vulnerability: Campo Dalias (Spain) Overdraft (2005) (hm 3 y -1 ) = 90 Drainage= 52 Draft = 142 Over-exploitation rate = x 2.7 Marine salt intrusion: a hidden risk Sand requirement (crop bedding): 1 hm 3 y -1 Manure requirement: 200 m 3 ha -1 each 4 years = 1.5 hm 3 y -1 Crop remains (3 t ha -1 y -1 ) = 768 x 10 3 y -1 Sheep feeding? Incineration?

9 Case study: Almeria-Dalias. Larger offer of workers causes lower daily salaries ( ) in orchard agriculture Sources: Institut Valencia d Estadistica Instituto de Credito Oficial Murcia Own enquiry in Almeria Valencia 48 Murcia Almeria 48 35

10 Case study: Almeria-Dalias. Impact of decreasing labour cost Labour cost is a major component of fixed costs per unit area (F a ). Stability Analysis shows that decreasing F a causes changes in the equilibrium values of the following target system variables: Greenhouse area Groundwater reserve Transition time to steady state Stability during transition time Increases Decreases Increases Increases Source: Ibañez et al Water Resources Reserch, 40.

11 Mountain Oasis types Depression (Fatnassa, Tunisia) P = 89 mm y -1 Close to chot El Djerid Fluvial Todgha Morocco P = 143 mm y -1 at 1350 m asl

12 Morocco: Todgha oasis

13 Traditional oases: self regulated systems for sustainability: Three layered crops

14 Traditional oases: self regulated systems for sustainability: water regulation

15 Case study: Oases Population growth in the Todgha oasis ( ) Total population (x1000) years Source: H de Haas MIgration and Developemnt in Southern Morocco. Amsterdam

16 Case study: Oases. Monthly income and migration status at Todgha Source: H de Haas MIgration and Developemnt in Southern Morocco. Amsterdam

17 Case study: oases Possession of pumps by household migration status in the Todgha oasis Possession of pumps (%) Private pumps Collective pumps 5 0 Nonmigrant Internal Indirect International Migrant status Current International Returned International Source: H de Haas MIgration and Developemnt in Southern Morocco. Amsterdam

18 Case study: Oases. Time evolution of irrigation modes at Todgha Source: H de Haas MIgration and Developemnt in Southern Morocco. Amsterdam

19 Case study: oases Location of purchased land by household migration status of Togha pupulation Total surface (%) Traditional oasis Recent extensions Outside Todgha Location of purchased land Source: H de Haas MIgration and Developemnt in Southern Morocco. Amsterdam

20 Case study: oases. Land location and irrigation modes Source: H de Haas MIgration and Developemnt in Southern Morocco. Amsterdam

21 Case study: oases. Effects of remittances inflow (de Haas et al Final Scientific Report. IMAROM project) Breaking common regulations and structures for using water resources. Lowering water tables Difficulties in managing drainage and salinisation risks.

22 Case study: oases. Effects of remittances inflow >>> soil salinization

23 Case study: oases. Effects of remittances inflow >>> soil salinization

24 Conclusions Intensive agriculture close to sustainability treshold people remittances Traditional agriculture self regulated to sustainability Lower fixed costs Higher investor capacity Hindering common regulations Breaking self-organization Increasing unbound pressure on soil / water resources Sustainability loss towards desertification

25 END

26 A perceptual model of desertification Steady state Population /Resource System Over-exploited Population /Resource System Boudary condition change Climate Demography Market Technology Reversible? N DESERTIFICATION Y

27 Traditional oases: self regulated systems for sustainability: water regulation

28 Morocco 7