WATERSHED ENGINEERING AND MANAGEMENT
Year:2018 | Volume:9 | Issue:4 |Papers Count:10

Morphometric analysis is considered as quantitative evaluation of geometric features landforms and landscape. In the study of basin tectonic features, the use of some morphometric parameters can provide very substantial information. Gavkoshak Basin with an area of 46. 73 km2 is located in Zagros simply folded belt. The objective of this research is to use the morphometric indices such as hypsometric integral, basin shape, stream length-gradient, asymmetric factor, and the valley width/height ratio. As a result, these indices are converted to the tectonic activity index. This index can be used to assess the overall performance of the region's tectonic activity. Morphometric indices of area are studied by dividing this area into 43 sub-basins, using the Digital-Elevation Model (DEM) and Geographic Information System )GIS). Morphotectonics index method with the use of geographic information systems provide procedures and a powerful tool for estimating tectonic activity in the region. It should be borne in mind that the results of these indices can show different values in different sectors. By examining the relative index of tectonic activity, the basin in this research is divided into two parts namely active (25. 6% of the watershed) and semi-active (74. 4 % of the watershed). Through statistical analysis, the area under investigation includes four clusters: cluster one with 91. 83% similarity, cluster two with 95. 19% similarity, cluster three with 96. 18% similarity, and cluster four with 91. 09% similarity. In this way, homogeneous regions were determined based on clustering algorithm ward. The active tectonic basin in this research can be studied in another research project, using other morphometric parameters.

Today, land degradation is inevitable due to growing population and corresponding demands, and also economic development, unscientific and illogical utilization of resources. Monitoring and identification of factors affecting is therefore essential for controlling and management of land degradation in an area. However, such important issues have been less considered by experts and managers. To this end, the present study aimed to analyze the trend and identifying the important affecting factors on land degradation in the Shazand Watershed, Iran, based on the Environmental Sensitive Area Index (ESAI) for significant changes due to a variety of uses, management and industrial development from 1986 to 2014. According to the ESAI maps in five year nodes of 1986, 1998, 2008 and 2014, some 16. 56, 33. 39, 42. 32 and 49. 52 percent of the study area were in critical condition of land degradation, respectively. Based on the results, the process of land degradation in the region was increasing and land degradation was considerable in the periods leading up to 1998 and 2014. The sensitivity analysis on factors influencing land degradation in the study area also revealed that the role of vegetation, anthropogenic and managerial factors on ESAI changes were more than other factors and therefore could moderate or intensify the land degradation.

Efficiency of sediment fingerprinting by using tracers as a successful method to determine the sources of sediment has been proved. Selection of the suite subset of tracers, capable of discriminating sediment sources, is the first and the most important step in the sediment fingerprinting method. The presence of outliers affects the selection of the suite subset and possibly prevents picking the important tracers and reducing the accuracy of classification. Therefore, the outliers must be detected in order to be corrected or omitted, if enough evidences were present. The present study aims to detect outliers in the subset of tracers, to identify the best combination. For detecting outliers, We used univariate methods such as Grubbs test, Gauss test, Dioxin test, box plot, the Median ± 3MAD, the mean ± 3standard deviation and also multivariate methods such as squared Mahalanobis distance, separate box plots of squared Mahalanobis distance for each of sediment sources, principal component analysis and plot of the squared Mahalanobis distances against the quantiles of the chi-square distribution. we consider an observation as the outlier that at least half of these methods have detected it as an outlier. The results showed that Median ± 3MAD method introduced a larger number of data as outliers Methods of multivariate outlier detection has low agreement with each other. Univariate methods to identify outliers show higher agreement with each other. To use univariate analysis techniques to detect outliers namely Median ± 3MAD, box plot, and Dioxin one can recommended to test their sensitivity. The results also showed that the maximum consensus for univariate analysis techniques is four samples (observations) and for multivariate methods is two samples (observations). In general, there is no observation that is identified as an outlier by half of the used methods.

Sharp-crested weirs are widely used for the purposes of flow measurement, flow diversion and water level control in hydraulics, irrigation, and environmental projects. Discharge coefficient at these weirs is a function of head to weir height ratio (H/P). In a constant head, flow increases by increasing the length of weir in the plan. One of these weirs is the duckbill weir. Sometimes, it is changed upstream and downstream bed level by deposition of sediments in the upstream of weir, erosion in the downstream of the weir, etc. These changes cause changes in the flow characteristics such as discharge coefficient. In this study, the effect of these changes on the discharge coefficient of duckbill weir is studied. The results showed that the change in the height of duckbill weir has no effect on the discharge coefficient. But, increasing L/W ratio (L and W are respectively length of weir and width of flume) decreases discharge coefficient. Also, with increasing, maximum of discharge coefficient gives in the amount of H/P less. So that maximum of discharge coefficient in L/W ratio 2, 3 and 4 is respectively 0. 73, 0. 68 and 0. 63 which respectively occurred in the amount of H/P of 0. 5, 0. 3 and 0. 25. Discharge coefficient is reduced with increasing upstream bed level. In submerged flow, Reducing the downstream bed level increase discharge coefficient but changes in downstream bed level have no effect on discharge coefficient until flow is not submerged, also, conditions of aeration are the same. By increasing the L/W ratio in duckbill weir from 3 to 4, amount of H/P in threshold of flow Interference and local Submergence decreased from 0. 5 to 0. 3.

The 21st century will face the controversial debate on sustainable development with the priority of sustainable urban development. Urban planning has not paid enough attention to the sustainability of cities dependent on natural resources. The development of the city without regard to its watershed makes no sense. Urban strategies have focused on the implementation of static plans, followed by the modernist school, and the need for the interconnection, sustainability, and vitality of urban watersheds, which are the city's feeding vessels, has not been addressed. This research was conducted with the main purpose of explaining the sustainable development strategies of Garmsar city based on integrated management of urban watershed by understanding the factors affecting the stability of the watershed and analyzing the causal relationships of urban sustainability in the operation with Halbehrood watershed stability factors. The research method is descriptive-analytical and collecting the information required for research through library studies and field observations. In order to analyze the information, the DPSIR environmental evaluation model, the AHP model and the SWOT model have been run integrated to determine the best sustainable development strategies of the Garmsar city. The results of the studies showed that Garmsar city is not sustainable as a city dependent on urban watershed and it is not sustainable in terms of providing necessary resources of the basin, but the sustainability of the watershed and the Garmsar city is possible through the implementation of Strategies appropriate to existing resources. Based on the results of quantitative and analytical matrix analysis, eight of the main identified strategies were prioritized. Among them, the development of a joint program for water, agriculture and natural resources in order to explain the effective measures of the chain of production, distribution, and use of water in the upstream lands is the first priority.

Consciousness of preventing factors affecting on stakeholder participation in watershed areas' plans is a main principle in realization of effective participation of stakeholder and obtaining integrated watershed management goals. There are twelve watershed areas surrounding the city of Tehran that their runoff influence on northern and northeast parts of Tehran. Different factors can prevent stakeholder' participation that they have been classified into economic, social, human and planning indices. Obtained results from prioritizing effective indices on preventing stakeholder' participation in watershed plans based on obtained weights from Fuzzy-AHP method and questionary data obtained from Administration of Natural Resources and Watershed Management and its branches indicate that economic and human indices have respectively maximum and minimum priorities, in the manner that prioritization of indices based on normalized weights from maximum to minimum importance are economic, planning, social and finally human, respectively. In this research, preventing sub-indices affecting on stakeholder' participation in watershed area´ s plans were created based on library studies, expert ideas and also interviewing with 240 residences and finally the validity of questionary was verified based on expert ideas. Obtained results with ranking sub-indices based on the Friedman test show that sub-indices have different roles in preventing stakeholder' participation in watershed plans, in the manner that “ ignoring people´ s income as a direct economic motivation” with mean rank of 10. 77 and “ being low literacy and knowledge” with mean rank of 1. 80 have a maximum and minimum of mean rank, respectively. In this research, sub-indices of “ ignoring people´ s income as a direct economic motivation” from economic index, “ concentration of decision making power in center” from planning index, “ shortage of trust to project results” from social index and finally “ shortage of education of watershed residents about plants and their purposes” from human index were ranked as the most important sub-indices.

Landslides are major natural hazards which not only cause damages to human life but also provide economic losses on infrastructures. In order to determination of the most important method of estimation recognizing appropriate method to estimate landslide, in this research, the efficiency of two methods of landslide hazard zonation including methods of Artificial Neural Network and Multivariate regression were compared. Therefore, in this research, first, landslide inventory map was obtained using aerial photos interpretation, satellite images processing, geology maps review and field surveying. Also, the 9 important effective factors are in occurrence of landslide including lithology, land use, slope angle, slope aspect, elevation, precipitation, distance to fault, distance to road, density of drainage were determined using inspect of field and literature review. After producing of layers and weighting to effective factors using inventory map, landslide hazard zonation was made by Artificial Neural Network and Multivariate regression models. From 200 landslides identified, 140 (≈ 70%) locations were used for the landslide susceptibility maps, while the remaining 60 (≈ 30%) cases were used for the model validation. The quality sum (Qs) and precision (P) indices for Artificial Neural Network model are 0. 15, 0. 08 and for Multivariate regression model are 0. 14, 0. 05 respectively. This results show that artificial Neural Network is the better model in landslide hazard zonation in this area, therefore an accurate landslide hazard zonation map can be prepared by selecting and applying the proper method.

The objective of this paper is introducing and applying a two-dimensional electrical tomography method in detection of water movement and evaluating the effects of watershed management measures. For these, four Dipole– Dipole profiles were designed operated and the data were recorded. These profiles included; profile A in the east-west direction, profile B and C in the north-south on the right bank upstream and downstream of the dam site and the D and E profiles, perpendicular to the river, on the right bank of the river valley. The RES2DINV software was used for two dimensional modeling. The results checked and calibrated using geological survey. Two water leakage path of a buried river channels and other stalagmites along the right bank of the river were detected. Results from profiles A indicated that fault damage zone North-South and seepage from the right abutment. The recorded resistivity of dam embankment was high; so the clay, which is used for construction of dam, is dry and shows a stable condition. The profile B was recorded at the distance of 50 meters from dam axis. A zone of low resistivity (with a dimension of 20*15 meters) was detected. This zone represents a pore space containing a high percentage of recharged water. The stored water flow slowly into other fracture zones down gradient along the watercourse. The D profile indicates the presence of buried river is the path that hydraulic gradient and direction with corresponding points A and B is consistent in the profiles. In conclusion, application of a two-dimensional electrical tomography method showed promise as a low cost and relatively quick methodology in evaluation of water movement in catchments. All in all, the effectiveness of the implemented watershed management activities was quantitatively approved by applying the aforesaid technique.

Flood control, artifcial feeding of ground water aquifers and effort to optimize the productivity of natural resources are component the most results that have gotten from implementation of spreading project in spreading statious of country. One of the most important goals of spreading is the creation of positive changes in economical variables of area including agricultural and rangeland productionsand their development. In other words, each of spreading projects implemented in different stations have specific economical effects in desired area. The goal of this project is determination of economical effects of floodwater spreading project on Dehloran aquifer through monitoring and surveying its behavior and recording relevant data steadily. For this purpose, profit ability and economical justification of the project have been determined through economical indicator evaluation of projects. Results demonstrated that irrigated lands of downstream villages have been inceased 3. 5 times in 2010 compared to the year1995. The added value of the injected floodwater was estimated to be 14. 6 billionRial. The added value of rangeland products was about 1353. 96 billion Rial. The added value of wood production was estimated about 13. 38 billion Rial. The added value of agricultual products was about 657. 05 billion Rial. NPV, ROR and B/C of the project were 1398. 61 billion Rial, 0. 38 and 2. 87, respectively that show economical justification of the project.

Knowing the effects of climatic factors on the farming plants is one of the most important factors on the increase or decrease of production and this subject has an important effect on the production especially in rainfed condition and specifically wheat as a strategic product. Successive droughts which occurred in recent years are one of the climatic factors which affect the agricultural products. The aim of this research was to evaluate the wheat production in the drought conditions in rainfed lands of the Ilam Province. In this regard, the regression and Pearson tests were used to evaluate the effects of drought on wheat production. The results of correlation of drought frequency on decrease of wheat production in Dehloran, Ilam and Darreh-shahr townships showed as much as 45, 67 and 45 percent, respectively. Besides, the correlation coefficient indicated that the relationship of drought and wheat production in Mehran is 58, in Dehloran and Abdanan is 61, in Ilam is 46, in Aynan is 74, in Darreh-shahr is 63 and in Shirvan-Chardavol is 85 percent.