DROUGHT is a hydrologic and climatic phenomenon, this phenomenon can occur in different watersheds and climatic conditions. Water resources management, design of water transmission and distribution systems and determination of agriculture water demands depend to applied methods for management and controlling of DROUGHT considerably. In this study for distinguishing of occurred DROUGHTs in upstream of the Dez Dam, annual precipitation data of Tangpanj and Telezang stations have been applied in a 17 years period (1994-2010).Occurred DROUGHTs have been determined using of these data and DROUGHT INDEXES as Percent of Normal (PN), Deciles Index (DI), Standard of Precipitation Index (SPI), Chinese Z Index (CZI), Modified Chinese Z Index (MCZI) and Z-Score index (ZSI). Results illustrated that most of severe DROUGHTs were observed in Telezang station. PNI, MCZI, ZSI INDEXES showed them (these INDEXES showed one DROUGHT in 2007-2008, 1995-1996 and 2007-2008 respectively). Also DI and SPI INDEXES illustrated an occurred severe DROUGHT in Telezang (2007-2008) and Tangpanj stations (1999-2000) respectively. But CZI index did not show occurrence any DROUGHT in these stations. RAI index distinguished that three (1999, 2008 & 2011) and four (1994, 1999, 2008 & 2011) severe DROUGHTs occurred in the Tangpanj and Telezang stations respectively. These INDEXES showed that most of DROUGHTs have occurred from 2007 till 2009.

DROUGHT stress is one of major cause of yield and yield components reduction, so in order to evaluate DROUGHT tolerance in wheat cultivars using susceptibility and tolerance stress INDEXES, an experiment was carried out in strip-plot based on randomized complete block design with three replications in 2005 in Karaj region. In this experiment four irrigation levels (control (a1), mild stress (a2), moderate stress (a3), high stress (a4)) and eleven cultivars were levels of horizontal and vertical factors, respectively. In this experiment line source sprinkler was applied to irrigate cultivars, so amount of water used for each treatments were: (a1=5700 cubic meters, a2=4500 cubic meters, a3=3000 cubic meters, a4=2100 cubic meters). By using mean productivity (MP), geometric mean productivity (GMP), stress tolerance index(STI), stress Susceptibility Index (SSI) and tolerance (TOL) INDEXES, DROUGHT tolerance and DROUGHT resistance of cultivars were evaluated and results showed that there were positive correlations between MP, GMP, STI INDEXES with yield potential(Yp) and yield under stress conditions. therefore these INDEXES can be used to identify tolerant genotypes. Finally two-D plots used to classify cultivars into four groups and display that Sardari and Azadr2 cultivars had higher yield than others in both conditions.

DROUGHT is one of the natural disasters that inflict serious damages on human life and natural ecosystems. It differs from other natural phenomena such as flood, tornado and earthquake. Most of these differences relate to the gradual effect of DROUGHT during a relatively long-terin periods, impossibility of determining its exact beginning and end, and the geographic extent of its impact. In the other hand, the lack of an exact and acceptable universal definition of DROUGHT has mad this phenomenon complicated. Generally there are three types of DROUGHT: meteorological, hydrological and agricultural. Meteorological or climatic DROUGHT is basically caused by rainfall deficiency which in case of continuation culminates in hydrological and agricultural DROUGHT. Precipitation is the most important parameter that is used for defining DROUGHT and its lack or deficit implies the threshold of DROUGHT. In this paper, considering 52 year of rainfall data from Ekbatan and Nogeh Metrological, stations (1328-1329 to 1379-1380), DROUGHT in Hamadan region has been evaluated on seasonal and yearly basis. At first the homogeneity of data was evaluated using Double Mass and Run-Test methods. Then, DROUGHT was explained on the basis of fallowing INDEXES: 60% threshold index, percent of normal index, rainfall standard index, deviation form mean index, and classification of rainfall range on seasonal and yearly scale index. Considering the decrease of precipitation it was concluded that in Hamadan region DROUGHT has occurred as a seasonal or a yearly basis. Considering the decrease of precipitation in Hamedan region, DROUGHT has occurred either on seasonal or yearly basis.

Introduction: DROUGHT Stress is one of the most important and common environmental stresses that restricts agricultural production and reduces production efficiency in semi-arid and dryland areas (Sarmadnia, 1993). Information on yield stability of genotypes under both favorable and DROUGHT stress conditions is essential to identify DROUGHT-tolerant genotypes by plant breeders and genotypes with good performance in both environments are preferred (Uddin et al., 1992). In International Maize and Wheat Improvement Center (CIMMIT), the F3 and F4 generations are selected under limited irrigation conditions. The selected plant materials in the fifth and sixth generations are evaluated under normal conditions, and in seventh and eighth generations performance comparison and other evaluations are studied under water stress and natural conditions. This method of evaluation and selection under stress and non-stress conditions has been suggested and applied by many researchers on wheat and other crops (Ehdaie et al., 1988). The goal of this study was selection of DROUGHT tolerant bread wheat lines based on their tolerance indices and pedigree analysis. Materials and Methods: In this experiment, 291 lines and cultivars of bread wheat along with four check cultivars including Parsi, Pishtaz, Sirvan, and Sivand were evaluated to identify tolerant genotypes for terminal DROUGHT using two identical experiments, one under non-stress condition and the other one under DROUGHT stress condition (irrigation cut-off after 50% of anthesis). Experiments were conducted using the observational method without replication. During the developmental stages, the traits including green percentage, days to heading, days to maturity, plant height, grain color, thousand-grain weight, lodging percentage, shattering and grain yield per plot were recorded. DROUGHT susceptibility and tolerance indices such as STI, SSI, GMP, MP and TOL were calculated for all the investigated entries based on 1000-grain weight and grain yield. In order to investigate the genetic background of selected lines, the percentage of genetic contributions of each genotype was calculated based on the pedigree of the lines. Results & Discussion: The results indicated that under both stress and non-stress conditions, the selected lines were relatively early mature. Comparison of arithmetic means (MP), geometric mean (GMP) and DROUGHT tolerance index (STI) of the genotypes revealed that selection based on these criteria leads to the selection of high yield genotypes under both stress and non-stress conditions. In terms of grain yield, genotypes 33, 2, 34, 23, 10 and 11 had the lowest SSI, which was associated with a higher yield of these lines under DROUGHT stress. Also, in terms of 1000-grain weight, genotypes 10, 11, 32, 33, 34, 8 and 5 had the lowest SSI indices where this trait was significantly correlated with high seed weight under DROUGHT stress. Lines 11, 14 and 34 had the highest STI index for grain yield and 1000-grain weight, which was significantly associated with high grain yield and 1000-grain weight under normal conditions. Finally, 34 superior DROUGHT tolerant lines were selected in two stages according to STI and SSI indices. Pedigree analysis of the selected lines showed that genotypes PASTOR, WBLL1, SKAUZ, and Y50E had contributions of 11. 21%, 6. 34%, 4. 04%, and 4. 04% in germplasm composition under DROUGHT condition, respectively, indicating their impact on DROUGHT tolerance. On the other hand, genotypes CHIBA, KACHU and 1-73-240 had 0. 01%, 0. 02%, and 0. 02% contribution in germplasm composition under DROUGHT conditions, respectively, showing no influence in DROUGHT tolerance. Conclusion: The results of this study showed that the genetic structure of some Iranian wheat cultivars such as Omid, Pishtaz, Parsi, Marvdasht, Alborz and Atrak, respectively, made contributions of 2. 78%, 2. 39%, 1. 47%, 1. 47% and 1. 44% to the genome of the selected lines. Finally, it was suggested that, in addition to the above-mentioned Iranian cultivars, breeding lines derived from genotypes such as PASTOR, KAUZ, SKAUZ, WBLL1, PBW343, Y50E and MUNAL #1 can be used in breeding programs to produce suitable germplasm with early maturity and tolerance to terminal-DROUGHT stress for temperate climate of Iran.

Background and Objectives: Due to absolute dependence of agriculture on water, determine of DROUGHT condition in each region is very useful in planning the food sourcing. Unfortunately, there is no same definition about the “ DROUGHT condition” , so there are some INDEXES to determine it. Standardized Precipitation Index (SPI) is one the meteorological INDEXES, which widely used to determine agricultural DROUGHT conditions. Evapotranspiration Deficit Index (ETDI) was also designed for this purpose. This index is used to determine agricultural DROUGHT conditions in arid and semi-arid region. Although there were most research about other DROUGHT INDEXES such as SPI, but there is few studies in oversea countries about use of ETDI index. Thus in this study tried to determine DROUGHT by ETDI and SPI INDEXES in Neyshabur plain by used of climate change models. Materials and Methods: This research was conducted to determine DROUGHT condition in Neyshabur plain located at longitude between 58˚ 13’-59˚ 30’ N and latitude between 35˚ 40’-36˚ 39’ E, Iran. Evapotranspiration Deficit Index (ETDI) was developed based on weekly evapotranspiration deficit to determine DROUGHT condition in this region. In order to comparison of the ETDI results to other DROUGHT indices, we used Standardized Precipitation Index (SPI) as one the most common DROUGHT index. The data were collected from Neyshabur meteorological station for irrigated farms (wheat in Soleymani and Faroub farms, barley and corn) and rain-fed farms (rain-fed wheat) during 1992-2011. In order to estimate weather data for each index in the irrigated farms during two future periods (2020-2039 and 2080-2099), HADCM3, ECHOAM and CGCM3 T47 models were used based on A2, B1 and A1B scenarios and the climate model that has been used in rain-fed farm is the HADCM3 based on A2 and B1 scenarios. Root mean square error (RMSE), mean absolute error (MAE) and coefficient of determination (R2) were used to comparison of the ETDI and SPI results. Results: Results showed that average ETDI were in initial wet condition for Faroub farm during base period (1992-2011) while it will be in DROUGHT condition during future periods (2020-2039 and 2080-2099). ETDI index was in normal condition for Soleymani farm during base period. Average ETDI INDEXES for these farms were in normal and initial dry condition during 2020-2039 and 2080-2099 periods, respectively. For barley and corn, ETDI INDEXES were in normal and initial dry condition during base period, respectively. This index was in normal statute for both of them during future periods. The ETDI value for rain-fed wheat was less compared to irrigated wheat during base period, although, this index will be increased during future periods. In most of scenarios, ETDI INDEXES showed negative values. It means that high DROUGHT condition will be happened during future periods due to deficit evapotranspiration. Results according to SPI index revealed that this region was in moderately DROUGHT condition and this situation will not change. Conclusion: High differences were obtained between ETDI and SPI results. Since agricultural DROUGHT depends on evapotranspiration deficits, ETDI is better index compared to SPI. The value of RMSE revealed poor adaptation between two INDEXES during future periods. In addition, ETDI were not correlated with SPI for all the scenarios in all scenarios. These differences are reasonable because SPI index only uses precipitation data and ETDI uses evapotranspiration. According to the results, it seems that SPI cannot be suggested as a good index in agricultural studies.

For identifying DROUGHT tolerance genotypes 29 wheat genotypes as cultivar factor and irrigation and non irrigation treatments as an irrigation factor in a split block design with 3 blocks were planted at a Research Filed of College of Agriculture, Tehran University, Iran. There was a low and non significant correlation (R=0.35) between yield at non irrigating (ys) and yield at irrigating (yp) condition. The low correlation implies the independence of yield at two conditions. For identifying tolerant genotypes the INDEXES of STI, TOL, SSI, MP, HARM, TI and GMP were used. The first two components explained 97% of variation. Based on the coefficients of components the first and second components were considering tolerance and sensitivity respectively. Using the biplot analysis genotypes Roushan, Inia, Kavir, Alvand, Ws-82-6, Ghods, Ws-82-9 and back cross of Roushan were identified as tolerant and Omid, Ghafghaz, Marvdasht, Navid and Tajan were detected as sensitive to DROUGHT.

Dust phenomenon is one the problem that is developed due to human interference and unreasonable utilities from natural resources and their destruction. In this review, the dust phenomenon frequency was done using selected synoptic stations statistical in Alborz and Qazvin provinces during 2000 to 2014 that annual frequency was evaluated by extraction of dust codes from meteorological data statistically. In order to study of velocity and direction of region winds, wind rose and storm rose of Karaj and Qazvin stations were drew and prevalent wind direction was determined that it showed prevalent wind is northwest and southeast at Karaj and Qazvin stations respectively. Study of the effect of DROUGHT on dust phenomenon event was done using SPI, PNI, ZSI indicator for annual scale and was evaluated via SPSS software. The DROUGHT result show that 2013 was the driest year at Karaj station and the SPI, PNI and ZSI values were obtained-1. 64, 58 and-1. 39 respectively. Also 2008 was the driest year at Qazvin station and SPI, PNI and ZSI values were calculated-2. 34, 50 and-1. 99 respectively. With studying of annual dust frequency with regard to 06 and 07 codes detected that totally 169 days was reported as day with dust at Karaj station that 2012 and 2014 had the most event frequency. Furthermore, totally 115 days with dust accrued at Qazvin station that 2011 with 23 days had the most event frequency.