Low Vulnerability Zone Research Articles

Assessment of Aquifer Vulnerability Using Multi-Criteria Decision Analysis around Akure Industrial Estate, Akure, Southwestern Nigeria

This study is aimed at evaluating of aquifer vulnerability in a typical basement complex environment of Akure industrial estate, Akure, Southwestern Nigeria. A multi-criteria model is developed for achieving this aim; the vulnerability model which is based on topsoil resistivity, longitudinal conductance, thickness of layer overlying aquifer, and hydraulic conductivity of each sounding point across the study area is successfully used to evaluate the aquifer vulnerability of the area for future groundwater development programme in the area. Geophysical investigation involving vertical electrical sounding is carried out across the study area. A total of thirty one (31) vertical electrical soundings (VES) data were acquired using Schlumberger array with maximum half-current electrode separation of 100 m. Three to five geoelectric layers were delineated across the study area. The curve types obtained are the A, H, K, KH, HA, AA, QHA and KHA.The map of topsoil resistivity, longitudinal conductance, thickness of layer overlying aquifer, and hydraulic conductivity were generated and synthesized to producing the vulnerability map. The vulnerability map shows that the area is characterized by five zones; very low, low, moderate, high and very high. The mid-western, southeastern and closure at the northern part of the study area are delineated to be very low to low vulnerable zones, followed by the eastern and part of the western and central part of the study area which are categorized as moderate vulnerable zones, and finally the southern and northern part of the study area which are characterized by high and very high vulnerable zone.

Mapping of Groundwater Vulnerability Index in the Alluvial Plain of Semarang City Using the Susceptibility Index Method

One of the negative impacts of settlements and urbanization is the decline in groundwater quality. In maintaining the sustainability of groundwater for a long period of time, a special study is needed, which can be done by examining groundwater vulnerability. The alluvial plain of Semarang City currently faces environmental problems such as degradation of groundwater quality which is the negative impact of the settlement, The purpose of this study was to examine groundwater vulnerability in the alluvial plain area of Semarang City. The Susceptibility Index method is using a spatial analysis tool based on rating and weighting value of some parameters, i.e. Depth of groundwater, recharge, aquifer media, slope, and land use. The result of this research reveals that about 41.3% area is covered under the high vulnerable zone, 50.3% area under moderately vulnerable zone and 8.4% area under the low vulnerable zone. 7 sub districts namely Tugu, Semarang Barat, Semarang Utara, Semarang Timur, Gayamsari, Pedurungan and Genuk, most of which are in the high vulnerability zone. Whereas the Ngaliyan, Semarang Selatan, Semarang Tengah, Candisari, and Gajah Mungkur, which are mostly in the low to moderate vulnerability zones.

Modified-DRASTIC, modified-SINTACS and SI methods for groundwater vulnerability assessment in the southern Tehran aquifer

This study aims to modify the SINTACS and DRASTIC models with a land-use (LU) layer and compares the modified-DRASTIC, modified-SINTACS and SI methods for groundwater vulnerability assessment (GVA) in the southern Tehran aquifer, Iran. Single parameter sensitivity analysis (SPSA) served to determine the most significant parameters for the modified-DRASTIC, modified-SINTACS and SI approaches, and to revise model weights from “theoretical” to “effective.” The inherent implementation of LU in the SI model may explain its better performance compared to unenhanced versions of DRASTIC and SINTACS models. Validation of all models, using nitrate concentrations from 20 wells within the study area, showed the modified-SINTACS model to outperform other models. The SPSA showed that the vadose zone and LU strongly influenced the modified-DRASTIC and modified-SINTACS models, while SI was strongly influenced by aquifer media and LU. To improve performance, models were implemented using “effective” instead of “theoretical” weights. Model robustness was assessed using nitrate concentrations in the aquifer and the outcomes confirmed the positive impact of using “effective” versus “theoretical” weights in the models. Modified-SINTACS showed the strongest correlation between nitrate and the vulnerability index (coefficient of determination = 0.75). Application of the modified-SINTACS while using “effective” weights, led to the conclusion that 19.6%, 55.2%, 23.4%, and 1.6% of the study area housed very high, high, moderate and low vulnerability zones, respectively.

ASSESSMENT OF SOCIAL VULNERABILITY TO THE IMPACT OF FLOOD HAZARD: A CASE STUDY OF KOPILI RIVER BASIN, ASSAM, INDIA

Abstract. In the present study, an attempt is made to understand the impact on Social Vulnerability of the Kopili basin due to various severities of flood hazard. The flood hazard is generated using multi-temporal historical satellite based analysis and integration of annual flood inundation layers. The census of India data of 2001 and 2011 is spatially joined with village database to study the impact at village level. Using 5 Census variables from both Census 2001 & 2011 as vulnerability indicators, the Social Vulnerability Index (SVI) is derived and classified into various vulnerable zones namely Low, Moderate and High Vulnerable zones. The findings of the study show that the number of villages falling in Low and High Vulnerable zones had decreased during Census 2011 when compared to 2001 and a rise of 6% in villages falling in moderate vulnerable zones during 2011 is observed. The spatial database generated is useful to understand the impact of floods on the Social Vulnerability status of the basin and can be a useful input to further study the Physical, Economic and Environmental Vulnerabilities of the basin.

GIS-based DRASTIC model for groundwater vulnerability and pollution risk assessment in the Peshawar District, Pakistan

Groundwater is the most economic natural source of drinking in urban and rural areas which are degraded due to high population growth and increased industrial development. We applied a GIS-based DRASTIC model in a populated urban area of Pakistan (Peshawar) to assess groundwater vulnerability to pollution. Six input parameters—depth to phreatic/groundwater level, groundwater recharge, aquifer material, soil type, slope, and hydraulic conductivity—were used in the model to generate the groundwater vulnerable zones. Each parameter was divided into different ranges or media types, and ratings R = 1 – 10 were assigned to each factor where 1 represented the very low impact on pollution potential and 10 represented very high impact. Weight multipliers W = 1 – 5 were also used to balance and enhance the importance of each factor. The DRASTIC model scores obtained varied from 47 to 147, which were divided into three different zones: low, moderate, and high vulnerability to pollution. The final results indicate that about 31.22, 39.50, and 29.27% of the total area are under low, moderate, and high vulnerable zones, respectively. Our method presents a very simple and robust way to assess groundwater vulnerability to pollution and helps the decision-makers to select appropriate landfill sites for waste disposals, and manage groundwater pollution problems efficiently.

Assessing Groundwater Resource Vulnerability by Coupling GIS-Based DRASTIC and Solute Transport Model in Ajmer District, Rajasthan

Abstract Groundwater aquifer vulnerability has been assessed by incorporating the major geological and hydrogeological factors that affect and control the groundwater contamination using GIS-based DRASTIC model along with solute transport modeling. This work demonstrates the potential of GIS to derive a vulnerability map by overlying various spatially referenced digital data layers (i.e., depth to water, net recharge, aquifer media, soil media, topography, the impact of vadose zone and hydraulic conductivity) that portrays cumulative aquifer sensitivity ratings in Kishangarh, Rajasthan. It provides a relative indication of groundwater aquifer vulnerability to contamination. The soil moisture flow and solute transport regimes of the vadose zone associated with specific hydrogeological conditions play a crucial role in pollution risk assessment of the underlying groundwater resources. An effort has been made to map the vulnerability of shallow groundwater to surface pollutants of thestudy area, using soil moisture flow and contaminant transport modeling. The classical advection-dispersion equation coupled with Richard’s equation is numerically simulated at different point locations for assessing the intrinsic vulnerability of the valley. The role of soil type, slope, and the land-use cover is considered for estimating the transient flux at the top boundary from daily precipitation and evapotranspiration data of the study area. The time required by the solute peak to travel from the surface to the groundwater table at the bottom of the soil profile is considered as an indicator of avulnerability index. Results show a high vulnerability in the southern region, whereas low vulnerability is observed in the northeast and northern parts. The results have recognized four aquifer vulnerability zones based on DRASTIC vulnerability index (DVI), which ranged from 45 to 178. It has been deduced that approximately 18, 25, 34, and 23% of the area lies in negligible, low, medium and high vulnerability zones, respectively. The study may assist in decision making related to theplanning of industrial locations and the sustainable water resources development of the selected semi-arid area.

Evaluation of groundwater vulnerability to pollution using a GIS-based multi-criteria decision analysis

The groundwater contamination is due to different factors such as rapid urbanization, intensive fertilizer application, and wastewater disposal systems associated with human settlements and industries activities. Vulnerability mapping is considered as a fundamental aspect of sustainable groundwater management especially in overexploited and threatens aquifers by various sources of pollution. In the present study vulnerability and risk pollution maps were produced using a GIS based-multi-criteria decision analysis in an appropriate case study in Agareb area (southern Tunisia),and the results were validated using nitrate concentration. Eight appreciation criteria such as: aquifer type, hydraulic conductivity and depth to water table, slope, and proximity to concentrated land use, proximity to rivers, proximity to residential areas and proximity to main roads were selected. These factors were rated in one common interval from 0 to 10 using the fuzzy membership functions. Analytic Hierarchy Process (AHP) is adopted to weight factor assessment. The final groundwater vulnerability maps were created by weighted linear combination (WLC). The results reveal that about 1% area is covered under very high vulnerable zone, 6% area under moderately high vulnerable zone, 18% area under moderately vulnerable zone, 25% area under moderately low vulnerable zone, and 50% area under low vulnerable zone. The results were validated using nitrate concentration in groundwater. Observed nitrate concentrations in boreholes are in accordance with the vulnerability map. The GIS-based multi-criteria decision analysis was observed to be more conclusive in groundwater vulnerability assessment in overexploited areas.

Population vulnerability assessment of geological disasters in China using CRITIC–GRA methods

Population vulnerability of geological disasters is an important way in research on the relationship between human society and its geo-environment. This study examines the provincial administrative units of China as a research object. Twelve indicators are selected on the basis of three aspects, namely population exposure, population capacities, and environmental conditions surrounding people, to construct an index system for the assessment of population vulnerability to geological disasters (including landslide, debris flow, collapse, and land collapse) in China. Criteria importance through Inter-criteria Correlation (CRITIC) and Gray Relational Analysis (GRA) methods is employed to evaluate the population vulnerability of geological disasters in this country. The zoning map of China’s population vulnerability to geological disasters and the ranking of evaluation results are obtained. The results show that the population vulnerability of geological disasters considerably differs in China, which is bounded by the Yellow River. The north of the Yellow River is basically a low population vulnerability zone, whereas the south of this river covers zones with moderate, high, and very high vulnerability. This study can be used as a basis for the reconstruction of the regional population’s ability to resist geological disasters and undergo disaster recovery.

Assessment of Groundwater Vulnerability in Upper Betwa River Watershed using GIS based DRASTIC Model

ABSTRACT Groundwater, the most vital water resource being used for irrigation, domestic and industrial purposes is nowadays under severe threat of contamination. Groundwater contamination risk assessment is an effective tool for groundwater management. In the study, a DRASTIC model which is based on the seven hydro-geological parameters viz: depth of water, net-recharge, aquifer media, soil media, topography, impact of vadose zone and hydraulic conductivity was used to evaluate the groundwater pollution potentiality of upper Betwa watershed. ArcGIS was used to create the ground water vulnerability map by overlaying the seven layers. Based on groundwater vulnerability map, the watershed has been divided in three vulnerable zones viz; low vulnerability zone with 42.83 km2 of area, moderate with 369.21 km2 area and high having 270.96 km2 of area. Furthermore, the DRASTIC model has been validated by nitrate concentration over the area. Results of validation have shown that in low vulnerable zone, no nitrate contamination has been recorded. While in the moderate zone nitrate has been found in the range of 1.6-10ppm. However, in high vulnerable zone 11-40ppm of nitrate concentration in groundwater has been recorded, which proves that the DRASTIC model is applicable for the prediction of groundwater vulnerability in the watershed and in similar areas too.

Evaluation of Groundwater Vulnerability to Contamination Based on DRASTIC Model and GIS in Tianjin Plain Area

Assessment of groundwater vulnerability to contamination is the basement approaches for preserving the quality of groundwater. Based on DRASTIC model containing seven hydrogeological parameters and GIS techniques, groundwater vulnerability assessment was carried out in the plain area of Tianjin City, China. The results indicate that the studied area can be divided into five zones: low, slightly lower, middle, slightly higher, and high groundwater vulnerability zones, with coverage area of 1.8%, 24.8%, 53%, 19.6% and 0.8%, respectively. Low vulnerability zone locates in downtown, where the ground is covered by impervious surface. High and slightly higher vulnerability zones mainly locate in the groundwater recharge areas and the suburban areas surrounding downtown. Medium vulnerability zone covers most parts of the plain areas in the south of Baodi fraction. The result is consistent with the actual situation.

Cyclone vulnerability assessment of cuddalore coast in Tamil Nadu, India using remote sensing, and GIS

Over the years, cyclones have left a deep and dark footprint on the coastal region of the Cuddalore district in southeast India, which was one of the worst affected districts in the mainland. These disasters over the past several years have revealed the differential impacts due to social structure, economic conditions, and level of infrastructure. Therefore, there is a need for strategies to address the aspects of socioeconomic and infrastructural vulnerability. Cuddalore district is one of the most vulnerable districts for Cyclone. The present study investigates the vulnerability of eastern coastal states of India from potential cyclones using Remote Sensing and GIS. Mapping of cyclone vulnerability zone on 1:50000 scale along the Tamil Nadu coast has been carried out using Remote Sensing and GIS techniques with six physical parameters such as elevation, wind speed, historical cyclone event significant wave height, probable maximum precipitation, and Landuse and Landcover. The regular rank and weight method have been used to integrate the above parameters to achieve the cyclone vulnerability zone map. The resultant cyclone vulnerability zone map has been divided into five cyclone vulnerability categories, namely very high, high, moderate, low, and very low. The output of the study showed significant results, which reflect that the entire northern coastal taluks come under very high cyclone vulnerability zone whereas central and southern coastal taluks fall under high to low cyclone vulnerability zone. This information would serve useful in advanced planning to minimize associated cyclone losses and reduce threats to future coastal development.

Vulnerability zoning of earthquake disaster of Palu

<p class="Abstract">Palu is the area traversed by Palu-Koro faults and some small faults arround, which causes the frequent occurrence of earthquakes in Palu. Therefore, this study aims to determine the vulnerability of earthquake zone. Determination of this zona is one way to reduce the risk of earthquake disaster. This study used two methods, they are are descriptive and overlay weighted sum. For the overlay of data processing method using GIS application. The result of the study showed 45 district in Palu, 12 district located in low vulnerability zone, 11 district located in moderate vulnerability zone and 22 district located in high vulnerability zone.</p>

Evaluation of road failure vulnerability section through integrated geophysical and geotechnical studies

In order to investigate the competence of the proposed road for pavement stability, geotechnical and geophysical investigations involving Land Magnetic, Very Low Frequency Electromagnetic (VLF-EM) and Electrical Resistivity methods were carried out along Akure-Ipinsa road Southwestern Nigeria. The magnetic profile was qualitatively and quantitatively interpreted to produce geomagnetic section that provides information on the basement topography and structural disposition beneath the proposed road. Similarly, the VLF-EM profile was equally interpreted to provide information on the possible occurrence of linear features beneath the study area. These linear features pose a potential risk to the proposed road as they are capable of undermining the stability of the pavement structure. The geoelectric parameters obtained from the quantitative interpretation of the VES data were used to generate geoelectric section. The geoelectric section generated shows that the study area was underlain by four geoelectric layers namely the topsoil, the weathered layer, the partly weathered/fractured basement and the fresh basement. The major part of the topsoil, which constitutes the subgrade, is characterized by relatively low resistivity values (<100Ωm) suggestive of weak zones that are capable of undermining the stability of the proposed road. This therefore suggests that the layer is composed of incompetent materials that are unsuitable for engineering structures. Furthermore, fractured basement was also delineated beneath some portion of the proposed road. Since fracture is a weak zone, its presence can facilitate failure of the proposed road especially when it is occurring at shallow depth. The geotechnical results reveal that most of the investigated soil samples are clayey in nature. Integration of the results demonstrates that there is a good correlation between geophysical results and the geotechnical results. Furthermore, a vulnerability section that divided the road segments into three zones based on the degree of vulnerability was produced. These zones were high, moderate and low vulnerability zones. It is estimated that about 60% of the road segments constitutes moderate degree of vulnerability while 30% and 10% of the segments respectively constitute high and low degree of vulnerability.

Vulnerability assessment of an agro-stressed aquifer using a source-pathway-receptor model in GIS

Agro-stresses on greater Punjab aquifer are rising because of unchecked growths of agriculture. Secondary salinity and pollution loads from non-point sources (NPS) are two environmental concerns of these growths. In order to assess the impacts of NPS pollution on underlying aquifer, a source-pathway-receptor model commonly refered to as DRASTIC is applied in a GIS environment. The model is applied by combining data sets that describe the depth to groundwater, recharge rates, aquifer material, soils composition, topography, vadose zone materials, and hydraulic conductivity. Resultant vulnerability values are scaled into three vulnerability zones based on DRASTIC Vulnerability Index as low, moderate and high vulnerability. A major portion of the study area about 1798 km squares (57.6%) fall under low vulnerability zone, while the porportions of the study area under moderate, and high vulnerabilities are 790 km2 (25.3%), and 551 km2 (17.6%), respectively. The vulnerability of Tehcil Kot Addu is related positively to the recharge rates and agricultural landuse. Results of this study can be used for sustainable agriculture in the study area and other regions having silmilar hydrogeological characteristics.

Comparison of DRASTIC and DC resistivity modeling for assessing aquifer vulnerability in the central Nile Delta, Egypt

DRASTIC indexing and integrated electrical conductivity (IEC) modeling are approaches for assessing aquifer vulnerability to surface pollution. DRASTIC indexing is more common, but IEC modeling is faster and more cost-effective because it requires less data and fewer processing steps. This study aimed to compare DRASTIC indexing with IEC modeling to determine whether the latter is sufficient on its own. Both approaches are utilized to determine zones vulnerable to groundwater pollution in the Nile Delta. Hence, assessing the nature and degree of risk are important for realizing effective measures toward damage minimization. For DRASTIC indexing, hydrogeological factors such as depth to aquifer, recharge rate, aquifer media, soil permeability, topography, impact of the vadose zone, and hydraulic conductivity were combined in a geographical information system environment for assessing the aquifer vulnerability. For IEC modeling, DC resistivity data were collected from 36 surface sounding points to cover the entire area and used to estimate the IEC index. Additionally, the vulnerable zones identified by both approaches were tested using a local-scale resistivity survey in the form of 1D and 2D resistivity imaging to determine the permeable pathways in the vadose zone. A correlation of 0.82 was obtained between the DRASTIC indexing and IEC modeling results. For additional benefit, the obtained DRASTIC and IEC models were used together to develop a vulnerability map. This map showed a very high vulnerability zone, a high-vulnerability zone, and moderate- and low-vulnerability zones constituting 19.89, 41, 27, and 12%, respectively, of the study area. Identifying where groundwater is more vulnerable to pollution enables more effective protection and management of groundwater resources in vulnerable areas.

Geoinformatics based landslide vulnerable zonation mapping using analytical hierarchy process (AHP), a study of Kallar river sub watershed, Kallar watershed, Bhavani basin, Tamil Nadu

Landslide is one of the most horrible catastrophic events among the various disasters to the human society, which is caused by the influence of various phenomena of the earth, atmospheric and anthropogenic activities individually or collectively. Landslides not only affect the loss of human life, but also cause economic burden on the society. In the very recent past Geoinformatics based decision support system and techniques are being used for landslide hazard mapping and zonation maping. It enables the combination of different data layers at varies levels. In the present study, Analytical Hierarchy Process (AHP) method was applied to prepare landslide Vulnerable Zonation mapping for Kallar River Sub Watersheds, Bhavani basin, Tamil Nadu by taking ten relevant factors. All these factors were converted into layers by extraction of related spatial data. The Landslide Vulnerable Zonation Index was calculated using the weighted linear combination technique based on the assigned weight and the rating given by using AHP method. Finally the study area was brought under five classes of vulnerable zones. In this 33% of area occupied by very high and high zones followed by moderate zone covers 41 and 26% of the area under very low vulnerability and low vulnerability zones. Further resulted vulnerable zone map and land use/land cover map were overlaid to check the vulnerability status by comparing the previous significant landslide locations. The landslide Vulnerable Zonation map is useful for landslide hazard prevention, mitigation, and improvement to society and implementation of appropriate landuse planning.

Modelling the vulnerability of groundwater to contamination in an unconfined alluvial aquifer in Pakistan

The area of Thal Doab is located in the Indus Basin and is underlain by a thick alluvial aquifer called the Thal Doab aquifer (TDA). The TDA is undergone intense hydrological stress owing to rapid population growth and excessive groundwater use for livestock and irrigated agricultural land uses. The potential impact of these land uses on groundwater quality was assessed using a DRASTIC model in a Geographic Information System environment. Seven DRASTIC thematic maps were developed at fixed scale and then combined into a groundwater vulnerability map. The resultant vulnerability index values were grouped into four zones as low, moderate, high and very high. The study has established that 76% of the land area that is underlain by the TDA has a high to very high vulnerability to groundwater contamination mainly because of a thin soil profile, a shallow water table and the presence of soils and sediments with high hydraulic conductivity values. In addition, only 2 and 22% of the total area lie in low and moderate vulnerability zones, respectively. The outcomes of this study can be used to improve the sustainability of the groundwater resource through proper land-use management.

Assessment of Groundwater Vulnerability in Kaduna Metropolis, Northwest Nigeria

DRASTIC index model was employed in the assessment of the intrinsic groundwater vulnerability to contamination in Kaduna metropolis, Nigeria. The model evaluates the contribution of seven environmental parameters (Depth to water level, Net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone, and Hydraulic Conductivity) in the protection of groundwater against contamination. The mapping was conducted within the framework of Geographical Information System. The study area has very low, low to slightly moderate vulnerability with highest and lowest DRASTIC values of 131 and 77 respectively. To have better understanding of the spatial vulnerability of groundwater in the area, the DRASTIC map was reclassified into five (very high, high, moderate, low and very low) vulnerability zones. Generally, the distribution of the vulnerability classes indicated the low to moderate vulnerability status of the majority parts of the study area, with high vulnerability at the center. Strict control measures should be put in place when locating land uses with high potential hazards in the high and very high vulnerability areas.

Evaluation of aquifer vulnerability in a coal mining of India by using GIS-based DRASTIC model

The objective of this study is to estimate the aquifer vulnerability in the West Bokaro coalfield, Jharkhand, India, by using a geographic information system (GIS)-based DRASTIC model. The DRASTIC model incorporates seven hydrogeological data, i.e. depth of water table, net recharge, aquifer media, soil media, topography, impact of vadose zone and hydraulic conductivity. The model was validated by comparing the model output (vulnerability index map) with a statistical analysis and the actual SO4 2− and Fe concentrations in the groundwater of the study area. Thirty-three well samples were collected from the West Bokaro coalfield area. These were analyzed in the laboratory to measure the level of SO4 2− and Fe in the groundwater. The GIS-based DRASTIC result showed that 0.06 % of the area fell into the low-vulnerability zone and 10.8 % fell into the moderate vulnerability zone. About 87.7 % of the study area fell into the moderate to high-vulnerability zone, and 1.4 % of the study area was classified as the highly vulnerable zone. From the vulnerability map, it was observed that some of the western part and some of the middle part of the study area lay in the high-vulnerability zone, and therefore, they were more susceptible to aquifer pollution. The geogenic and anthropogenic activities are responsible for the high vulnerability in the study area. The shallow water level, topography, high net recharge and permeable vadose zone of the area served as the major influential parameters in mapping the vulnerability. The mining and related activities are also responsible for the high aquifer vulnerability of the area. The aquifer vulnerability maps generated in this study could also be used for the management of future water resources and environmental planning in all the mining regions.

A modified-DRASTIC model (DRASTICA) for assessment of groundwater vulnerability to pollution in an urbanized environment in Lucknow, India

Groundwater contamination and vulnerability in urbanized areas are of major concern and need proper attention. Several models including the DRASTIC model are used to evaluate groundwater vulnerability. In the present study, a modified DRASTIC model named as DRASTICA was used, by including anthropogenic influence as a model parameter. The study included an innovative methodology to characterize the anthropogenic influence by using satellite observations of night-lights from human settlements as a proxy and land-use/land-cover surrounding the urbanized area in Lucknow, the capital city of the most populous State of Uttar Pradesh in India. Geographical information system was used for spatial integration of different parameter maps. The groundwater vulnerability to pollution indicated that about 0.7 % area is covered under very high vulnerable zone, 24.5 % area under high vulnerable zone, 66.6 % area under moderately vulnerable zone and 8.2 % area under low vulnerable zone. The results were validated using nitrate concentration in ground water. It was shown that the proposed DRASTICA model performed better than conventional DRASTIC model in an urbanized environment. Sensitivity analysis indicated that anthropogenic impact and depth to water table largely influenced the groundwater vulnerability to pollution, thereby signifying that anthropogenic influence has to be addressed precisely in such studies. The modified-DRASTIC/DRASTICA model proposed in this study will help in better categorization of groundwater vulnerable zones to pollution where anthropogenic contamination is high, particularly in and around urban centers.