Relationships between meteorological extremes and crop phenology-yield and perception of climate change in the Antalya region

Global climate change has occurred in various forms across all regions of the Earth, particularly affecting the Mediterranean Basin, which has been inhabited by humanity for thousands of years, and transforming it into a hotspot. Increasing temperatures have caused more frequent and severe extreme weather events which have had a tremendous impact on both the natural and human systems in the region. Accordingly, this study examined the relationship between temperature/precipitation extremes and crop phenology, yield, land use and climate change perception in the Mediterranean/Antalya Region of Turkey. A comprehensive examination of 30 indices was conducted to ascertain the temporal progression of temperature and precipitation extremes; PMF-test for homogeneity; Modified Mann-Kendall and Sen's Slope for trend analysis; interpolation techniques for spatial analysis and SPEI methods for drought analysis were used. The Pearson correlation analyses were used to examine the associations between extreme weather events with crop phenology and yield as opposed to averages. Changes in land cover were mapped, the effects of climate change on farming land and the perceptions of farmers and agricultural engineers regarding climate change were assessed by conducting field studies, surveys, interviews, and observations. The findings of the analyses indicate that the initial changepoint in temperature occurred in 1990 in the region, followed by a second increase at the beginning of 2010. On a global scale, temperatures have experienced a noteworthy increase of approximately 1°C, while the region in question has undergone an average increase of 2°C since 1980. Accordingly, it was determined statistically significant temperature increases in approximately 5°C on average summer temperatures, 2.4°C in maximum temperatures and 4°C in minimum temperatures. The occurrence of heat waves and hot days and nights increased, whereas the number of frosty days, cold days, and nights decreased. There has been an increase in the variability of seasonal rainfall in the region, with a notable upward trend in extreme rainfall particularly in the elevated and coastal areas of the Teke Peninsula facing the Mediterranean Sea. Hail events in the region were found to have increased especially since 2010, when the second changepoint in the temperature was experienced. Although the coastal regions tend to be humid, an increase in severe and prolonged drought events has led to an elevated risk of hydrological drought in the inland areas. The significant correlation coefficients between meteorological extremes and annual grain yield ranged from -0.48 to 0.38, with extremes explain 12-23% of the variance in yield. For annual orange yield, it was ranged from -0.76 to 0.87 and extremes explain 57-75% of the variance in yields. For annual olive yields ranged from -0.63 to 0.70 and extremes explain 39-49% of the variance in yields. Significant correlation relationships were generally found during the seed development and spiking stages of cereals (winter, spring period) and during the flowering and fruit development stages of fruits (spring, summer period). The reduction of inland water resources is a severe consequence of increasing temperatures, drought conditions, and intensive agricultural irrigation activities. Similarly, the changes in land cover in the coastal areas are intensified by excessive migration and urbanization. Based on the common findings of field research, it was reported by the participants that the increase in temperature led to an increase in agricultural diseases and pests, while the period of planting and harvesting was significantly reduced. Furthermore, there was a noticeable surge in the yield losses. Despite a general decline in precipitation, the variability and intensity of precipitation were increased. Groundwater levels were observed to decline owing to the detrimental effects of drought, unconscious agricultural irrigation practices, and illicit drilling. In addition, it was stated that there was an overall increase in the frequency and severity of extreme weather events.