sefatollah rahmani; Mohammad Mazhari; Jafar Tahmasabi
Abstract
Introduction
In most of the countries of the world, both developed and under-developed, applied and developmental research in various economic and social sectors, including agriculture and natural resources is very important. To implement executive projects based on the results of research over the ...
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Introduction
In most of the countries of the world, both developed and under-developed, applied and developmental research in various economic and social sectors, including agriculture and natural resources is very important. To implement executive projects based on the results of research over the past years based on predetermined goals, financial, resources and relatively appropriate facilities in the agriculture and natural resources sector, including the watershed sector, have been considered and spent. Nevertheless, it has always been accompanied by many discussions from supporters and opponents. This article is the result of a study to evaluate the effectiveness of watershed management projects implemented based on the results of research in the Chandab Watershed of Tehran Province. which includes effective, flood distribution, rain catchment surface system, catchments, underground dam, water supply channels, flood expansion channels, and sediment catchment in this area. To investigate this issue, research projects based on solving the problems and issues of the study area, and the results in the form of watershed management plans and projects to control runoff and soil erosion, improve the condition of vegetation, and finally improve the economic and social status of watershed residents in the operational area have been implemented.
Materials and methods
To investigate this issue, research projects based on solving the problems and issues governing the study area, and their results in the form of watershed management plans and projects to control runoff and soil erosion, improve the condition of vegetation, and finally the improvement of the economic and social status of watershed residents in the region has been operationalized and implemented their identification and effectiveness in achieving the set goals of watershed management have been studied and analyzed from an economic and social point of view. This study is a descriptive and descriptive type, and the data required for the research was collected in the field by filling out the questionnaire from the residents and beneficiaries of the studied watershed and reviewing the financial reports for the expenses incurred. Before completing the questionnaire, its reliability and validity were measured using Cronbach's alpha coefficient. The estimated alpha coefficient was 0.87, which indicates integration and coordination in the framework of the questionnaire. Then, the present value of the cost and income during the period was estimated. The benefit-cost method (B/C), rate of return and profit, satisfaction level, and economic efficiency index have been tested and analyzed.
Results and discussion
The results of the research showed that the farmers and villagers living in the studied watershed are fully satisfied with the implementation of the underground dam projects and watershed flood distribution catchments, and the implementation of these projects in the state of the watershed in terms of improving vegetation, control Floods, development of agriculture, animal, husbandry and improvement of income and livelihood of villagers have had significant positive effects. The selected projects implemented are economically and socially effective and have economic and social, justification. Thus, the benefit-cost ratio is estimated at 1.85 units, and the economic efficiency index is at 0.85 units.
Conclusion
The study results show that the watershed projects implemented in the study area are economically and socially effective. From a social, point of view, most of the users living in the studied area are fully satisfied with the implementation of watershed management projects. Considering the economic and social justification of watershed management projects, it is recommended to develop the implementation of watershed management operations in this and other watershed areas. For the local, people to benefit from the achievements of these projects and also to satisfy the local, people from the previous projects, it is suggested that these projects be carried out within the boundaries of the land of the beneficiaries so that the maximum participation of the beneficiaries is realized. To provide the possibility of entrusting the maintenance of watershed operations in watershed areas to the local, people and users with a specific and defined mechanism.
Rahim Kazemi
Abstract
During the last two decades, there has been a lot of research on the base flow issue in the country, but so far, no comprehensive and specific article review of base flow research has been conducted, untill the various aspects of this issue be identified and the cases ignored, be introduced and addressed. ...
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During the last two decades, there has been a lot of research on the base flow issue in the country, but so far, no comprehensive and specific article review of base flow research has been conducted, untill the various aspects of this issue be identified and the cases ignored, be introduced and addressed. In this research, first, by literature review at the global and national level, the progress of studies in different fields of this issue were investigated and then dissertations, articles and reports published in international journals and related conferences have been classified and discussed for the past two decades. The main purpose of this research was to identify issues of research at base flow and to identify lesser and overlooked issues in country research. The articles reviewed in this research were analyzed based on spatial domain, research method, theory, data analysis techniques and topic. Results showed that research orientation in base flow in Iran can be divided into four general categories; 28.21% of studies related to applied orientation; 37.18% to comparison and introduction of proper baseflow separation method; 19.23% to investigation of factors affecting base flow and 15.38% to general use and description of hydrological conditions of the study area. The overall conclusion, indicates limited studies, lack of innovative, and focus on the use of conventional and repetitive methods and also lack of attention to this issue by scientific and research centers of the country.
Reza Bayat; Afsaneh Alinejadian; majid soufi; abbas maleki; Omidali Akbarpour
Abstract
Recognition of influential factors is required for management of gully erosion. The purpose of this study was gully classification and determining the most effective variables on the soil loss in the Fath Abad, Buin Zahra in Qazvin Province. Twenty four gullies were selected, surveyed and recorded by ...
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Recognition of influential factors is required for management of gully erosion. The purpose of this study was gully classification and determining the most effective variables on the soil loss in the Fath Abad, Buin Zahra in Qazvin Province. Twenty four gullies were selected, surveyed and recorded by GPS, and their morphologic characteristics including length, width and depth were measured. Surface soil samples were taken from headcut and were analyzed for texture, EC, pH, organic matter and some anions and cations. Indices related to the form of watershed were extracted from the digital elevation model which derived from UAV image processing. The Ward method was used for cluster analysis of gullies and their properties. Factor analysis, the correlation between factors and multivariate regression were performed to determine important and effective factors on the formation of gullies in SPSS. The results of the research indicated that gullies have vertical headcuts, trapezoidal cross-sections and linear general plans. The average depth of headcuts, depth at 50% of the gully length and the average gully length were 0.4, 0.6 and 25 m, respectively. Soil texture was loam and average soil texture components including sand, silt and clay were 30, 46 and 24%, respectively. The mean EC and pH of the samples was 8 dSm-1 and 8.4 respectively. Linear correlation between the total volume of soil loss and other gully characteristics showed that the average cross section, average gully lower width and upper width, sand content, average gully depth and total length have meaningful correlation coefficients greater than 0.6 at 1% percent level. Also, multivariate regression results showed that the most effective factors on soil loss by gully erosion were saturation percentage, sand content, roundness coefficient, basin length and area respectively, which had more effect on soil loss prediction, which entered into the loss prediction equation.
Somayeh Emami; Javad Parsa
Abstract
Due to the flow regime and consequently the sediment regime are not constantly in the watersheds, the prediction of sediment discharge is a great help in estimating and managing the sediment input to hydraulic structures. Measurement of sediment in the usual way is not justified in nowadays and may also ...
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Due to the flow regime and consequently the sediment regime are not constantly in the watersheds, the prediction of sediment discharge is a great help in estimating and managing the sediment input to hydraulic structures. Measurement of sediment in the usual way is not justified in nowadays and may also lead to human error. Therefore, in this study, three meta-heuristic optimization algorithms, including imperialist competitive algorithm (ICA), grey wolf optimizer algorithm (GWO) and election algorithm (EA), were used to predict the suspended sediment load of the Zarrineh river. In order to calculate the sediment discharge by the models, firstly, the necessary statistics and data were collected from the studied station in the period 1993-2015. After processing the data, 210 corresponding discharge and sediment data were selected. The corresponding discharge-sediment data from the study station were randomly separated into two parts, 70% for training and 30% for testing. In order to evaluate the performance of the algorithms, four statistics consist of R2, RMSE, MAE and the NSE were used. The results showed that GWO algorithm with values of statistical criteria R2=0.96, RMSE=228.86 ton/day, NSE=0.74 and MAE=67.32 ton/day, has a very high accuracy compared to other algorithms used which this would lead to comprehensive planning for the design and construction of hydraulic structures.
Gholamreza Ghahari; Samad Shadfar; Hamid Hosseini Marandi
Abstract
Erosion and sediment resulting from it, is one of the most important factors in watershed management. The estimation of sediment yield and prioritization of watersheds in terms of water erosion is the main objectives of watershed management. One of the ways to estimate soil erosion and sediment yield ...
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Erosion and sediment resulting from it, is one of the most important factors in watershed management. The estimation of sediment yield and prioritization of watersheds in terms of water erosion is the main objectives of watershed management. One of the ways to estimate soil erosion and sediment yield is to use empirical models. The aim of this research is to evaluate the efficiency of the EPM Model in Fars Province. To examine this, five small watersheds were selected in Fars Province. Five basins in which the earth dams and check dams were built were selected. There is no overflow from these dams in rainfall events and the most of them was made near to 10 years. The amount of sediment deposited in upstream of the reservoirs was calculated by means of precision mapping. Deposit bulk density was determined in the field to convert the volume into the weight. In parallel, the sediment yield of the basins was determined by EPM Model. Results showed that the minimum and maximum sediment yield measurements varied from 0.89 to 2.62 tonh-1y-1, but the estimated sediment was between 3.3 to 6 tonh-1y-1. The results of the relative error of estimation of EPM Model in each of the studied basins showed an over estimation in all basins (minimum 121.5 and maximum 447.2 percent). The Relative Root Mean Square Error (RRMSE) of the model was calculated as 2.39, which indicates a too much error of the model. Statistical analysis results comparison of actual sediment yields of watersheds with estimated values by model, using paired t-test, shows that there is a significant difference between these values (t=8.728 and sig.=0.001). According to the presented findings, the results of this model estimation for the investigated areas are not accepted.
Abstract
Physicochemical properties and the forms of erosion of marl formations as well studied in this experiment within Zanjanrud watershed basin. At first, the distribution and erosion landscape maps for different marl formation were prepared and then by overlying different maps the final map of working units ...
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Physicochemical properties and the forms of erosion of marl formations as well studied in this experiment within Zanjanrud watershed basin. At first, the distribution and erosion landscape maps for different marl formation were prepared and then by overlying different maps the final map of working units were produced. Soil samples from selected points within each working unit were collected and after laboratory measurements statistical analyses were applied. The results suggested that surface and sheet erosion were more dominated than other forms of erosion. While gypsum content was concentrated at surface, some elements such as Ca, Mg, and dissolved Na subsided in lower layers. Marl units account for 20% of the total area of the basin, which consists of two types of Marl Pliocene (Plm) (99.75%) and the upper Red marl (Mur) (0.25%). In this basin, there are four superficial erosional facies, surface,rill, badland and gully erosin, with the rill erosion facies having the highest and most expanse of 61%. Toward the deeper layers in marl soils level of salinity, pH and clay percentage increases as the result of leaching of salts and fine material by runoff and transferring them from surface to depth. There is statistical significant difference in the amount of EC, clay, limestone, and gypsum among various forms of erosion, so that the highest and lowest level of EC were found respectively in deep gully and upper layers of surface erosions. Highest content of gypsum was found in badland erosion while the lowest of that was found in surface erosion. Therefore, changes of chemical properties are mostly found in surface and badland erosions. Finally, prevention of these two types of erosion must be prioritized because they can be precursors to other forms of erosion in this type of marl soil.
Seysd Mostafa Tabatabaei; Hossein Khozeymehnezhad; Abolfazl Akbarpour; Peyman Varjavand
Abstract
Deposition of density current the main threats reservoir and its watershed numerous areas of application.In this study Six types of vegetation arrangement similar impact convergent, divergent similar, parallel, z(ed) shape, zigzag and checkered studied the density current control is completed. The experiments ...
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Deposition of density current the main threats reservoir and its watershed numerous areas of application.In this study Six types of vegetation arrangement similar impact convergent, divergent similar, parallel, z(ed) shape, zigzag and checkered studied the density current control is completed. The experiments were performed in a channel length of 10 meters. Made of plastic and the covering vegetation was three meters. Then density current speed in 6 sections 0.5 and 4 meters between the Vegetation was measured after coating. Experiments with 3 Slope bed 0, 1 and 2%, with a salt concentration of 40 and 80 g/l was repeated. The results show if there are vegetation in front of density currents, the speed of the front reduces consequently. Also results showed that vegetation leading to an average of 21-59 per cent density current. After passing density current vegetation Density current rate rises at one point that this speed is not impressive and always density current Substrate without vegetationis also affected.
Narges Ghasemiamin; Nasim Arman; Hossein Zeinivand
Abstract
Land use and its fluctuations is one of the most important factors that affects on the natural cycle in the ecosystem. Land use changes cause change in watershed hydrological cycles, water balance between precipitation, evaporation, infiltration and runoff response. Understanding the relationship between ...
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Land use and its fluctuations is one of the most important factors that affects on the natural cycle in the ecosystem. Land use changes cause change in watershed hydrological cycles, water balance between precipitation, evaporation, infiltration and runoff response. Understanding the relationship between land use changes and its factors and secondary effects on the hydrological regime provides the necessary information for planning of land use and sustainable management of natural resources. At first, land use maps related to years of 2000 and 2014 were prepared, then CLUE-s model was applied to simulate land use map of 2025. For simulating runoff, WetSpa model was employed to simulate daily runoff with land use maps related to years of 2000, 2014 and 2025. According to the results, the Nash-Sutcliffe evaluation criterion was calculated 68.26 % and 66.75 % for the calibration and validation periods, respectively. In addition, model Aggregate Measure (AM) was calculated 64 % and 54.15 % for the calibration and validation periods, respectively. Land use maps comparison showed, the main land use changes in Nojian Watershed was the conversion of forest and rangeland areas to agricultural lands .As a result of these changes the annual runoff volume, peak discharge, mean daily discharge increased to 16.20, 11.35 and 9.15 percent, respectively. Results of statistical analysis using paired t-test showed that land use change has effect on discharges in the study area at the level of 1%.
Ata Amini; Rangin Haydari; Majid Hosseini; Nader Jalali
Abstract
The land use programming is vital since inappropriate land use can endanger soil and water resources in a region and reduce their quality and quantity for future generations. While land development based on its ability are always facing limitations. This research is conducted with a sustainable approach ...
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The land use programming is vital since inappropriate land use can endanger soil and water resources in a region and reduce their quality and quantity for future generations. While land development based on its ability are always facing limitations. This research is conducted with a sustainable approach to manage water resources and land programming in line with make optimal use of limited land, soil and water in the watershed. For this purpose, the required information to prepare a development model based on the land potential, were collected. Using the ArcGIS software, essential maps including map of slope, altitude, driving directions, land form, hydrographic, soil and vegetation, and density, were derived. By combining layers of information, the lands abilities were extracted in term of 107 ecological units. The meteorological data, hydrometer and the sources and consumptions of water resources of the watershed were collected and analyzed. The results showed that 88.2 percent and 11.6 percent are currently the area of agriculture and orchards. While the watershed potential for these practices are as 78.9 and 19.1, respectively. However, lack of attention to the potential water resources of the region, which is mostly as groundwater, caused a drop in groundwater level about 0.85 m per year and consequently the risk of soil and water resources in the region. The results indicate the importance of integrated water resources management and natural potentials in sustainable development in the watershed.
Behrouz Mohseni; Hadi Razzaghian; Abdollah Darzi-Naftchali; Esmaeel Nikzad
Abstract
Runoff as one of the water balance components of a basin, is of great importance in watershed and water resources management. Suitable estimation of runoff is requires to determination of runoff coefficient. In this study, runoff coefficient was estimated for return periods of 25 and 50 years using rational, ...
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Runoff as one of the water balance components of a basin, is of great importance in watershed and water resources management. Suitable estimation of runoff is requires to determination of runoff coefficient. In this study, runoff coefficient was estimated for return periods of 25 and 50 years using rational, SCS and Cypress-Creek methods for basins up to 50 square kilometers. GIS software was used to overlay layers and basin analysis. Chow, s table was used to correspondence different methods. Due to the lack of compliance with Chow, s table and estimating lower runoff coefficients than reality in most of the study area, Rational Method did not provide suitable results. Cypress-Creek method was also effective in some basins due to it similarity with the SCS method. Average equivalent runoff coefficient of C25=0.37 and C50=0.41 demonstrated high accuracy of SCS method compared with two other methods. According to the soil conservation service method, minimum and maximum runoff coefficients of 25- year return period were related to Chalakrud 1 (0.06) and Safarood 4 (0.61) watersheds, respectively. Also, the minimum and maximum runoff coefficients of 50- year return were 0.1 (for Chalakrud 1) and 0.65 (for Safarood 4), respectively. According to the results of three methods, the lowest runoff coefficients were obtained for watersheds with the highest area and the lowest rainfall intensity.
Pari Saeidi; Seyed Hamidreza Sadeghi; Abdulrasul Telvari
Abstract
Sediment graph is an important tool for soil and water resources management of watersheds. It is therefore important to find an appropriate procedure to simulate sediment graph data in different watersheds with inadequate and unreliable suspended sediment data. However, achieving simple procedures based ...
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Sediment graph is an important tool for soil and water resources management of watersheds. It is therefore important to find an appropriate procedure to simulate sediment graph data in different watersheds with inadequate and unreliable suspended sediment data. However, achieving simple procedures based on easily accessible data has been less considered. Hence, the present study was conducted in Galazchai Watershed in West-Azerbaijan Province, Iran, with an area of some 103 km2 to investigate the ability of synthetic sediment graph development by using hydrograph. Towards this attempt, a databank of 18 storm events occurred during autumn 2011 and spring 2014 was developed and corresponding total and direct hydrographs and sediment graphs were prepared. All total and direct sediment graph components were simulated using corresponding hydrograph components with the help of different bivariate regression models and the best performed model was ultimately determined by applying different criteria. The results showed that the simulation of different total sediment graph components was possible using hydrograph components except for base time and ordinates of 50 and 75 percent of peak. Direct sediment graph simulation results also verified the simulation ability of all components except for ordinates of 75 percent of peak. According to the results, simulation of temporal components with the lower relative errors had better performance than the other components. So that, for total sediment graph, the lowest relative estimation and validation errors for time to peak were 48.86% and 45.65%, respectively. Also, the best performed model developed for the direct sediment graph base time had the lowest relative estimation and validation errors of 23.03% and 21.75% and the highest coefficient of efficiency of 0.93.
Ebrahim Borooshke; Mahmood Arabkhedri
Abstract
Soil erosion and sediment transport is an important issue in many Iranian watersheds. Watershed planning without accurate estimates of erosion and sediment yield with appropriate models is not possible. The objective of this study was evaluating of two common empirical models of MPSIAC and EPM. First, ...
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Soil erosion and sediment transport is an important issue in many Iranian watersheds. Watershed planning without accurate estimates of erosion and sediment yield with appropriate models is not possible. The objective of this study was evaluating of two common empirical models of MPSIAC and EPM. First, 10 small watersheds were selected in Western Azerbaijan Province, with several consecutive check dams on their streams implemented under watershed management projects. No flow over the last downstream check dam was considered as the main criterion in each selected basin. In addition to the direct measurement of sediment deposited behind the dams, sediment yield of watersheds were estimated using the models. Comparison of means using (Mann-Whithney) did not show any significant difference at 0.05 percent level between measured and estimated data. At final step, both models were tested by MAE and MBE statistics. The MPSIAC showed better performance than EPM with MAE=1.34 and MBE =-0.12.
Hamid Reza Peyrowan; Mohsen Shariat Jafari
Abstract
One of the most important problems that empirical model users in Iran are facing with, is that these models are prepared for countries with special conditions such as lithology factor, which scores are given based on geology condition of origin country that are not compatible for a vast country like ...
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One of the most important problems that empirical model users in Iran are facing with, is that these models are prepared for countries with special conditions such as lithology factor, which scores are given based on geology condition of origin country that are not compatible for a vast country like Iran with a great lithological variation. This research was conducted to reduce such problems and increase the efficiency and localization of these kind of models and provides rock erosion sensitivity factor for their special conditions. In PSIAC and EPM as a common experimental models, lithology factor is an important agent among other effective factors. In this research, a comprehensive classification of erodibility has been produced in 10 orders, based on mineralogy, chemistry, texture, structure and mechanical properties. Regarding to aridity of many parts of the country, and low rate of soil generation, erodibility rates of geological formations would be an important tasks. Results showed that, about 70 percent of the area covered with very low to low strength lithology to erosion and have a high potential of sediment yielding. Geological formations’ erodibility has been classified in30 Tamab watershed with order of 4 and the results are compared with EPM results and monitored values in river gauging stations. Results also indicated a good agreement with high confidence with natural conditions and with respect to other important factors of the watersheds such as topography and rainfall.
Reza Ghafoorian; Hossein Sanaeinejhad; Najafgholi Ghiasi; Abolghasem Dadrasi; Javad Eizi
Abstract
Determination of mean slope of a watershed area is an essential parameter in most of the water resources projects. There are many methods for determining this parameter. The methods frequently used can be listed as Justin, Networking, Horton, Eight points, Average slope curve and a Geographic Information ...
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Determination of mean slope of a watershed area is an essential parameter in most of the water resources projects. There are many methods for determining this parameter. The methods frequently used can be listed as Justin, Networking, Horton, Eight points, Average slope curve and a Geographic Information System (GIS). Generally experts based on their experiences use one of the mentioned methods. Investigations in some watershed areas showed that the results of applying the various methods are considerable different in a given area. In order to obtain the most accurate method, it is necessary to compare the results of experimental methods with the mean slope which is directly measured in the field, namely direct method. In this study, three regions were selected in different parts of Khorasan Province. For these regions topographic maps with large scales of 1:1000 to 1:3000 were prepared. Afterward seven mountain slopes were chosen in the regions and mean slope was computed for the slopes using the above mentioned methods. The mean slope was directly measured in the field for all seven mountain slopes as well. The obtained results from the various methods have been compared with the direct method by Paired-Samples T test. Analysis showed that the Horton method is the most accurate method with respect to the others. Justin and GIS methods are in next order of accuracy in comparison with the direct method.
Mohammad Shabani
Volume 1, Issue 4 , February 2010, , Pages 240-247
Abstract
Estimation of soil erosion and sediment yield in a river is a difficult task and several methods have been suggested for its estimation. One the new methods in river engineering and suspended sediment estimation is application of artificial neural networks which uses the same algorithm of human brain ...
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Estimation of soil erosion and sediment yield in a river is a difficult task and several methods have been suggested for its estimation. One the new methods in river engineering and suspended sediment estimation is application of artificial neural networks which uses the same algorithm of human brain to find out the internal relation between data based on the training process. The objective of current study is to explore the capability of artificial neural networks method for estimation of daily suspended sediment in Kharestan watershed located in the northwest of Fars province, Iran. The study of efficiency is based on the comparison of neural network with regression models. For this purpose, 22 years of water and sediment discharge data of Shoor Kharestan River were considered and tested for outliers. Then the estimation was done based on neural networks and linear regression method (sediment rating curve) and were compared based on RMSE, MAE and R2. The results showed that estimation of neural network is more accurate than that of linear regression (sediment rating curve). The estimations of RMSE, MAE and R2 for neural networks method was 19.27, 12.14 and 0.98 respectively while these values for linear regression were 36.84, 20.75 and 0.74 which showed the lower errors of neural networks method compared with linear regression.
Ali Mollaie; Abdol Rasoul Telvari
Volume 1, Issue 2 , July 2009, , Pages 70-77
Abstract
The first step for design flood estimation of a watershed is determination of the design rainfall characteristics. One of rainfall characteristics is its distribution over the rainfall duration. This is known as the temporal pattern of the design rainfall. In the present study, the data of four synoptic ...
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The first step for design flood estimation of a watershed is determination of the design rainfall characteristics. One of rainfall characteristics is its distribution over the rainfall duration. This is known as the temporal pattern of the design rainfall. In the present study, the data of four synoptic stations in Kohkiloyeh and Boyerahmad province have been used to determine the temporal pattern of rainfall, using the Pilgrim (ranking) method. Rainfalls of various durations less than 30 hours were classified into 1, 2, 3, 6, 9, 12, 18, and 24 hour durations, and then dimensionless temporal pattern were derived. In ranking method, each event is divided into a number of equal periods. Then, each individual burst is ranked according to the amount of rainfall in that period. The percentages of rain in all periods could be then ranked. The average percentages of rainfall among all recorded rainfall are estimated. The results show that, short duration rainfalls have maximum intensity in the second quarter, while longer duration rainfalls (12, 18, 24 hours) have maximum intensities in the third and fourth quarters. Thus, as rainfall duration increases, the maximum rainfall intensity moves towards the second half of time duration.
