WATERSHED ENGINEERING AND MANAGEMENT
Year:2016 | Volume:8 | Issue:1 |Papers Count:10

In flood water spreading site selection, Electrical resistivity tomography (ERT) plays an essential role in identification of the geological characteristics such as: depth of bedrock, thickness of the alluvial deposits, water table, fault and impermeable layer. ERT methods try to answer some of the important parameters for flood water spreading site selection. ERT method is based on a new approach for modeling distribution of resistivity values under different topographic condition. In this research, ERT studies were designed in a rectangular grid with three profiles in parallel, perpendicular to the channel and the average distance of 600 meters and a length of 1250 meters that covers water spreading and adjacent area. On the profiles, a total of 18 Schlumberger sounding with broadening the AB/2, 100 and 147 meters to 250 meters away from each other were considered. The exact location of the fault was determined by preparation of Two-dimensional cross sections obtained from inverse modeling that were performed with the RES2DINV software. By extraction and interpretation of data which is modeled by SURFER, ver7 and providing pseudo resistivity sections in different depth, type of fault, amount of sedimentary strata displacement and alluvium thickness were determined. By comparing the resistivity values with the existing well logs in the study area, the relative permeability of underlying layers were determined.

In many regions especially dry areas such as Iran, groundwater resources are the main sources of drinking and agricultural water. In areas where natural supply and discharge of aquifer are not balanced, the water table will be dropped and the quality and quantity of aquifer water will be affected. The aims of present study, was to use decision support tools to provide appropriate management method for artificial recharge of Hamedan-Bahar’ s aquifer, using Boolean and Fuzzy pattern in GIS environment. Also, to provide a more economical solution, the possibility of using industrial wastewater treatment in the area, has been investigated. For this purpose, seven geographical information layers including slope, land use, surface infiltration, aquifer depth, aquifer quality, net feeding and transfer capability were interpolated. The resulted output maps showed that according to Boolean pattern 2. 34 percent of the lands (equivalent to 10. 95 km2 of the aquifer) are located in the central and eastern areas and according to fuzzy pattern 9. 44 percent of the lands (equivalent to 44. 22 km2 of the aquifer) which are scattered distributed, rated very good in terms of artificial recharge of Hamedan-Bahar aquifer. Also, the results showed that the Bu-Ali industrial estate water treatment plan outlet can be used to recharge the aquifer.

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.

Understanding the spatial distribution and variability of erodibility and soil properties is essential for planning of water conservation methods, controlling of flood and runoff and managing of soil erosion or watershed. Selecting and using appropriate interpolation techniques for soil properties and erodibility mapping by erosion models such as WEPP is essential. The objective of this study was regionalization of interrill erodibility and effective factors like clay, organic matter and lime using kriging and cokriging and remote sensing data (Landsat 7). For this purpose, 100 soil samples were selected randomly from 0-15 cm depth of Selin watershed in Kaleibar region of East Azerbaijan. Interrill erodibility of WEPP model and some soil properties as clay, organic matter and lime were measured. Correlation analysis between soil properties and digital number (DN) ETM+ image showed that clay, organic matter, lime and interrill erodibility had the highest correlation with DN of Band 7, 1, 1 and 3 ETM+ image (− 0. 406,-0. 431, 0. 291 and 0. 299), respectively. Therefore, the DN of these bands used as auxiliary data for cokriging estimator. The spherical model was fitted the best model to calculate variogram of interrill erodibility, clay, organic matter and lime. No significant difference were noted between kriging and cokriging despite using remote sensing data as auxiliary data. This can be attributed no strong correlation between interrill erodibility, clay, organic matter and lime and remote sensing data.

Hydrologic drought can be studied in different ways. One of the common methods is the use of low flow indexes. In this study for the purpose of determine of the identity of aspects of low flow, the homogenous zones, the extraction of regional regression models, and finally, the study of low flow trends of Karkheh river basin, applied the data of 13 hydrometric stations during the statistical period of 1960-2000. After qualitative and quantitative controlling and the retrieval of missing data used flow duration curves for indexes such as Q75, Q90 and Q95. Also frequency analysis of 10-day, and 20-day low flows was carried out for indexes such as Q10, 5, Q10, 50, Q10, 100, Q30, 5, Q30, 50, Q30, 100 and some more indexes. Afterwards, some other factors like physiographic, climatic, geologic and vegetation cover were applied as influential parameters in the regional analysis. These factors were used in cluster analysis and stepwise regression estimations. Final step was the trend analysis of times series of the indexes. Results indicate that among the indexes being calculated, Q10, 100 and Q95 had the minimum quantities, whose amounts reduced as the return periods increased. On the hand, the time spans of 1998-1999, 1999-2000, 2000-2001 have undergone severe and long droughts in most of the stations. The review of the spatial distribution of indexes show better conditions of the south-eastern parts of the study area compared to the northern and southern sections in terms of dryness. Results of cluster analysis divided the area into two distinct homogenous units (in 0. 01 significant level). In the area No. 1, the elevation factor, in the area No. 2, the drainage density, and in general, the factors such as the mean of area and drainage density have the highest effects. The Spearman statistic, and Mann-Kendall findings also indicate that the low flow in upper basin have negative trend during the statistical period.

Because of data lacking in the most of watersheds, many researchers applied spatial analysis in GIS environment to study the hydrological and flooding condition. This study aims to map flood susceptibility through frequency ratio technique using some parameters such as digital elevation technique, slope, curvature, topographic wetness index, stream power index, average rainfall, distance from river, geology, soil type and land use in Pole-Doab, Shazand Watereshed, Makazi Province, Iran. First, digital map of all of the parameters were prepared based on raster format using Arc GIS 10. 1 and SAGA GIS2 softwares. To prepare land-use map IRS-1C satellite image, ENVI 4. 8 software and maximum likelihood algorithm were applied. Then flood inventory map was produced by mapping 95 flood prone locations in the study area using documented information on the May-2003, May-2004 and March-2004 floods. These 95 locations divided into two groups including 67 points (70%) and 28 points (30%) for calibration and validation, respectively. For calibration, flood prone locations defined as dependent variable and ten parameters that are affecting flooding condition were introduced to frequency ratio as independent variables. Then flood probability was determined for each class of each parameter. Finally, obtained weights for each class in GIS were implemented in corresponding layers and using the overlay algorithm, susceptibility and probability maps were prepared. Based on the susceptibility map, study area was divided into 5 classes as very high, high, medium, low and very low sensitivity. The findings of the assessment of frequency ratio histogram indicated that the likelihood of very high and very low flooding classes are equal to 67. 86 and zero percent, respectively. Therefore, the obtained frequency ratio histogram confirms the adequacy of the implemented method in flood susceptibility and probability mapping for the case study.

The biggest restriction of natural resources in Iran is dry and semi-dry climate and deficit of water resources. Non-normative use of natural resources causes imbalance between water components and demand. The main objective of this study is to test the performance and usability of the simulation model to estimate water balance and groundwater flow in 223. 9 km2 of Golgol catchment in Ilam Province using Soil and Water Assessment Tools (SWAT) model and SUFI2 Program. The input data model include topographic, land use and soil maps and also climatologically data, including daily precipitation, temperature, relative humidity and stream flow. In order to determine the important parameters of the model, the parameter sensitivity analysis using "One At a Time " (OAT) was performed and the effect of various parameters such as stream flow, lateral flow and ground water flow on water balance evapotranspiration was examined. In order to calibrate the model SUFI2 algorithm was used. Simulation model for 13 years from 1997 to 2009, was the first of eight years (2004, 1997) for model calibration and the next five years (2009-2004) were selected for validation of model results. Statistical indices P-factor, d-factor, Nash Sutcliffe (NS) and the coefficient of determination (R2) on a monthly basis for the evaluation model was chosen. The Nash-Sutcliff coefficient for calibration and validation period is 0. 65 and 0. 49 respectively. The results show satisfactory performance of the SWAT model to simulate the water balance components in the Golgol catchment. The obtained values of R2 in both calibration and validation are 0. 66 and 0. 51 respectively which is indicating the relative desirability of the model. The results of simulation show that the average annual rainfall of 503 mm, the maximum amount is belong to evapotranspiration that equal 366 mm (72%) of the total precipitation in the catchment. The total groundwater and lateral flow is equal 77 mm (15. 3 %), the surface runoff is 47. 8 mm (9. 5 %) and annual losses equivalent to 3% of total precipitation. The share of 15. 3 percent of the total sub surface flow and groundwater from total precipitation is valuable for planners to implement management plans in study area.

Landslides are major natural hazards and adopting a regional strategy is very necessary to reduce its damages and maintains natural and human resources. The purposes of this study are the recognition of effective factors in landslide and the zonation and assessment of in terms of the occurrence of this phenomenon using the Dempster-Shafer theory and GIS technique. In this research with integration of Landslide map and effective factors maps such as lithology, land use, slope angle, slope aspect, elevation, precipitation, distance to fault, distance to road, and density of drainage were done analysis of hazard. Finally, landslide occurrence zones were recognized from very low risk to very high risk. Total area of region is 1780516, 12/66 percentage of area (237259) existed in very high risk, 12/78 percentage of area (239045) existed in high resk, 21/24 percentage of area (397316) existed in medium, 29/33 percentage of area (548649) existed in low and 23/96 percentage of area (448247) existed in very low class. Model evaluated using one to third of landslide points, Frequency Ratio (FR), Seed Cell Area Index (SCAI) and ROC. The results show that Frequency Ratio and Seed Cell Area Index indicate appropriate accuracy of classification to 5 class. Also accuracy of ROC in Dempster-Shafer theory with AUC (%73) indicate high correlation between Risk map and Landslide hazard map and good evaluation of model. The results of these studies can be used as fundamental information by environmental managers and planners.

Construction activities on the river branches and the middle areas of the watersheds can lead to changes on the river bed morphology of down streams. Understanding the river bed morphology changes and its effects on the lands next to river is essential to rehabilitate and stabilize the bed and banks. This study aim to identify the river bed morphology changes over the past five decades in Zarrinehrud River. In this research a range of 25 km at the end of Zarrinehrud River in West Azerbaijan province was studied using aerial photos of year 1334 and 1346, topographic maps of year 1375 and SPOT satellite image of year 1382. Results showed that morphological changes of the river bed and the surface area of adjacent lands were reduced from 561. 1 ha to 221. 3 ha. The sand dam area at river bed in 1346 was 13. 8 ha and at 1382 was 2. 7 ha, this result represents a large discharge fluctuations and changes in the hydrological and hydraulic conditions of the river. Meander form of River morphology also has been changed. Number of Meanders reduced from 4 to 3. The effective factors on the morphological changes were, changes in the hydrological regime due to dam construction, runoff reduction and sediment deposition in the river bed.

Floods are the main natural disasters that produce serious agricultural, environmental, and socioeconomical damages in many parts of the world. Accurate estimation of river flow in streams can have a significant role in water resources management and in protection from possible damages. This study aims to compare the abilities of Support Vector Machine (SVM), M5 model trees and Linear Regression (LR) methods in forecasting hourly discharge flow of Aharchay River. The hourly water level-discharge and 14 flood events data of Aharchay River measured at the Tazekand hydrometric station was used for modeling. The results showed that the SVM method gives more accurate results than the M5 model and LR method in forecasting river flow for next one and two hours with the R2=0. 96 and RMSE=0. 0472 (m3s-1) and the R2=0. 90 and RMSE=0. 1596 (m3s-1), respectively. Comparing the performance of SVR and M5 models indicated that, however the SVR approach may present more accurate results than the M5 model tree, but the M5 model provides more understandable, applicable and simple linear relation in forecasting hourly discharge. Thus, the M5 model tree can be used as an alternative method in forecasting hourly discharge.