تحقيقات جغرافيايی (Apr 2019)
Zoning of Iranian Heavy Precipitation Regime
Abstract
Aims & Backgrounds: One of the most important incidents of heavy precipitation is the heavy loses. Heavy Precipitation regimes can help to identify the climate of each region. Many economic activities (especially agriculture) are adjusted based on the precipitation regime. Change of precipitation regime, in addition to significant environmental impacts, can affect the habits and economic activities and their incomes. Identification of homogeneous precipitation regions is one of the most important prerequisites for environmental planning, especially resource management and spatial planning programs. This research aimed to zoning the Iranian Heavy precipitation regime over 20 years (1996-2016). Methodology: The daily precipitation data of 153 synoptic station were used to zoning the heavy precipitation regime. For implementation of the PCA model, a matrix with the dimensions of 153×12 was created. By analyzing the main components on the matrix, the first six components were selected. The stations were grouped in the six areas of homogeneous heavy precipitation by k-mean clustering of Standard score matrix of selective components. Findings: The regime of autumn heavy precipitation had the most factor score among the 6 regimes. The maximum heavy precipitation of spring-summer pattern (second pattern) was in April to July. The third pattern (absolute spring regime) had the highest heavy precipitation in April and May. The fourth pattern of early winter had the highest heavy precipitation in October, November, December, and January. In the fifth pattern, a large part of the heavy precipitation was in the summer. The heavy precipitation maximum of the sixth pattern was in the summer. Conclusion: There are 8 regimes of heavy precipitation in Iran which the maximum of heavy precipitation is in the Azerbaijani and north Azerbaijan regimes at the first half of the year and in the other regimes at the second half of the year.
