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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.