scholarly journals Modified DRASTIC model for groundwater vulnerability to nitrate contamination in the Dagujia River Basin, China

2021 ◽  
Author(s):  
Aihua Wei ◽  
Pan Bi ◽  
Jie Guo ◽  
Shuai Lu ◽  
Duo Li
Keyword(s):  
Land Use ◽  
Mean Squared Error ◽  
Groundwater Vulnerability ◽  
Nitrate Pollution ◽  
Nitrate Contamination ◽  
Support Vector ◽  
Drastic Model ◽  
Rapid Economic Growth ◽  
Groundwater Samples ◽  
Over Exploitation

Abstract Due to rapid economic growth and over-exploitation of groundwater, nitrate pollution in groundwater has become very serious. The main objective of this study is to modify the DRASTIC model to identify groundwater vulnerability to nitrate pollution. The DRASTIC model was firstly used to analyze the intrinsic vulnerability. The DRASTIC model with the inclusion of a land-use factor (DRASTIC-LU) was put forward to map the specific vulnerability of groundwater. Furthermore, the Support Vector Machine (SVM) was introduced to avoid the drawback of the overlay and index methods, and the improved integrated models of DRASTIC + SVM and DRASTIC-LU + SVM were built. Moreover, 103 groundwater samples were collected for building and validating the models. The Root Mean Squared Error (RMSE) of DRASTIC, DRASTIC-LU, DRASTIC + SVM, and DRASTIC-LU + SVM was found to be 0.853, 0.755, 0.631, and 0.502, respectively. The model DRASTIC-LU was more precise than the original one. The results also showed that the integrated model using SVM exhibited better correlation between the vulnerability value and the nitrate pollution. The study indicated that the modified models including the land-use factor as well as SVM in the DRASTIC model were more suitable to assess the groundwater vulnerability to nitrate.

Groundwater Vulnerability Mapping in Urbanized Hydrological System Using Modified Drastic Model and Sensitivity Analysis

2018 ◽  
Vol 24 (3) ◽  
pp. 293-304 ◽  
Author(s):  
Ismail Chenini ◽  
Adel Zghibi ◽  
Mohamed Haythem Msaddek ◽  
Mahmoud Dlala
Keyword(s):  
Land Use ◽  
Vadose Zone ◽  
Vulnerability Assessment ◽  
Groundwater Vulnerability ◽  
Vulnerability Index ◽  
Drastic Model ◽  
Groundwater Vulnerability Mapping ◽  
Groundwater Vulnerability Assessment ◽  
Modified Drastic ◽  
The Impact

Abstract The groundwater vulnerability assessment is normally applied to rural watersheds. However, urbanization modifies the hydrogeological processes. A modified DRASTIC model was adopted to establish a groundwater vulnerability map in an urbanized watershed. The modified DRASTIC model incorporated a land-use map, and net recharge was calculated taking into account the specificity of the urban hydrogeological system. The application of the proposed approach to the Mannouba watershed demonstrates that the groundwater vulnerability indexes range from 80 to 165. The study's results shows that 30 percent of the Mannouba watershed area has a high vulnerability index, 45 percent of the area has a medium index, and 25 percent of the study area has a low vulnerability index. To specify the effect of each DRASTIC factor on the calculated vulnerability index, sensitivity analyses were performed. Land use, topography, and soil media have an important theoretical weight greater than the effective weight. The impact of the vadose zone factor has the most important effective weight and affects the vulnerability index. The sensitivity assessment explored the variation in vulnerability after thematic layer removal. In this analysis, the removal of hydraulic conductivity and impact of vadose zone modified the vulnerability index. Groundwater vulnerability assessment in urbanized watersheds is difficult and has to consider the impact of urbanization in the hydrogeological parameters.

scholarly journals Assessing Groundwater Vulnerability Potential using Modified DRASTIC in Ajabshir Plain, NW of Iran

2021 ◽  
Author(s):  
Asghar Ashari Moghaddam ◽  
Sorayya Nouri sangarab ◽  
Ali Kadkhodaie Ilkhchi
Keyword(s):  
Fuzzy Inference ◽  
Pollution Index ◽  
Primary Source ◽  
Groundwater Vulnerability ◽  
Nitrate Pollution ◽  
Inference System ◽  
Drastic Model ◽  
Northwest Of Iran ◽  
Optimized Model ◽  
Agricultural Areas

Abstract The vulnerability of groundwater, as the primary source of water for human survival, should be assessed for the purpose of pollution management. The Ajabshir plain, one of the major agricultural areas in the northwest of Iran, is always prone to pollution. Therefore, to prevent the increase in pollution, it is necessary to determine the polluting factors and areas prone to groundwater pollution. In this study, by modifying the DRASTIC method using the land-use layer, called DRASTICL, vulnerable areas and pollution index were mapped. To ensure dealing with the uncertainty of the parameters, the DRASTICL model was optimized utilizing the Sugeno-type fuzzy inference system. The models were validated based on nitrate pollution. The correlation of DRASTICL and its optimized model with the nitrate pollution are 0.31 and 0.80, respectively. The results of this study show that integrating the DRASTIC model and fuzzy knowledge is an instrumental way for assessment of vulnerability potential.

scholarly journals Anthropic Pollution Impacts on Groundwater Vulnerability Based on Modified DRASTIC-FAHP

2021 ◽  
Author(s):  
Mohammad Reza Goodarzi ◽  
Amirreza R. Niknam ◽  
Vahid Jamali ◽  
Hamid Reza Pourghasemi ◽  
Mahboobeh Kiani-Harchegani
Keyword(s):  
Land Use ◽  
Nitrate Concentration ◽  
Groundwater Resources ◽  
Pearson Correlation ◽  
Groundwater Vulnerability ◽  
Vulnerability Index ◽  
Linear Regression Method ◽  
Drastic Model ◽  
Modified Drastic ◽  
Hierarchy Process

Abstract In arid and semi-arid regions such as Iran, groundwater is more important for humans and ecosystems than surface water. Different models of groundwater vulnerability assessment can be used to better manage water resources. The purpose of this study is to evaluate the qualitative vulnerability of groundwater resources in the Birjand Plain aquifer using the DRASTIC model and 7 hydrogeological components. DRASTIC model was also modified by adding a land use component (MDRASTIC) based on Analytical Hierarchy Process (AHP) and Fuzzy Analytic Hierarchy Process (FAHP) methods. After calculating the vulnerability index, the vulnerability of each method was mapped and the final index obtained from each method was classified into 4 different categories. Nitrate concentration was used to confirm the results and to analyze the sensitivity of a single parameter. Sensitivity analysis showed that the groundwater vulnerability is mainly affected by water depth and land use. To validate each of the models, their correlation with nitrate concentration was calculated and compared. To determine the correlation coefficient, simple linear regression method was performed and the Pearson and Spearman methods were used. According to the obtained Pearson correlation results, the DRASTIC, MDRASTIC, MDRASTIC-AHP, and MDRASTIC-FAHP models resulted in values of 0.550, 0.680, 0.778, and 0.794respectively. The results show a good correlation between the modified DRASTIC-FAHP model and nitrate concentration as an indicator of groundwater pollution.

scholarly journals Groundwater vulnerability assessment with using GIS in Hamadan–Bahar plain, Iran

2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Balal Oroji
Keyword(s):  
Land Use ◽  
Land Use Planning ◽  
Vulnerability Assessment ◽  
Anthropogenic Activities ◽  
Groundwater Vulnerability ◽  
Anthropogenic Sources ◽  
Drastic Model ◽  
Aquifer System ◽  
Groundwater Vulnerability Assessment ◽  
Basic Purpose

Abstract Vulnerability assessment to delineate areas that are more susceptible to contamination from anthropogenic sources has become an important element for sensible resource management and land use planning. It has been recognized for its ability to delineate areas that are more likely than others to become contaminated as a result of anthropogenic activities near the earth’s surface. The main methods of mapping and assessing intrinsic vulnerability in porous media are the following: SI, GOD, SINTACS and DRASTIC. The basic purpose of these maps is to divide an area into more classes, each of which will represent a different dynamic for a specific purpose and use. These models have been used to map groundwater vulnerability to pollution in Hamadan–Bahar aquifer. The results showed in models of DRASTIC, SI, GOD and SINTACS, respectively, 7.1, 44.21, 29.56 and 20.16 percent of the areas are high potential vulnerabilities. According to the model DRASTIC at study area, 33.6% of has a low class of groundwater vulnerability to contamination, whereas a total of 29.4% of the study area has a moderate vulnerability. The final results indicate that the aquifer system in the interested area is relatively protected from contamination on the groundwater surface. The correlation between models shows that DRASTIC model has the highest CI, which is 141, and the GOD model has the highest CI, which is 139. Also, the highest CI for SINTACS and SI is 137 and 136, respectively. Therefore, DRASTIC model is the best model among these models for predicting groundwater vulnerability in Hamadan–Bahar plain aquifer.

scholarly journals Groundwater Vulnerability and Nitrate Contamination Assessment and Mapping Using DRASTIC and Geostatistical Analysis

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2022
Author(s):  
Moustafa El Baba ◽  
Prabin Kayastha ◽  
Marijke Huysmans ◽  
Florimond De Smedt
Keyword(s):  
Land Use ◽  
Nitrate Concentration ◽  
Gaza Strip ◽  
Groundwater Vulnerability ◽  
Geostatistical Analysis ◽  
Nitrate Contamination ◽  
Kriging Interpolation ◽  
Regression Kriging ◽  
Contamination Assessment ◽  
The Gaza Strip

The Gaza Strip is in a chronic state of water shortage and the coastal aquifer as the only freshwater source is increasingly depleted and polluted, especially by nitrate. Assessment of groundwater vulnerability to pollution is essential for adequate protection and management. In this study, the assessment of the aquifer vulnerability to contamination is derived by applying the DRASTIC procedure, firstly with original default weights and ratings and, secondly, improved by estimating rating values by multiple linear regression of observed log-transformed nitrate concentration in groundwater, with DRASTIC factors extended to land-use. The results are very different because high and low vulnerability areas shift considerably. Subsequently, a geostatistical analysis of the spatial distribution of the nitrate concentration is performed, firstly by ordinary kriging interpolation of the observed nitrate concentration and secondly by regression kriging using DRASTIC factors and land-use as indicators of the spatial variation in nitrate occurrence. These maps differ because the map obtained by regression kriging interpolation shows much more details of environmental factors such as dunes, ridges, soil types and built-up areas that affect the presence of nitrate in groundwater. The results of this study can be used by the Palestinian authorities concerned with sustainable groundwater management in the Gaza Strip.

scholarly journals Nitrate contamination in groundwater agricultural of Samno and Elzegan area, Fazan region, Libya

2018 ◽  
Vol 7 (2.29) ◽  
pp. 56 ◽  
Author(s):  
Mabroka Mohamed Daw ◽  
Elhadi Ramadan Ali ◽  
Mohd Ekhwan Toriman
Keyword(s):  
Water Samples ◽  
Nitrate Pollution ◽  
Nitrate Contamination ◽  
Public Utilities ◽  
Major Portion ◽  
Agricultural Activities ◽  
Paper Study ◽  
Chemical Fertilizers ◽  
Groundwater Samples

This paper study explores the groundwater nitrate pollution associated with agricultural activities in Samno and Elzegan areas, Libya. The study’s main aim is to evaluate the condition of groundwater agricultural in the study area. 40 water samples were collected from forty established wells used of daily domestic and public utilities from first of January to end of July 2014 the samples were collected subjected from different aquifer levels and depths. The water samples’ NO3 concentration was measured using the hack-spectrophotometer nitrate test. The findings revealed that a major portion of the groundwater samples had a significant NO3 concentration; only 12.5% wells were recorded at the saver level. Meanwhile, 87% wells were recorded as polluted with NO3, 27.5 % wells were in severing level and 60% wells were recorded as slightly to moderate levels. The main sources of NO3 in the groundwater come from an excessive use of chemical fertilizers and pesticides. This study recommends that most of the wells operated within the study areas are not suitable for any household or agricultural purposes.  

scholarly journals Assessment of Groundwater Contamination Hazard by Nitrate in Samas Area, Bantul District, Yogyakarta, Indonesia

2017 ◽  
Vol 2 (1) ◽  
pp. 36 ◽  
Author(s):  
Thilavanh Souvannachith ◽  
Doni Prakasa Eka Putra ◽  
Heru Hendrayana
Keyword(s):  
Groundwater Contamination ◽  
Water Samples ◽  
Groundwater Resources ◽  
Shallow Groundwater ◽  
Groundwater Vulnerability ◽  
Nitrate Contamination ◽  
High Class ◽  
Settlement Area ◽  
Groundwater Samples ◽  
Potential Map

Groundwater resource is an essential for various purposes in Bantul district, Yogyakarta Special Province, Indonesia, especially on Poncosari village where the water supply are depending on shallow groundwater resources. On this village, most of the houses using dug wells to provide their water needs and applying inappropriate on-site sanitation system, however there are also difference land uses. This condition increase the hazard of groundwater contamination by fecal coli bacteria and nitrate. Therefore, this research aims in term of three main objectives: firstly, to know the level of nitrate concentration in groundwater, secondly, to assess groundwater vulnerability and thirdly, to assess the level of groundwater contaminant hazard. Hydrogeology observation was conducted and 47 water samples (44 groundwater samples and 3 surface water samples) were collected from different land use type and analyze for nitrate (NO 3) content. Methodology used to assess the groundwater vulnerability was Simple Vertical Vulnerability method and the groundwater contamination hazard built based on the combination of groundwater vulnerability and nitrate loading potential map. Results show that groundwater concentrations of nitrate range from 0.09–74.80 mg/L and the highest concentration found in the settlement area. Assessment of groundwater vulnerability reveals three areas of moderate, moderate high and high classes of vulnerability due to shallow groundwater and the sandy dominated overlying material in the study area. Combination of groundwater vulnerability and nitrate loading potential map indicated that groundwater contaminant hazard of nitrate range from low to high class. High class of hazard located in the settlement area, and low hazard of nitrate contamination found in the irrigated rice field area

scholarly journals Drastic method to map groundwater vulnerability to pollution using nitrate measurements in agricultural areas

2017 ◽  
Vol 47 (2) ◽  
pp. 981 ◽  
Author(s):  
T. Samara ◽  
G. Yoxas
Keyword(s):  
Land Use ◽  
Nitrate Concentration ◽  
Groundwater Vulnerability ◽  
Original Method ◽  
Northwestern Part ◽  
Drastic Model ◽  
Agricultural Areas ◽  
The Relationship ◽  
Better Than

DRASTIC model has been used to map groundwater vulnerability to pollution in many areas. Since this method is used in different places without any changes, it cannot consider the effects of pollution type and characteristics. Therefore, the method needs to be calibrated and corrected for that aquifer and specific land use. In this research, by correcting the rates of DRASTIC parameters, one can assess the vulnerability potential to pollution more accurately. The new rates were computed using the relationships between DRASTIC INDEX (DI) corresponding to land use and to nitrate concentration in groundwater. The proposed methodology was applied in deltaic region of alluvial aquifer of Volinaios catchment located in the northwestern part of Peloponnesus. In order to determine the quality of the ground waters, either for watering or irrigating purposes, in the study area, a sampling was made. Correlation was used to find the relationship between the index and measured pollution in each point and therefore, to modify the rates. The results showed that the modified DRASTIC is better than the original method for nonpoint source pollution in agricultural areas.

scholarly journals GROUNDWATER VULNERABILITY MAPPING USING A MODIFIED-DRASTIC MODEL IN AJABSHIR PLAIN, SOUTHEAST COAST OF URMIA LAKE, IRAN

2019 ◽  
Vol XLII-4/W18 ◽  
pp. 789-792
Author(s):  
M. Nakhostinrouhi ◽  
M. H. Rezaei Moghaddam
Keyword(s):  
Land Use ◽  
Water Cycle ◽  
Groundwater Resources ◽  
Groundwater Vulnerability ◽  
Urmia Lake ◽  
Drastic Model ◽  
Hydrogeological Parameters ◽  
Groundwater Vulnerability Mapping ◽  
Modified Drastic ◽  
East Azerbaijan

Abstract. Groundwater resources play an important role not only in providing drinking water but also in irrigation, industry and power generation. In general, groundwater is a part of the water cycle in nature that can be collected by wells, qanats, drains, or natural springs. In this research, the potential of groundwater vulnerability in Ajabshir plain, located in the Southwest of East Azerbaijan Province and Southeast of the Urmia Lake, Iran, is investigated using 7 hydrogeological parameters as well as land-use criterion. Depth to water map is provided using 26 boreholes. Twenty-seven drilling points are also used in generating aquifer media and impact of vadose zone maps. After providing and ranking all layers, they are multiplied by appropriate weights and overlaid to produce vulnerability map. Modified-DRASTIC model is applied to achieve the aim. According to the results, an approximately large part of the aquifer (29 percent), mostly located in the west of the plain, is covered with moderate vulnerability class. Spearman correlation coefficient is calculated 0.63 between the vulnerability and land use maps.

Rapid Determining Contents of the Rhubarb Anthraquinones Compounds by Support Vector Machines Modeling based on Near Infrared Spectra

2020 ◽  
Vol 16 ◽  
Author(s):  
Linqi Liu ◽  
JInhua Luo ◽  
Chenxi Zhao ◽  
Bingxue Zhang ◽  
Wei Fan ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Mean Squared Error ◽  
Rapid Determination ◽  
Partial Least Square ◽  
Least Square ◽  
Support Vector ◽  
Near Infrared Spectra ◽  
Aloe Emodin ◽  
Relative Differences

BACKGROUND: Measuring medicinal compounds to evaluate their quality and efficacy has been recognized as a useful approach in treatment. Rhubarb anthraquinones compounds (mainly including aloe-emodin, rhein, emodin, chrysophanol and physcion) are its main effective components as purgating drug. In the current Chinese Pharmacopoeia, the total anthraquinones content is designated as its quantitative quality and control index while the content of each compound has not been specified. METHODS: On the basis of forty rhubarb samples, the correlation models between the near infrared spectra and UPLC analysis data were constructed using support vector machine (SVM) and partial least square (PLS) methods according to Kennard and Stone algorithm for dividing the calibration/prediction datasets. Good models mean they have high correlation coefficients (R2) and low root mean squared error of prediction (RMSEP) values. RESULTS: The models constructed by SVM have much better performance than those by PLS methods. The SVM models have high R2 of 0.8951, 0.9738, 0.9849, 0.9779, 0.9411 and 0.9862 that correspond to aloe-emodin, rhein, emodin, chrysophanol, physcion and total anthraquinones contents, respectively. The corresponding RMSEPs are 0.3592, 0.4182, 0.4508, 0.7121, 0.8365 and 1.7910, respectively. 75% of the predicted results have relative differences being lower than 10%. As for rhein and total anthraquinones, all of the predicted results have relative differences being lower than 10%. CONCLUSION: The nonlinear models constructed by SVM showed good performances with predicted values close to the experimental values. This can perform the rapid determination of the main medicinal ingredients in rhubarb medicinal materials.

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