نتایج جستجو برای: month spi time series scale end of march then
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the drought caused a series of effects on many sectors of economy, especially natural resources. during two last decades, iran has suffered from several severe to extreme agricultural droughts which caused significant decreases in rangeland and agriculture yields. this paper discusses the detection of agricultural drought severity over the rangelands of markazi province between 2000 and 2014 us...
In this study, the trends of changes of the standardized precipitation index in a 12-month timescale (SPI-12) and seasonal and annual precipitation were investigated in 21 humid and semi-arid stations of Iran during the 1976-2014 time period. After removing the serial correlation of some series, the trend of precipitation and SPI-12 was detected using the Mann-Kendall nonparametric trend test. ...
The effect of the length of record on the standardized precipitation index (SPI) calculation was investigated by examining correlation coefficients, the index of agreement, and the consistency of dry/wet event categories between SPI values derived from different precipitation record lengths. The effect was also illustrated by comparing SPI values derived from different lengths of record in some...
there are many approaches for solving variety combinatorial optimization problems (np-compelete) that devided to exact solutions and approximate solutions. exact methods can only be used for very small size instances due to their expontional search space. for real-world problems, we have to employ approximate methods such as evolutionary algorithms (eas) that find a near-optimal solution in a r...
the study of air infiltration into the buildings is important from several perspectives that may be noted to energy and design of hvac systems, indoor air quality and thermal comfort and design of smoke control systems. given the importance of this issue, an experimental and numerical study of air infiltration through conventional doors and windows has been explored in iran. to this end, at fir...
the impact of meteorological and hydrological drought on groundwater resources in coastal deserts in the south of iran was investigated during 1991-2011, using standardized precipitation index (spi), standardized runoff index (sri), and groundwater resources index (gri). the results indicated that wet and drought spells governed the area in the first and second decades, respectively, which was ...
sange siyah dam is located two kilometers down the kabod khani village. the environ of ghorrve city in kurdestan province. this is an clay core dam. in this dam instrumentation is performed in three section and consist of electrical piezometers, total pressure cells, settlement cells and so on. the main objective of instrumentation is to control the behavior of dam body and foundation, end else...
in reality, most structures involved in geotechnical engineering are three dimensional in nature, and although in many, plane strain or axisymmetric approximations are reasonable, there are some, for which 3-d treatment is required. the quantity of data, and the size of the various vectors and matrices involved in such analysis, increase dramatically. this has sever implications for computer r...
Received: 29 December 2008 Revised: 1 October 2009 2nd Revision: 13 November 2009 3rd Revision: 28 February 2010 Accepted: 1 March 2010 Abstract Software Process Improvement (SPI) projects are large-scale, complex organization-wide change initiatives. They require considerable investments in personnel, time and money and impact just about every aspect of software firms. The group charged with c...
this study is an outlook of iranians religious practices and customs in eras such as nasser one. it attempts to answer the main question, "religious practices and ceremonies in the society during naseri ruling" and other subsidiary questions with scientific and historical theories. iran was a traditional and religious community . people abided by their religious practices and duties within reli...
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