Spatial and temporal variability of precipitation concentration in Iran

Abstract

Precipitation concentration is an important factor to assess climate hazards such as flood and availability of water resources at a regional scale. This paper investigates the spatial and temporal changes of precipitation concentration using the precipitation concentration index (PCI) in 113 stations in Iran for a duration of 30 years (1988-2017). The results show that the mean average of the annual rainfall in Iran varies from 55 mm in the Eastern and central regions (Zabol and Yazd) to 1838 mm in the southwest coast of the Caspian Sea (Bandar Anzali). The highest coefficient of variation (CV) of precipitation is related to the southeastern and southern parts of the country, whereas the lowest CV is observed in the Caspian Sea coast and northwest region. Therefore, its value is mostly a function of latitude. Precipitation concentration and its CV are also influenced by topography and reveal more homogeneity in the northern regions. The Mann-Kendall (MK) test on precipitation concentration data indicates that except for 6 stations (ascending in 2 stations and descending in 4stations), there was no significant trend in others. The stations with non-significant ascending values are located mostly in the Eastern, central and western parts of the country while the non-significant descending ones can be seen in the central and northeastern regions. The results of Sen's slope estimator are also similar to the values of the MK test.

Assessment of spatial–temporal variation of precipitation and meteorological drought in Shanxi province, China

“…The precipitation concentration index (PCI) proposed by Oliver (1980) is a commonly used index to quantify the relative distribution of precipitation patterns, and to estimate the seasonality of the precipitation in a given study area (Coscarelli and Caloiero 2012;Ghaedi and Shojaian 2020). Using DPCI and PCI indices, Coscarelli & Caloiero (2012) analyzed the concentration of daily and monthly rainfall in Southern Italy and detected a very inhomogeneous temporal distribution of the daily rainfall in the eastern region.…”

Changing Properties of Daily Precipitation Concentration in the Hai River Basin, China

“…Higher values of precipitation concentration in a certain region mean that precipitation amount would mostly concentrate within a shorter period of time. Since the DPCI has been developed by Cortesi et al, it has been widely used in the analysis of precipitation concentration in Europe [11], Peninsular Malaysia [12], Iran [8,13], Southern Russia [14], Central-Southern Chile [4], Puerto Rico [15], and Central Asia [16]. In China, spatial and temporal variabilities of DPCI have been investigated in diferent regions.…”

Spatiotemporal variability of monthly precipitation concentration in Argentina

“…floods and erosion), and studying the concentration of precipitation allows characterising the climate of a region (Zhang et al 2019). One problem with a high concentration of precipitation is that it increases the duration of dry seasons, causing a reduction in soil moisture and even extreme situations such as desertification (Ghaedi and Shojaian 2020).…”