1 2251-7812 University of Hormozgan 129 Evaluation of Sivand Basin Erosion by RUSLE Model During 1998 to 2009 1 6 2013 3 1 1 18 11 05 2014 11 05 2014 The presence of human in nature and his willing or unwilling activities have culminated in a series of destruction and balance that clash in nature. Today, the increase of population and high demand for agriculture production has resulted in the destruction of plant coverage on the land, particularly forests and grassland, by human use that leads to increased erosion. We have investigated via using the world soil erosion equation, TM satellites images (1998) and ETM (2009) the erosion of Sivand River during 1998 and 2009. For the extraction and processing of satellite images, ERDAS was used for mapping and its related analysis we used Arc GIS and SPSS software.The results showed that erosion in 1998 was 406,172,389 tons and in 2009 it was 416,364,377 tons, an increase of 1.87 tonsper hectare. The main cause of erosion changes during the course of this study was the decrease in plant coverage which resulted from increased population as well as the interference in nature and immethodical grazing in grassland areas. These decreased soil coverage and weakened the soil against rainfall and other factors.
131 Estimation of Soil Infiltration in Agricultural and Pasture Lands using Artificial Neural Networks and Multiple Regressions 1 6 2013 3 1 19 34 11 05 2014 11 05 2014 Common methods to determine the soil infiltration need extensive time and are expensive. However, the existence of non-linear behaviors in soil infiltration makes it difficult to be modeled. With regards to the difficulties of direct measurement of soil infiltration, the use of indirect methods toestimate this parameter has received attention in recent years. Despite the existence of various theoreticaland experimental equations, other indirect methods such as artificial neural networks are used to estimate this soil phenomenon. Currently, artificial neural networks are highly efficient in modeling non-linear equations. In the present studywe have collected 200 soil samples from Ghoshe location in Semnan Province. Half of samples were collected from agricultural lands and the other half were collected from nearby pasture lands. Some soil chemical as well as physical properties such as electrical conductivity (EC), soil texture, lime percentage, sodium adsorption ration (SAR) and bulk density were considered to be easy, rapidly obtainable features whereas soil permeability was considered to be a difficult, time consuming feature. The collected data were randomly divided in two categories of training and testing to be used for two artificial neural networks, multi-layer perception using back-propagation algorithm (MLP/BP).radial basis functions (RBF) and a nonlinear regression model. Results of this research showedthe high efficiency of the artificial neural network compared with multiple regression. The MLP network was better than the RBF network. Sensitive analysis was used to determine the correlation between independent parameters and permeability. 130 Assessing the Implications of Planting Haloxylon aphyllum on the Vegetation and Soil Properties of Stabilized Sandy Desert (Samad Abad, Sarakhs) 1 6 2013 3 1 35 44 11 05 2014 11 05 2014 Planting Haloxylon aphyllum under oil mulches has frequently been used for stabilizing mobile sands in Iran for during the last three decades. This study is carried out in stabilized sandy desert of Samad Abad-e-Sarakhs to evaluate the implications of planting Haloxylon aphyllum on the vegetation and soil attributes. Sampling was carried out random-systematically in the representative areas of the treatment and control plots. In each treatment and control area nine transects of 50 m were placed and data including the density and the canopy cover of the two dominant species of the field (viz. Astragalus squarrosus & Convolvulus hamadae) as well as the total canopy cover of the understory plants were recorded. In addition, in each area 220 plants of the two species were selected and examined for their total and living aerial foliage volumes. What’s more, four soil profiles were used in each area and sampling was made at the depths of 0-20 cm and 20-80 cm to be further analyzed for the organic matter content. Data analysis was performed using the independent t-test. Results indicated that planting Haloxylon aphyllum has reduced the total canopy cover beside the canopy cover and densities of the two dominant species. The implications also include the reduction of the total volume of Astragalus squarrosus, yet there was no such reduction for Convolvulus hamadae. As a result there was significantly reduction of organic matter content at the surface depth and accumulation of it in the deeper depth. 134 Investigation of the Role of Collaboration Network Between State and Formal Public Institutions in Implementation of Watershed Management Projects and Soil Erosion Decrease Case Study: Berentin-Hormozgan Province 1 6 2013 3 1 45 58 11 05 2014 11 05 2014 In spite of successfulness of watershed management project, this science could not be able to combat soil erosion lonely and it needs the participation of habitants of watersheds that their livelihood completely depends on sustainable resources. So, this research through analysis of collaboration network between state and formal public institutions in implementation of mechanical and biological watershed management projects and comparing them together tries to answer this question: Whether the extent of collaboration of formal public institutions with state institutions in implementation of mechanical and biological watershed management projects differ? The data was gathered through questionnaires were filled by asking from formal public institutions of Rural District of Berentin located in Hormozgan province and the experts and managers of Organization of Natural Resources and Watershed Management. Data analysis was done by Network Analysis Method. The results showed that in spite of allocation of the most budget of watershed management to mechanical projects in order to combat soil erosion, the formal public institution had much more participation and collaboration in biological projects. Also, the network connectivity and involvement of public and state institutions of these projects is more than the other one. So, because of the high social support of public institutions from biological watershed management projectsin this Rural District, these projects could be the best, the most effective and the cheapest solution for soil erosion decrease in this Rural District and even in Hormozgan Province 133 Numerical Study Scour Pattern on Channel Bend Using Flow-3D Software 1 6 2013 3 1 59 72 11 05 2014 11 05 2014 In nature, a direct route to the river is uncommon. Most rivers have channels that bend wherea complex scour pattern dominates. We have intended to study the behavior patterns necessary to scour a river known as the dominant bends. Numerical models are powerful instruments for the prediction of such areas and can provide a good understanding of these areas. In the present study we have used a three-dimensional numerical model Flow-3D to determine the effects of parameter U/Uc, flow rate and channel width of the scour pattern at a 90 degree arc of the moving beds. The results were compared with experimental data. Analysis of results relevant to scour pattern in cross sections and different plans were among other points introduced in this paper. 132 Investigation of Possibility of Suspended Sediment Prediction Using a Combination of Sediment Rating Curve and Artificial Neural Network Case Study: Ghatorchai River, Yazdakan Bridge 1 6 2013 3 1 73 82 11 05 2014 11 05 2014 Estimation of sediment loads in rivers is one of the most important, difficult components of sediment transport studies and river engineering. Accessing new methods that can be effective in this background are more important. In this research, we have used the artificial neural network (ANN) to optimize the results of the sediment rating curve (SRC) to predict the suspended sediment loads. For doing that, the Yadakan station on Ghatoor-Chai River was considered. An equation by SRC method was obtained followed by an ANN method by the same data, and finally by combining them, we built a new model. It should be mentioned that before using the combined model, each method was used and the obtained results were compared with the observed data. Based on this research, the results of using the combined model were more precise than the ANN and SRC separately as the Dr value from 1. 402 (in SRC) and -2. 395 (in ANN) changed to 0. 963 in the combined model. The RMSE has also obtained 692.286 and 616.96 for SRC and ANN, respectively, whereas this value decreased to 603.094 for the combined model.