CHANGE ON AGRICULTURAL WATER CONSUMPTION REGARDING TO CLIMATE CHANGES

Subject Areas : crop production

حسین ابراهیمی ¹ (استادیار گروه عمران دانشگاه ازاد اسلامی واحد تهران جنوب)

Received: 2011-01-08 Accepted : 2011-07-30 Published : 2010-10-09

Keywords: Climate change, Consumed water, Evapotranspiration, , Water balance.,

Abstract :

Climate change and increase in the temperature are important ecological issue in human life which can affect regional agricultures. Evaporation, potential transpiration, and water requirements of the culture pattern in every region are affected by changes in the climates. The studied area is located between 36°00'N & 37°05'N, and 58°20'E & 60°08'E, with an average temperature of 12.5°C and annual precipitation of 278.6 mm. Results assert that water requirement has been ascending within the 50 recent years, especially during the second 25 years (1975-2000). Evapotranspiration for the 2000-2050 periods was calculated by means of The Global Climate Change Model. The ratio of the recent-50-year January to September monthly evapotranspiration to the coming same period is bigger than one; the 1.05-1.22 ratio indicates a 22 percent growth of water requirement in the period ending in 2050. The total net water requirements for the current culture pattern were estimated at 410 million m3 per year; while the figure for the next 50-year period -with a 19 percent of increment- will be 490 million m3. Water requirement for a majority of the culture pattern will be 22 percent up. The least increase was 14 percent, which was calculated for alfalfa. Exceeding the yearly available water supplies, in the changing conditions of climate, agricultural water consumption in the plain touches 1388.4 million m3. Given the climate change, the shortage will reach 198 percent in June and July. The present critical water shortage coefficient of 0.98 (yearly) and 2.4 (monthly) will go up to 1.15 and 2.4. These figures indicate extremely crucial conditions in the region. Findings assert that even optimistically assuming that the water supplies will be enduring, agricultural water consumption (i.e. the major type of consumption) will dramatically increase, due to the warming weather, climate change originated in industrialization, and greenhouse gasses; so managerial solutions are needed to tackle the problem.

References:

 Alizadeh, A., and GH.Kamali. 2002.The effect of climate change in decreasing agricultural water expedition on Mashhad plain. Geographical Research. Quarterly journal .66:189-201. (In Persian)
 Arnnell G., and H.Reynard.1993. The effects of climate change to global warming on river flows in Great Britain.
 Ebrahimi, H.2008. Study term of climate in Khorasan Razavi province. Research plan. (In Persian)
 Ebrahimi, H., and A,. Alizadeh. 2005.The study of temperature variation in the plain of Mashhad as the index of climate change in the region. Geographical Research. Quarterly journal .79:5-18. (In Persian)
 Farshi,A., and M. Emdad.1996.Investigating the effect of land heat on decreasing agricultural water expedition. 1th Climate change conference. (In Persian)
 Hobbins, M., and J. Ramirez, 1999. The complementary relationship on regional evapotraspiration: the crae model and the advection – aridity approach”. Hydrology days, 19:199-212.
 Hulme, M.Z.,C. Zhao, and T. Jiang, 1994 .” Recent and future climate change in East Asia”. Int. j. clim., 14:637-658.
 Jesen,M.E, .1977. '' Evapotranspiration and irrigation water requirements.ASCE manuals and reports on eng. No.70
 Karimzadeh, M., and B.Ghahraman 2005. The theory of gradual decreasing of referential evatransporation in Mashhad . Collection papers of first national conference on comparison ways to water tension. Zabol university. (In Persian)
 Lapin,M.,1990.Climatological monitoring of territory affected by construction of the Danube hydroelectric power project and evaluation of initial impact”. Slovak hydrometerological institute, jeseniova 17, slovalia , 15pp.
 Nasiri,M. 2002. The effect of global climate change on agricultural products. Ferdowsi uninersity press.358 (In Persian)
 Nasiri,M. 2004. Study the effect of climate change on wheat growth characteristics and dry-farming wheat yield in Iran. (In Persian)
 Norian.A.1999. Climate change and heating the weather. Niovar journal.no 81. Pp 1-3. (In Persian)
 Ragab , R., 2000. Climate change and water resources management in the arid region. Institute of Hydrology , NERC , Wallingford , OXON , OX10 , 8BB , UK.
 Shirgholami,M.2002. Study of reference evapotransporation in Iran.Thesis. (In Persian)