The Hydrochemical Characteristics of a Stressed Sand-Gravel Aquifer: Kazan Plain, Ankara, Turkey (original) (raw)
Related papers
A case study is presented that characterizes the hydrogeology of a karstic aquifer system nearby the city of Izmir, Turkey. The main objective of this study is to provide an assessment on the spatial distribution of specific groundwater quality parameters, and to gain insight into their temporal evolution. The study area is the Nif Mountain karstic aquifer system located to the southeast of the city of Izmir that is an important recharge source for the densely populated surrounding area. The 1000 km 2 study area is within the boundaries of the third largest city, and in the vicinity of one of the most industrialized areas of Turkey. Therefore, it is under significant environmental stresses due to residential, industrial and agricultural activities. Field work was conducted as a series of field excursions to study the hydrogeology, and to mark sampling points for consecutive groundwater sampling. A total of 59 sampling points were selected constituting of 25 wells and 34 springs. Sampling was performed in April and September 2006, during the wet and dry season of the year to assess possible temporal changes in water quality and isotopic composition. Samples were analyzed for several groundwater quality parameters including major ions, arsenic, boron, heavy metals and isotopic composition. In addition to geochemical characterization, discharge rates of some springs were measured. It is found that the hydrogeological structure is fairly complex with springs having a wide range of discharge rates. High-discharge springs originate from allochthonous limestone units and surface outcrops of conglomerate and sandstone units. On the other hand low-discharge springs are formed at the contacts of claystone and limestone units, and at the contact zones of allochthonous limestone and flysch units. High-discharge springs typically have rates higher than 200 L/s in the winter months, with a maximum of about 1000 L/s. However, a 65% decrease was observed for the summer months. Based on stable isotope analysis data, an oxygen18deuterium relationship is obtained that lies somewhere between the Mediterranean meteoric and mean global lines. Tritium analyses confirm that low-discharge springs originating from contact zones have longer circulation times compared to high-discharge karstic springs. Isotopic composition of groundwater does not change throughout the year, except for tritium. Furthermore, spatial assessment of geochemical data revealed a correlation of sampling elevation with nitrate, chloride and electrical conductivity (EC). This result implies that groundwater quality significantly deteriorates as water moves from the mountain to the plains. The same "elevation effect" was also observed for the CaCO 3 concentrations, therefore indicating continuous rock dissolution as groundwater flows through the system. Heavy metal, arsenic and boron concentration are generally below drinking water quality standards with a few exceptions occurring in residential and industrial areas located at the foothills of the mountain. Comparative evaluation of winter and summer quality data shows an overall increase in electrical conductivity values. Nitrate contamination was more sporadic and concentration changes in time were less predictable. Although lower contaminant concentrations due to dilution effects were expected for the winter months, the internal hydrodynamics and the ongoing dissolution processes in the karstic aquifer system are suspected to seclude any temporal trends. It is concluded that the Nif Mountain overall has a significant potential to provide high quality water, although the available groundwater quantity is expected to drop significantly for the summer months, due to decrease in discharge and also because of deterioration of groundwater quality. From a water quality point of view, direct consequences of anthropogenic activities were observed, which requires close monitoring of Nif Mountain's pristine water resources. The study revealed that less groundwater recharge in the dry period of the year does not always translate to higher concentrations for all groundwater quality parameters. It was also evident from the study results that water circulation times, lithology, quality and extent of recharge also play an important role on the alteration of groundwater quality.
Environmental Earth Sciences, 2003
Human activities and agriculture have had direct and indirect effects on the rates of contamination of groundwater in the Incesu-Dokuzpınar spring area. Direct effects include dissolution and transport of excess quantities of fertilizers with associated materials and hydrological alterations related to irrigation and drainage. Indirect effects may include changes in water-rock reactions in soils and aquifers caused by increased concentrations of dissolved oxidants, protons, and major ions. Agricultural activities have directly or indirectly affected the concentrations of a large number of inorganic chemicals in groundwater, for example NO 3 , N 2 , Cl, SO 4 2 , H + , K, Mg, Ca, Fe, Cu, B, Pb, and Zn, as well as a wide variety of pesticides and other organic compounds. For reactive contaminants like NO 3 , it is recommended that a combination of hydrochemical and environmental-tracer analytical approaches might be required to resolve changing inputs from subsequent alterations as causes of concentration gradients in groundwater. The water type of Dokuzpınar springs is mainly Na-Mg-Ca-Cl-HCO 3 . Note that the water types of the springs were directly related to the hydrogeochemical properties of outcrops at the study area. Thus, the high concentration of Ca 2+ and HCO 3 is mainly related to the high CO 2 contents in the marbles, whereas the high Na concentration arises from the existing syenite, volcanic ash, basalt, and clay units, although the _ I Incesu-Dokuzpınar springs cover most of the drinking and irrigation water demands of this area. The high concentrations of NO 3 and NaCl show that the area around the springs is continuously being contaminated by untreated sewage and agricultural wastes, especially during dry periods. Therefore, this approach is based on the vulnerability studies of the catchment area, determination of the transfer time of the pollutant, and the water-bearing formations of _ I Incesu-Dokuzpınar springs. Vulnerability in this study is defined as the intrinsic hydrogeochemical characteristics of an aquifer, which may show the sensitivity of groundwater to be contaminated by different human activities.
Human activities and agriculture have had direct and indirect effects on the rates of contamination of groundwater in the Incesu-Dokuzpınar spring area. Direct effects include dissolution and transport of excess quantities of fertilizers with associated materials and hydrological alterations related to irrigation and drainage. Indirect effects may include changes in water-rock reactions in soils and aquifers caused by increased concentrations of dissolved oxidants, protons, and major ions. Agricultural activities have directly or indirectly affected the concentrations of a large number of inorganic chemicals in groundwater, for example NO 3 , N 2 , Cl, SO 4 2 , H + , K, Mg, Ca, Fe, Cu, B, Pb, and Zn, as well as a wide variety of pesticides and other organic compounds. For reactive contaminants like NO 3 , it is recommended that a combination of hydrochemical and environmental-tracer analytical approaches might be required to resolve changing inputs from subsequent alterations as causes of concentration gradients in groundwater. The water type of Dokuzpınar springs is mainly Na-Mg-Ca-Cl-HCO 3 . Note that the water types of the springs were directly related to the hydrogeochemical properties of outcrops at the study area. Thus, the high concentration of Ca 2+ and HCO 3 is mainly related to the high CO 2 contents in the marbles, whereas the high Na concentration arises from the existing syenite, volcanic ash, basalt, and clay units, although the _ I Incesu-Dokuzpınar springs cover most of the drinking and irrigation water demands of this area. The high concentrations of NO 3 and NaCl show that the area around the springs is continuously being contaminated by untreated sewage and agricultural wastes, especially during dry periods. Therefore, this approach is based on the vulnerability studies of the catchment area, determination of the transfer time of the pollutant, and the water-bearing formations of _ I Incesu-Dokuzpınar springs. Vulnerability in this study is defined as the intrinsic hydrogeochemical characteristics of an aquifer, which may show the sensitivity of groundwater to be contaminated by different human activities.
Groundwater quality and hydrogeochemical properties of Torbali Region, Izmir, Turkey
Environmental Monitoring and Assessment, 2008
The large demand for drinking, irrigation and industrial water in the region of Torbalı (Izmir, Turkey) is supplied from groundwater sources. Almost every factory and farm has private wells that are drilled without permission. These cause the depletion of groundwater and limiting the usage of groundwater. This study investigates spatial and temporal change in groundwater quality, relationships between quality parameters, and sources of contamination in Torbalı region. For this purpose, samples were collected from 10 different sampling points chosen according to their geological and hydrogeological properties and location relative to factories, between October 2001 and July 2002. Various physical (pH, temperature, EC), chemical (calcium, magnesium, potassium, sodium, chloride, alkalinity, copper, chromium, cadmium, lead, zinc) and organic (nitrate, nitrite, ammonia, COD and cyanide) parameters were monitored. It was observed that the groundwater has bicarbonate alkalinity. Agricultural contamination was determined in the region, especially during the summer. Nitrite and ammonia concentrations were found to be above drinking water standard. Organic matter contamination was also investigated in the study area. COD concentrations were higher than the permissible limits during the summer months of the monitoring period.
Human activities and agriculture have had direct and indirect effects on the rates of contamination of groundwater in the Incesu-Dokuzpınar spring area. Direct effects include dissolution and transport of excess quantities of fertilizers with associated materials and hydrological alterations related to irrigation and drainage. Indirect effects may include changes in water-rock reactions in soils and aquifers caused by increased concentrations of dissolved oxidants, protons, and major ions. Agricultural activities have directly or indirectly affected the concentrations of a large number of inorganic chemicals in groundwater, for example NO 3 , N 2 , Cl, SO 4 2 , H + , K, Mg, Ca, Fe, Cu, B, Pb, and Zn, as well as a wide variety of pesticides and other organic compounds. For reactive contaminants like NO 3 , it is recommended that a combination of hydrochemical and environmental-tracer analytical approaches might be required to resolve changing inputs from subsequent alterations as causes of concentration gradients in groundwater. The water type of Dokuzpınar springs is mainly Na-Mg-Ca-Cl-HCO 3 . Note that the water types of the springs were directly related to the hydrogeochemical properties of outcrops at the study area. Thus, the high concentration of Ca 2+ and HCO 3 is mainly related to the high CO 2 contents in the marbles, whereas the high Na concentration arises from the existing syenite, volcanic ash, basalt, and clay units, although the _ I Incesu-Dokuzpınar springs cover most of the drinking and irrigation water demands of this area. The high concentrations of NO 3 and NaCl show that the area around the springs is continuously being contaminated by untreated sewage and agricultural wastes, especially during dry periods. Therefore, this approach is based on the vulnerability studies of the catchment area, determination of the transfer time of the pollutant, and the water-bearing formations of _ I Incesu-Dokuzpınar springs. Vulnerability in this study is defined as the intrinsic hydrogeochemical characteristics of an aquifer, which may show the sensitivity of groundwater to be contaminated by different human activities.
Groundwater quality and hydrogeochemical properties of Torbalı Region, Izmir, Turkey
Environmental Monitoring and Assessment, 2008
The large demand for drinking, irrigation and industrial water in the region of Torbalı (Izmir, Turkey) is supplied from groundwater sources. Almost every factory and farm has private wells that are drilled without permission. These cause the depletion of groundwater and limiting the usage of groundwater. This study investigates spatial and temporal change in groundwater quality, relationships between quality parameters, and sources of contamination in Torbalı region. For this purpose, samples were collected from 10 different sampling points chosen according to their geological and hydrogeological properties and location relative to factories, between ) and organic (nitrate, nitrite, ammonia, COD and cyanide) parameters were monitored. It was observed that the groundwater has bicarbonate alkalinity. Agricultural contamination was determined in the region, especially during the summer. Nitrite and ammonia concentrations were found to be above drinking water standard. Organic matter contamination was also investigated in the study area. COD concentrations were higher than the permissible limits during the summer months of the monitoring period.
Environmental Earth Sciences, 2003
Human activities and agriculture have had direct and indirect effects on the rates of contamination of groundwater in the Incesu-Dokuzpınar spring area. Direct effects include dissolution and transport of excess quantities of fertilizers with associated materials and hydrological alterations related to irrigation and drainage. Indirect effects may include changes in water–rock reactions in soils and aquifers caused by increased concentrations of dissolved oxidants, protons, and major ions. Agricultural activities have directly or indirectly affected the concentrations of a large number of inorganic chemicals in groundwater, for example NO3, N2, Cl, SO42, H+, K, Mg, Ca, Fe, Cu, B, Pb, and Zn, as well as a wide variety of pesticides and other organic compounds. For reactive contaminants like NO3, it is recommended that a combination of hydrochemical and environmental-tracer analytical approaches might be required to resolve changing inputs from subsequent alterations as causes of concentration gradients in groundwater. The water type of Dokuzpınar springs is mainly Na–Mg–Ca–Cl–HCO3. Note that the water types of the springs were directly related to the hydrogeochemical properties of outcrops at the study area. Thus, the high concentration of Ca2+ and HCO3 is mainly related to the high CO2 contents in the marbles, whereas the high Na concentration arises from the existing syenite, volcanic ash, basalt, and clay units, although the İncesu-Dokuzpınar springs cover most of the drinking and irrigation water demands of this area. The high concentrations of NO3 and NaCl show that the area around the springs is continuously being contaminated by untreated sewage and agricultural wastes, especially during dry periods. Therefore, this approach is based on the vulnerability studies of the catchment area, determination of the transfer time of the pollutant, and the water-bearing formations of İncesu-Dokuzpınar springs. Vulnerability in this study is defined as the intrinsic hydrogeochemical characteristics of an aquifer, which may show the sensitivity of groundwater to be contaminated by different human activities.
Environmental Earth Sciences, 2013
The Tefenni (Burdur) plain is located in the southwest of Turkey and is semi-closed basin. Groundwater is densely used as drinking, irrigation and domestic water in the Tefenni plain. Hydrogeochemical processes controlling groundwater chemistry and geochemical assessment of groundwater were investigated in the Tefenni (Burdur/Turkey) plain. The conceptual hydrogeological model of the plain was prepared for qualitative description of the underground geology and interpretation of hydrogeochemical processes of the study area. In this study, groundwater samples for two seasons were analyzed and major ion chemistry of groundwater was researched to understand the groundwater geochemistry. Two major hydrochemical facies (Ca 2?-Mg 2?-HCO 3 and Mg 2?-Ca 2?-HCO 3-) were determined in the area. Mg 2? , Na ? , SO 4 2and Clconcentrations of water samples increased seasonally related to ion exchange of minerals in rocks by rainwater in wet season. Various graphical plots and multivariate statistical analysis (Pearson correlation analysis) were used for identifying the occurrence of different geochemical processes. Carbonate weathering in dry season and silicate weathering in wet season were the major hydrogeochemical processes in the study area. In addition, ion exchange and reverse ion exchange were two possible processes of water-rock interaction in the basin. The mechanism controlling groundwater chemistry at the Tefenni plain is originally regulated by the geogenic process rather than antropogenic activities.
Environmental Earth Sciences, 2019
This study seeks to decipher the hydrochemistry, recharge sources, and the possible factors controlling the chemistry of groundwater in Niğde Province of central Turkey. This was done by conducting hydrochemical, multivariate statistical, and stable isotope analysis on 37 well and spring water samples collected in the wet and dry seasons of 2016. The major ion abundance in the groundwater is in the order Ca 2+ > Na + > Mg 2+ > K + and HCO 3 − > SO 4 2− > Cl −. This accounted for the dominance of Ca-SO 4-HCO 3 water type with other mixed water types, reflecting the geology of the area, which is predominated by carbonate lithologies. All the physico-chemical parameters generally comply with the WHO and Turkish national guideline values for drinking water except TDS, Ca 2+ , SO 4 2− , NO 3 − , and As. The elevated amounts of TDS, SO 4 2− , and NO 3 − were largely from anthropogenic sources. The studied well and spring water samples are suitable for irrigation purposes in terms of their sodium hazard, but with regard to salinity hazard, the well water samples are not suitable for irrigation purposes due to their high salinity values. Three factors that explain 85.2% of the total variance of the data point to water-rock interaction and mixing with thermal waters as the principal factors controlling the chemistry of the groundwater. Metal pollution load was significantly higher in the wet season than in the dry season with arsenic as the key contaminant (0.69-391.14 µg/L and 0.29-43.6 µg/L in the wet and dry seasons, respectively). The tritium concentrations reveal that the well waters have longer residence time and water-rock interaction than the spring waters and are thus recharged from older groundwater sources.