فهرست مطالب ناصر جبراییلی اندریان

Iran's groundwater reservoirs have faced significant and related challenges in the past three decades. The simultaneous decrease in the volume and quality of these waters, which are increasingly contaminated with pollutants, renders them largely unusable for many uses. Therefore, there is an increasing emphasis on evaluating the quality of groundwater and identifying anthropogenic or geogenic factors that affect its quality more than ever before. In this study, the hydrogeochemical pollution caused by major, minor, and trace elements was identified by examining the water table against the electrical conductivity of water resources in Azarshahr plain. Long-term data on water levels and electrical conductivity were obtained from regional water resources in East Azerbaijan province. After initial examination, 33 samples were collected from wells and qanats in the area and transferred to the water laboratory of Tabriz University for analysis. The measured parameters included pH, electrical conductivity, major, minor, and trace elements.The results of chemical analysis showed that the concentrations exceeding the permissible drinking limit for nitrates and elements such as Arsenic, Lead, Nickel, and Chromium. Piper diagrams and Stiff diagrams were used to determine the water type in the area; it was found that the water type is mainly sulfate and bicarbonate-based. The origin of the available water is related to the geological formations in the area as a result of mixing and ion exchange.Furthermore, multivariate statistical analysis using factor analysis revealed four influential factor groups affecting water quality in the area; only the fourth factor was attributed to anthropogenic. In general, most of the trace elements in water sources are influenced by formations and aquifer-rock interactions.The overall trend of groundwater quantity over a 25-year period is relatively stable with a slight downward slope; however, the general trend of electrical conductivity is ascending with a much steeper slope indicating an increase in anthropogenic activities as well as the presence of saline layers, which leads to a decrease in the quality of groundwater. Most of the contaminated samples in terms of major and trace elements are located around Gowgan city at the end of the plain. The pollution at this end is related to dissolution trends along with movement paths of groundwater flow and density of pumping wells in this area.

Azarshahr plain is one of the wide plains in Lake Urmia basin which has an important source of groundwater and it is at risk of nitrate pollution due to the agricultural prosperity in this plain. Therefore, it is necessary to protect these groundwater resources using the most suitable and inexpensive solutions by identifying the areas exposed to the risk of pollution. In this study, in order to investigate the inherent vulnerability and risk of contamination, geological data, hydrogeological information and geophysical data were used as well as the digital elevation map of SRTM satellite with a spatial accuracy of 30 meters. Also the concentration of nitrate contaminant sampled from 35 different sources with appropriate distribution was used for validation. The pollution risk of Azarshahr plain aquifer was investigated using "Source-Pathway- Receptor" method. In this method, after identifying the source of pollution, the aquifer vulnerability was considered as a pathway. Improved DRASTIC method by SFL, M5P and RS models were used to evaluate the aquifer vulnerability, then the vulnerability map to nitrate contaminant was obtained. Based on the highest correlation (r = 0.87) and the lowest error (RMSE = 0.06), the M5P model was selected as the best model for vulnerability assessment. Finally, the risk map of nitrate pollution was obtained by multiplying the vulnerability of the aquifer (based on the M5P model) and the velocity of the groundwater. The results showed that the pollution risk of aquifer to nitrate pollutant is high in the central part of the aquifer.

Recently, due to the trend of decreasing rainfall and increasing groundwater pumping rate, there have been concerns about the risks caused by the decrease in the volume of aquifer reserves and the drop in the groundwater level, and as a consequence the land subsidence. Also, in Ajabshir plain due to a gradual decrease in the water level, it is necessary to estimate the subsidence and investigate the subsidence potential to prevent its harmful risks in the future. For this purpose, using the ALPRIFT framework, which includes seven layers of parameters affecting subsidence, the subsidence potential map was zoned. The subsidence potential index was obtained in low and moderate ranges. In the next step, using Sentinel-1 satellite images, the subsidence during the years 2020-2021 was estimated to be 2.4 cm, which had a significant correlation with the groundwater level of the water year 2020-2021 and subsidence potential. In addition, artificial intelligence optimization methods including fuzzy logic (Sugeno) and genetic algorithm were used in order to fix the defects of applying expert opinions and increase the correlation between subsidence (Insar) and ALPRIFT, among these models, Sugeno's fuzzy method provided the best correlation between the two subsidence maps and ALPRIFT. The correlation between subsidence with ALPRIFT, ALPRIFT-GA and ALPRIFT-SFL was obtained as 0.46, 0.62 and 0.72 respectively.

In order to investigate the quality of groundwater in September 2022, 35 samples were collected from various groundwater sources in the Azarshahr plain, and the main elements, nitrates, and trace elements such as chromium, cadmium, nickel, lead, and arsenic, as well as two types of pesticides such as imidacloprid and chlorpyrifos, were analyzed and compared to drinking water standards. The drinking water quality index for the study area was calculated based on the concentration of parameters in the samples, and the health risk of cancerous and non-cancerous diseases for two age groups, children and adults, was calculated using the criteria of the United States Environmental Protection Agency (USEPA). According to the findings of the studies, the region's water quality index is average, and the non-carcinogenic risk index for children and adults is less than one. It is hazardous, but the risk of carcinogenesis in the entire region is greater than 10-4, and its consumption poses health hazards due to skin contact. The health risk of cancer is many times higher in the region's south, in the cities of Azarshahr and Gogan, as well as the adjacent villages. The correlation between the GQI map and the health risk maps revealed that the correlation of carcinogenic risk is greater than the correlation of non-carcinogenic risk, and based on the correlation between the parameters in the region's groundwater, the elements influencing the health risk of carcinogenesis caused by geogenic factors and human activities do not play a significant role.

Considering the quality of drinking water in human health, an important role should be given to the quality of aquifers as the main source of water supply required for rehabilitation experiences. The purpose of this study was to investigate the groundwater quality required for drinking in the northeast of Bijar plain with GQI index using GIS software. Study area of Bijar plain aquifer is one of the aquifers of Kurdistan province, which is the source of drinking water in part of Bijar city and affects more than 12 villages.. Drinking water quality index was prepared using four methods GQI, GQI-GA, GQI-FL-GA and GQI-FG for this aquifer and then the correlation coefficient and RMSE were used to validate and compare the results of the four methods. Based on the obtained results, GQI-FL-GA method with correlation coefficient of 0.89 and RMSE 0.01 showed the best results and GQI-FG method with correlation coefficient of 0.86 and RMSE 0.11 presented the weakest results. According to this method, about 8.8 and 91.2 percent of the plain has acceptable and suitable quality, respectively, that most of the northeastern parts that are the output of the plain have lower quality than other areas.

The rocks that can be karstified are divided into two categories of carbonate rocks (limestone and dolomite) and evaporates (salt and gypsum). One of the karstic landforms are caves. Hydrogeologically, caves are dissolved cavities with diameter larger than 5 to 15 mm. This is the threshold of turbulent flow. One of the important characteristics of the caves is the cross-sectional pattern and this parameter is a controlling factor of the cave development mechanism. Caves are developed in general due to tectonic factors are structure control with irregular cross section. These types of caves are developed along faults, joints and bedding. On the other hand, caves which are caused by hydraulic phenomena (hydraulic control), have a circular or ellipsoidal cross-section. However, the first factor in the creation of such caves may also be tectonic structures, but the most important factor for their development was the flow of water (Karimi, 2010).The karstic flow model was divided into two types of diffuse and conduit types according to velocity and governor flow equations. In diffuse flow systems, the water moves linearly through the connected fractures less than a centimeter. In this type of flow, the output of the springs is numerous and with low discharge. While in conduit system, water moves through the joints and channels larger than one centimeter and is usually exposed as a large discharge spring. Due to the high distribution of carbonate rocks in Kurdistan province and extensive exploitation of karst springs, recognizing these resources and identification of the role of karstification in supplying the water resources of the province is a necessity. Karstic water sources are strategic water supply sources specially in crisis of drought period. In this research, after determining the karst areas of the province, caves and karstic springs as two important indicators of karst development were studied to evaluate the characteristics of caves and springs of the province in terms of development model and flow system.

In order to investigate the development of karst and formation of caves and karstic springs, at the first, comprehensive knowledge of the region's petrology is necessary. The formation and structural conditions of the region should also be identified in order to recognize areas with high potential of karstification. Understanding the types of karstic units also helps to identify the level of karstification in different parts of the areas. Using plan of the caves, it is possible to compare the passage strike of the caves with fault's rose diagram. Study of spring density and the discharge rate of karstic springs in different parts of the area can be done to find out whether the karst development system is conduit or diffuse type. Also, to study the relation between the water quality of the springs with the geological formations, hydraulic conductivity (EC) was focused on. The lower electrical conductivity (EC) values are belonged to springs originated from hard rock and karstic units of the area. One of the ways that can be used to evaluate the permeability of hard and carbonate formations is Special Discharge assessment for each formation.

About 29% of the province area is formed of karstic units including impure and pure lime, lime with volcanic layers, and dolomite with the most coverage percent. The results of this study showed that all caves of the area are located on the karstic units of the province and their dominant strikes are concordant with dominant strike of the faults. By comparing Rose diagrams of fault lines around several caves with that’s of cave passage the effect of water or structure on controlling the development pattern of these caves was determined. The total discharge of the springs is 13.7 m3/s   which 9.5 m3/s (about 70%) of that belongs karstic springs.Most springs with discharge above 5 L/S originated from karstic formations are located especially in limestone, impure limestone and limestone with volcanic layers. Average discharge of total karstic springs are 0.4 liters per second, showing poor development of karst or development of diffuse model of flow system.  However, karst development system seems to be conduit dominated in the southern parts of the province and diffuse dominated at the other areas. The minimum electrical conductivity (EC) of the study area belongs to springs that discharge fractured and karstic units.The results of this study showed that all caves of the area are located on the karstic units and their dominant length is consistent with the dominant length of the faults. By comparing the Rose diagrams of fault lines around several caves with the cave passage strike revealed that structure and tectonics have the main control on development, pattern and profile of the caves. About 69.5 % of the total discharge of the springs of study area are originated from the karstic units. Karstic springs provide 79.32% of the water use in agriculture and 4% of urban and rural drinking water in Kurdistan province. The karst development system seems to be conduit dominated in the southern parts of the province and diffuse dominated at the other parts. The minimum electrical conductivity (EC) is belongs to springs which discharge fractured rock and karstic units. The most specific discharge rates are related to carbonate rocks and lowest discharge rates are related to crystalline rocks of the province.