Showing 41 results for Correlation
V. Narjesi, H. Zeinal Khaneghah, A. Zali,
Volume 11, Issue 41 (10-2007)
Abstract
Thirty soybean cultivars from different maturity groups were evaluated in a randomized complete block design with four replications in Research Station of College of Agriculture at Tehran University in Karaj in 2004. The purpose was to determine genetic relationship of some important agronomic traits related to seed yield. Analysis of variance showed that there were significant differences among varieties for the traits under study, indicating the existence of genetic variation among varieties. Number of pods/plant, number of seeds/plant and 100-seed weight, all of which are considered yield components, had the highest genotypic correlation with seed yield. Using stepwise regression analysis, 85.6 % of seed yield variation was attributed to four traits, including harvest index, biological yield, protein precent and number of seeds /plant. Harvest index was more important for predicting seed yield compared to other traits based on standardized ßs. Results of path analysis showed that the harvest index and protein precentage had the highest and lowest direct and positive effect (p=0.536), (p=0.008), respectively. Therefore, harvest index may be considered as a selection criteria to improve seed yield in breeding programs. Results of factor analysis showed five independent factors accounted for 80.2 % of total variations in data. The first principle determined 28.2 % of total variation and was designated as phenologic factor.
M. Yousofi Azar, A.m. Rezai,
Volume 11, Issue 42 (1-2008)
Abstract
This study was conducted at Research Farm of Isfahan University of Technology to evaluate drought tolerance potential of 23 F2:4 wheat lines derived from the cross of Virmarin (susceptible line) and Sardari (tolerant line). A randomized complete block design with three replications was used in each irrigation treatment (i.e. irrigation after 70±3 and 120±3 mm evaporation from class A pan for non-stress and stress conditions, respectively). Drought tolerance and susceptibility indices were calculated for yield, and principal components analysis was performed on the basis of indices. Rosielle and Hambline tolerance index and Fisher and Maurer stress susceptibility index had positive and significant correlation, but their correlations with drought yield and the first two principal components were negative. High value of these components indicates low sensitivity to drought. The first component had high and positive correlations with geometric mean productivity, stress tolerance index and harmonic mean. Lines number 4, 17, 11 and 14 with high yields in drought condition, showed high values for these indices. Line number 2 with high yield in non-stress condition and in spite of high sensitivity to stress, was a superior genotype based on these indices.
M. Sabokdast , F. Khyalparast,
Volume 11, Issue 42 (1-2008)
Abstract
This research was conducted in order to determine the relationship between grain yield and yield components, using 30 common bean varieties in a randomized complete block design with four replications at the Agricultural filed faculty of Agriculture,Tehran university In this study 18 traits were assessed on 10 random plants from each plot. The result showed that there were significant differences among varieties in terms of trait under study, indicating the existence of genetic variation among varieties. Also results showed that the grain yield had a positive and significant genotypic correlation with number of seed/pod, pod weight, number of pod/plant, biological yield, days to flowering and maturity. Stepwise regression analysis showed that the maximum variation in grain yield could be attributed to the number pod/plant, number seed/plant, 100 seed weight and pod length. The results of path analysis showed that the highest direct effect, being positive, was related to number seed/plant and the lowest direct effect, which was related to number pod/plant. Factor analysis resulted in three factors that accounted for 78/7% of total variation. The first factor accounted for 38.39% of total variation and was designated as yield and yield component factor. This factor is comprised of pod weight, biological yield, grain yield and number of pod/plant traits.
M. Ramazani, H.a. Samizadeh Lahiji, H. Ebrahimi Koulabi, A. Kafi Ghasemi,
Volume 12, Issue 45 (10-2008)
Abstract
In order to study agronomic and morphological traits in maize hybrids in Hammedan, two early (108 and 301), three medium (604, 647 and TWC647) and two late maturing (704 and 711) hybrids were evaluated in a randomized complete block design with three replications in Agricultural and Natural Resources Research Station in Hammedan in 2005. 33 morphological and phonological traits were recorded from 10 plants randomly selected from two central rows of each plot. The maximum and minimum grain yield was obtained from SC647 and SC301, respectively. The grain yield had the highest correlation with dehusked ear weight. Factor analysis of data after varimax rotation identified four factors that accounted for 98.03% of total variance. The scatter plot of hybrids based on the two first factors (the seed yield factor and phenological structure factor) showed that SC704 had the maximum forage yield and the best physiological characteristics and SC647 had the maximum grain yield, cob diameter and number of seed in row.
M. Bayat, B. Rabiei, M. Rabiee, A. Moumeni,
Volume 12, Issue 45 (10-2008)
Abstract
To study relationship between grain yield and important agronomic traits of rapeseed in paddy fields as second culture, fourteen varieties of spring rapeseed were grown in a randomized complete block design of experiment with three replications at Rice Research Institute of Iran, Rasht, during 2005-2006. Analysis of variance showed that there were significant differences between varieties for most of traits. Broad sense heritability ranged from 0.29 for pod length to 0.99 for days to maturity. Phenotypic and genotypic coefficients of variation for days to maturity and the number of pods in secondary branches were the lowest and highest, respectively. Moreover, genetic advance with 5% of selection intensity varied from 3.68% (0.25 cm) for pod length in main branch to 31.48% (915.58 Kg.ha-1) for grain yield. Results from genotypic correlation coefficients demonstrated that there were positive significant correlations between grain yield and the number of secondary branches, the number of pod in main and secondary branches, pod length in secondary branches, pod diameter in main and secondary branches, 1000-grain weight and oil percentage, and negative significant correlations between grain yield and days to 90% of flowering and days to maturity. Path analysis on genotypic correlations for grain yield as a dependent variable and the other traits as independent variables showed that the 1000-grain weight and the number of pods in secondary branches had the highest direct effects and days to 90% of flowering had low and negative direct effect on grain yield. Therefore, indirect selection for increasing 1000-grain weight and the number of pods in secondary branches are recommended for improving grain yield in rapeseed as second culture in paddy fields.
N. Parsafar , S. Marofi,
Volume 16, Issue 62 (3-2013)
Abstract
In this research, we estimated soil shallow depths temperatures using regression methods (Linear and Polynomial). The soil temperatures at soil depths (5, 10, 20, 30, 50 and 100 cm) were correlated with meteorological parameters. For this purpose, temperature data of Hamedan station (in the period 1992-2005) were employed. Soil temperature data were measured on a daily basis at 3 PM, 9 PM and 3 AM. MS Excel was used for deriving the regressions between soil temperature and meteorological parameters (air temperature, relative humidity and sunshine hours). The results showed that the highest coefficient of determination (R2) of the linear regression was between soil temperature in 20 cm soil depth and air temperature at 3 AM (R2= 98.15%) and the lowest value in 100 cm soil depth at 3PM (R2= 83.96%). Also, the highest R2 of non-linear regression was observed between soil temperature in 10 cm soil depth and air temperature at 3 AM (R2= 98.45%) and lowest value in 100 cm soil depth at 3PM (R2= 84.11%). The results showed that the highest and lowest values of R2 of linear relations between meteorological parameters (relative humidity and sunshine hours) and soil temperature were observed in 10 cm soil depth (at 3 AM) and in 100 cm soil depth, respectively. Correlations of soil temperature with air temperature were greater than those with the other two parameters. Moreover, R2 values of non- linear relation were higher than linear relation.
H. Karimi, A. Fotovat, A. Lakzian, Gh. H. Haghnia, M. Shirani,
Volume 18, Issue 68 (9-2014)
Abstract
In recent years, due to the increased population, urbanization and changes in human consumption patterns, urban, industrial and agricultural soils have been exposed to various pollutants such as heavy metals. The objective of this research was to identify hotspots of Pb by using global and local Moran Indices in urban and suburban soils of Kashafrood catchment. A total of 261 surface soil samples (0-15 cm deep) were taken using irregular girding network method and their total Pb concentrations were measured. The positive Moran index at confidence level of more than 99 percent showed the spatial clusters between observations. On the basis of local Moran index results, 15 samples were introduced as hotspots (high-high value) located southeast of Mashhad plain. Exclusion of extreme values resulted in the addition of high-high cluster (hotspots) leading to the extension of these areas to the West of the Mashhad city.
These areas are introduced as hotspots due to the urban land use, the direction of prevailing wind, and the area being close to Mashhad airport.
L. Kashi Zenouzi, Sh. Banej Shafiee, A. A. Jafari,
Volume 20, Issue 76 (8-2016)
Abstract
In this study the effect of temperature, evaporation or evapotranspiration, precipitation, hillside direction and altitudinal classes, texture and acidity of soil on organic carbon content in the depths of 15 and 45 cm were evaluated. Paired t-test results showed that there is a significant difference between measured parameters in two soil depths. After preparing required data and processing them, outlier's data were removed. Then, base maps for each of the information layers were prepared by Arc GIS9.3 software and all relatd information fit together by overlapping them. Pearson correlation between environmental factors and soil organic carbon values were calculated and it was found that in the depth of 15 cm, the correlation between soil organic carbon values and two environmental factors including temperature and altitude were significant at the level 0.01. As well the results of statistical analysis by using principal component analysis (PCA) method showed that the factors temperature, evaporation (1%), and silt and clay (5%) have had a significant effect on the amount of soil organic carbon. The first, second, and third axes with eigenvalues of 98/4, 78/3 and 92/1, respectively, explained the values 0.33, 0.25, and 0.13 % of correlation between organic carbon and environmental data.
M. Khoshravesh, M. Valizadeh,
Volume 21, Issue 2 (8-2017)
Abstract
Construction of a dam in the upstream of Tajan basin, as one of the human activities in order to provide drinking water, hydropower, agriculture, flood control or other purposes, can be effective on other sectors such as water resources. The purpose of this study is investigating the impact of Rajaei dam on groundwater resources in Sari-Neka plain during 26 years period (1985-2011) using geostatistical method, parametric and non-parametric tests. The results of statistical tests showed that groundwater table variation during 26 years has experienced insignificant upward trend. Quality factors such as EC, TDS, TH, Cl, SO4, Mg, Na and SAR had significant downward trend at 5% confidence level for Pearson and Kendall test. The Quality changes of groundwater resources in the region had good condition due to construction of dam. The results of spatial analysis for the study area using Kriging interpolation method in the three years for 1985, 1999, 2011 showed that in 1999 (the year of exploitation of the dam) most of the quality factors had reached the highest level from 1985 until the dam operation (1999) and then decreased to 2011. The results of this study showed that, agricultural activities after dam construction, operation of irrigation system and drainage network design of Rajaei dams, have raised the water table in northern part of the region and consequently had a significant impact on the quality of water resources.
. A. A. Sabziparvar1, S. Ebrahimzadeh2, M. Khodamoradpour3,
Volume 21, Issue 4 (2-2018)
Abstract
The most important factor in determining crop water requirement is estimation of evapotranspiration (ET). Majority of the methodsestimate ET apply series of relatively complex formula,which is then used to determine crop evapotranspiration (ETc). The parameters used in aforesaid methods are: Solar radiation, wind speed, humidity, etc. Unfortunately, in Iran and many countries, long-term records of these parameters are not readily available. The purpose of this study is to calculate the Selianinov Hydrothermic Index that merely requires daily temperature and precipitation data in order to determine correlation coefficients (r) versus ET and Crop Water Requirement (CWR) of some agricultural crops of Iran. First, the Selianinov index is calculated from daily precipitation and temperature during the growth season. Further, the results are correlated against both ETc and CWR. The model results indicate inverse (negative) strong exponential and polynomial relations between the dependent and independent variables. Coefficient of determination (R2) for polynomial equations (on average 0.84) in all crops was better than exponential equations (on average 0.72). Correlation between Selianinov index and CWR indicates that coefficient of determination in both equations was close together (0.83 for polynomial equations and 0.82 for exponential equations).
M. Nouri, M. Homaee, M. Bannayan,
Volume 22, Issue 1 (6-2018)
Abstract
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 results revealed that the trends of annual precipitation had been declining in all stations over the past 39 years. The seasonal precipitation trend in winter, spring, autumn and summer was downward in approximately 90, 95, 47 and 37% of the studied stations, respectively. In addition, the descending trend of wintertime precipitation was significant in Sanandaj, Khoy, Urmia, Hamedan, Mashhad, Torbat-e-heydarieh, Nozheh and Qazvin. Also, the temporal trend of SPI-12 was decreasing in all surveyed stations except Shahrekord. Furthermore, SPI-12 showed a significant downward trend only in Sanandaj and Fasa. Moreover, the most severe meteorological drought occurred in the period 1999-2000, in Ramsar, Urmia and Hamedan, and in the period 2008-2009, in Tabriz, Sanandaj, Shiraz, Fasa, Qazvin, Mashhad, Torbat-e-heydarieh, Shahrekord, Gorgan and Kermanshah stations. Overall, the results of this study indicated that the trend of precipitation in most studied sites, particularly in semi-arid parts of the northeast and southwest of Iran, has changed due to the severe and long metrological drought that has occurred in the recent decade (2005-2015).
S. Ghasemi, A. Hosseinpur, Sh. Kiani,
Volume 22, Issue 3 (11-2018)
Abstract
The rate of metal transfer from the solid phase to solution is an important factor governing their concentration in the soil solution and its availability. In this research, the release rate of Zn in contaminated soils from Isfahan was studied using solutions citric acid, oxalic acid and malic acid 0/01 M during the period of 2 - 504 hours and its relationship with soil characteristics was investigated. The results showed that low molecular weight organic acids could release Zn in the contaminated soils. The Zn released by acids was in the order citric acid> oxalic acid> malic acid. Variation range of Zn released a solution of citric acid, oxalic acid and malic acid, which was 38/9 -21173, 25/2 - 26761 and 25/5 – 20650
mg/kg of soil. Zn released in citric acid solution was higher than that of the two acids. Based on the determination coefficient and standard error estimates done by the kinetic equations, the release of Zn of the contaminated soils and three acid solution was described by the first order equation, elovich, parabolic diffusion and power function, with a high coefficient of determination and a low standard error. Correlation results showed that for the Zn release with the index of Zn usability, there was a significant correlation at 5% level. Showed Multivariate regression model showed that Calcium carbonate, pH and EC affected characteristics of Zn desorption.
S. Ghorbani, R. Moddress,
Volume 23, Issue 3 (12-2019)
Abstract
The purpose of this study was to model the relationship between the frequency of dust storms and climatic variables in desert areas of Iran. For this purpose, climatic data of temperature (maximum and minimum), rainfall, wind speed (maximum and minimum), and their relationship with the number of days with dust recorded in 25 meteorological stations (statistical period since their inception until 2014) in summer using Pearson correlation coefficient and linear regression method multivariate was analyzed in SPSS software. Also, due to regional analysis, correlation coefficient between climatic variables and frequency of drought storms in desert areas of Iran, the mapping of these coefficients was prepared by method of Inverse distance weighting (IDW) in Arc GIS software. The results showed that the stations in the south and southwest of the study area have the highest dust incidence in the summer season. So that Zabul station with (3892 days) has the most frequent occurrence of dust storms. In most stations, there was a significant relationship between the frequency of dust storms and the variables of average wind speed and maximum wind speed. The highest correlation coefficient of the mean wind speed was related to the station of the Chabahar Konarak with correlation coefficient of 0.710 and Iranshahr station with a correlation coefficient of 0.65, showed the highest correlation with maximum wind speed. The maximum temperature variable at Qom station with a correlation coefficient of 0.398 shows a significant and positive relationship. Iranshahr station has a correlation coefficient of -0.620 with a mean temperature and Minab station has a correlation coefficient of -0.446 with maximum temperature. The results of temperature correlation with the frequency of dust storms indicate that ground low pressure is effective in creating the phenomena in the warm course of the year. Most stations have inverse correlation with precipitation. The highest correlation coefficients between precipitation and dust events were observed at -0.208 and -0.185 at east of Isfahan and Torbat Heidariyeh stations, respectively. Multivariate regression modelling between dust and climatic variables in summer also shows that the most important parameter in dust events are average wind speed, maximum wind speed and average temperature. Regression models show that, at the best condition, climate variables explain only 70% of the variation of dust frequency.
M. Boustani, F. Mousavi, H. Karami, S. Farzin,
Volume 23, Issue 4 (12-2019)
Abstract
River discharge is among the influential factors on the operation of water resources systems and the design of hydraulic structures, such as dams; so the study of it is of great importance. Several effective factors on this non-linear phenomenon have caused the discharge to be assumed as being accidental. According to the basics the chaos theory, the seemingly random and chaotic systems have regular patterns that are predictable. In this research, by using methods of phase space mapping, correlation dimension, largest Lyapunov exponent and Fourier spectrum power, a period covering 43 years of Zayandehrud River discharge (1971-2013) was evaluated and analyzed based on the chaos theory. According to the results, the non-integer value of the correlation dimension for Eskandari and Ghale Shahrokh stations (3.34 and 3.6) showed that there was a chaotic behavior in the upstream of Zayandehrud-Dam Reservoir. On the other hand, in the Tanzimi-Dam station, the correlation dimension curve was ascending with respect to the embedding dimension, showing that the studied time-series in the downstream of Zayandehrud-Dam Reservoir was random. The slope of the Lyapunov exponent curve for Eskandari, Ghale Shahrokh and Tanzimi-Dam stations was 0.0104, 0.017 and 0.0192, respectively, and the prediction horizon in the chaotic stations was 96 and 59 days. The non-periodical feature of time series was studied by using the Fourier spectrum power. The wide bandwidth, besides other indices, showed that river discharge in the upstream stations of Zayandehrud Reservoir was chaotic.
L. Cheraghpoor, M. Pajoohesh, A. Davoodyan, A. Bozorgmehr,
Volume 23, Issue 4 (12-2019)
Abstract
River discharge is among the influential factors on the operation of water resources systems and the design of hydraulic structures, such as dams; so the study of it is of great importance. Several effective factors on this non-linear phenomenon have caused the discharge to be assumed as being accidental. According to the basics the chaos theory, the seemingly random and chaotic systems have regular patterns that are predictable. In this research, by using methods of phase space mapping, correlation dimension, largest Liapunov exponent and Fourier spectrum power, a period covering 43 years of Zayandehrud River discharge (1971-2013) was evaluated and analyzed based on the chaos theory. According to the results, the non-integer value of the correlation dimension for Eskandari and Ghale Shahrokh stations (3.34 and 3.6) showed that there was a chaotic behavior in the upstream of Zayandehrud-Dam Reservoir. On the other hand, in the Tanzimi-Dam station, the correlation dimension curve was ascending with respect to the embedding dimension, showing that the studied time-series in the downstream of Zayandehrud-Dam Reservoir was random. The slope of the Lyapunov exponent curve for Eskandari, Ghale Shahrokh and Tanzimi-Dam stations was 0.0104, 0.017 and 0.0192, respectively, and the prediction horizon in the chaotic stations was 96 and 59 days. The non-periodical feature of time series was studied by using the Fourier spectrum power. The wide bandwidth, besides other indices, showed that river discharge in the upstream stations of Zayandehrud Reservoir was chaotic.
M. Noshadi, A. Ahadi,
Volume 23, Issue 4 (12-2019)
Abstract
Groundwater supplies a major portion of two basic human needs: drinking and agricultural water. Forecasting, monitoring, evaluating the performance and planning of this vital resource require modelling. The lag time of the groundwater level fluctuations against the rainfall is one of the essential data of the models. The purpose of the present study was to evaluate the piezometers behaviour by using the Pearson cross-correlation method between SPI and GRI indices in the Shiraz alluvial plain in order to determine the mentioned lag time. The results showed a similar behaviour for 86.2% of the piezometers. In 79.3% of the piezometers, groundwater level was declined one month after the rainfall event. The best correlation coefficient between the aforementioned indices was observed along the southwestern to the northeastern axis of the plain. The northern alluvial plain has a better correlation, as compared to the southern section because of the northern-southern slope of the plain. The central area of the plain had the highest correlation coefficient. The maximum correlation coefficients occurred at a time scale of 48 months. Also, since 2004, due to the decline in the atmospheric precipitation in the Shiraz plain, the SPI index has surpassed the drought level, although the trend has not been significant. However, the GRI does not follow this trend, showing a significant hydrological drought. The reason can be the disproportionate water extraction to recharge ratio in the alluvial aquifer of the plain.
M. H. Nasserzadeh, B. Alijani, M. Paydari,
Volume 24, Issue 2 (7-2020)
Abstract
Given the climatic changes and threats to food security in recent years, they have have become a major issue in agricultural climatology. The present study aimed to investigate the status of agricultural climate suitable for the cultivation of rice in the light of the influential climatic conditions in the past. Given the effect of temperature and the amount of precipitations on rice growth and the sensitivity of rice to these two variables, the study examined the predicted future temperature and rainfall and their effects on rice. Data related to the temperature and rainfalls were obtained from the Meteorological Organization. Additionally, the temperature and agricultural potential of the region were considered. By preparing the agricultural calendar for the cultivation of rice, the correlation between temperature, precipitation and rice productivity was calculated using the Spearman Correlation coefficient. By using the SDSM model, future data and temperature and precipitation return period were determined in the SMADA software. The results demonstrated that minimum spring temperature tended to be late spring. The minimum temperature had the highest impact in April, the maximum temperature had the highest impact in July and the maximum rainfall had the highest effect in both June and July. Based on the results of the prediction models, the studied region would experience an increase in temperature and rainfall by providing favorable conditions for the cultivation of rice. However, delays in the cold season and shortness of the growth period increased the risks associated with the cultivation of rice in this period.
P. Mohit Esfahani, S. Soltani, R. Modarres, S. Pourmanafi,
Volume 24, Issue 3 (11-2020)
Abstract
Drought, as one of the most complicated natural events, causes many direct and indirect damages each year. Hence, single variable identification and monitoring of drought may not be appropriate enough for decision-making and management. In this study, in order to monitor the meteorological-agricultural drought in Chaharmahal and Bakhtiari province, Multivariate Standardized Drought Index (MSDI) was calculated using precipitation and soil moisture variables. In addition, to evaluate the performance of MSDI in drought identification and monitoring, Standardized Precipitation Index (SPI) and Standardized Soil Moisture Index (SSI) were used for meteorological and agricultural drought monitoring, respectively. MSDI was calculated based on the soil moisture and precipitation joint probabilities. We used the Gringorten probability as an empirical method and Archimedean copulas as the parametric method to calculate the joint probability between soil moisture and precipitation time series. The results indicated that MSDI was twice more capable of detecting drought as SSI and SPI. Furthermore, the MSDI-based drought monitoring results showed Charmahal and Bakhtiari province had experienced severe meteorological-agricultural drought in 2000, 2008, 2011 and 2014.
. M. Karimaei Tabarestani,
Volume 25, Issue 1 (5-2021)
Abstract
One of the most common and practical methods in controlling the local scour around bridge pier is to place a protective riprap layer. Due to various uncertainties in the design of this countermeasure method, in the present study, the reliability analysis method was applied for the design of a riprap size around a real bridge pier as a case study. Therefore, four different methods including First Order Second Moment, First Order Reliability Method, Spread Sheet and Monte Carlo Simulation Technique were used to quantify the uncertainties and design of riprap size. The results showed that the probability of riprap size failure, which was calculated by the empirical equation and the use of the mean value of effective parameters in the case study, was very high, nearly 34%. In the following, the relationship between safety factor and the reliability index at the site of this case study was determined. Finally, in order to achieve more realistic results, the hydraulic correlation coefficient between depth and flow velocity parameters and its effect on the probability of the riprap failure were studied. It was shown that the correlation coefficient between these two hydraulic parameters was very high and more than 90%, and its maximum effect on the probability of the riprap failure was less than 10%.
F. Hooshmandzade, M.r. Yazdani, F. Mousavi,
Volume 26, Issue 1 (5-2022)
Abstract
Investigating the behavior of water surface evaporation is one of the basic issues in design, operation, and studies related to water engineering. Therefore, the application of new methods such as chaos theory in hydrology and water resources has recently been considered due to its innovation and capabilities. Since the fluctuations of evaporation from free water surfaces are dynamic and non-linear in nature, the aim of this study was to investigate the possibility of chaotic behavior in evaporation from the free water surface in the Semnan synoptic station on daily and monthly time scales in 1995-2018 using the concepts of chaos theory. The daily, monthly, and annual evaporation rates of this synoptic station were calculated to be 68.8, 200, and 2600 mm, respectively. To reconstruct the state space, two parameters of delay time and embedding dimension are needed. The mean of mutual information and false nearest neighborhood has been used to estimate these two parameters. The first step to study a process with chaos theory is to investigate the chaotic nature of the correlation dimension method as one of the most common methods. First, the embedded dimension was calculated by the nearest neighborhood method equal to 3. To calculate the delay time, cross-evaporation diagrams were drawn at Semnan station at different time scales. According to this method, the first local minimum in the diagram is considered the latency, which was obtained for evaporation at daily and monthly scales of 30 and 3, respectively. Unlike complicated and conventional computational methods, these results are obtained by observation and in the least amount of time, as follows: monthly data are more chaotic than daily data. The enclosed dimension and the slope of the correlation dimension diagram were obtained at 8.8 and 9.8, respectively, after calculating the latency and reconstruction of the state space.
