Hiscock et al. (1995) stated a GIS methodology is very suitable for groundwater vulnerability mapping, producing an ability to integrate multiple layers of information and derive additional information, for example pollution risk . Therefore, groundwater vulnerability maps are good tools to make local and regional assessment of groundwater vulnerability potential, to identify areas susceptible to contamination, to design monitoring networks and to evaluate groundwater contamination, particularly non-point contamination and to overcome problems of hazard, uncontrolled development of land and of undesirable activities having an impact on ground water quality. According to Goodchild (1993), GIS have become very useful in mapping, data processing, modeling and policy making for dealing with various environmental problems . For example, in India remote sensing and GIS were successively used to delineate potential zones of groundwater and to produce ground water vulnerability map in Muradaiyar Basin, Tamilnadu  .
Groundwater is vital to the sustenance and well-being of man-kind, although it is constantly under immense pressure. For this reason, there is need to de- velop an effective, reliable, scientific and sustainable means of delineating zones of groundwater occurrence and distribution with high precision in other to effectively explore for this resource. In this study, remote sensing (RS) and geographical information system (GIS) have been combined to de- velop thematic maps of the zones of groundwater occurrence and distribution based on variable factors such as; elevation, drainage, lineament, slope, litholo- gy and soil. The analytical hierarchy procedure (AHP) was employed to classify and subsequently assign weight to each variable factor through weighted overlay analysis. Integration of these factors with their relative classes defined was used to produce a 2D-model for predicting surface aquifers mapped within Obubra. The study delineated three (3) surface aquifer zones representing groundwaterpotential zones. Zones representing high groundwaterpotential cover an area of approximately 331.94 Km 2 , accounting for 29.58% of the
Groundwater irrigation presently covers around 2 × 10 6 ha in Africa, equivalent to 1 % of the cultivated land 3 (Siebert et al., 2010). In Asia, similar figures amount to 38 × 10 6 ha or 14 % of cultivated land (Siebert et al., 2010). Hence, it is fair to assume that there is appreciable scope for fur- ther developing GWI in the continent. Barriers to an expan- sion of groundwater-based irrigation in Africa, and in par- ticular SSA, include lack of knowledge of the resource and best options for sustainable development. So, while present levels of development are comparatively low and most de- velopment occurs in the informal sector (Villholth, 2013), progress towards greater and long-term benefits need to be informed by estimations of upper limits for sustainable de- velopment and most appropriate geographic areas for devel- opment. The need for qualified estimates of groundwater irri- gation potential (GWIP) is recognized at the national (MoFA and GIDA, 2011; Awulachew et al., 2010) as well as regional scale (MacDonald et al., 2012). Qualitative, relative ground- water potential was mapped for Ethiopia by MacDonald et al. (2001), however, with no specific focus on the potential for irrigation. You et al. (2010) estimated the potential con- tribution from small-scale irrigation (including ponds, small reservoirs, rainwater harvesting, and groundwater) in Africa to be 0.3 to 16 × 10 6 ha based on a continental distributed mainly economic multi-criteria analysis at a 5 min. resolu- tion. Pavelic et al. (2012, 2013) afforded a relatively sim- ple water balance approach to provide country or catchment scale estimates, respectively, of gross GWIP in terms of ir- rigable cropland, taking into consideration the crop irriga- tion water needs and disregarding existing irrigation devel- opment. Water available for irrigation was constrained by re- newable groundwater resources, priority demands from do- mestic, livestock, industrial uses as well as environmental requirements. They determined the GWIP of 13 semi-arid countries in SSA to be in the range of 13.5 ± 6.0 × 10 6 ha, or between 0.1–3.9 × 10 6 ha per country. While the previous estimations of GWIP in Africa were continental (You et al., 2010), national (Pavelic et al., 2013), or sub-national (Pavelic
The SHORE procedure leads to the selection of some geological variables that are consistent with previous literature and expertise of field scientists, however it also contains some variables that are not expected and are selected potentially due to data and model limitations. For instance, Garnet Mica Schist is not normally associated with elevated dissolved radon, but it was likely selected due to its proximity to high values overlaying geology more commonly associated with elevated radon. Nonetheless, the model results lead to a better understanding of the possible scales at which the geology is impacting the groundwaterradon concentration. Henderson Gneiss geological formation is a known hot spot for high groundwaterradon concentration in western North Carolina. Henderson Gneiss was available as a potential explanatory variable as a class D variable, the variable class that is most detailed. However, granitic gneiss, a class C variable, was favored ahead of Henderson Gneiss, which is a more generalized classification of Henderson Gneiss. Furthermore, the granitic gneiss was selected with a buffer of 28km which means large area variability is perhaps over powering any small area variability in groundwaterradon. The validation analysis using separate training and validations sets shows that the model produces results in the validation set that are consistent with those obtained in the training set. The shrinkage on cross-validation is usually equal to about 25%, though there was an iteration that produced a validation r-squared slightly greater than training set (Figure 15), resulting in a negative shrinkage. The random iterations of the training sets produced different models, but the most consistent variable selected was the Granitic Gneiss.
In addition to the exposure through inhalation, the contribution of radiation dose through ingestion of radon in drinking water has also been assessed by some researchers. The associated health risk due to ingestion of dissolved radon in water is stomach cancer. In consideration of potential hazards attributed to long-term consumption of water rich in radon, the interest in the study of radon in water has increased worldwide such as in Brazil (Bonotto, 2014), Cyprus (Sarrou and Pashalidis, 2003), India (Bajwa et al., 2005; Choubey et al., 2000, Choubey et al., 2010; Prasad et al., 2008). Iran (Pourhabib et al., 2011), Iraq (Al-Hamadwi et al., 2012; Al-Mashhadany et al., 2013), Italy (Kozlowska et al., 2009), Malaysia (Ahmad et al., 2015; Saat et al., 2012), Pakistan (Khan et al., 2010; Nasir and Shah, 2012), Saudi Arabia (Alabdula’aly, 1999), Spain (Moreno et al., 2014), Sweden (Erlandsson et al., 2001), Taiwan (Han et al., 2006) and USA (Gosink, et al., 1990; Sloto and Senior, 1998).
Samples were analyzed by gamma and alpha spectrometry, by liquid scintillation techniques and inductively coupled plasma-mass spectrometry (ICP- MS) in order to determine radionuclide concentrations, particularly those of uranium and thorium families [6,7,10]. Radon measurements were performed in surface air outdoors and indoors in dwellings in villages of the mining regions [6,7]. Furthermore, risks of conventional accidents to humans and cattle posed by galleries, open pits, ventilation stacks, waste heaps, landslides, and mine drainage were identified. The potential for the dispersion of waste containing radionuclides into soils, freshwater streams, and groundwater was also assessed .
Abstract: In this study Soil gas radon 222 Rn activity was measured in different locations at Al-Tuwaitha Nuclear Site and the surrounding areas using RAD7 (radon detector). Radon activity in the soil gas varied from (866±150 to 16004±521 ) Bq/m 3 near Alaibtihal School and Ishtar \ Al-Ttakhi School respectively. These concentrations values are well below the allowed levels that range from (0.4 to 40) KBq/m 3 . The annual effective doses related to the inhalation of radon gas and its progeny which were calculated from the Concentration of emanation in air near ground ranged from (0.0082305 to 0.152102) mSv/y. these results are less than the recommended global average dose from the inhalation of radon from all sources, which is 1 mSv/y. The Health risks originating from indoor radon concentration can be attributed to natural factors and is characterized by geogenic radonpotential (GRP), The highest values were found in Ishtar \ Al-Ttakhi school which is (16.004) and The lowest values were found Near Alaibtihal school which is (0.288666667), the lowest value according to Neznal was classified as low (GRP < 10) and the highest value was classified as medium (10 < GRP < 35), according to Barnet and Pacherová low GRP causes <230 Bq m -3 while medium GRP causes 230-460 Bq m -3 indoor radon concentration. From these different values of GRP a geogenic radon risk map was created, which assists human health risk assessment and risk reduction since it indicates the potential of the source of indoor radon. The results from this study shows that the region has background radioactivity levels within the natural limits.
Groundwater is considered as one of the most valuable hidden natural resources in the sub-surface. Generally, the rapid growth of population, urbanization and agricultural development leads to a major issue for progressively stresses of water in all over the world. Therefore, groundwater is gaining extensive attention to meet the demands. This study aims to delineate the groundwaterpotential zone (GWPZ) in parts of Noyyal basin, Tamil Nadu, India using remote sensing (RS) and geographical information system (GIS). Fissile hornblende-biotite gneiss, hornblende-biotite gneiss, fluvial (black cotton soil with gypsum), granite, charnockite, garnet sillimanite – graphite gneiss are the major rock types and amphibolite, fuchsite, sericite – quartzite, pyroxene granulite, patches of ultramafic rocks and calc – granulite and limestone are minor rock types in this region. Usually, the river flow is dependent both on northeast and southwest monsoons. The downstream portion of the river mostly in Coimbatore city is extensively polluted due to the direct discharge of domestic sewage and effluent from dyeing and bleaching industries. Consequently, groundwater close to the river turns into contaminated. Hence, proper management and planning of the aquifer in this region are mandatory. This planning includes preparation of groundwater prospective map to identify the groundwaterpotential of the study area using RS and GIS. Several thematic layers such as geology, geomorphology, drainage, drainage density, lineament, lineament density, slope, soil type, soil texture, soil depth and land use/land cover (LU/LC) were built in the GIS environment to generate the groundwaterpotential zonation map of the study area. Each individual thematic layer was given appropriate weight and ranking based on their contribution towards groundwater recharge and storage using spatial analyst tool in ArcGIS 10.2. In this manner, a final map i.e. groundwaterpotential zonation map (GWPZM) was produced by compiling all the required themes. The map indicates that the GWPZ of the study area can be classified into four categories such as very good (32 km 2
Groundwater is an important source of water for drinking, cultivation, irrigation etc. the groundwater behavior in the Deccan Basaltic province is highly complicated due to occurrence of the diversified geological formations with considerable lithological and structural variations, climatological lithological and structural variations, hydro-chemical conditions. During last two decades, in the absence of regulatory guidelines, uncontrolled and inconsistent exploitation of groundwater had adversely affected its potentiality unevenly. The reserves of water on Earth are immense, but this is mostly salt water which is unsuitable for drinking and irrigation purpose. The amount of fresh water is huge as well. But its distribution over the globe is uneven. The demand for drinking water and other domestic need is a modern town varies from 100 to 500 liters a day per person. As man uses water, be pollutes it inevitably and when the water is returned to open bodies it contaminates the natural water. Water is one of main resources essential for the overall socio-economic development of any region and it requires careful planning and appreciates exploration. In this study area of the data gathered from GPS surveys and from environmental remote sensing systems can be fused within a GIS for a successful characterization and assessment of watershed functions and conditions (Khadri and Kanak 2015). The hydrogeological investigations are important facets of any groundwater management strategy. The groundwaterpotential of an area depends on the geological and geomorphologic setup, rainfall pattern, aquifer type, groundwater flow pattern, boundary conditions, aquifer properties, etc. (Selvam et. al. 2012, Rangarajan 2009). Thus, scientific understanding about the occurrence, distribution, movement and sustainability of this dynamic natural resource becomes important. Hydrological characters of basalt flows have indicated that the two distinct types of lava flows have distinct qualities as far as their porosity and permeability are concerned. These are amygdaloidal basalt flow and simple basalt flow and the hydro-geological characteristics are described below.
Groundwater samples were collected from seventeen private wells in Tabouk and Al Sharqiya regions in Saudi Arabia for radiometric, physical and chemical analyses. In Tabouk, eight groundwater samples were collected from scattered wells that located between (36.0 - 36.9) long and (28.0 - 29.1) lat. For Al Sharqiya region, the sampled wells were located between (50.0 - 50.2) long and (26.2 - 26.5) lat. The water samples were allowed to run in a continuous flow for a short period, transferred into large polyethylene containers for radon measurements. A special 250 mL glass bottle (Durridge RAD-7)  was immersed in the water sample and filled with utmost care to avoid the water disturbance and eliminat- ing air and closed carefully for radon measurements on-site. For radium, five li- ters were filtered with 0.45 µ membrane filter, collected in polyethylene contain- ers and acidified. For chemical analysis, the water samples were collected in suitable bottles without the acidification step and some chemical parameters; pH, total dissolved solids (TDS), redox potential (Eh) and temperature were monitored.
With the present work it was possible to estimate the average radon levels in each of the 1206 municipalities of Piemonte (ﬁg. 9), more interestingly, to assess the percentage of the population exposed above a given radon con- centration (ﬁg. 10), and to deﬁne the radon prone areas of the Region, an important achievement in order to evaluate the possible health eﬀects for the population. The overall results (Regional arithmetic mean = 71 Bq m − 3 ) were also in good agreement (ﬁg. 11) with those obtained in the ﬁrst radon survey (National survey: 69 Bq m − 3 ), performed in 1991 with a limited sam- pling program (430 dwellings).
of the classes as well as the selection of the conditioning fac- tors. They were selected mostly based on characteristics of the study area and previous similar studies (Xu et al., 2013). As the slope increases, the probability of water infiltration re- duces and runoff generation will increase. Thus, the steeper the slope, the lower the spring occurrence probability. Ac- cording to the results of the SWARA method, the springs tend to occur at middle altitudes or on mountain slopes. Land in the flat curvature class retains rainfall which then infil- trates. Therefore, the amount of groundwater in these areas is higher than for concave or convex curvature. The east as- pect has more springs than other aspects. These results are in accordance with Pourtaghi and Pourghasemi (2014), who reported that most springs occurred at elevations of 1600– 1900 m with an east slope aspect (using the FR method).
Abstract-Ground water contributes to about 80% of the drinking water requirements in the rural areas, fifty percent of the urban water requirements and more than fifty percent of the irrigation requirements of the nation.The search for new groundwater resources is essential to sustained economic development in arid environment. The study area is around Bengaluru urban falling between latitude of 12° 58‘ N to 77° 38' E at Survey of India toposheets 57 G & H covering an area of 2,191 sq.km in Karnataka State, India. In the present paper, by methodological approach based on remote sensing &GIS, Topographical maps are to be prepared using the ARCGIS, and LISS IV data. The area is characterized by undulating terrain interspersed by low ranges of rocky hills. The elevation ranges from 883 to 940 m above MSL .Thus the different ground water potential zones are identified in to 4 classes namely ‘good’, ’moderate’ , ‘moderate- poor’ and ‘poor’.
confounding variables are included in the logistic cluster membership model as in the incidence rate model; how- ever, differences due to the address-level information are present, which are explained in detail in the supplementary material (available as Supplementary data at IJE online). The odds ratio (OR), or the ratio of the odds that a case is a member of a cluster when a given predictor variable is increased by one unit, is calculated for each variable by exponentiating the logistic regression model coefficient. The OR does not directly reflect individual-level risk as in a classical case-control study design; however, individual- level explanatory variables provide additional evidence of associations with the cancer outcomes that is otherwise lost in an ecological study design. Similarly to the incidence rate model, we create and compare models with increasing levels of controlling for confounding variables. First, the crude model with only groundwaterradon is developed. Second, the adjusted model controls for the effects of gen- der and age. And last, the full model controls for the add- itional factors of indoor air radon, smoking, race, public water supply, residential tenure, gender and age.
Their results are shown in Table 1.6. We can find that these measurements are also gross under estimate of true radon content in ground water in these locations similar to Sheeja measurements in Trivandrum and hence require appropriate scaling corrections. From Table 1.5 we can find the value reported by CGB for RGW in Karunagapally coast is roughly one fourth of the maximum value of RGW in Chavara. Since Mangalore University has reported a value of 0.15 Bq/l for Karunagapally we expect a value of at least 0.6 for Chavara region. The average values of Chavara and Neendakara found by MU may considered as the true value for Chavara which comes exactly 0.6 Bq/l . Let this value be C. The maximum value for Chavara found by Nandakumaran et al be D. The ratio D/C will yield the scaling factor (S 2 ) for correcting MU radon measurements in
The strong gradients of radon between the reservoirs are used for applications in aquatic systems. For example, 222 Rn has been used as a tracer for the examination of the air-sea gas exchange (Roether and Kromer, 1978; Kawabata et al., 2003) or the estimation of vertical and horizontal mixing near the bottom boundary of lakes (Imboden and Emerson, 1984; Colman and Armstrong, 1987). Radon is particularly well suited to study groundwater-surface water interaction, because activity concentrations in groundwater (on the or- der of 1 to 100 kBq m −3 , depending on the lithology) are much higher than in surface water (about 1 to 100 Bq m −3 ). This contrast has been used to study groundwater recharge and flow in the vicinity of rivers (Hoehn and von Gunten, 1989; Schubert et al., 2006). Furthermore, radon has been applied successfully and quite extensively in the investiga- tion of submarine groundwater discharge (e.g. Cable et al., 1996; Corbett et al., 1999, 2000; Crusius et al., 2005). Simi- larly, some studies used radon to asses groundwater exfiltra- tion into lakes (Corbett et al., 1997; Tuccimei et al., 2005; Trettin et al., 2006).
The methodology employed to fulfil the various objectives of this project was derived from reviewing several literature. Active and Passive techniques are used for the measurement of radon. Instruments like Alphaguard, Doseman, DosemanPro, and Lucas Cells are widely used. Alpha spectrometry and Gamma spectrometry are used for spectroscopic analysis of various materials. For the measurement of integrated radon exposures, Solid State Nuclear Track Detectors (CR-39 and LR-115 films) are being used. Radon in air can also be detected using charcoal canisters with a detection limit 20 Bq l -1 (US EPA, 1986). Several well-established methods exist for the collection and measurement of radon in water.
Abstract— Groundwater quality depends on the quality of recharged water, atmospheric precipitation and inland surface water. The groundwater quality is equally important as that of quantity. Assessing and monitoring the quality of groundwater is therefore, important to ensure sustainable safe use of these resources for the various purposes. The present study has been undertaken to analyze the physico-chemical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS), turbidity, dissolved oxygen (DO), total alkalinity (TA), total hardness (TH), Calcium (Ca 2+ ), magnesium (Mg 2+ ), Sodium (Na+), Potassium (K+),Sulphates (SO 4 2 -), Chloride (Cl) were analyzed (APHA, 1998) to know