Groundwater is the most important source of water in the Halabja-Saidsadiq Basin. In this study, to generate a map of groundwater pollution vulnerability of the basin, the standard DRASTIC method has been applied. Due...Groundwater is the most important source of water in the Halabja-Saidsadiq Basin. In this study, to generate a map of groundwater pollution vulnerability of the basin, the standard DRASTIC method has been applied. Due to the close relation between lineament density and groundwater flow and yield, the lineament density map was applied to the standard DRASTIC model in order to ensure accuracy towards the consideration of the effects of potential vulnerability to contamination. A lineament map is extracted from Enhanced Thematic Mapper plus (ETM+) satellite imagery using different techniques in remote sensing and GIS. The lineament density map illustrates that only six classes of lineament density can be identified ranged from (0 - 2.4). The lineament density map was rated and weighted and then converted to lineament index map. This index map is an additional parameter which was added to the standard DRASTIC model so as to map the modi?ed DRASTIC vulnerability in HSB. The standard vulnerability map, classified the basin into four vulnerability index zones: very low (34%), low (13%), moderate (48%) and high (5%). While the modified model classified the area into four categories as well: very low (28.75%), low (14.31%), moderate (46.91%) and high (10.04%). The results demonstrate that there is no significant variation in the rate of vulnerability. Therefore, the nitrate concentration between two different seasons (dry and wet) was analyzed from (30) water wells, considerable variations in nitrate concentration from dry to wet seasons had been noted. Consequently, it confirmed that the HSB are capable to receive the contaminant because of suitability in terms of geological and hydrogeological conditions. Based on this verification, it could be claimed that the effect of lineament density is weak on the vulnerability system in HSB, because of its low density value.展开更多
To avoid groundwater from contamination, the groundwater vulnerability tool can be examined. In this study, two methods were applied, namely: DRASTIC (Groundwater depth, Net recharge, Aquifer media, Soil map, Topograp...To avoid groundwater from contamination, the groundwater vulnerability tool can be examined. In this study, two methods were applied, namely: DRASTIC (Groundwater depth, Net recharge, Aquifer media, Soil map, Topography, Impact of vadose zone and Hydraulic Conductivity) and COP (Concentration of flow, Overlying layer and Precipitation) to model groundwater vulnerability to pollution. The result illustrated that four vulnerability classes were recognized based on both models including very low, low, moderate and high vulnerability classes. The coverage areas of each class are (34%, 13%, 48% and 5%) by DRASTIC model and (1%, 37%, 2% and 60%) by COP model, respectively. The notable dissimilarity between these two models was recognized. For this reason, nitrate elements were selected as a pollution indicator to validate the result. The concentrations of nitrate were recorded in two following seasons in (30) watering wells;as a result, the substantial variation was noted. This indicates that contaminants can be easily reached the groundwater due to its suitability in geological and hydrogeological conditions in terms of contaminant transportation. Based on this confirmation, the standard DRASTIC method becomes more sensible than COP method.展开更多
To understand and anticipate flow in various groundwater media, the magnitude and direction of groundwater flow velocity must be deemed. The studied area which is called Halabja-Sadiq Basin is in the northeastern part...To understand and anticipate flow in various groundwater media, the magnitude and direction of groundwater flow velocity must be deemed. The studied area which is called Halabja-Sadiq Basin is in the northeastern part of Iraq and covers an area of approximately 128,000 square hectometers. There are several groundwater aquifers in this region that supply nearly over 90% of all water needs. Subsequently, it is of highly requirement to identify various groundwater behaviors in the area. The objective of this study is to estimate the magnitude and direction of the groundwater seepage velocity with the aid of groundwater tool in Geographic Information System technology. Refer to the results of this analysis, the magnitude value of groundwater flow velocity ranged from 0 to 51 m/d, whilst the general flow movement is from the eastern part to the western part of the study area. The factor governing the direction of flow and velocity magnitude indicates the direction of dipping of the geological formation strata, the high head of groundwater in the eastern part, and the low transmissivity properties of aquifer materials in the western part.展开更多
Groundwater plays important roles as one of the essential source of water supplies of the studied area. Consequently, it needs to be prevented from contamination. In this study, two methods have been examined, namely ...Groundwater plays important roles as one of the essential source of water supplies of the studied area. Consequently, it needs to be prevented from contamination. In this study, two methods have been examined, namely DRASTIC （depth to groundwater, net recharge, aquifer media, soil map, topography, impact of vadose zone and hydraulic conductivity） and VLDA （vadose zone lithoiogy, land use patterns, depth to groundwater and aquifer media） to model a map of groundwater vulnerability for contamination of the basin. The standard DRASTIC vulnerability maps classified the basin of four vulnerability index zones： very low （34%）, low （13%）, moderate （48%） and high （5%）. While the VLDA model classified the area into four categories as well： low （2%）, moderate （44%）, high（53%） and very high （1%）. The results demonstrate that there is a significant dissimilarity in the rate of vulnerability. Validation of the constructed maps is required to confirm the validity of the theoretical sympathetic of current hydrogeological conditions. In this study, nitrate concentration analysis was selected as a contamination indicator to validate the result. The nitrate concentration of two different seasons （dry and wet） was analyzed from （30） watering wells, considerable variations in nitrate concentration from dry to wet seasons had been noted. Consequently, it points toward that groundwater in the HSB （Halabja Saidsadiq Basin） is capable to receive the contaminant due to suitability of overlies strata in terms of geological and hydrogeological conditions. Based on this confirmation, the result exemplifies that the degree and distribution of vulnerability level acquired using VLDA model is more sensible than that attained from the standard DRASTIC method .In addition, the DRASTIC models need to be modified based on the land use pattern, which clarifies the role of human activity on the vulnerability system.展开更多
文摘Groundwater is the most important source of water in the Halabja-Saidsadiq Basin. In this study, to generate a map of groundwater pollution vulnerability of the basin, the standard DRASTIC method has been applied. Due to the close relation between lineament density and groundwater flow and yield, the lineament density map was applied to the standard DRASTIC model in order to ensure accuracy towards the consideration of the effects of potential vulnerability to contamination. A lineament map is extracted from Enhanced Thematic Mapper plus (ETM+) satellite imagery using different techniques in remote sensing and GIS. The lineament density map illustrates that only six classes of lineament density can be identified ranged from (0 - 2.4). The lineament density map was rated and weighted and then converted to lineament index map. This index map is an additional parameter which was added to the standard DRASTIC model so as to map the modi?ed DRASTIC vulnerability in HSB. The standard vulnerability map, classified the basin into four vulnerability index zones: very low (34%), low (13%), moderate (48%) and high (5%). While the modified model classified the area into four categories as well: very low (28.75%), low (14.31%), moderate (46.91%) and high (10.04%). The results demonstrate that there is no significant variation in the rate of vulnerability. Therefore, the nitrate concentration between two different seasons (dry and wet) was analyzed from (30) water wells, considerable variations in nitrate concentration from dry to wet seasons had been noted. Consequently, it confirmed that the HSB are capable to receive the contaminant because of suitability in terms of geological and hydrogeological conditions. Based on this verification, it could be claimed that the effect of lineament density is weak on the vulnerability system in HSB, because of its low density value.
文摘To avoid groundwater from contamination, the groundwater vulnerability tool can be examined. In this study, two methods were applied, namely: DRASTIC (Groundwater depth, Net recharge, Aquifer media, Soil map, Topography, Impact of vadose zone and Hydraulic Conductivity) and COP (Concentration of flow, Overlying layer and Precipitation) to model groundwater vulnerability to pollution. The result illustrated that four vulnerability classes were recognized based on both models including very low, low, moderate and high vulnerability classes. The coverage areas of each class are (34%, 13%, 48% and 5%) by DRASTIC model and (1%, 37%, 2% and 60%) by COP model, respectively. The notable dissimilarity between these two models was recognized. For this reason, nitrate elements were selected as a pollution indicator to validate the result. The concentrations of nitrate were recorded in two following seasons in (30) watering wells;as a result, the substantial variation was noted. This indicates that contaminants can be easily reached the groundwater due to its suitability in geological and hydrogeological conditions in terms of contaminant transportation. Based on this confirmation, the standard DRASTIC method becomes more sensible than COP method.
文摘To understand and anticipate flow in various groundwater media, the magnitude and direction of groundwater flow velocity must be deemed. The studied area which is called Halabja-Sadiq Basin is in the northeastern part of Iraq and covers an area of approximately 128,000 square hectometers. There are several groundwater aquifers in this region that supply nearly over 90% of all water needs. Subsequently, it is of highly requirement to identify various groundwater behaviors in the area. The objective of this study is to estimate the magnitude and direction of the groundwater seepage velocity with the aid of groundwater tool in Geographic Information System technology. Refer to the results of this analysis, the magnitude value of groundwater flow velocity ranged from 0 to 51 m/d, whilst the general flow movement is from the eastern part to the western part of the study area. The factor governing the direction of flow and velocity magnitude indicates the direction of dipping of the geological formation strata, the high head of groundwater in the eastern part, and the low transmissivity properties of aquifer materials in the western part.
文摘Groundwater plays important roles as one of the essential source of water supplies of the studied area. Consequently, it needs to be prevented from contamination. In this study, two methods have been examined, namely DRASTIC （depth to groundwater, net recharge, aquifer media, soil map, topography, impact of vadose zone and hydraulic conductivity） and VLDA （vadose zone lithoiogy, land use patterns, depth to groundwater and aquifer media） to model a map of groundwater vulnerability for contamination of the basin. The standard DRASTIC vulnerability maps classified the basin of four vulnerability index zones： very low （34%）, low （13%）, moderate （48%） and high （5%）. While the VLDA model classified the area into four categories as well： low （2%）, moderate （44%）, high（53%） and very high （1%）. The results demonstrate that there is a significant dissimilarity in the rate of vulnerability. Validation of the constructed maps is required to confirm the validity of the theoretical sympathetic of current hydrogeological conditions. In this study, nitrate concentration analysis was selected as a contamination indicator to validate the result. The nitrate concentration of two different seasons （dry and wet） was analyzed from （30） watering wells, considerable variations in nitrate concentration from dry to wet seasons had been noted. Consequently, it points toward that groundwater in the HSB （Halabja Saidsadiq Basin） is capable to receive the contaminant due to suitability of overlies strata in terms of geological and hydrogeological conditions. Based on this confirmation, the result exemplifies that the degree and distribution of vulnerability level acquired using VLDA model is more sensible than that attained from the standard DRASTIC method .In addition, the DRASTIC models need to be modified based on the land use pattern, which clarifies the role of human activity on the vulnerability system.
