Showing 58 results for زمان
S. Dodangeh, J. Abedi Koupai, S. A. Gohari,
Volume 16, Issue 59 (4-2012)
Abstract
Due to the important role of climatic parameters such as radiation, temperature, precipitation and evaporation rate in water resources management, this study employed time series modeling to forecast climatic parameters. After normality test of the parameters, nonparametric Mann-Kendall test was used in order to do trend analysis of data at P-value<0.05. Relative humidity and evaporation (with significant trend, -0.348 and -0.42 cm, respectively), as well as air temperature, wind speed, and sunshine were selected for time series modeling. Considering the Autocorrelation function (ACF) and Partial Autocorrelation function (PACF) and trend of data, appropriate models were fitted. The significance of the parameters of the selected models was examined by SE and t statistics, and both stationarity and invertibility conditions of Autoregressive (AR) and Moving average (MA) were also tested. Then, model calibration was carried out using Kolmogorov-Smirnov, Anderson- Darling and Rayan-Joiner. The selected ARIMA models are ARIMA(0,0,11)*(0,0,1), ARIMA(2,0,4)*(1,1,0), ARIMA(4,0,0)*(0,1,1), ARIMA (1,0,1)*(0,1,1), ARIMA (1,0,0)*(0,1,1) for relative humidity, evaporation, air temperature, wind speed and sunshine, respectively. The fitted models were then used to forecast the parameters. Finally, trend analysis of forecasted data was done in order to investigate the climate change. This study emphasizes efficiency of time series modeling in water resources studies in order to forecast climatic parameters.
M. Khodagholi, R. Saboohi, Z. Eskandari,
Volume 18, Issue 67 (6-2014)
Abstract
The geographical location of Isfahan province has led the province to be at risk of drought. One of the ways to mitigate drought is evaluation and monitoring of drought based on indices that can determine its intensity and permanence in each region. In this research, for drought and trend analysis standard precipitation index and Mann-Kendall test were used, respectively. Also, monthly precipitation time series of Isfahan province was applied to forecast drought from 1970 to 2009. For this purpose, Box and Jenkins modeling approach (1976) was used which has three main steps, namely model identification, parameter estimation, goodness of fit test or time independency and normal test of residual. The results showed that most of the stations in Isfahan province were faced with severe drought in the year 2000 and this situation was repeated one more time in 2008. Also, the results brought forth multiplicative models in all the stations. ARIMA (1,0,0) (0,1,1) showed the highest correlations between control and forecast data in Isfahan, Meime and Ardestan stations, and the model ARIMA (0,0,1) (0,1,1) displayed the highest correlation between control and forecasted data in Naein, Freydoonshahr, Khansar and Natanz. These models were selected as the best models through which the amount of precipitation was predicted till 2015. The trend of forecast data across Isfahan province showed that in most months the trend is not significant.
H. Shekofteh,
Volume 18, Issue 69 (12-2014)
Abstract
In order to study the effect of depth of drip placement in soil in subsurface drip irrigation, and fertilization time during irrigation events, on tuber yield of potato, an experiment was carried out in Jiroft area in 1389. This experiment was in a completely randomized block design with four replications, with depth placement of drip tape as the main plot, and fertilization time as the sub-plot. Results showed that depth placement of drip tape had a significant effect on tuber yield, plant height, number of stems, stem diameter and dry plant weight at 1% level, number of tubers in plant, and wet plant weight and stolen height at 5% level. Fertilization time had a significant effect on tuber yield, stem diameter, stem number in plant, and plant height at 1% level and on dry plant weight and plant tuber number at 5% level. But, it did not show any significant effect on other attributes. Also, interactional effects of treatments were significant on tuber yield per plant, stem diameter, plant height, and number of tubers at 1% level, and on dry plant weight at 5% level, but the effect on other traits was not significant. According to the statistical results, the highest yield was obtained from the depth of 15 cm and middle time of fertilization.
H. Beigi. Harchegani, G Banitalebi,
Volume 18, Issue 70 (3-2015)
Abstract
Texture fractal dimension is a physical index to describe soil particle size distribution having a variety of applications. Fractal dimension may be calculated from three relations of mass-time, mass-diameter and modified mass-diameter (Kravchenko-Zhang) with two linear and nonlinear options for fittings. The aim of the present study was to compare methods and select an appropriate one and fitting option for determining the fractal dimension using hydrometer data. Sixty soil samples were collected from four fields of Taqanak, near Shahrekord. After removal of organic matter and other initial treatments, hydrometer readings were obtained at 0.67, 1, 2, 5, 15, 30, 60, 120, 180, 1440 and 2880 minutes and were converted to mass-time or mass-diameter data. Nonlinear fitting of the Kravchenko-Zhang mass-diameter relation was selected as the most appropriate method of calculating the fractal dimension of solid particles, due to its highest coefficient of determination and smallest mean square error and lowest Akaike Information Criteria. Error analysis also confirmed this conclusion. There was a significant, though not very strong, relationship between the fractal dimension obtained by linear and nonlinear fitting of mass- diameter and Kravchenko-Zhang mass-diameter methods. These relationships can be used to correct the fractal dimension determined by other methods and fitting options.
S. Norouzi, H. Khademi,
Volume 19, Issue 72 (8-2015)
Abstract
Spatial and temporal distribution of dust deposition rate (DDR) in Isfahan city and the influencing climatic parameters were studied. Dust samples were collected using glass trays placed on the roof of one-story buildings from 20 sites in Isfahan city for 12 months. Climatic data were obtained from Meteorological Organization and analyzed. The highest and the lowest amount of DDR in agreement with the direction of prevailing wind were observed for dry months with eastern and northeastern wind directions and wet periods with western and southwestern wind directions, respectively. This can indicate dust emission from the desert located in eastern part of Isfahan city. Statistically significant inverse correlation between DDR and precipitation and relative humidity, and significant and positive correlation of DDR with Min and Max temperatures in all the studied months and also with Max and average wind speed for dry sampling months may well justify the temporal distribution of DDR in the city. In dry months, finer particles from eastern desert can be transported a longer distance and deposited in the western part of the city, far from the source area. In wet seasons, however, soil aggregates become coarser as a result of particle adhesion. This, in turn, results in the deposition of dust near the source area as the transporting power of dust reduces.
M. Kermanpour, M. R. Mosaddeghi, M. Afyuni , M. A. Hajabassi,
Volume 19, Issue 73 (11-2015)
Abstract
Petroleum pollution is an important environmental issue in most of the countries especially those have an oil industry. This study was conducted to investigate the effect of petroleum pollution on soil water repellency and its relation to soil structural stability in Bakhtiardasht area, Isfahan. Polluted and adjacent non-polluted locations were selected to be representative in the green space around the Isfahan Oil Refinery. Soil water repellency was assessed using water drop penetration time (WDPT) in the polluted locations. Soil sample with least aggregates disturbance were collected and selected soil physical and chemical properties were measured. Soil structural stability was evaluated using the wet-sieving method and mechanically dispersible clay (MDC) structural stability indices of mean weight diameter (MWD) and geometric weight diameter (GMD) of aggregates and MDC were then calculated. Results showed that the positive effect of petroleum pollution on the MWD and GMD become significant. Negative impact of petroleum pollution on MDC was also significant. Increment of total petroleum hydrocarbons (TPHs) increased the soil water repellency. A positive correlation was observed between soil water repellency and GMD. However, TPHs concentrations greater than 6.4% decreased the MWD and GMD presumably due to anionic repulsion between clay particles and hydrocarbon functional groups. Although greater water repellency increased soil structural stability in the polluted locations when compared to control locations, however, diminished water retention of polluted soil has created an unfavorable condition for the green space in the area.
S. S. Okhravi, S. S. Eslamian, N. Fathianpour, M. Heidarpour,
Volume 19, Issue 74 (1-2016)
Abstract
In addition to kinematic description of biological reaction, flow pattern plays an important role in designing constructed wetlands. This study investigates the effects of flow distribution on constructed sub-surface horizontal flow wetland with a length of 26 m, width of 4 m and 1% bed slope in order to understand internal hydraulic functioning patterns. Inlet configuration is selected as a variable parameter. Three different cases of inlet and outlet configurations were 1) midpoint, 2) corner, and 3) uniform. Outlet has been fixed in all configurations. Uranine tracer was used to determine the influences of flow distribution by drawing hydraulic retention time curve in different cases. Results showed that mean residence times for each configuration were equal to 4.53, 3.24 and 4.65 days, respectively. Retention time distribution curve provided conditions, not only for showing dispersion patterns throughout system but also for interpreting hydraulic parameters like hydraulic efficiency and effective volume. According to the retention time curve, effective volume was 87.5% in configurations 1 and 3, and 62.1% in configuration 2 following numerous short-circuiting ratios. Finally, the best configuration of inlet-outlet layout to improve the performance of effluent treatment and use the geometry effectively was found to be the uniform-midpoint based on physical experiments followed by midpoint–midpoint as the second best.
S. H. Sadeghi, A. Allbuali, R. Ghazavi,
Volume 20, Issue 76 (8-2016)
Abstract
Nowadays, the increasing population and water demand in various sectors of agriculture, industry, drinking and sanitation has brought about tremendous pressure on groundwater resources. Changes in groundwater quality and salinity of the water resources are currently major threats to development, especially in the dry and too dry lands. The aim of this study is evaluation of the trend of changes in groundwater quality, both temporally and spatially, in Kashan plain over a period of 12 years (2002-2013) using geostatistical methods and classification methods namely Shouler and Wilcox. Thereby, Export Choice has been used and each parameter has been weighted according to its effect on water quality changes. Then, the weighted average of water quality parameters was used for zoning the drinking and agriculture water. The results showed that among the geostatistical methods, circular Kriging based on the correlation coefficient has more acceptable performance. Moreover, the results of spatial and temporal changes in water quality based on Shouler and Wilcox indicate a decrease of drink and agriculture water quality in the study area. Besides, 1.75 km2 of high quality drinkable water was annually decreased between 2002 and 2013 and replaced with moderate or poor quality water. Also, the same but more remarkable decline happened in agriculture water so that 11.06 km2 of high quality agriculture water annually diminished from 2002 to 2009 and plunged zero by 2009.
A. Taheri Tizro, H. Nozari, H. Alikhani,
Volume 20, Issue 76 (8-2016)
Abstract
To procure the status of groundwater level fluctuations in arid and semi-arid areas, it is necessary to obtain accurate forecast of fluctuations data. Time series as a linear model have been utilized to generate synthetic data and predict future groundwater level. Minitab17 software and monthly depth of groundwater level data of 20 years (1991-2011) for 25 piezometric wells of plain were used. Time series models of each well were selected and 5 years temporal forecasting was accomplished. The predicted depth of groundwater level data was converted to Groundwater level data using ARCGIS10 and GS+5.1.1 software. Ordinary kriging with a spherical variogram was selected for interpolation of groundwater level. Five years spatial forecasting was done and spatial forecasting and groundwater level drop forecasting maps were prepared. Forecasting results of groundwater level show that over the next 5 years, the area covered by two intervals of groundwater level, 1100-1140 m and 1140-1180 m, will increase and the area covered by three ranges of 1180 -1220 m, 1220-1260 m, and 1260-1300 m, will decline. Also, according to the 5-year groundwater level drop forecasting map of the plain, the highest level of groundwater level drop, more than 16 meters for Qasemabad bozorg areas, located in North East and central of the plain, and the lowest level of the groundwater level drop, about 0.5 m for Mohammad Abad Afkham Aldoleh Lands, located in outlet area of the plain, have been predicted.
Sh. Ghorbani Dashtaki, N. Karimian, F. Raeisi,
Volume 21, Issue 1 (6-2017)
Abstract
The use of organic matter such as urban sewage sludge may help sustainable soil fertility via improving the physical, chemical and biological soil characteristics. The main purpose of this study was to determine the effect of urban sewage sludge on chemical properties, soil basal respiration and microbial biomass carbon in a calcareous soil with silty clay loam texture. Therefore, three levels of water repellency (zero, weak and strong) were artificially created in a silty clay loam soil by adding urban sewage sludge (S0=0:100; S50=50:50 and S80=80:20 sludge weight: soil ratio). Water repellency was determined by water drop penetration time (WDPT) method. Also some chemical properties such as soil acidity (pH) and Electrical Conductivity (EC), Soil Organic Carbon (OC), soluble sodium (Na+) and soluble potassium (K+) were measured. The samples were incubated at 23-25 ºC for 30 days and their moisture was maintained at 70-80 % under field capacity and soil basal respiration and microbial biomass carbon of incubation period were evaluated. The results showed that the effect of urban sewage sludge on chemical properties was significant (P ≤0.0001). The application of urban sewage sludge led to significant increase in basal respiration (16 and 27 times) and microbial biomass carbon (15.2 and 26.5 times) in the water repellency soils (S50 and S80) compared to control soil. The observed positive effect of sewage sludge might be due to a high content of organic carbon and nutrients in urban sewage sludge and decrease in the labile organic matter and nutrients during incubation period.
M. Sadeghian, H. Karami, S. F. Mousavi,
Volume 21, Issue 4 (2-2018)
Abstract
Nowadays, greater recognition of drought and introducing its monitoring systems, particularly for the short-term periods, and adding predictability to these systems, could lead to presentation of more effective strategies for the management of water resources allocation. In this research, it is tried to present appropriate models to predict drought in city of Semnan, Iran, using time series, adaptive neuro-fuzzy inference system (ANFIS) and artificial neural networks (MLP and RBF). For these modeling processes, average monthly meteorological parameters of rainfall, temperature, minimum temperature, maximum temperature, relative humidity, minimum relative humidity, maximum relative humidity and SPI drought index were used during the period 1966 to 2013. The results showed that among the many developed models, the ANFIS model, with input data of average rainfall, maximum temperature, SPI and its last-month value, 10 rules and Gaussian membership function, showed appropriate performance at each stage of training and testing. The values of RMSE, MAE and R at training stage were 0.777, 0.593 and 0.4, respectively, and at testing stage were 0.837, 0.644 and 0.362, respectively. Then, the input parameters of this model were predicted for the next 12 months using ARIMA model, and SPI values were predicted for the next 12 months. The ANN and time series methods with low difference in error values were ranked next, respectively. The input parameters SPI and temperature had better performance and rainfall parameter had weaker performance.
Z. Bigdeli, A. Golchin, T. Mansouri,
Volume 21, Issue 4 (2-2018)
Abstract
To assess the effects of different levels of soil lead on mineralization of organic carbon and nitrogen, a factorial pot experiment was conducted using litter bag method. The factors examined were different levels of soil lead (0, 25, 50, 100, and 200 mg kg-1soil) and incubation periods (1, 2, 3 and 4 months) in three replications. At the end of incubation periods, the litter bags were pulled out of the pots and the weights of plant residues remained in bags were measured. The plant residues were also analyzed for organic carbon and nitrogen. Organic carbon and nitrogen losses were calculated by subtracting the remaining amounts of organic carbon and nitrogen in one incubation time interval from those of former one later incubation time interval. The results showed that the losses of organic carbon from wheat residues and carbon decomposition rate constant decreased as the levels of soil lead increased over than 25 and 50 mg/kg of soil respectively. The losses of organic nitrogen was more affected by lead pollution and decreased as the levels of soil lead increased, but nitrogen decomposition rate constant decreased as the levels of soil lead increased over than 25 mg/kg. The losses of organic carbon and nitrogen in 200 mg Pb/ kg of soil were 3.2 and 11.7 % lower than control treatment. The results of this research indicate that contamination of soil by lead increases residence time of organic carbon and nitrogen in soils and slows down the cycling of these elements.
H. Faghih, J. Behmanesh, K. Khalili,
Volume 22, Issue 1 (6-2018)
Abstract
Precipitation is one of the most important components of water balance in any region and the development of efficient models for estimating its spatiotemporal distribution is of considerable importance. The goal of the present research was to investigate the efficiency of the first order multiple-site auto regressive model in the estimation of spatiotemporal precipitation in Kurdistan, Iran. For this purpose, synoptic stations which had long time data were selected. To determine the model parameters, data covering 21 years r (1992-2012) were employed. These parameters were obtained by computing the lag zero and lag one correlation between the annual precipitation time series of stations. In this method, the region precipitation in a year (t) was estimated based on its precipitation in the previous year (t-1). To evaluate the model, annual precipitation in the studied area was estimated using the developed model for the years 2013 and 2014; then, the obtained data were compared with the observed data. The results showed that the used model had a suitable accuracy in estimating the annual precipitation in the studied area. The percentages of the model in estimating the region's annual precipitation for the years 2013 and 2014 was obtained to be 7.9% and 17.3%, respectively. Also, the correlation coefficient between the estimated and observed data was significant at the significance level of one percent (R=0.978). Furthermore, the model performance was suitable in terms of data generation; so the statistical properties of the generated and historical data were similar and their difference was not significant. Therefore, due to the suitable efficiency of the model in estimating and generating the annual precipitation, its application could be recommended to help the better management of water resources in the studied region.
F. Moosiri, N. Ganji Khorramdel, M. Moghaddasi,
Volume 22, Issue 1 (6-2018)
Abstract
To continue or develop the exploitation of underground water for different different uses and purposes, as well as building any water structure, set of quantitative features of aquifers can be detected. To achieve this goal, quantitative monitoring of groundwater level is only possible. Accordingly, this study compared the impact of both the concept of marginal entropy and ordinary kriging for groundwater level monitoring network design in the case Gotvand-Aghili Plain, Khuzestan province. It is important to note that a key aspect in groundwater level monitoring of the quantity measured was the variability or uncertainty in it. This created a considerable confidence to monitor and ultimately achieve favorable conditions in the future. In this study, the variability of the groundwater level was considered to evaluate the combined effects of marginal entropy and ordinary kriging. In order to determine the suitable areas for further monitoring or thinning as well as the compatibility of these two methods, the monitor network design was designed. The map classified according to the marginal entropy method, in a range between 0.07 to 5.26 of the marginal entropy change, areas with the higher rates of 2.13 in terms of density; this indicated the need for more observation wells. Ordinary Kriging method also changed the range of values; they also represented areas that needed monitoring more than 13.16. Comparison of the results obtained by the two methods showed that the marginal entropy of the kriging method with less uncertainty and by using it, there was less the need to be monitored and classified. Comparison of the two methods by the zoning map showed that fewer errors were taken to the marginal entropy method and it could be recommended for the groundwater level monitoring network design. The network was also based on the Cross validation estimation error evaluated. These tests and additional analysis were employed in this study to determine the suitable areas for the higher density of wells and the need for thinning areas. The results further confirmed the proper performance of the methods employed, as well as the superiority of the marginal entropy in the design of a small groundwater monitoring network.
A. Shahbaee Kotenaee, M. Foroumadi, O. Ahmadi,
Volume 22, Issue 3 (11-2018)
Abstract
One of the major issues in the contemporary world is climate change. The behavior and characteristics of parameters affecting climate change can cause them to be seen and hidden. As one of the effective ways to detect overt and covert behaviors for periodic climatic data series, Spectral analysis can be used. It is the analysis of each of the wavelengths series, making this behavior clear. Accordingly, the present study was an attempt to use the method of spectral analysis, data cycles in the minimum temperature, maximum temperature and precipitation in Ramsar station (located in the western regions of Mazandaran province) an nd Babolsar (located in the central parts of this province) in a period from1961 to 2014. For this purpose, temperature and precipitation data were obtained from these stations; MATLAB software environment and the environment for the software were logged for each of the variable in the stations. The results revealed that the minimum temperature at both stations had significant cycles, with the return period being 2 to 5 years; Remote Link could be fit into the cycle parameters such as NAO, AO and ENSO. Analysis of the period gram showed cycles 8 and 5/13-year-old and 5-year-old period in Ramsar and Babolsar. During the rainy cycles, the difference between the two stations and the difference in the geographical position affected systems, and rain accounted for the difference in speed dual-zone climate indicator for Remote Link.
S. Shiukhy Soqanloo, S. Golshan, M. Khoshravesh,
Volume 22, Issue 4 (3-2019)
Abstract
The effects of climate change can be released from the surface to the soil depth, thereby affecting soil thermal regime. Thermal energy in the soil plays a very important role in causing climate changes. In this study, for the assessment and detection of the climate changes, soil depths temperature, the measured data related to the daily air temperature at a height of 2 meters (screen) during the years (1951-2014), and the soil depths daily temperature (5-10-20-30-50 to 100 cm), for 3, 9 and 15 hours, were obtained during a period (1992-2014) in Shahrud station. The climate change detection was employed to compare the treatment mean. As well, for detection of trends related to the annual, seasonal and monthly time series and their relation to the soil depths temperature, parametric methods (regression analysis and Pearson) and nonparametric (Mann-Kendall, Spearman) were applied. The results showed that the soil temperature was increased in all months except January, February and March. Also, in the seasonal time series, the soil depths temperature was increased in all seasons except winter. In fact, based on the results, the soil temperature in spring, summer and autumn was increased. Detection trends of the annual soil depths temperature showed that, except for the Pearson correlation coefficient method, soil temperature was increased at all soil depths.
M. Habibian, S. Jafari, M. Sheklabadi,
Volume 23, Issue 1 (6-2019)
Abstract
Sugarcane is cultivated in the wide area in Khuzestan province. In these areas, irrigated sugarcane cultivation consumes more than 30,000 cubic meters per hectare annually. This research was carried out to determine the effect of sugarcane cultivation on the soil development process and forms of iron oxides. Different sugarcane fields with different utilization times were selected and soil physico-chemical properties and different Fe forms were measured. The results showed that with enhancing the utilization time, the total amount of total iron oxides (Fed) and crystalline iron oxides (Fed-Feo) was increased. The average value of the Fed from 6958 mg/kg in the fields with a medium utilization history was decreased to 4560 mg/kg in fields with a short utilization history. Similarly, the average amount of crystalline iron oxide from 5888.3 mg/kg in the fields with a long utilization history was decreased to 5003.9 mg/kg in the fields with a short utilization hostory. This increase reflected the effect of sugarcane cultivation on the soil development process in the cultivated fields. The amount of non-crystalline iron oxides (Feo) was decreased from 443.9 mg/kg from the soil surface to 273.8 mg/kg to the subsurface. This increase was related to the more organic matter and the microbial activity in the surface soil. The amount of active iron (Feo/Fed) was dropped in all fields after the cultivation. Also, this ratio was dropped from 0.055 in the fields with a long cultivation history to 0.064 in the fields with a short utilized field. The results, therefore, showed that the increase of crystalline iron oxides was due to sugarcane and its heavy irrigation.
O. Mohamadi, M. Heidarpour, S. Jamali,
Volume 23, Issue 3 (12-2019)
Abstract
Shortage of water resources and renewable per capita in last 30 years is put Iran on crisis threshold. Wastewater reuse is one of the battle solutions for water shortage and prevents wastewater depletion and environmental pollution. Thus, a pilot scale experiment was carried out to evaluate an integrated anaerobic/aerobic treatment for removal of BOD5 and COD, also to reduction of hydraulic retention time by considering optimum removal efficiency. The pilot was an anaerobic/aerobic bioreactor type under continuous-feeding regime based on a central composite design. The pilot was studied in different retention time and aeration was carried out between 5-15 hours. According to different retention times for COD removal efficiency, 24 hours was selected as optimum hydraulic retention time, that it is comparable to those obtained for 48 hours and over in plant roughly and could remove COD and BOD in acceptable ranges, results showed that average removal efficiency for BOD5 were 63.86 and 83.99 percent in aerobic and anaerobic phases, respectively. The average removal efficiency for COD was 76.5 and 74.35 percent for anaerobic and aerobic sections, respectively. The average removal efficiency for BOD5 and COD in this integrated aerobic-anaerobic pilot 95.24 and 94.8 percent, respectively.
Sh. Mohammadi, E. Karimian,
Volume 23, Issue 4 (12-2019)
Abstract
Nowadays, water supply for the sectors of household consumption, agriculture, green spaces and industry is currently one of the most important challenges for governments in many parts of the world, especially in arid and semi-arid climate regions such as Iran. The aim of this study was to simulate the amount of run-off from the daily precipitation for Sarpol-e Zahab city, for the purpose of estimating the required amount of water for the irrigation of the green spaces of the city. In this study. After providing information and using the Digital Elevation Model (DEM) map of city, all individual sub-basins of the basin were produced. All data related to creating and overlaying hydrologic, climatologic and physiographic layers were used according to the HEC-HMS hydrologic model. The run-off depth and flood volume of each sub-basin were obtained through the SCS method. Then the required amount of water for the green areas of Sarpol-e Zahab city was calculated. The efficient rainfall was estimated using four methods including SCS, 80 percentage, reliability, and USDA for each month, separately. Finally, the amount of needed water for the green area was obtained using these four mentioned methods. The results indicated that the role of curve number in the infiltration rate was more than other variants. Impermeability of urban basins and changes was created due to the growth and development of the city such as removal of vegetation, soil compaction, creation of the water collection and leading surface waters, decreasing the amount of water penetrating to soil significantly. The amount of surface water for sub-basins was estimated to be 266000 cubic meters. Besides, the results showed the amount of required water for 5 months of the year (from early May to September late) using four methods of SCS, 80percentage, reliability and USDA was equal to 243525, 238062, 267865 and 236458 cubic meters, respectively. The amount of the estimated runoff volume was 266,000 cubic meters. Regarding the area of green spaces in Sarpol-e Zahab city and its daily need of water, this volume of water could supply the required amount of water to irrigate the green area of the city for five months (From May to September).
S. Eslami Jamal Abad1, A. Sharafati, E. Mohammadi Golafshani, F. Farsadania,
Volume 23, Issue 4 (12-2019)
Abstract
Expert aquatic designers face many problems; among these, in hydrology, defective occurrences in time-series can cause errors in the ultimate results of the study. This more often happens in the regions where the number of hydrometric and rain gauge stations is limited. In addition, assessing, developing and maintaining the use of water resources require accessible long-term and high-quality quality hydrological time-series. Thus, this necessitates correcting the statistical flaws and magnifies the importance of how to deal with the problems in the hydrological analyses. Statistical methods are, currently, used to infill data and statistical gaps. In this study, in order to introduce a multivariate method for estimating the missing data on rainfall and runoff, in a hydrologic homogeneous region in the Mazandaran province, self-organizing map methods were examined under two scenarios and some reliable estimates were obtained. In this regard, the correlation coefficients between the observational data and the model output were calculated for the precipitation data up to 0.92 and up to 0.95 for the runoff data. Therefore, to avoid the reduction of uncertainty caused by the inadequate data in water resource management, this method could be used.
