Hydroclimatic impact on mediterranean tree crops area - Mapping hydrological extremes (drought/flood) prone parcels

摘要

Hydrological extremes such as droughts and floods are recognized as environmental disasters causing several negative effects especially on the agricultural section. These phenomena and their proper management have attracted the attention of hydrologists and agricultural scientists. This paper evaluates the climate change effects on hydrological extremes based on the Standardized Precipitation Index (SPI) in the North-Western part of Crete (Greece) for the period of 1960-2019. This area is considered to be one of the most important agricultural regions in the Mediterranean, dominated by tree cultivations. The climate trend line for SPI values shows slight decrease, indicating more intense dry periods for the next decades, especially for semi-mountainous areas. A notable result of this analysis is that more frequent dry and wet spells have appeared in the last three decades. In addition, a fuzzy based GIS modeling approach for estimating both droughts and floods prone areas named "SPIsERS" is developed, incorporating the special distribution of long-term time period Standardized Precipitation Index (SPIs), Evapotranspiration, Runoff accumulation and Soil available water capacity. The proposed methodology was validated for several flood and drought affected areas that have been historically recorded in the study area. According to the results 24.67% of the total tree crops parcels in the study region is prone to hydrological extremes (droughts or floods). Finally, for adapting to the inevitable adverse effects of climate change, water-saving and flood protection measures for Mediterranean tree crops areas are proposed.