Management Center for Strategic Projects

Shīrāz, Iran

Management Center for Strategic Projects

Shīrāz, Iran
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Ahani H.,Management center for Strategic projects | Kherad M.,Management center for Strategic projects | Kousari M.R.,Management center for Strategic projects | van Roosmalen L.,Flinders University | And 2 more authors.
Theoretical and Applied Climatology | Year: 2013

Currently, an important scientific challenge that researchers are facing is to gain a better understanding of climate change at the regional scale, which can be especially challenging in an area with low and highly variable precipitation amounts such as Iran. Trend analysis of the medium-term change using ground station observations of meteorological variables can enhance our knowledge of the dominant processes in an area and contribute to the analysis of future climate projections. Generally, studies focus on the long-term variability of temperature and precipitation and to a lesser extent on other important parameters such as moisture indices. In this study the recent 50-year trends (1955-2005) of precipitation (P), potential evapotranspiration (PET), and aridity index (AI) in monthly time scale were studied over 14 synoptic stations in three large Iran basins using the Mann-Kendall non-parametric test. Additionally, an analysis of the monthly, seasonal and annual trend of each parameter was performed. Results showed no significant trends in the monthly time series. However, PET showed significant, mostly decreasing trends, for the seasonal values, which resulted in a significant negative trend in annual PET at five stations. Significant negative trends in seasonal P values were only found at a number of stations in spring and summer and no station showed significant negative trends in annual P. Due to the varied positive and negative trends in annual P and to a lesser extent PET, almost as many stations with negative as positive trends in annual AI were found, indicating that both drying and wetting trends occurred in Iran. Overall, the northern part of the study area showed an increasing trend in annual AI which meant that the region became wetter, while the south showed decreasing trends in AI. © 2012 Springer-Verlag.


Kousari M.R.,Management Center for Strategic Projects | Kousari M.R.,University of Yazd | Asadi Zarch M.A.,University of New South Wales | Ahani H.,Management Center for Strategic Projects | Hakimelahi H.,Management Center for Strategic Projects
Climatic Change | Year: 2013

Reference crop evapotranspiration (ET0) is one of the most important climatic parameters which plays a key role in estimating crop water demand and scheduling irrigation. Under global warming and climate change conditions, it is needed to survey the trend of ET0 in Iran. In this study, ET0 values were determined based on FAO-56 Penman-Monteith equation over 32 synoptic meteorological stations during 1960-2005; and analyzed spatially and temporally in monthly, seasonal and annual time scales. After removing the significant lag-1 serial correlation effect by pre-whitening, non-parametric statistical Mann-Kendall (MK) test was used to detect the trends. The slope of the changes was determined by Sen's slope estimator. In order to facilitate in trend analysis, the 10 moving average low pass filter were also applied on the normalized annual ET0 time series. Annual ET0 time series and filtered ones were then classified by hierarchical clustering in three clusters and then mapped in order to show the patterns of different clusters. Results showed that the significant decreasing trends were more considerable than increasing ones. Among surveyed stations, and on an annual time scale, the highest and lowest annual values of Sen's slope estimator were observed in Tabas with (+) 72.14 mm per decade and Shahrud with (-) 62.22 mm per decade, respectively. Results also indicated that the clustered map based on normalized and filtered annual ET0 time series is in accordance with another map which showed spatial distribution of increasing, decreasing and non-significant trends of ET0 on annually time scale. Exploratory and visual analysis of smoothed time series showed increasing trend in recent years especially after 1980 and 1995. In brief, the upward trend of ET0 in recent years is a crucial issue with regard to the high cost of dam construction for agricultural aims in arid and semi-arid regions e.g. Iran. © 2013 Springer Science+Business Media Dordrecht.


Bari Abarghouei H.,Payame Noor University | Kousari M.R.,Management Center for Strategic Projects | Asadi Zarch M.A.,University of Yazd
Arabian Journal of Geosciences | Year: 2013

Drought is one of the most important natural hazards in Iran. It is especially more prevalent in arid and hyper arid regions where there are serious limitations in regard to providing sufficient water resources. On the other hand, drought modeling and particularly its prediction can play important role in water resources management under conditions of lack of sufficient water resources. Therefore, in this study, drought prediction in a hyper arid location of Iran (Ardakan region) has been surveyed based on the abilities of artificial neural. Standardized Precipitation Index (SPI) in different time scales (3, 6, 9, 12, and 24 monthly time series) computed based on the data gathered from four rain gauge stations. After evaluation and testing of different artificial neural networks (ANN) structures, gradient descent back propagation (traingd) network showed higher abilities than others. Then, the predictions of SPI time series with different monthly lag times (1:12 months) were tested. Generally, drought prediction by ANNs in the Ardakan region has shown considerable results with the correlation coefficient (R) more than 0. 79 and in the most cases and it rises more than 0. 90, which indicates the ANN's ability of drought prediction. © 2011 Saudi Society for Geosciences.


Bari Abarghouei H.,Payame Noor University | Asadi Zarch M.A.,University of Yazd | Dastorani M.T.,University of Yazd | Kousari M.R.,Management Center for Strategic Projects | Safari Zarch M.,Payame Noor University
Stochastic Environmental Research and Risk Assessment | Year: 2011

Drought is one of the most important natural hazards in Iran. Therefore, drought monitoring has become a point of concern for most of the researchers. In the present study, the changes and trend of drought was surveyed, under the current global climate changes, by non parametric Mann-Kendall statistical test for 42 synoptic stations at different places of Iran. Standardized Precipitation Index (SPI) was calculated to recognize the drought condition at different time scales (3, 6, 9, 12, 18 and 24 months' time series) for analyzing the drought trend in the recent 30 years. The obtained results have indicated a significant negative trend of drought in many parts of Iran, especially the South-East, West and South-West regions of the country. According to the results, although some parts of Iran such as North (around the Caspian Sea) and Northeast show no significant trend but in other parts of country, the severity of drought has increased during the last 30 years. © 2011 Springer-Verlag.


Zarch M.A.A.,University of Yazd | Malekinezhad H.,University of Yazd | Mobin M.H.,University of Yazd | Dastorani M.T.,University of Yazd | Kousari M.R.,Management Center for Strategic Projects
Water Resources Management | Year: 2011

Drought is one of the most important natural hazards in Iran and frequently affects a large number of people, causing tremendous economic losses, environmental damages and social hardships. Especially, drought has a strong impact on water resources in Iran. This situation has made more considerations toward the study and management of drought. The present study is focused on two important indices; SPI and RDI, for 3, 6, 9, 12, 18 and 24 months time scales in 40 meteorological synoptic stations in Iran. In the case of RDI computation, potential evapotranspiration was an important factor toward drought monitoring. So, evapotranspiration was calculated by Penman-Monteith equation. The correlation of RDI and SPI was also surveyed. Drought severity maps for SPI and RDI were also presented in the driest year (1999-2000). The present results have shown that the correlation of SPI and RDI was more considerable in the 3, 6 and 9 months than longer time scales. Furthermore, drought severity maps have shown that during 1999-2000, the central, eastern and south-eastern parts of Iran faced extremely dry conditions. While, according to SPI and RDI trends, other parts of the country suffered from severe drought. The SPI and RDI methods showed approximately similar results for the effect of drought on different regions of Iran. Since, RDI resolved more climatic parameters, such as evapotranspiration, into account which had an important role in water resource losses in the Iranian basins, it was worthwhile to consider RDI in drought monitoring in Iran, too. © 2011 Springer Science+Business Media B.V.


Kousari M.R.,University of Yazd | Kousari M.R.,Management Center for Strategic Projects | Dastorani M.T.,Ferdowsi University of Mashhad | Niazi Y.,University of Yazd | And 3 more authors.
Water Resources Management | Year: 2014

Drought is known as one of the main natural hazards especially in arid and semi-arid regions where there are considerable issues in regard to water resources management. Also, climate changes has been introduced as a global concern and therefore, under conditions of climate change and global warming, the investigation of drought severity trend in regions such as Iran which is mainly covered by arid and semi-arid climate conditions is in the primary of importance. Therefore, in this study, based on the application of Reconnaissance Drought Index (RDI) for assessment drought severities, and also the implementation of non-parametric Mann- Kendall statistics and Sen's slope estimator, the trends in different time series of RDI (3, 6, 9, 12, 18 and 24 monthly time series) were investigated. Results indicated the frequent decreasing trends in RDI time series particularly for long term time series (12, 18 and 24 monthly time series) than short term ones. Decreasing trend in RDI time series means the increasing trend in drought severities. Since the water resources especially ground water in most cases are affected by long term droughts, therefore, increasing trend in drought intensities in long term ones can be a threat for water resources management in surveyed areas. © 2014 Springer Science+Business Media Dordrecht.


Kousari M.R.,Management Center for Strategic Projects | Ahani H.,Management Center for Strategic Projects | Hendi-zadeh R.,Management Center for Strategic Projects
Global and Planetary Change | Year: 2013

Trends of maximum air temperature (T max) were investigated in three time scales including annual, seasonal, and monthly time series in 32 synoptic stations in the whole of Iran during 1960-2005. First, nonparametric Mann-Kendall test after removal of the lag-1 serial correlation component from the T max time series was used for trend detection and spatial distribution of various trends was mapped. Second, Sen's slope estimator was used to determine the median slope of positive or negative T max trends. Third, 10-year moving average low-pass filter was applied to facilitate the trend analysis and the smoothed time series derived from the mentioned filter were clustered in three clusters for each time series and then were plotted to show their spatial distribution patterns in Iran. Results showed that there are considerable significant positive trends of T max in warm months including April, June, July, August and September and warm seasons. These trends can be found in an annual time scale which indicated almost 50% positive trends. However, cold months and seasons did not exhibit a remarkable significant trend. Although it was rather difficult to detect particular spatial distribution of significant trends, some parts in west, north-east and south-east and central regions of the country showed more positive trends. In an annual time scale, Kermanshah located in west regions indicates most change at (+) 0.41. °C per decade. On the one hand, many clusters of normalized and filtered T max time series revealed the increasing trend after 1970 which has dramatically risen after around 1990. It is in accordance with many other findings for temperature time series from different countries and therefore, it can be generated from simultaneous changes in a bigger scale than regional one. On the other hand, the concentration of increasing trends of T max in warm seasons and their accordance to plants growing season in Iran can raise the importance of the role of frequent reported land use changes during past decades. Generally, the more sophisticated and comprehensive researches are needed to determine the role of different factors such as the emission of greenhouse gases and land use changes influencing temperature trends in Iran. © 2013 Elsevier B.V.


Ahani H.,Management Center for Strategic Projects | Kherad M.,Management Center for Strategic Projects | Kousari M.R.,Management Center for Strategic Projects | Rezaeian-Zadeh M.,Management Center for Strategic Projects | And 3 more authors.
Theoretical and Applied Climatology | Year: 2012

Under condition of climate changes as global warming, monitoring and detecting trend of precipitation volume is essential and will be useful for agricultural sections. Considering the fact that there were not enough research related to precipitation volume, this study aimed to determine trends in precipitation volume, monthly and annually in different regions of Fars province for the last three decades (33 years period; 1978-2010). Fars province is located in arid and semi-arid regions of Iran, and it plays an important role in agricultural production. Inverse distance weighting interpolation method was used to provide precipitation data for all regions. To analyze the trends of precipitation volume, Mann-Kendall test, Sen's slope estimator, and 10-year moving average low-pass filter (within time series) were used. The negative trends were identified by the Sen's slope estimator as well as Mann-Kendall test. However, all the trends were insignificant at the surveyed confidence level (95%). With regards to the application of 10-year moving average low-pass filter, a considerable decreasing trend was observed after around year 1994. Since one of the most important restrictions in agricultural development of the Fars province is lack of sufficient water resources, any changes onward to lack of sufficient precipitation impose impressive pressure and stress on valuable resources and subsequently agricultural production. © 2011 Springer-Verlag.


Kousari M.R.,Management Center for Strategic Projects | Ahani H.,Management Center for Strategic Projects | Hakimelahi H.,Management Center for Strategic Projects
Theoretical and Applied Climatology | Year: 2013

Wind plays an important role on the ecosystems and hydrological cycles besides other meteorological parameters such as temperature, precipitation, sunshine, and relative humidity. It strongly affects evapotranspiration, especially in arid and semiarid regions where there are serious problems in regard to water resource management. Evaluating the wind speed trend can provide good information for future agricultural planning. This study was conducted in order to investigate the wind speed trends over 24 synoptic meteorological stations located in arid and semiarid regions of Iran from 1975 to 2005. Near-surface wind speed was trended by nonparametric Mann-Kendall test spatially and temporally in three time scales (annual, seasonal, and monthly). Then, Sen's slope estimator was used to determine the amount of the changes; furthermore, 10-year moving average low-pass filter was applied to show general trends. Finally, the smoothed time series derived from the mentioned filter were classified in three clusters for each time series and then mapped to show their spatial distribution pattern. Results showed insignificant and significant, increasing and decreasing trends during the surveyed time. Wind speeds in less than 50 % of stations changed statistically in all time scales, and in most cases, the frequency of the upward trends was more than that of downward ones. The spatial distribution of significant wind speed showed that the increase mostly occurred in eastern part. Clustering gave us the turning point around 1990. Clearly, when clusters were mapped, they indicated the same pattern as the Z value maps derived from Mann-Kendall test which meant that the outputs of the mentioned method confirmed the other one. As the wind speed trends in different stations likely to follow the previous evapotranspiration (ET0) trend results in Iran, it confirms that wind speed was an effective parameter on ET0, even though other parameters should be considered too. © 2013 Springer-Verlag Wien.


Kousari M.R.,Management Center For Strategic Projects | Ahani H.,Management Center For Strategic Projects
International Journal of Climatology | Year: 2012

Evapotranspiration is one of the most important factors in agriculture and the hydrological cycle that can be influenced by global warming and climatic changes. In this study, the trend of reference crop evapotranspiration (ET0) computed by penman Penman-Monteith equation and surveyed in 42 synoptic weather stations during last 3 decades (1975-2005). Nonparametric statistical test, Kendall's rank correlation (or τ test) was used to determine ET0 trends. Although, downward and upward trends were observed, increasing trends had more frequency. Spatial analysis of results indicated upward trends especially in the boundary parts of the country while, no significant trends were distributed in central parts. In addition, correlation analysis between ET0 trend and other climatic parameters trend (the trend of mean temperature, mean of minimum temperature, and mean of maximum temperature, mean of relative humidity, mean of wind speed and mean of sunshine duration) showed that wind is the most effective parameter on ET0. Iran losses more than 70% of annual precipitation by ET0. It is obvious that in this country where there are many limitations for water resources management, increase in ET0 could lead to more problems. © 2011 Royal Meteorological Society.

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