فهرست مطالب nasser tahmasebipour

In semi-arid and mountainous regions, factors such as high wind speed and temperature in the hot seasons lead to high surface evaporation, which is the main cause of water losses. This evaporation even occurs at temperatures below the boiling point of water. So far, various solutions have been proposed to reduce evaporation. In the present study, which was conducted with the aim of investigating the performance of polypropylene balls without holes on the chemical quality of water, one-way analysis of variance (ANOVA) and Tukey and Duncan's mean comparison test were performed on 18 data sets. The selected chemical quality parameters included nitrate, phosphate, total dissolved solids (TDS), and turbidity.The results of the study showed that the use of polypropylene balls without holes can significantly reduce the turbidity and total dissolved solids of water. The average turbidity of the control pan was 1.78 NTU, while the turbidity of the pan with polypropylene balls without holes was 1.64 NTU. The average total dissolved solids of the control pan was 699.4 mg/L, while the total dissolved solids of the pan with polypropylene balls without holes was 671.2 mg/L. The study also showed that the use of polypropylene balls without holes can reduce the oxygen exchange rate of water. The average oxygen exchange rate of the control pan was 69%, while the oxygen exchange rate of the pan with polypropylene balls without holes was 59%.The results of this study suggest that polypropylene balls without holes can be a effective method to reduce the turbidity and total dissolved solids of water in semi-arid and mountainous regions. However, the use of these balls can also reduce the oxygen exchange rate of water.

Considering the importance of knowing and awareness of the watersheds water balance status, and analyzing the hydrological behavior of watersheds for planning and implementing water-related projects, the need to use new technologies in predicting water balance components is more evident than ever. Based on this, in the Kashkan basin by utilizing the TOPKAPI-X hydrological model, the water balance components of the basin were simulated according to the cellular network design. Digital maps of the basin, land use, outlet point, soil texture, elevation, and continuous time series of temperature, precipitation, and discharge in the daily time step are the main inputs of the model. The model in each cell network balances the water balance of the entire period. Model calibration was done for the 15 years of the statistical period (1999 to 2014) and model validation for the 6-year period (2014 to 2020). The results showed that 27.02 and 28.43 percent of the total precipitation of the Kashkan basin was discharged from the basin as total runoff (respectively for calibration and validation periods), which is consistent with the observation data at the outlet hydrometry station. Next, to evaluate the efficiency of the model, the simulated values in both statistical periods were compared to the observational discharge. Statistical methods such as the Nash-Sutcliffe evaluation criteria showed that the TOPKAPI-X model predicted the water balance components such as actual and potential evapotranspiration, infiltration, and the amount of runoff, especially the total runoff, in this basin with relatively good accuracy (coefficient above 60%).

Due to the heterogeneity in watersheds and the non-linearity of hydrological behaviors, it is very complicated and difficult to fully understand the relationships within watersheds. Therefore, in evaluating these systems, a modeling process is necessary. Over the last few decades, hydrological/hydraulic models have become essential in hydrology studies due to the development of programming languages and the provision of optimal and efficient algorithms for solving differential problems. The application of rainfall-runoff simulation models for flood events has been extensively studied by researchers in the field of water and soil protection, leading to the development of various models to simulate rainfall-runoff processes. One of the successful models in this field is the TOPKAPI-X model. This model was created in the 1990s at the University of Bologna by Professor Todini as a distributed rainfall-runoff model in watersheds. An important feature of distributed models is their ability to simulate components at any point of the watershed, allowing results to be extracted at any required point. Unlike lumped models that consider the entire watershed as a single unit, distributed models allow spatial distribution at any point in the watershed. Therefore, in this research, after calibrating and validating the TOPKAPI-X physical-distributed model in the studied basin, the model was optimized for flood estimation.

The Gamasiab basin is located in the west of Iran, in the northern region of the Zagros mountain ranges, to the north of the Karkheh dam basin, and primarily within the territories of Hamadan and Kermanshah provinces. The mountainous regions of this basin are mainly concentrated in the northern and southern parts, while its lowlands and plains are mostly located in the middle and southeastern parts of the basin (Ministry of Energy, 2014). In this research, the TOPKAPI-X model was used to simulate floods in the Gamasiab watershed. First, the watershed boundary was delineated using a digital elevation model (DEM) with a resolution of 30 meters. Land use maps, soil texture, watershed network, and climatic components were entered into the TOPKAPI-X model. The outlet location of the basin (hydrometric station) was used to simulate the flow using the TOPKAPI-X distributed hydrological model. Continuous time series data on a daily time step were used in this rainfall-runoff model. Specifically, daily rainfall data from 13 rain gauge stations and temperature data from 4 synoptic stations during the statistical period (1999 to 2020) were used to simulate the flow. After running the model several times, the general parameters were manually adjusted each time until the optimal values of the general parameters were obtained by considering the appropriate values of the evaluation criteria (NS and Bias) for the basin.

This research was conducted to analyze the flood discharge of one of the main sub-basins of the Karkheh dam basin using the TOPKAPI-X model on a daily time scale. In the TOPKAPI-X software environment, simulations were performed during the calibration period using input maps and observational rainfall, temperature, and discharge data. A visual comparison of the observed and simulated hydrographs allows for a general and quick evaluation of the model's accuracy. The graphical results of the comparison between the discharge generated by the TOPKAPI-X model with the calibrated parameters and the measured discharge in the Gamasiab basin were presented. The TOPKAPI-X model has the ability to estimate the maximum daily flow rates of the Gamasiab basin; however, some of the simulated flow rates are higher than the observed flow rates. Four criteria—NSE, R, BIAS, and RMSE—were used to evaluate the model. The evaluation results of the TOPKAPI-X model indicate the accuracy of flow simulation, with a Nash-Sutcliffe criterion of 0.697 during the calibration period (1999-2014) and 0.660 during the validation period (2015-2020) for the Gamasiab basin. Therefore, it can be concluded that this model has good performance for flow simulation.

The importance and usefulness of hydrological models for water resources management, understanding hydrological processes, and conducting impact assessment studies is clear. Hydrological models are crucial tools that enable scientists and policymakers to make informed decisions based on simulations of watershed behavior. Considering the increasing demand for water and the impact of climate change, hydrological simulation will be one of the essential methods for future water management. The results of this study showed that the TOPKAPI-X model has potential in simulating runoff in the selected basin. Due to the capabilities of the TOPKAPI-X distributed hydrological model, this software is recommended as a modeling tool for other basins.

Changes in precipitation patterns and its intensity due to the global climate change has led to intensifying floods as the most occurent natural disaster. ‏Flooding cannot be fully prevented, but its impacts can be mitigated by accurately identifying flood-prone areas and implmenting appropriate risk-based management measures. The Qarachai Watershed, located in the upstream of the Gorganrood River Basin in Golestan Province, Iran, was chosen as the study area, which has experienced several flood events in recent decades. ‏In this study, flood risk was assessed using the HEC-RAS, a two-dimensional hydraulic model. ‏Flood discharge values occured in the early 2019 were considered as model input, and based on ground truth, the manning roughness coefficient values were measured. To evaluate the results of the HEC-RAS model, some statistical criteria were used reflecting a good performance of the model. ‏The analysis showed that by increasing the return period, the extent, depth, and amount of flood risk increase. Moreover, the analysis showed that the flood zone in 100 year return period, affects parts of Seyedkalate Village. Approximately, half of the flood zone identified in this study was attributed with very low-risk. The results of the study are used to adopt appropriate strategies and plans to adapt to climate change and as an appropriate tool for identifying flood exposed and flood-prone zones.

Floods are one of the most damaging natural disasters in the world. So better understanding of the flood hazard phenomenon and its potential consequences is necessary. The present research is a part of the flood risk management approach based on the KULTURisk framework, in which vulnerability is examined as one of the flood risk components. The aim of the research is to assess the vulnerability of local communities exposed to the flood occurrence in the current conditions, and also to predict the effects of intervention scenarios to reduce it. Flood vulnerability assessment requires quantifying vulnerability components. In this research, the components, variables and indicators for the region existing conditions were selected based on the intended aim, region field observations and related literature review. The required data and information were collected using questionnaires and interviews with the local communities, statistical yearbooks, population and housing census data center, instructions and guidelines for the management system of statistics and hospital information, as well as referring to related executive organizations at the city and province levels. The statistical population includes local communities living in the 100-year flooding areas in a part of the Qarachai River in Ramian city (one of the tributaries of the Gorganroud River in the Golestan province). The reason for choosing this reach is the location of the villages in the vicinity of the river and the frequency of flood events that have occurred in the past years. The index values were normalized by classification scale and distance to reference methods and the weight of each index was determined by the Delphi method. The normalized index values were converted into spatial layers in the GIS environment. Then, a vulnerability map of the target area was prepared by combining the spatial layers of susceptibility, adaptation capacities and coping capacities variables. Based on the results, three intervention scenarios including early warning system establishment, risk governance intervention and risk spreading were selected in order to reduce the level of vulnerability in the face flooding for the study area. The degree of vulnerability of flood-affected areas in the study area for the current conditions was placed in the "highly vulnerable" class, while by applying intervention scenario under combined scenarios (including early warning system establishment, risk governance intervention and risk spreading), the vulnerability degree would change to "slightly vulnerable" level. The results of this research, is helpful for better understanding of the phenomenon of flooding and its potential consequences by the people and authorities of the Seyed Kalateh village. It also will facilitate the prioritization of measures appropriate to the region conditions in order to reduce vulnerability by increasing the capacity of adaptation and tolerance. Since, the effectiveness of the proposed measures such as creating an early warning system, intervention risk governance and risk spreading on reducing vulnerability and consequently reducing the amount of human and financial losses has been recognized, it is an important step in the direction of flood risk management at different scales. Moreover, the analysis shows the necessity of vulnerability assessment and adoption of specific policies at the local scale (the Seyed Kalateh village), while this issue is usually not considered in technical and financial planning of crisis management especially for flood risk management.

Site location is one of the spatial analyzes that has a great impact on reducing the costs incurred and launching various activities. So, this is one of the most important and effective steps in executive projects. Due to economic considerations and reduction of monitoring costs, optimization approaches in this study are to reduce groundwater quality monitoring stations in Dez watershed in Lorestan province. In this regard, using an algorithm based on the principle of maximum Shannon disorder index and based on the pollution index of TH, SAR, EC, SO4, Cl, HCO3, K, Na, Ca, Mg TDS and PH parameters, optimization was done for the available 63 monitoring stations in the statistical period of 1387 to 1396 (2008-2017). First, the average rank of each station in the 10 years data was obtained. Then, appropriates models were proposed for the network Shannon disorder index regarding the number of stations and time. After fitting the best model, the results showed that based on SO4, Cl, HCO3, K, Na, Ca, Mg, PH, TH SAR, TDS and EC parameters, 33, 34, 41, 24, 40, 34 , 30, 43, 33, 33, 41 and 28 stations are sufficient for groundwater in the study area, respectively. Also, among the 12 quality indicators evaluated for groundwater, potassium (K) had the highest value of Shannon disorder index. Therefore, it had the maximum Shannon disorder index and was selected as the superior index. The mean squared error and the mean absolute error value were used to validate the results.

In the methods of utilizing nanometer coatings, it is usually possible to reduce the amount of evaporation by using long chain molecules and spreading them on water and forming molecular monolayers. In this research, quantitative (evaporation reduction rate) and qualitative (chemical parameters) effects of octadecanol monolayer dissolved in ethanol as a chemical evaporation control method were investigated. Every three days, it was sprayed (4% concentration) on the water surface of natural ponds with dimensions of 2×2×2 cubic meters located in Faculty of Natural Resources meteorological research station. Accumulated evaporation for the two measured months in the control pond was 559 mm and in the pond with the octadecanol monolayer was 455 mm. Quantitative and qualitative analysis results in the two-month period between the two control ponds and the pond with octadecanol monolayer from 2021/8/23 to 2021/10/22 were performed based on ANOVA test, by comparing means with Tukey's and Duncan's methods. The octadecanol monolayer sample had a significant difference at 0.05 level in terms of changes in the rate of evaporation compared with the control, and the octadecanol monolayer with 20% efficiency was significantly effective in terms of reducing evaporation. Selected qualitative parameters including electrical conductivity, dissolved oxygen were investigated. The results of obtained data using SPSS software and ANOVA test, showed a non-significant difference due to sig greater than 0.05% of dissolved oxygen and electrical conductivity between the average of the control pond and the ponds with octadecanol monolayer. In the control pond, due to the possibility of contact with the air and more incoming radiation, the concentration of dissolved oxygen increased compared to the pond with octadecanol monolayer. The achieved results showed 5% decrease in electrical conductivity and in dissolved oxygen in the pond with the monolayer of the mentioned composition compared to the control pond. In terms of changes in water surface temperature (physical parameter), which was measured with a thermometer, its average was 24.4 ⁰C in the pond with octadecanol monolayer, while it was 23.11 ⁰C in the control pond with monolayer. Empirically, the effect of a dense layer in reducing evaporation losses is proportional to the increase in water surface temperature.

Optimization of monitoring network is a decision-making process through which, the best combination of existing stations is selected. Regarding the economic considerations and reducing monitoring costs, optimization approach in this study is to reduce the number of surface water quality monitoring stations in Dez basin in Lorestan province. In this regard, using an algorithm based on the principle of maximum entropy and water quality index of SO44, Cl, HCO3, K, Na, Ca, Mg, pH, TH, SAR, EC and TDS parameters, the optimization procedure was done for 18 existing monitoring stations during the statistical period of 1387-1396 (2008-2017). First, the average rank of each station in the mentioned 10 statistical years was obtained, then some models were proposed for the network entropy according to the number of stations and year. After fitting the best model, the results showed that based on SO4, Cl, HCO3, K, Na, Ca, Mg, pH, TH, TD, SAR and EC parameters, the number of sufficient stations as surface water quality monitoring network in the study area were 9, 9, 7, 11, 11, 11, 10, 7, 10, 10, 10, and 11, respectively. In order to validate the proposed network, by comparing the entropy of the proposed network with the entropy of random networks with the number of stations based on the 12 mentioned parameters in each year, the efficiency of the selected network was confirmed. Also, among the 12 evaluated quality indicators, chloride showed the highest entropy of weight. Therefore, chloride had the maximum entropy and was selected as the superior index.

The regional flood analysis was used for estimating magnitude of flood in ungagged watersheds or on watersheds withless than 0 to 20 years of flood data. The study area is located in the south of Sistan and Baluchestan province and its area is 27,654 square kilometers. In this paper, maximum instantaneous discharge of five hydrometric stations has been studied over the 963-2003 period and after testing data homogeneity by using the log Pearson type distribution that has been detected as the most appropriate distribution, maximum instantaneous discharge for various return periods was obtained. It also, 20 physiological characteristics of watersheds in the upstream stations was calculated by Arc GIS software and using cluster analysis, watersheds was classified into three homogeneous groups. By using multiple regressions, physiographical models were specified for all return periods. In this models, equivalent rectangle width, maximum height of river, concentration's time and curve number are more effective factors to estimate maximum instantaneous discharge with various return periods and by increasing maximum instantaneous discharge the effect of three parameters including equivalent rectangle width, maximum height of river and concentration's time are increased whereas the effect of curve number parameter is decreased.