A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Risk Analysis of Water Demand for Agricultural Crops under Climate Change
AbstractThis paper assesses the risk of increase in water demand for a wide range of irrigated crops in an irrigation network located downstream of the Aidoghmoush Dam in East Azerbaijan by considering climate change conditions for the period 2026–2039. Atmosphere-ocean global circulation models (AOGCMs) are used to simulate climatic variables such as temperature and precipitation. The Bayesian approach is used to consider uncertainties of AOGCMs. Climate change scenarios of climatic variables are first weighted by using the mean observed temperature-precipitation (MOTP) method, and related probability distribution functions are produced. Outputs of AOGCMs are used as input to water requirement models. Then, produced by using the Monte Carlo method, 200 samples (discrete values) from the probability distribution functions of monthly downscaled temperature and precipitation in the study area are extracted by using a software for sensitivity and uncertainty analysis. Time series of climatic variables in future periods are then generated (temperature variable to calculate potential evapotranspiration and rainfall variable to calculate effective rainfall). To estimate crop water requirements, crop evapotranspiration (from the product of potential evapotranspiration in the previous step and coefficient of crop computed) and effective precipitation (from time series of the previous step) are calculated. The Food and Agricultural Organization of the United Nations (FAO) methods, FAO-24 and Penman-Monteith, were used to compute crop and potential evapotranspiration, respectively. Because of lack of required data, potential evapotranspiration in future periods is computed through the relationship of temperature and potential evapotranspiration in the baseline period; the same procedure is conducted for temperature. Net water requirement (NWR) and the risk of changes in water demand volume of crops (e.g., wheat, barley, alfalfa, soybean, feed corn, forage, potato, and walnut orchards) are computed by entering 200 monthly time series of downscaled temperature and precipitation in future periods. The results indicate that risk of changes in crop water requirements increases by approximately 3% for a 25% risk, approximately 17% for a 50% risk, and approximately 33% for a 75% risk. Also, based on the current cultivated area, on average, the volume of water demand only for the aforementioned crops will be approximately 2.5(106 m3/year) with a risk of 25%, approximately 16(106 m3/year) with a risk of 50%, and approximately 31(106 m3/year) with a risk of 75%. Wheat and barley are more resistant and less sensitive to climate change than other crops considered.
Risk Analysis of Water Demand for Agricultural Crops under Climate Change
AbstractThis paper assesses the risk of increase in water demand for a wide range of irrigated crops in an irrigation network located downstream of the Aidoghmoush Dam in East Azerbaijan by considering climate change conditions for the period 2026–2039. Atmosphere-ocean global circulation models (AOGCMs) are used to simulate climatic variables such as temperature and precipitation. The Bayesian approach is used to consider uncertainties of AOGCMs. Climate change scenarios of climatic variables are first weighted by using the mean observed temperature-precipitation (MOTP) method, and related probability distribution functions are produced. Outputs of AOGCMs are used as input to water requirement models. Then, produced by using the Monte Carlo method, 200 samples (discrete values) from the probability distribution functions of monthly downscaled temperature and precipitation in the study area are extracted by using a software for sensitivity and uncertainty analysis. Time series of climatic variables in future periods are then generated (temperature variable to calculate potential evapotranspiration and rainfall variable to calculate effective rainfall). To estimate crop water requirements, crop evapotranspiration (from the product of potential evapotranspiration in the previous step and coefficient of crop computed) and effective precipitation (from time series of the previous step) are calculated. The Food and Agricultural Organization of the United Nations (FAO) methods, FAO-24 and Penman-Monteith, were used to compute crop and potential evapotranspiration, respectively. Because of lack of required data, potential evapotranspiration in future periods is computed through the relationship of temperature and potential evapotranspiration in the baseline period; the same procedure is conducted for temperature. Net water requirement (NWR) and the risk of changes in water demand volume of crops (e.g., wheat, barley, alfalfa, soybean, feed corn, forage, potato, and walnut orchards) are computed by entering 200 monthly time series of downscaled temperature and precipitation in future periods. The results indicate that risk of changes in crop water requirements increases by approximately 3% for a 25% risk, approximately 17% for a 50% risk, and approximately 33% for a 75% risk. Also, based on the current cultivated area, on average, the volume of water demand only for the aforementioned crops will be approximately 2.5(106 m3/year) with a risk of 25%, approximately 16(106 m3/year) with a risk of 50%, and approximately 31(106 m3/year) with a risk of 75%. Wheat and barley are more resistant and less sensitive to climate change than other crops considered.
Risk Analysis of Water Demand for Agricultural Crops under Climate Change
Ashofteh, Parisa-Sadat (author) / Haddad, Omid Bozorg / Mariño, Miguel A
2015
Article (Journal)
English
Risk Analysis of Water Demand for Agricultural Crops under Climate Change
| British Library Online Contents | 2015
| British Library Online Contents | 2015