Rahim Kazemi
Abstract
During the last two decades, there has been a lot of research on the base flow issue in the country, but so far, no comprehensive and specific article review of base flow research has been conducted, untill the various aspects of this issue be identified and the cases ignored, be introduced and addressed. ...
Read More
During the last two decades, there has been a lot of research on the base flow issue in the country, but so far, no comprehensive and specific article review of base flow research has been conducted, untill the various aspects of this issue be identified and the cases ignored, be introduced and addressed. In this research, first, by literature review at the global and national level, the progress of studies in different fields of this issue were investigated and then dissertations, articles and reports published in international journals and related conferences have been classified and discussed for the past two decades. The main purpose of this research was to identify issues of research at base flow and to identify lesser and overlooked issues in country research. The articles reviewed in this research were analyzed based on spatial domain, research method, theory, data analysis techniques and topic. Results showed that research orientation in base flow in Iran can be divided into four general categories; 28.21% of studies related to applied orientation; 37.18% to comparison and introduction of proper baseflow separation method; 19.23% to investigation of factors affecting base flow and 15.38% to general use and description of hydrological conditions of the study area. The overall conclusion, indicates limited studies, lack of innovative, and focus on the use of conventional and repetitive methods and also lack of attention to this issue by scientific and research centers of the country.
Nasrin Mirzaee; Amirpouya Sarraf
Abstract
River runoff forecasting in watersheds has a special place in the management and planning of water resources for the design of water facilities, water intake from rivers, consumption management and etc. In the present study, the performance of some data integration models including simple averaging, ...
Read More
River runoff forecasting in watersheds has a special place in the management and planning of water resources for the design of water facilities, water intake from rivers, consumption management and etc. In the present study, the performance of some data integration models including simple averaging, weighted averaging and integrated artificial neural network model in monthly discharge modeling has been evaluated and compared. For this purpose, monthly flow prediction in upstream basin of Jiroft Dam was examined using Artificial Neural Network (ANN) models, Adaptive Neural-Fuzzy Inference System (ANFIS), ARIMA model and Support Vector Regression (SVR) model as an individual model. Then, the individual models were trained and validated using selected predictor variables and their results were selected for use in the integration process. Large-scale climatic signals including NAO, ENSO and PDO are also used in hydrological forecasts of river flow and the performance of single and integrated models in two modes with and without considering these signals has been compared based on the evaluation of three criteria Nash-Sutcliffe (NSE), Coefficient of determination (R2) and Mean Square Error (MSE). Results of this study indicated that the integrated approach significantly increases the accuracy of predictions. In addition, large-scale climatic signals were found to improve results, especially during the test period. For example, the results of the integrated model of artificial neural network with large climatic scale signals show that this model has the best performance among the integrated models. Also, the NSE criterion has improved by 0.04 in training compared to the integrated model of artificial neural network without large-scale signals and the MSE error has been reduced by 0.001.
Nosrat Aghazadeh; Manochehr Chitsazan; Yahya Mirzaee; Hamed Ebrahimi
Abstract
Due to various sources of contamination in the urban aquifers, the potential for pollution of groundwater resources is high. Thus, the vulnerability of groundwater resources can be very effective in identifying vulnerabilities and sensitive groundwater aquifers. The aim of this study was to present a ...
Read More
Due to various sources of contamination in the urban aquifers, the potential for pollution of groundwater resources is high. Thus, the vulnerability of groundwater resources can be very effective in identifying vulnerabilities and sensitive groundwater aquifers. The aim of this study was to present a modified DRASTIC Model to determine groundwater vulnerability in Urmia urban aquifer. To this end, parameters with low impact such as slope and aquifer media were ignored from the DRASTIC Model. Instead, land use, urbanization index, water value and pollution sources were added to the model. Also, the impact of unsaturated zone media and recharge layers were corrected. Results of the modified DRAST-VUL Model in the study area demonstrate that in most areas, the risk of pollution is low to moderate and the vulnerability in 29% of study area is high due to agricultural and industrial activities and low groundwater depth. Considering the results, the vulnerability index is the most sensitive measure to the parameter of pollutant sources, land use and the unsaturated zone. The sensitivity of the model to recharge, transmissivity and water value parameters were low due to the increase of impermeable surface in urban area. Based on positive results obtained from model validation through nitrate, the proposed model can be considered as an effective tool for the protection, revention and optimal utilization of groundwater resources in the study area. Also, this vulnerability model can be used for other urban aquifers.
Hersh Entezami; Sayed Kazem Alavipanah; Hamidreza Matinfar; Ali Darvishi; Kamran Chapi
Abstract
The importance of snow and its water equivalent in water resources supply has caused many studies and researches to measure snow characteristics and runoff. Conducted in the Saqqez Watershed, this research attempted to estimate snow–induced runoff in a mountainous area and the SRM Model was ...
Read More
The importance of snow and its water equivalent in water resources supply has caused many studies and researches to measure snow characteristics and runoff. Conducted in the Saqqez Watershed, this research attempted to estimate snow–induced runoff in a mountainous area and the SRM Model was selected to simulate daily runoff from snow-melt. Based on the data and variables for four consecutive years of 2006 to 2009 collected and snowmelt runoff was estimated. MODIS satellite images were used to calculate the snow coverage area. After segregating the snow coverage from the images, the daily snow area was calculated using GIS, and along with the other variables, imported into the model. For better evaluation of efficiency of the model, the model was calibrated and validated. The process of calibration was led to the best estimate for each parameter. To evaluate the accuracy of model and comparing results with field data Nash-Sutcliffe coefficient and the percentage difference were used. The results of the Nash-Sutcliffe coefficient were between 0.90 to 0.94 and the differences in the volume were 6.8 to 7.2 percent, which indicates the high-performance of modeling.
Behnam Farid Giglou; Reza Ghazavi; Siamak Dokhani
Abstract
Rivers have always been considered by human societies as one of the main sources of drinking water and agriculture during human life and have been very effective in the formation of human civilizations. Aras River is a border river that is one of the most important sources of drinking water in many surrounding ...
Read More
Rivers have always been considered by human societies as one of the main sources of drinking water and agriculture during human life and have been very effective in the formation of human civilizations. Aras River is a border river that is one of the most important sources of drinking water in many surrounding towns and villages. The aim of this study is to evaluate the water quality of Aras River at present and predict it for the future period under RCP release scenarios. In this study, monthly data of discharge, precipitation, TDS, SO4, EC, BOD, Do, COD, No3, and Po4 during the statistical period of 1995-2018 were analyzed using WQI water quality index. Also, changes in precipitation and temperature were predicted under RCP release scenarios. To investigate the impact of climate change on river water quality, regression relationships were established between rainfall, discharge and water quality parameters and according to the forecast for rainfall and discharge in the period 2017-2036, water quality conditions with WQI index for scenarios. RCP8.5, RCP4.5 and RCP2.6 were calculated. In addition, the effect of changes in climate parameters on the quality parameters of phosphate and nitrate was estimated using the SWAT model for the future. The results of statistical studies showed that the amount of nitrate, phosphate and COD parameters in all three scenarios will be increasing. Also, the simulation results of phosphate and nitrate parameters using SWAT model have predicted incremental conditions for all three scenarios. The results of the effect of climate change on water quality using the WQI index showed that water quality is in poor condition at baseline (WQI index is 15.69) and under the influence of climate change based on scenarios of RCP8.5, RCP4.5 and RCP2.6 WQI value 11.17, respectively; 12.23 and 12.45 and water quality will change to very bad, which requires attention to the quality of the Aras River and the prevention of pollutants.
Jalal Heidari; Alireza Vaezi; Mohammad amir Delavar
Abstract
The variety of factors affecting soil properties leads to temporal changes in the soil erosion process. This research was conducted to assess short-term changes in runoff and soil loss in rainfed wheat furrows under fallow conditions. To this end, three rainfed lands with 15% slope gradient were selected ...
Read More
The variety of factors affecting soil properties leads to temporal changes in the soil erosion process. This research was conducted to assess short-term changes in runoff and soil loss in rainfed wheat furrows under fallow conditions. To this end, three rainfed lands with 15% slope gradient were selected in south west of Kermanshah Province. In each land, furrows with five m in length and 30 cm in width were created using sowing set. Runoff and soil loss were measured using simulated flows with a discharge of 0.5, 1, 1.5 and 2 L.min-1 at intervals of five minutes to 60 minutes 60 minutes in three replications. Results showed that the lowest soil loss was recorded in flow discharge of 0.5 L.min-1 (2.66 g.m-2) and the highest of soil loss was produced in flow discharge of 2 5 L.min-1 (85.33 g.m-2). Also, the lowest runoff was recorded in flow discharge of 0.5 L.min-1 (0.47 L) and the highest of soil loss was produced in flow discharge of 2 5 L.min-1 (7.65 L). The effect of time on runoff and sediment variables was significant in all flow discharge (p<0.01). Runoff production was low at the beginning of the experiment and increased over time. The pattern of temporal changes in soil loss was different from runoff production, amount of soil loss at the beginning of the experiment was higher values than the final test times, which associated with to supply of erodible soil particles in the rills in the beginning of the experiment. With starting the experiment to 25 minutes, the rate of soil loss changes drastically and then until the end of the experiment, it followed a uniform reduction pattern and in the final stages, it is almost constant. The results showed that rill erosion is strongly influenced by flow intensity and its value changes over time and these changes are independent of flow production and depended on the transmittance of soil particles transferable in the rill.
Mohammadjafar Soltani; Amir Sarreshtehdari; Samad Shadfar
Abstract
Inadequate temporal and spatial distribution of precipitation in arid and semi-arid regions, cause destructive floods in addition to loss of surface runoff. Therefore, controlling surface runoff and its proper utilization through the construction of rainwater catchment systems can be a good way to prevent ...
Read More
Inadequate temporal and spatial distribution of precipitation in arid and semi-arid regions, cause destructive floods in addition to loss of surface runoff. Therefore, controlling surface runoff and its proper utilization through the construction of rainwater catchment systems can be a good way to prevent water loss. Traditional methods may be time wasting and concise. Geographic information systems provide new methods and models of using huge number of maps and data for analysis in a short time with best results and conciseness. This project was implemented in Kan Basin as a pilot which covers an area about 197 km2. Different maps including slope, land use, precipitation, vegetation cover, soil hydrologic groups and geology were overlayed. Land use maps were extracted from ETM+ 8 satellite images of 2014 along with field controls. Then layers were weighted according to their importance and role of each map. Suitable areas for establishing rainwater catchment systems in each model were determined by overlaying in the frameworks of different models including Boolean logic, Index overlay and Fuzzy logic and compared with control points which were implemented with Ministry of Jihad Agriculture. The results showed that the operators gamma=0.2, gamma=0.3 and Product from Fuzzy logic model had the most overlap with the control areas, the best integrated model for determining the appropriate locations for the construction of rainwater catchment systems in the study region.
Noorangiz Gholami; Karim Solaimani; Ataollah Kavian; Vahid Gholami
Abstract
Destruction of the riverbed and activities in the river area, including mining activities, road construction, non-standard bridges, etc., often increase the risk of floods. Due to importance of this issue in the present study, the effect of mining activities on determination of channel boundary of Haraz ...
Read More
Destruction of the riverbed and activities in the river area, including mining activities, road construction, non-standard bridges, etc., often increase the risk of floods. Due to importance of this issue in the present study, the effect of mining activities on determination of channel boundary of Haraz River, (Noorrud junction to Kelerd forest area as a given reach) has been investigated with a length of 40 km. In this regard, to study changes in river mineral activity levels during the years 1985 to 2021 from satellite images, to simulate the hydraulic behavior of the river from the HEC-RAS hydraulic model and to compare changes in river area during the study period the DLSRS model were used. Thus, satellite data with visual interpretation techniques were used to determine the level of mining activities. Then, a 1: 2000 scale topographic map of the riverbed in the HEC-GeoRAS (GIS) extension and the HEC-RAS model was used to simulate the hydraulic behavior of the river. Finally, by estimating the five parameters of the DLSRS model, the quantitative values of the river at 10-year intervals were determined in the period 1300-1399. The results of changes in the levels of mining activities indicate geometric changes of the bed of the given reach such as displacement and narrowing process. The results of the study of the factors of channel boundary changes also showed that increasing human activities and changing the river flow regime increase the quantitative boundary of the channel. The results also showed that during the last century, the level of mines in the study area has increased from 3.35 to 13.57 ha in 2021, the maximum development of which has been since 2011. As a result, the quantitative area of the river has increased from 9 m in 1922 to 17 m in 2021.
Saeedeh Nateghi; Elham Rafiiei sardooi; Ali Azareh; Farshad Soleimani Sardoo
Abstract
Changes in water cycles in different parts of the world is one of the effects of climate change in recent decades. Evapotranspiration, as the part of the hydrological cycle, will also undergo these changes. Therefore, in the present study, the effect of climate change on potential evapotranspiration ...
Read More
Changes in water cycles in different parts of the world is one of the effects of climate change in recent decades. Evapotranspiration, as the part of the hydrological cycle, will also undergo these changes. Therefore, in the present study, the effect of climate change on potential evapotranspiration changes in Halilrood Watershed, under RCP2.6, RCP 4.5 and RCP 8.5 scenarios using LARS-WG downscaling model and the output of the general circulation model of HadGEM2 in future (2021-2040) was studied and the rate of evapotranspiration at the basin scale was calculated based on the predicted climatic parameters using Tornthwaite method in future. According to the results of the LARS-WG model, in the study area, precipitation will decrease and the temperature will increase under all scenarios in future compared to the baseline period. Evapotranspiration will also increase based on the predicted temperature and precipitation. So that, at the basin scale, evapotranspiration will increase by 3.4, 6.8 and 8.5 under RCP 2.6, RCP 4.5 and RCP 8.5 scenarios in future (2040-2021), respectively. According to the results, the highest increase in temperature and evapotranspiration and the highest decrease in precipitation at the basin scale is related to the RCP 8.5 scenario. The results of this study can be used in studies related to water resources management, agricultural and environmental studies.
Afshin Partovi; Hamidreza Peyrowan; Samad Shadfar; Fazel Iranmanesh
Abstract
Land cover change is one of the most effective factors of environmental change. So, understanding and predicting the causes, processes and consequences of land cover has become a major challenge. The remote sensing and satellite data technologies can be used effectively to detect and quantify land cover ...
Read More
Land cover change is one of the most effective factors of environmental change. So, understanding and predicting the causes, processes and consequences of land cover has become a major challenge. The remote sensing and satellite data technologies can be used effectively to detect and quantify land cover changes and its effects on the environment. This research used the MODIS MCD12Q1 yearly data at 500 m resolution to evaluate the spatio-temporal changes in the national land cover of Iran from 2001 to 2015 in five years periods. Land cover maps of Iran were generated based on 12 classes for years of 2001, 2005, 2010 and 2015 and then evaluated using “Landcover Change Matrix”. Areal distribution analysis showed that the most parts of Iran covered by barren areas (more than 60%). The area of forests, croplands and grasslands were reduced from 0.8, 4.8 and 21.4 percent respectively in the year of 2001 to 0.6, 4.5 and 20.9 percent of Iran’s area in 2015. Furthermore, to evaluate land cover changes in five years’ period, the land cover map of the first and last years of each period were compared using “Landcover Change Matrix”. Results showed that in the five years periods of 2001-2005, 2005-2010 and 2010-2015 land cover of Iran changed increasingly as 2.13, 3.25 and 3.30 percent respectively of Iran’s area. And the overall changes of land cover in Iran from 2001 to 2015 is 6.08 percent of Iran’s area.
