Download Solution sheet about the case studies Egypt and Spain

Food & Climate – More – Predicting the future - Worksheet 3 –
Solution sheet about the case studies Egypt and Spain
1. Irrigation systems
As you know the agriculture in Egypt is restricted to the fertile lands of the Nile valley and the Nile delta. There the
agricultural land has to be irrigated almost permanently. Therefore the regularly occurring flood water of the Nile was
stacked up on the fields without control in former times. On the opposite some parts of the agricultural land in
Spain is irrigated by the so-called drip-irrigation, a special form of localized irrigation. That means that the water is
given drip by drip into the area of the plants through special nozzles.
Search the internet for pictures of drip-irrigation. Then compare those two sorts of irrigation and consider
carefully the pros and cons. Which technique is the best for the situation in the respective countries?
Pros
1. stacking up the water
uncontrolled
 Low facility and running costs
 Special knowledge is not needed
 Machines can be used easily
2. drip-irrigation
 Very low evaporation
 High efficiency
 Good adaption to water uses of
different plants
 Possible distribution of fertilizer
and pesticides
 A very economical way of
irrigation
 Drainage is not needed
Cons
1. stacking up the water
uncontrolled
 Erosion
 Very low efficiency
 Big water losses (evaporation,
water trickles away, surplus water)
 Mostly no drainage  oversalted
fields
 Uneven water distribution (only in
times of floods)
2. drip-irrigation




The nozzles are easily blocked up
The technique is very expensive
Machines can hardly be used
Qualified workers with lots of
knowledge are needed
As a result you can say that the use of one of the discussed techniques depends on the economic
and knowledge background of the farmers in the respective countries. In general, the drip-irrigation
has more advantages than stacking up the water as it saves the precious resource water in dry
countries. It can be used everywhere where enough water can be stored in reservoirs and tanks
whereas stacking up the water depends on the natural flowing off or floods of a river which often is
extremely variable.
Source of the pictures: http://satgeo.zum.de/satgeo/beispiele/interpretation/klipicts.htm
2. Climate change scenarios in Spain
a) Look into your atlas and find out the main agricultural areas in Spain and what is cultivated there.
Make a rough list with products and regions where these products are cultivated!
Product
Regions
Wheat
Mainly around Valladolid, west of Madrid, east of Sevilla, north and west of Albacete, along
the river Ebro from Victoria to Zaragoza, south and along the river Guadalquivir from Sevilla
to Linares, around Badajoz
Corn
Along the Atlantic coast in the North
Rice
Only a small region south of Sevilla along the delta arms of the Guadalquivir
Sugar-beets
Around Valladolid, Lerida and Zaragoza
Cotton
Also along the Guadalquivir from Linares to Sevilla
Olives
Mainly south of the Guadalquivir and near the Mediterranean coastline, partly also along
the Ebro and the Guadiana
Agrumes
Along the Mediterranean coastline starting south of Tarragona
Fruits and vegetables
Mainly also along the Mediterranean coastline
Sunflowers
East of Madrid in the centre, south of the Guadalqqivir, around Badajoz
Wine
Along the Ebro, around Barcelona, south of the Guadiana in central Spain, along the
Mediterranean coastline in the South, around Alacete
(List was drawn up after the data of the DIERCKE Weltatlas, Westermann Germany 1996. Page 100/101.)
b) Describe and compare the four scenario maps of Spain roughly and draw a conclusion referring to
the present state in Spain. Therefore read the accordant text once again.
Where do you see alternatives for the future?
In general GS scenarios for 2050 are more hopeful concerning the yield change. Only in the Northeast under rainfed
conditions and in the South paradoxically under irrigation conditions (perhaps important drainage is missing and soil
gets over salted or there is lot of erosion because of irrigation that reduces the quality of soil) there is a smaller
negative yield change.
In the GG scenarios you can see that in the main production areas in the South, along the Mediterranean coastline
and in the Northeast the yield change will be extremely negative (between –20 and –35%).
Another thing is that irrigation only helps in some areas to achieve a positive yield change e.g. in central Spain either
in GG and GS scenarios or in the Northeast under GS scenario.
In regions with more precipitation in summer (the regions in the North and Northwest) irrigation is not needed to get
positive yield chance results.
If you compare the actual main agricultural production areas in Spain with the scenarios, one result is that the actual
regions are those with the predicted most negative yield changes. A possible consequence could be that agriculture
in these negative yield change regions will be given up and other sorts of income possibilities will be preferred
(tourism, industry). At the same time an important export factor of Spain (agricultural products) will be missing if shifts
to better regions in the North won´t take place. Other sectors would have to fill the gap in the GNP. Another
possibility would be to cultivate plants that endure dryness.
The best solution of course would be a minimization of CO² emissions, but this will be a utopiaI fear.