To understand the natural environments of drylands, deserts, arid and semi-arid regions of the earth is to understand the processes and forms of their rivers. One of the river studies and fluvial processes are morphom...To understand the natural environments of drylands, deserts, arid and semi-arid regions of the earth is to understand the processes and forms of their rivers. One of the river studies and fluvial processes are morphometry analyses. The channel forms in an alluvial plain reflecting the movement of water and the particle size of the load flowing down the channel. The dynamics of channel change has led to conflict with human resource development. Three basic channel patterns are detected in the region. They are braided, meandering and straight. In this research for assessment of meandering Maroon River, we used DEM (Digital Elevation System), Topography maps, Arc GIS software, Google earth, field work and library studies and mathematic formula. The two general indices for analyzing meandering patterns are 1) sinuosity coefficient 2) central angle. In this paper, the authors were used these factors and improved them. One of the results is creation of direction index and the second result is the Maroon River which has a type of sinuosity in any reach.展开更多
Lost circulation is the most common problem encountered while drilling oil wells.Occurrence of such a problem can cause a lot of time and cost wastes.In order to drill oil wells,a fast and profitable way is necessary ...Lost circulation is the most common problem encountered while drilling oil wells.Occurrence of such a problem can cause a lot of time and cost wastes.In order to drill oil wells,a fast and profitable way is necessary to predict and solve lost circulation problem.Expert system is a method used lately for problems that deal with uncertainty.In this paper,three approaches are carried out for prediction of lost circulation problem.These approaches include design of experiments(DOE),data mining,and adaptive neuro-fuzzy inference system(ANFIS).Data of 61 wells of Maroon oilfield are selected and sorted as the feed of the systems.Seventeen variables are used as inputs of the approaches and one variable is used as the output.First,DOE is conducted to observe the effects of variables.Plackett-Burman method is used to determine the effects of variables on lost circulation.After that,data mining is conducted to predict the amount of lost circulation.The class of regression is used to determine a function to model the data and the error of the model.Then,ANFIS is applied to predict the amount of lost circulation.The chosen data are used in order to train,test,and control the ANFIS.Furthermore,subtractive clustering is used to train the fuzzy inference system(FIS)of the model.The performance of the ANFIS model is assessed through the root mean squared error(RMSE).The results suggest that ANFIS method can be successfully applied to establish lost circulation prediction model.In addition,results of ANFIS and data mining are investigated through their prediction performances.The comparison of both methods reveals that ANFIS error is much lower than data mining.展开更多
The major objective of this study was to evaluate the effects of sand mining disturbances on the diversity of arbuscular mycorrhizal fungi（AMF）. In addition, the proportional changes in the diversity of AMF to the d...The major objective of this study was to evaluate the effects of sand mining disturbances on the diversity of arbuscular mycorrhizal fungi（AMF）. In addition, the proportional changes in the diversity of AMF to the distances from riverbanks were assessed. For this purpose, the riparian forest of the Maroon River, Iran was divided into three locations with a 200-meter wide zone in between. Thus, the locations studied were named Distance I（riverbank）, Distance II（intermediate）, and Distance III（farthest from riverbank）. In each of these distances, 10 Tamarix arceuthoides and Populus euphratica of each species were randomly selected. At the same time, soil and root samples were collected from the rhizosphere of the tree species studied. Results indicated that totally 13 AMF species were observed in T. arceuthoides and 19 AMF species were recorded in P. euphratica rhizosphere belonging to 6 genera and 6 families. In these AMF species, Glomus segmentatum, G. geosporum, G. rubiforme, G. nanolumen, G. spinuliferum, Claroideoglomus drummondii, Gigaspora gigantea and Acaulospora paulinae appeared only in P. euphratica rhizosphere, while G. multiforum and Claroideoglomus claroideum were observed only in T. arceuthoides rhizosphere. Moreover, Distance II had the least AMF species both in T. arceuthoides and in P. euphratica rhizospheres, and also the least spore density and root colonization rate. Our results are important in that they provide a list of resistant AMF species that could be used in the conservation of biodiversity.展开更多
文摘To understand the natural environments of drylands, deserts, arid and semi-arid regions of the earth is to understand the processes and forms of their rivers. One of the river studies and fluvial processes are morphometry analyses. The channel forms in an alluvial plain reflecting the movement of water and the particle size of the load flowing down the channel. The dynamics of channel change has led to conflict with human resource development. Three basic channel patterns are detected in the region. They are braided, meandering and straight. In this research for assessment of meandering Maroon River, we used DEM (Digital Elevation System), Topography maps, Arc GIS software, Google earth, field work and library studies and mathematic formula. The two general indices for analyzing meandering patterns are 1) sinuosity coefficient 2) central angle. In this paper, the authors were used these factors and improved them. One of the results is creation of direction index and the second result is the Maroon River which has a type of sinuosity in any reach.
文摘Lost circulation is the most common problem encountered while drilling oil wells.Occurrence of such a problem can cause a lot of time and cost wastes.In order to drill oil wells,a fast and profitable way is necessary to predict and solve lost circulation problem.Expert system is a method used lately for problems that deal with uncertainty.In this paper,three approaches are carried out for prediction of lost circulation problem.These approaches include design of experiments(DOE),data mining,and adaptive neuro-fuzzy inference system(ANFIS).Data of 61 wells of Maroon oilfield are selected and sorted as the feed of the systems.Seventeen variables are used as inputs of the approaches and one variable is used as the output.First,DOE is conducted to observe the effects of variables.Plackett-Burman method is used to determine the effects of variables on lost circulation.After that,data mining is conducted to predict the amount of lost circulation.The class of regression is used to determine a function to model the data and the error of the model.Then,ANFIS is applied to predict the amount of lost circulation.The chosen data are used in order to train,test,and control the ANFIS.Furthermore,subtractive clustering is used to train the fuzzy inference system(FIS)of the model.The performance of the ANFIS model is assessed through the root mean squared error(RMSE).The results suggest that ANFIS method can be successfully applied to establish lost circulation prediction model.In addition,results of ANFIS and data mining are investigated through their prediction performances.The comparison of both methods reveals that ANFIS error is much lower than data mining.
基金Behbahan Khatam Al-Anbia University of Technology for its support during this study
文摘The major objective of this study was to evaluate the effects of sand mining disturbances on the diversity of arbuscular mycorrhizal fungi（AMF）. In addition, the proportional changes in the diversity of AMF to the distances from riverbanks were assessed. For this purpose, the riparian forest of the Maroon River, Iran was divided into three locations with a 200-meter wide zone in between. Thus, the locations studied were named Distance I（riverbank）, Distance II（intermediate）, and Distance III（farthest from riverbank）. In each of these distances, 10 Tamarix arceuthoides and Populus euphratica of each species were randomly selected. At the same time, soil and root samples were collected from the rhizosphere of the tree species studied. Results indicated that totally 13 AMF species were observed in T. arceuthoides and 19 AMF species were recorded in P. euphratica rhizosphere belonging to 6 genera and 6 families. In these AMF species, Glomus segmentatum, G. geosporum, G. rubiforme, G. nanolumen, G. spinuliferum, Claroideoglomus drummondii, Gigaspora gigantea and Acaulospora paulinae appeared only in P. euphratica rhizosphere, while G. multiforum and Claroideoglomus claroideum were observed only in T. arceuthoides rhizosphere. Moreover, Distance II had the least AMF species both in T. arceuthoides and in P. euphratica rhizospheres, and also the least spore density and root colonization rate. Our results are important in that they provide a list of resistant AMF species that could be used in the conservation of biodiversity.
