Applying the AOGCM-AR5 models to the assessments of land suitability for walnut cultivation in response to climate change: A case study of Iran

• Published in: PloS one 2019-06, Vol.14 (6), p.e0218725
• Main Authors: Vahdati, Kourosh, Massah Bavani, Ali Reza, Khosh-Khui, Morteza, Fakour, Poya, Sarikhani, Saadat
• Format: Article
• Language: English
• Subjects: Agricultural production; Agriculture; Analysis; Arid regions; Arid zones; ASTER (radiometer); Banks (Finance); Biology and Life Sciences; Case reports; Climate; Climate Change; Computer and Information Sciences; Computer simulation; Crop Production - methods; Crop Production - trends; Crops; Crops, Agricultural - growth & development; Cultivation; Data banks; Earth Sciences; Ecology and Environmental Sciences; Electrical conductivity; Electrical resistivity; Emission analysis; Emissions; Environmental Monitoring; Food supply; Fruits; Future climates; Gaging; Geographic Information Systems; Global temperature changes; Handbooks; Health aspects; High temperature; Horticulture; Humidity; Iran; Irrigation; Juglans - growth & development; Juglans regia; Mathematical models; Maximum temperatures; Models, Theoretical; Natural Resources; Nut industry; Parameters; People and Places; Precipitation; Prospective Studies; R&D; Real estate appraisal; Relative humidity; Research & development; Resource management; Semi arid areas; Semiarid lands; Semiarid zones; Sensors; Soil; Soil microbiology; Soil water; Thermal emission; Walnuts; Water; Water availability; Water management; Water resource management; Water resources; Water Resources - supply & distribution; Water resources management
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0218725

Due to higher temperatures and lower water availability, climate change is likely to have a major impact on walnut production in the near future. Climate change will alter the land suitability for walnut cultivation around the world, especially in arid and semi-arid regions like Iran. Here, land suitability for the cultivation of walnut (Juglans regia L.) in Iran was determined using the GIS for present and future conditions (2020-2049) with an approach to climate change. Accordingly, data from 375 synoptic stations throughout Iran were gathered for climatic factors including average, minimum and maximum temperatures, relative humidity and chilling requirement. Also, ASTER sensors (Advanced Spaceborne Thermal Emission and Reflection Radiometer) and their data provided this research with cells that make a precision of 150 m (5 s), and the data were used for gauging geological parameters such as altitude and land slope. The electrical conductivity (EC) of soil and water were informed by the data bank of the Iranian Water Resources Management. The results of temperature simulations for the future (2020-2049) were analyzed by 21 AOGCM-AR5 models under the RCP4.5 emission scenario. In the first phase of evaluations, the maps of land suitability were constructed for present conditions by considering a network of the above-mentioned parameters. By combining these layers of information, the final map of land suitability was illustrated for walnut cultivation. In the second phase, the NEX-GDDP was used in order to determine land suitability for the future (2020-2049). The results showed that Iran currently has 582844 km2 of land suitable for walnut cultivation. However, the future will see less suitable lands: the current area will be reduced by 6.19%, from 582844 km2 to 546710 km2. In general, the northern, northwestern and western margins of Iran are currently suitable for walnut cultivation. By approximation, these lands will also be major areas for prospective cultivations of walnut in the future (2020-2049), even though their current stretch will be reduced.