A global view of managing water resources in Tunisia

Transcription

1 OCP Polcy Center Conference seres A global vew of managng water resources n Tunsa Jamel Chahed & Mustapha Besbes & Abdelkader Hamdane June 2014

2 Tunsan water resources Average ranfall Pluval water resources Mm mm/year Renwable Water Resources 4850 Mm 3 < 500 m3/cap/year Surface water : 2700 Mm 3 round water : 2150 Mm3 Non-Conventonal water resources 120 Mm 3 TWW Treated Waste Water

3 Tunsan water resources : Transfers and Water uses Water Uses Drnkng Water: 400 Mm 3 40 m 3 /Cap/year Water for Industry: 100 Mm 3 10 m 3 /Cap/year Water for Toursm: 50 Mm 3 5 m 3 /Cap/year Water for Agrculture : 2100 Mm m 3 /Cap/year Rate of water wthdrawal lobal 90 % Surface water 85 % roundwater 95 %

4 Water resource development and management n Tunsa Water resources n Tunsa are scares not unformly dstrbuted and hghly wthdrawn Water wthdrawal has reached the water potental especally for groundwater The drect demand drnkng water ndustry toursm s ncompressble and ncreases wth the populaton but stll moderate An mportant part of «Blue Water» s used n agrculture : As water supply stablzes agrcultural water allocatons wll be reduced. Ths s the key queston that determnes the water polcy n Tunsa

5 Blue Water for Irrgaton BW Trends n agrcultural water use Drect water uses collectvtes toursm ndustry - Represent around 20 % of water uses - Beneft from a prorty n the water allocaton Irrgated Agrculture - Uses more than 80 % of water. - Occupes 1/10 of cultvated areas - Produces 1/3 of food producton Ranfed Agrculture - Occupes 9/10 of cultvated areas - Produces 2/3 of food producton n value -- has not receved as much attenton as rrgated agrculture

6 reen Water W Ranfed agrculture : Olve groves and wheat sown area Wheat cultvated area [ha] Olve roves area [ha]

7 Water and food securty ssues n Tunsa Irrgaton has been the key of agrculture development. An mportant part of wthdrawal water «Blue Water» s used n agrculture more than 80%. Ranfed agrculture «reen Water» plays an mportant role n food securty. It takes an mportant part n food trade balance. But ranfed agrculture has not receved the same attenton as rrgated agrculture and ts contrbuton s not drectly taken nto account n the global balance of water resources Imports of cereals edble ol and other basc foodstuffs «Vrtual Water» s requred to fll the defct of the local producton. The part of Vrtual Water s already mportant and t s expected to ncrease sgnfcantly. How mprove Food Securty? Should frst mprove the knowledge of the dfferent contrbutons to the provson of food

8 reen Water assessment n S n Y 1000 n W Wn : reen Water of ranfed producton regon year n : Specfc Equvalent Water [m3/kg]; Y n : Yeld of ranfed producton [ton/hectare] S n : Envronmental Water demand n Y 100 h n h n h S W 1 n h n h n h p p W S w h h Y At the natonal level s n Y Y W W s n h h S S s h h n S n S s

9 Yeld Q/ha Yeld [Q/ha] reen Water assessment Cereals Olves Durum Wheat Barley and trtcale Total cereals R² = 0819 R² = 0812 R² = 0823 R² = Olve R² = Spatal average ranfall mm Spatal average ranfall [mm] Potental of "reen Vrtual-Water" content of ran-fed agrculture n Tunsa. Weghted Ranfal h W [mm] Water threshold h [mm] S reen water heght h [mm] Ranfed agrculture Total V Maxmun Ranfed Area [10 3 ha] reen water Potental [km 3 ] Cereals Olve trees plantatons Other ranfed crops

10 A feld of olve trees near Sfax Tunsa Average Ranfall # 250 mm/y

11 Water-equvalent [km 3 ] Water-equvalent of rrgated agrculture green water rrgated agrculture blue water rrgated agrculture Water-equvalent of rrgated agrcultural producton Year

12 Water-equvalent [km 3 ] Water-equvalent of vegetal producton green water ranfed agrculture green water rrgated agrculture blue water rrgated agrculture Water-equvalent of agrcultural producton Year

13 Water-equvalent of vegetal producton Structure of water-equvalent of vegetal producton Average value Perod Irrgated agrculture blue water 15% Irrgated agrculture green water 10% ranfed agrculture green water 75%

14 Water-equvalent [ km 3 ] Water-equvalent of anmal producton Sustaned polcy for ncreasng anmal producton has led to a sgnfcant development of the sector eggs mlk other meat poultry sheepmeat beef meat Water-equvalent of anmal products Tunsa proudly dsplays a relatve self-suffcency n anmal products snce the early 2000s Year and even there are sgns of overproducton durng the last perod

15 .Déversement de lat sur la RN 17!... Protests aganst the dffcultes of mlk marketng: producers dscharge mlk on the publc way Mars 2014 But ths abundance s not real : lets analyze the mports n waterequvalent of anmal products and of fodder

16 Imports n water-equvalent of anmal products and of fodder Water-Eq [km 3 ] fodder mports anmals products mports Evoluton of the water-equvalent of fodder and of anmal food products Year the decrease n mports of anmal products that began n the late 1980s was accompaned by a sgnfcant amplfcaton of anmal feed mports n the early 1990s : so that the defct n equvalentwater s sgnfcantly ncresed

17 Water-equvalent of vegetal producton Structure of water-equvalent of anmal producton average values perod blue water green water 2% rrgated agrculture Vrtual water 4% mport-export 31% green water ranfed agrculture 35% green water rangeland 28%

18 Water-equvalent of vegetal producton Structure of water-equvalent of food productons green water rangelands 10% vrtual water mport-export 14% Blue water rrgated agrculture 12% green water rrgated agrculture 7% green water ranfed agrculture 57%

19 Evoluton of the specfc food demand waterequvalent [1000 m3/hab/an] Water requrements for food have ncreased from about 1000 m3/year/capta n the early 1970s to more than 1500 m3/year/capta n the last 2000s Det has changed : the consumpton of anmal products ncreased more rapdly than that of vegetal products anmal products vegetal products Evoluton of the water-equvalent of the food demand Takng nto account the relatvely low level of the actual anmal products consumpton we may expect n the comng years more change of the det accompaned wth an ncrease of the water year requrement for food needs ncreasng the equvalent-water mports

20 Structure of the specfc food demand waterequvalent [1000m3/hab/an] vrtual water: anmal products vrtual water: vegetal products green water: anmal products green water: vegetal products blue water: anmal products blue water: vegetal products Structure of the water-equvalent of food demand Year

21 Covrage rate Water equvalent [km3] Covrage rate Evoluton of the food trade balance waterequvalent The coverage rate of food mports gradually deterorated n connecton wth the ncrease n mports of agro-almentary products The water-equvalent of the food trade balance s very favourable to Tunsa: the coverage rate of the food trade balance whch reached n value around 80% n the late 2010s represents less than 30% n water-equvalent % 120% 100% 80% 60% 40% 20% 0% Imports water-equvalent exports water-equvalent covrage rate In Value In Water-Eq Evoluton of the water-equvalent of the food trade balance Année Evoluton of the covrage rate of food trade balance Year

22 Average lobal Water Balance Blue Water 33 Irrgaton 21 Urban [Ctes toursm] 04 Industry 01 Envronment [conservaton of humd areas] 01 Water Bank [Storage n dams for droughts] 06 reen Water 121 Ranfed agrculture 66 Forests and Rangelands 55 Net Vrtual Water 63 Defct of food balance[imported Vrtual Water] 63 Total Water Demand 225 Food Water Demand 158 Drect Water demand Collectvtes Industry Toursm 05 Water Bank [Storage n dams for droughts] 06 Envronmental Water demand 56

23 Improvement of the global water balance Enlargement of the Water Resource noton to all knd of the contrbutons to the lobal Water Balance : «Blue Water» «reen Water» «Vrtual Water» «Non-conventonal Water». Enlargement of the Demand Management noton to all knd of water uses ncludng the water requrements for food demand Optmzaton of all water uses ncludng the water nvolved n the ranfed agrculture producton «reen Water» and n the nternatonal trade exchange «Vrtual Water»

24 Conclusons The development of rrgaton sector s lmted by the avalablty of water: rrgated agrculture s ncreasng ts effcency and promotng better use of water. The potental of reen Water s large. Its development requres the mplementaton of a coherent strategy to promote the sector of ranfed agrculture vulnerable to ranfall varablty: 1. Development of techncal tools for better assessment of the reen Water resource n order to make t more vsble: dentfcaton mappng etc. 2. Establshment of regulatory and legslatve measures: encourage sol water resources developments promote foodstuffs storage mplementaton of drought nsurance mechansms 3. Analyss of the market condtons and prces for specfc products Edble ols cereals... But frst explan and convnce