Evaluation of Coastal Groundwater Quality for Irrigation Use in Thiruchendur Region of Tamil Nadu, India

Evaluation of ground water quality and hydro-geochemistry of shallow and deep aquifer (with respect to guideline values of WHO 2004, geochemical classifications, ion exchange processes and mechanisms controlling ground water chemistry) and evaluation of water quality (with respect to different sodium hazards, Ca2+/Mg2+ ratio) for irrigation purpose in mining area were the aims of the present study. Accordingly ground water samples were collected from shallow, deep aquifers of Gadchandur, Chandrapur in pre and post monsoon seasons 2010. Quality of the water samples collected from the deep aquifer found satisfactory in comparison with water samples collected from the shallow aquifer. Geochemical nature of shallow aquifer was earth alkaline with increased portion of alkalis with prevailing bicarbonate, followed by chloroalkaline disequilibrium type of ion exchange process. Chemical weathering of rock forming minerals was the major driving force controlling shallow aquifer water chemistry. Hydro-geochemistry of deep aquifer in pre-monsoon season hydrogeochemistry of the deep aquifer shifted towards alkaline with sulphate and bicarbonate. Ion exchange process in this aquifer showed complete dominance of base exchange reaction in both the seasons. Chemical weathering along with evaporation was the two major driving forces controlling the water chemistry of the shallow and deep aquifer in pre-monsoon and post-monsoon seasons. RSC (residual sodium carbonate), %Na, SAR (sodium adsorption ratio), Ca2+/Mg2+ ratio and concentration of Cl, F in irrigation water revealed that some water samples were not good enough for irrigation in pre-monsoon season in comparison to that of post monsoon season.

A geospatial approach for understanding the spatio-temporal variability and projection of future trend in groundwater availability in the Tawi basin, Jammu, India

In this study, an attempt has been made to use the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) model to classify groundwater suitability (n = 40) of Kadava river basin during pre and post monsoon season of 2012. The CCME WQI model computed for drinking and irrigation through guidelines of the Bureau of Indian Standards (BIS) and Food and Agricultural Organization (FAO). The pH, EC, TDS, TH, Calcium, Magnesium, Sodium, Potassium, Chloride, Fluoride, Sulfate and Nitrate variables were considered. The groundwater samples were classified into five categories from poor to excellent, ranges from 0 to 100. The result reveals that, the groundwater quality is poor to fair and majority of samples having marginal water quality for drinking. The groundwater quality is quite good for irrigation and it ranges from fair to good type with maximum samples fall in fair category. In the study area, the groundwater quality is considerably affected and found vulnerable in pre monsoon season due to intensive agriculture and anthropogenic activities. Spatial distribution maps of water quality index for pre and post monsoon season were prepared through GIS technique. In pre monsoon season, except Central part, many groundwater samples are found vulnerable and restricting their use for drinking. Three vulnerable hotspots are identified in North, NE and South region in post monsoon season. In pre monsoon season, Central, South and North part is affected; while, in post monsoon season, few patches in North, Central and Southern area are critical for irrigation use. In the study area, few aquifers are found to be problematic and thus limiting their use for drinking and irrigation. The CCME WQI is an effective tool to assess the groundwater quality and to communicate the health of water to multiple users. It gives precise results and water quality report in an easier way to the policy and decision makers. Finally, the study confirmed that the groundwater quality is influenced by agricultural activities and appropriate water management plan is essential to nurture precious groundwater resources in the study area.

Water is one of the most valuable and essential natural resources for sustenance of life on earth and for any developmental activity. Water resources, being exploited from time to time, may become short of supply or may not be easily available at any site. Surface water is commonly present with different degrees of availability and distribution of the earth. There has been an increase in surface water management and utilization for agriculture, domestic, industry and rural supply schemes for the development of nations. Increasing consumption of water resources due to anthropogenic influences on urban, industrial and agricultural needs and erratic precipitation due to metrological changes greatly degrade water sources. In this study, Water Quality Index (WQI) of Jharipani waterfall, Mussoorie was analyzed with the ten physicochemical parameters such as alkalinity, calcium, chloride, electrical conductivity, magnesium, nitrate, pH, sulfate, total dissolved solid and total hardness to know the suitability for drinking purpose during pre and post monsoon seasons of the year 2022. The value of calcium and total dissolved solid which exceeded the permissible limit during pre-monsoon seasons but average during post monsoon season. The calculated Water Quality Index values are 83.371 during pre-monsoon season and 74.599 during post monsoon season. This water quality rating study clearly shows that, the status of the water body is not suitable for drinking. According to Standard Rating of Water Quality, it is very poor in pre monsoon season and poor in post monsoon season and not healthy for drinking purpose.

Suitability of water quality for the drinking and irrigation purposes is indispensable for the endurance of life and sustainability of the ecosystem. The present study is aimed to evaluate the groundwater quality for suitability of drinking and irrigation purposes in the central Gangetic plain area (Bhagarpur district, Bihar), India using the geo-spatial and waterqaulity index (WQI) techniques. Groundwater samples were collected randomly from 45 locations in the pre-monsoon (April -May) and post-monsoon (October-November) season respectively during the period between 2015 and 2016. The different major water quality parameters such as pH, Electrical Conductivity (EC), Total hardness, Calcium (Ca++), Magnesium (Mg++), Sodium(Na+), Potassium (K+), Chloride (Cl−), Carbonate (CO3−), Bicarbonate (HCO3−), and Fluoride (F−) were analyzed using standards methods. Sodium adsorption ratio (SAR) and residual sodium carbonate (RSC) were estimated for suitability of irrigation uses. Pearson’s correlation coefficient was calculated to measure the degree of relation between groundwater variables. The spatial variation maps of these groundwater quality parameters were generated through Inverse distance weightage (IDW) interpolation technique in Arc-GIS software. The pH value of 4.4% of the groundwater samples was found exceeding the acceptable limit established by the WHO (2011)/BIS (2012). Cl− values ranges between 3.24 to 28.74 mg/l−1 in the pre-monsoon season and from 2.50 to 64.98 mg/l−1 in post-monsoon season. Magnesium are cross the limits (<50 mg/l−1) of WHO/BIS in both the pre- and post-monsoon seasons. The F− concentration is higher in both the pre-monsoon and post-monsoon season. The water quality index (WQI) indicates 4.44% of the pre-monsoon samples are good for drinking purposes, whereas the value increases to 31.11% during the post-monsoon in the study area. The higher value of RSC was portrayed in the entire Naugachhia block and the eastern part of the Goradih block for both the season. The higher concentration of sodicity problem is portrayed in the entire Goradih block, north-east of Gopalpur block, and south-west of Naugachhia block for both the pre-monsoon and post-monsoon season. These results will be help planners, decision makers, local peoples, and Government to take necessary measures.

Due to a sharp increase in groundwater demands in coastal regions, groundwater levels are getting depleted day by day. The local groundwater table fluctuation eventually speeds up sea water intrusion. The present study investigates spatial and temporal groundwater level fluctuations to identify the area affected by sea water intrusion as well as for sustainable water resource management in coastal stretch of Sindhudurg district, Maharashtra, which is about 121 km. Using groundwater level data collected from Central Groundwater Board (CGWB), Sindhudurg for the period from 1991 to 2022, fluctuations of groundwater levels were examined. The collected levels were evaluated for monsoon, pre-monsoon & post-monsoon seasons and all levels were interpolated over the study area using the Inverse Distance Weighted Method as a spatial interpolation technique in QGIS 3.22.1, in order to obtain the actual differences in groundwater levels. According to the results, the groundwater level varies from 1.88m to 13.45 m below ground level (bgl) in the pre-monsoon season, from 0.1m to 7.05 m (bgl) in the post-monsoon season and from 1m to 10.6m (bgl) in the monsoon season. Using statistical tests like Mann-Kendall test & Sen's slope estimator, the pattern of variation of groundwater levels was anticipated. According to our findings, over 80% of the basin has a falling water table during the monsoon season. It was observed that the groundwater level in the pre-monsoon season was more as compared to those in the monsoon and the post-monsoon seasons in the entire study area. The overall outcome of the study demonstrates that the groundwater level fluctuations were non-uniform in the study area, which may cause an increase in the sea water intrusion, leading to a decrease in crop production. Keywords: GIS, Groundwater level, Sea water intrusion, Mann Kendall test, Spatial interpolation, Sen’s slope estimator.

Abstract. Exposure to air pollution is a leading public health risk factor in India, especially over densely populated Delhi and the surrounding Indo-Gangetic Plain. During the post-monsoon seasons, the prevailing north-westerly winds are known to influence aerosol pollution events in Delhi by advecting pollutants from agricultural fires as well as from local sources. Here we investigate the year-round impact of meteorology on gaseous nitrogen oxides (NOx=NO+NO2). We use bottom-up NOx emission inventories (anthropogenic and fire) and high-resolution satellite measurement based tropospheric column NO2 (TCNO2) data, from S5P aboard TROPOMI, alongside a back-trajectory model (ROTRAJ) to investigate the balance of local and external sources influencing air pollution changes in Delhi, with a focus on different emissions sectors. Our analysis shows that accumulated emissions (i.e. integrated along the trajectory path, allowing for chemical loss) are highest under westerly, north-westerly and northerly flow during pre-monsoon (February–May) and post-monsoon (October–February) seasons. According to this analysis, during the pre-monsoon season, the highest accumulated satellite TCNO2 trajectories come from the east and north-west of Delhi. TCNO2 is elevated within Delhi and the Indo-Gangetic Plain (IGP) to the east of city. The accumulated NOx emission trajectories indicate that the transport and industry sectors together account for more than 80 % of the total accumulated emissions, which are dominated by local sources (>70 %) under easterly winds and north-westerly winds. The high accumulated emissions estimated during the pre-monsoon season under north-westerly wind directions are likely to be driven by high NOx emissions locally and in nearby regions (since NOx lifetime is reduced and the boundary layer is relatively deeper in this season). During the post-monsoon season the highest accumulated satellite TCNO2 trajectories are advected from Punjab and Haryana, where satellite TCNO2 is elevated, indicating the potential for the long-range transport of agricultural burning emissions to Delhi. However, accumulated NOx emissions indicate local (70 %) emissions from the transport sector are the largest contributor to the total accumulated emissions. High local emissions, coupled with a relatively long NOx atmospheric lifetime and shallow boundary layer, aid the build-up of emissions locally and along the trajectory path. This indicates the possibility that fire emissions datasets may not capture emissions from agricultural waste burning in the north-west sufficiently to accurately quantify their influence on Delhi air quality (AQ). Analysis of daily ground-based NO2 observations indicates that high-pollution episodes (>90th percentile) occur predominantly in the post-monsoon season, and more than 75 % of high-pollution events are primarily caused by local sources. But there is also a considerable influence from non-local (30 %) emissions from the transport sector during the post-monsoon season. Overall, we find that in the post-monsoon season, there is substantial accumulation of high local NOx emissions from the transport sector (70 % of total emissions, 70 % local), alongside the import of NOx pollution into Delhi (30 % non-local). This work indicates that both high local NOx emissions from the transport sector and the advection of highly polluted air originating from outside Delhi are of concern for the population. As a result, air quality mitigation strategies need to be adopted not only in Delhi but in the surrounding regions to successfully control this issue. In addition, our analysis suggests that the largest benefits to Delhi NOx air quality would be seen with targeted reductions in emissions from the transport and agricultural waste burning sectors, particularly during the post-monsoon season.

Spatio-seasonal water presence frequency and water depth change is tried to identify in two manmade reservoirs (Massanjore dam and Tilpara barrage) over Mayurakshi river of Eastern India. These reservoirs use to supply water for hydroelectricity and irrigation services. Multi-temporal image base analysis in three phases (phase 1:1987–1999; phase 2: 2000–2006 and phase 3: 2007–2016) clearly depicted that (1) in case of Massanjore dam (67.4 km2) water presence area in pre-monsoon season is declined from 44.13 to 23.54 km2 in between phase 1 and 3. (2) In post monsoon season, same is declined from 63.37 to 37.57 km2. (3) In case of Tilpara reservoir, water presence area is declined from 3.61 to 2.20 km2 in pre monsoon season and 3.76–2.67 km2 during post monsoon season since phase 1–3. Both average and maximum NDWI scores indicating qualitative depth of water in pre and post monsoon seasons have declined over time with significant rate (R2 ranges from 0.42 to 0.58). All these indicate growing attenuation of water availability within reservoirs. This may invite hardship to the stakeholders depends on the reservoir and ecological set up of the reservoir.

The present study examines the seasonal relationship between land surface temperature (LST) and normalized difference water index (NDWI) on various land surfaces in Raipur City of India by using a series of Landsat images for four specific seasons since 1991-92. The LST is retrieved using the mono-window algorithm technique. The results show that the LST of the study area is noticeably affected by surface composition. The best correlation (correlation coefficient r = 0.42) between the LST and NDWI is achieved in the post-monsoon season, followed by the monsoon season (r = 0.33), pre-monsoon season (r = 0.25), and winter season (r = 0.04). There is a moderate negative correlation (r = -0.49, -0.33, -0.31, and -0.25 in the pre-monsoon, monsoon, post-monsoon, and winter season, respectively) generated between the LST and NDWI on water bodies. On green vegetation, this LST-NDWI correlation is moderate positive (r = 0.67, 0.43, 0.50, and 0.25 in the pre-monsoon, monsoon, post-monsoon, and winter season, respectively). On human settlement and barren land surface, the correlation is weak positive (r = 0.24, 0.21, 0.27, and 0.15 in the pre-monsoon, monsoon, post-monsoon, and winter season, respectively). The output of the research work can be used in the town planning section of any urban agglomeration.

The present study was aimed to evaluate the impact of leachate derived from uncontrolled municipal landfill on surrounding groundwater quality in Kolkata, India. Seasonal variation of twenty physico-chemical parameters in pre-monsoon (PRM) and post-monsoon (POM) season were analysed in forty groundwater samples around the landfill site. Groundwater pollution was identified by the spatial distribution maps of TDS, Na⁺, Cl⁻, Mn and Fe along with the heavy metals like Pb, Hg andCr in both the seasons. Hydrogeochemical characteristics of groundwater samples showed that the area was dominated by brackish water, [Ca⁺2−Cl⁻], [Mg⁺2−Cl⁻] and [Na⁺−Cl⁻] type in PRM season whereas [Na⁺−HCO3⁻] type dominated in POM season. Hierarchical cluster analysis (HCA) was also applied to identify the source of groundwater pollution. In PRM season, groundwater samples closer to the active landfill site were physico-chemically different from upstream samples but more related to downstream samples. However, in POM season, groundwater samples closer to the active landfill site represented distinctly different physico-chemical characteristics from upstream and downstream samples as a result of high influx of leachate pollutants. In specific, the present study urges for proper pollution control measures along with landfill leachate treatment process to improve the surrounding water quality.

The biomass and distribution of black clam (Villorita cyprinoides) in Vembanad, a tropical estuary located along the southwest coast of India varied significantly. Sampling was done in freshwater-dominated zone in the south (distal) and brackish water zone in the north (proximal), during pre and post monsoon seasons. Clam biomass was estimated from samples, collected from different stations during the study period. Water transparency and temperature were measured at the sample sites. Water samples were collected and analysed for salinity, dissolved oxygen (DO), pH and hardness. There was a significant difference in the clam biomass during the two seasons in the distal zone, and those collected from the distal and proximal zones during pre-monsoon season. The data were further analysed to determine the factors affecting the clam biomass distribution in the two zones and seasons. Factor analyses, comparing the distal zone during two seasons and zonal variations were similar to earlier observations. Step wise regression analyses found that dissolved oxygen (adjusted R2 = 0.3) is the only variable affecting clam survival during pre-monsoon period in the distal and proximal zones. A geographic map of the region obtained from the Indian satellite sensor LISS (Linear Image Self Scanner) was used along with in situ data to map the results using inverse distance weightage model.

The present study reports on aerosol characteristics and radiative properties utilizing ground based Aerosol Robotic Network (AERONET) data for the pre-monsoon (March, April, May) and post-monsoon (September, October, November) seasons over Lahore, Pakistan, for the two years during 2009–2010. The Aerosol Optical Depth (AOD) data from AERONET and a Moderate Resolution Imaging Spectro-radiometer (MODIS) were compared in order to validate both systems. The correlation coefficient for the post-monsoon season was > 0.68 in comparison to > 0.66 for the pre-monsoon season. In the pre-monsoon season, AERONET and MODIS AOD values were in the range of 0.2 to 1.2, and 0.2 to 1.67, respectively. For the post-monsoon season, these values were in the range of 0.17 to 2.46, and 0.15 to 2.45 for AERONET and MODIS, respectively. Strong dust loading resulted in higher values for the coarse particles during the pre-monsoon period, followed by an increase in the absorbing anthropogenic aerosols with the change from the pre-monsoon to post-monsoon season. The higher dust loading corresponded to the higher values of the real part of the refractive index in the pre-monsoon season, causing a relatively large single scattering albedo (SSA) (0.85–0.915) and thus a higher value for the asymmetry parameter (ASY). Similarly, the higher value of absorbing anthropogenic aerosols resulted in a higher value for the imaginary part of the refractive index in the post-monsoon period, followed by relatively lower values for SSA (0.88–0.911) and ASY. The averaged aerosol radiative forcing (ARF) for the pre-monsoon period at the top of the atmosphere was –19 ± 6 W/m2, while at the surface it was –93 ± 22 W/m2 leading to an atmospheric forcing of +74 ± 16 W/m2. Likewise, the averaged ARF for the post-monsoon period at the top of the atmosphere was –28 ± 8 W/m2, while at the surface it was –98 ± 24 W/m2 leading to an atmospheric forcing of +70 ± 15 W/m2, indicating significant heating of the atmosphere.

Consistently monitoring groundwater quality (GWQ) is essential to reduce the risk of geochemical contaminants and ensure its suitability for agriculture and human consumption. The current investigation aims to assess groundwater (GW) acceptability in the Nand Samand catchment (NSC), utilizing the water quality index (WQI) and irrigation water quality indices (IWQIs) for domestic and irrigation purposes. To achieve this, GW samples were collected from 95 open wells which were located spatially in the catchment, during the pre-monsoon (PRM) and post-monsoon (POM) seasons of 2019 and 2020, and subsequently analysed for 11 physico-chemical parameters. Electrical conductivity (EC) varied from 1.25 to 6.61 dS/m and 0.58 to 7.42 dS/m during the PRM and POM seasons, respectively. Total dissolved solids of the study area ranged between 180 and 1,180 (27%) to 1,180 and 2,180 (62%) during PRM 1,180 (63%) to 1,180–2,180 (31%) during POM, respectively. The study also computed the ‘sodium adsorption ratio’ (SAR) and ‘residual sodium carbonate’ (RSC) to estimate GW's appropriateness for agriculture, finding it suitable in most locations due to its balanced composition. Based on WQI, varying percentages of samples were classified as ‘good’ and ‘poor’ for potable water quality in both seasons.

Atmospheric aerosols in the Indo-Gangetic Plain (IGP) depicts high spatial and temporal heterogeneity in their radiative properties. Despite the fact that significant advancement in terms of characterizing aerosols radiative and physiochemical properties in the IGP have been made, information regarding the organic content towards total absorbing aerosol budget is lacking. In the present study we have analyzed two years of aerosol spectral light absorption measurements from the central-IGP, Gorakhpur (26.75°N, 83.38°E, 85m amsl), in order to study their seasonal behavior and to quantify their magnitude in terms of absorbing aerosols loading and source speciation. Remote sensing data in the form of 'Cloud corrected Fire Count' from MODIS Terra and 'Absorption Aerosol Index' from OMI satellites platform have been used to identify absorbing aerosol source regions. Spectral absorption analysis reveals a four-fold enhancement in absorption in the winter (W) and the post-monsoon (PoM) seasons at UV wavelengths as compared to 880 nm on account of increased biomass aerosol contribution to total absorbing aerosol load. Despite having higher fire events and absorption aerosol index, both indicating high biomass burning activities, in the pre-monsoon (PM) season, aerosols from the biomass sources contribute ~ 27% during the W and the PoM seasons as against ~17% in the PM season to the total absorbing aerosol content. This is due to near stagnant wind conditions and shallow height of air masses travelling to the central IGP in the W and the PoM seasons.

The present study highlights techniques to identify suitability of water for drinking and irrigation uses. Twenty water samples from Dang district of Gujarat state were collected in pre-monsoon (PRM) and post-monsoon (POM) seasons and analyzed for different physico-chemical properties. The Water Quality Index varied from 37.83 to 121.68 in PRM season and from 40.09 to 152.83 in POM season. Surface water quality in the Dang district was good for drinking in 58.43 % and 64.43 % area in PRM and POM season, respectively. The US Salinity diagram showed that most of the water samples belong to the categories C2S1 and C2S2 (suitable class for irrigation) in both the seasons. Some samples falling in the category C3S2 are also acceptable for irrigation use in both the seasons.