Spatial and Temporal Analysis of Precipitation over Iran Using Gridded Precipitation Data of APHRODITE

摘要

In order to achieve risk management of water-related disasters such as droughts and floods in Iran, it is essential to obtain knowledge of the exact quantities of spatial and temporal precipitation over the long term. In this regard, this paper presents the results of monitoring precipitation on monthly, seasonal and annual timescales during the period of 1986-2006 (21 years) over Iran using a product of 0.5-degree-gridded data sets provided by the Asian Precipitation-Highly-Resolved Observational Data Integration (APHRODITE) Towards Evaluation of the Water Resources project, namely APHRO_ME_V003R1. Spatial distribution of mean seasonal and annual precipitation shows two rainfall peaks that extend from the northwest to the southeast along the Zagros Mountains and along the Caspian Sea and Alborz Mountains in the northern part of the country. With respect to a seasonal spatial analysis of rainfall over Iran, it is concluded that in winter, DJF (December- January- February), and spring, MAM (March-April-May), most precipitation occurs in the west, northwest and southwest along the Zagros Mountains, but in summer. JJA (Jun-July-August), and autumn, SON (September-October-November), most precipitation occurs along the southern Caspian Sea in the north. Annual and seasonal drought condition using APHRODITE data have showed that mean annual precipitation amount were low (drought condition) over Iran in 1989, 1990, 1991, 1992, 1996, 1998, 1999, 2000, 2001 and they are in accordance with Yazdani et al (2011)'s study about drought analysis over Iran.