University of Tabriz Journal of Geography and Planning 2008-8078 16 39 2012 05 04 Analysis of Heavy Precipitation Trends in Zanjan City Analysis of Heavy Precipitation Trends in Zanjan City 73 88 186 FA Hossein Asakereh Humor of Geography, University of Zanjan 0000-0001-7699-0547 Journal Article 2010 07 24 Understanding the heavy precipitation behaviors tend toward easy planning, designing, act and management of the water recourses. There are many definitions on heavy precipitation in different professional references. Two important extreme indices are maximum precipitation and five highest precipitations in a year. One characteristic of heavy precipitation is variation in time and space. Accordingly’ it is important to study this phenomenon by high resolution in time and space. To investigate heavy rains in Zanjan, daily precipitation during 1961-2006 have been analyzed. The trends of maximum precipitation and their ratio to annual precipitation, the trends of five highest precipitations and their ratio to annual precipitation have been modeled by Non-parametric methods. <br />The results in two scales (annual and monthly) show no trends in time series, while there are high fluctuation periods during 1961-1973 and low fluctuation periods during 1974-2006. Understanding the heavy precipitation behaviors tend toward easy planning, designing, act and management of the water recourses. There are many definitions on heavy precipitation in different professional references. Two important extreme indices are maximum precipitation and five highest precipitations in a year. One characteristic of heavy precipitation is variation in time and space. Accordingly’ it is important to study this phenomenon by high resolution in time and space. To investigate heavy rains in Zanjan, daily precipitation during 1961-2006 have been analyzed. The trends of maximum precipitation and their ratio to annual precipitation, the trends of five highest precipitations and their ratio to annual precipitation have been modeled by Non-parametric methods. <br />The results in two scales (annual and monthly) show no trends in time series, while there are high fluctuation periods during 1961-1973 and low fluctuation periods during 1974-2006. https://geoplanning.tabrizu.ac.ir/article_186_eec06d917141a339e2768cd6f771a072.pdf