Analysis of Trend in Groundwater-Quality Parameters: A Case Study

In the 21st century, groundwater has a pivotal role in ensuring water, food, and environmental securities worldwide. Systematic observation, protection and restoration are essential for sustainable management of water resources. Regular monitoring is key to investigate temporal changes in groundwater quality, and statistical trend tests define whether these changes are significant or not. This study focuses on investigating trend in seasonal groundwater quality in an alluvial coastal basin of West Bengal, India. The seasonal groundwater-quality data (pH, TH, TDS, Fe2+ and HCO3ˉ) of pre-monsoon and post-monsoon seasons were collected for 2011–2018 period and analyzed using three non-parametric statistical trend detection tests, namely: (i) Original Mann-Kendall (M-K) test, (ii) Modified Mann-Kendall (mM-K) test, and (iii) Spearman Rank Order Correlation (SROC) test. The trend magnitudes were estimated by using the Sen’s slope estimation test. Statistical analyses revealed that seasonal concentrations of all five groundwater-quality parameters have large spatial (block-wise) variation within the study area. The results of trend analyses indicated that seasonal TH and TDS concentrations mainly have significant decreasing trends (α = 5% or 1%), whereas seasonal HCO3ˉ and Fe2+ concentrations mostly show significant increasing trends (α = 5% or 1%) in different blocks. However, seasonal pH concentrations exhibited no trend. The mM-K test was found to be over-sensitive in finding trends than M-K and SROC tests. The SROC test was found to be less sensitive in detecting trends than M-K and mM-K tests. Trend magnitudes of seasonal pH, TH, TDS, HCO3ˉ and Fe2+ concentrations varied from –0.03/year to 0.23/year, –57.44 mg/L/year to 25.88 mg/L/year, –172.98 mg/L/year to 92.58 mg/L/year, –15.81 mg/L/year to 27.88 mg/L/year, and –0.05 mg/L/year to 0.61 mg/L/year, respectively. Continuous and proper groundwater-quality monitoring is critically required in all aquifer systems. The outcomes of this study will aid policy-makers in appropriately monitoring and managing groundwater quality

Performance Evaluation of a Hand pump with Provision of a Sealed Secondary Water Sump

Nowadays, a large number of water lifting devices and pumps are available for lifting water or other liquids from lower elevation to higher elevation. However, none of these hand pumps use a secondary water sump or any other such kind of device which increases efficiency of commonly used hand pumps. Also, measurement of operating forces for the performance evaluation of hand pumps is often missing. In this study, a commonly used hand pump was fitted with a 54-liter capacity sealed secondary water sump. The secondary water sump is again linked with the shallow well water or aquifer water. It was estimated that the provision of secondary water sump fitted with a hand pump results in significant reduction in the input power. The performance on a hand pump when fitted with a secondary water sump found that there is a significant reduction in the input power; thus it requires lesser operating force.  The experiments also revealed that use of larger the capacity of secondary water sump requires lesser operating force of the pump. The output powers in both the cases viz. with and without a secondary water sump are found to be approximately same. The provision of secondary water sump fitting with a hand pump thereby provides more comfort in operating the hand pumps

Understanding the evolution of catalytically active multi-metal sites in a bifunctional high-entropy alloy electrocatalyst for zinc–air battery application

Zinc–air batteries are known for high theoretical energy density and environmental friendliness. The successful commercial utilization of rechargeable zinc–air batteries is limited by unstable electrochemical interfaces and sluggish kinetics with poor round-trip efficiency. In this study, we report a nanocrystalline high entropy alloy (HEA) comprising Cu–Co–Mn–Ni–Fe (CCMNF) prepared by casting-cum-cryomilling method. This multi-component HEA embodies multiple catalytically active sites with diverse functionalities, thus enhancing the electrochemical redox reactions, e.g., oxygen reduction (ORR) and oxygen evolution reaction (OER). The bifunctional electrocatalytic performance of this HEA is comparable to that of standard catalysts, RuO2 and Pt/C, as evidenced by low overpotential requirements towards OER and ORR. The HEA was tested for use in the air electrode catalyst in the zinc–air battery, where it performed stable oxygen electrocatalysis that was durable over 1045 charging–discharging cycles for ∼90 hours of continuous operation. The microstructural analysis of HEA at different time scales (0, 24, 87 h) during the zinc–air battery operation suggested a dynamic participation of multiple metal active sites on the catalyst surface. Detailed studies revealed that despite leaching in harsh alkaline operation conditions, the synergistic electronic interactions between the component metal sites sustained good electrocatalytic performance and promoted oxygen electrocatalysis through the modification of electronic and chemical properties

Food Legumes and Rising Temperatures: Effects, Adaptive Functional Mechanisms Specific to Reproductive Growth Stage and Strategies to Improve Heat Tolerance

Ambient temperatures are predicted to rise in the future owing to several reasons associated with global climate changes. These temperature increases can result in heat stress- a severe threat to crop production in most countries. Legumes are well-known for their impact on agricultural sustainability as well as their nutritional and health benefits. Heat stress imposes challenges for legume crops and has deleterious effects on the morphology, physiology, and reproductive growth of plants. High-temperature stress at the time of the reproductive stage is becoming a severe limitation for production of grain legumes as their cultivation expands to warmer environments and temperature variability increases due to climate change. The reproductive period is vital in the life cycle of all plants and is susceptible to high-temperature stress as various metabolic processes are adversely impacted during this phase, which reduces crop yield. Food legumes exposed to high-temperature stress during reproduction show flower abortion, pollen and ovule infertility, impaired fertilization, and reduced seed filling, leading to smaller seeds and poor yields. Through various breeding techniques, heat tolerance in major legumes can be enhanced to improve performance in the field. Omics approaches unravel different mechanisms underlying thermotolerance, which is imperative to understand the processes of molecular responses toward high-temperature stress

Development and analysis of the Soil Water Infiltration Global database

In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements ( ∼ 76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76% of the experimental sites with agricultural land use as the dominant type ( ∼ 40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it. Supplementary data are available at https://doi.org/10.1594/PANGAEA.885492 (Rahmati et al., 2018). Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend and update the SWIG database by uploading new data to it

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Not AvailableIn this study, 43-year (1965-2007) monthly and annual rainfall of ten rainfall stations in a semi-arid region of western India are analyzed by adopting three tests for testing normality, and by applying autoregressive technique for examining persistence. Gradual trends are detected by three tests, and their magnitudes are estimated by Sen’s slope estimator. Further, abrupt changes are identified by using four tests and are further confirmed by two tests. The box-whisker plots revealed that the rainfall of June and September are right-skewed for all the stations. The annual rainfall of Bhinder, Dhariawad and Gogunda stations is found considerably right-skewed. The normality tests indicated that the rainfall in July does not deviate from the normal distribution at all the stations. The annual rainfall is found non-normal at five stations. The monthly rainfall of June, July and August has persistence at 3 (Mavli, Salumber, and Sarada), 2 (Kherwara and Sarada) and 1 (Mavli) stations, respectively. The annual rainfall is persistent at Girwa and Mavli stations. The significantly increasing trend is detected at Mavli in the monthly rainfall of July and in the annual rainfall (p-value>0.05), whereas the negative trend at Dhariawad in August month is found significant (p-value>0.10). This study revealed that the presence of serial correlation does not affect performance of the Mann-Kendall test. The mean values of the trend magnitudes for rainfalls of June, July, August and September months are 0.3, 0.8, -0.4, and 0.4 mm year-1, respectively, and the overall mean value at the annual scale is 0.9 mm year-1. It is found that the standard normal homogeneity test and Pettitt test are biased towards the end of the series to locate the change point. However, the Bayesian test has a tendency to look for a change point at the beginning of the series. The confirmed abrupt changes in rainfall occurred in the year 2003 (Bhinder) in June; years 1974 (Mavli) and 1989 (Dhariawad and Salumber) in July; years 1972 (Sarada), 1990 (Dhariawad), and 2003 (Mavli) in August; years 1977 (Dhariawad), 1991 (Sarada), and 2004 (Kotra) in September; and the year 1972 (Mavli and Sarada stations) at the annual scale. It is suggested that the significantly increasing trend of rainfall may have linkages with the climate change and variability. Moreover, this study recommends use of multiple statistical tests for making reliable decisions while analyzing a hydrologic time series.Not Availabl

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Not AvailableThis study aimed at investigating hydrogeology and groundwater dynamics in a lateritic terrain of West Bengal, India, under limited data conditions. A field setup was developed comprising six observation wells, two onfarm reservoirs and three artificial excavations. Groundwater levels, groundwater quality and water levels of surface water bodies were monitored during 2003–2005 period. Regression and correlation analyses of groundwater levels with rainfall and surface water levels were performed to study rainfall–groundwater dynamics and surface water–groundwater interaction. Depth-wise geologic samples of six sites were subjected to grain-size analysis (GSA) and stratigraphy analysis. Hydraulic conductivities (K) of subsurface formations at different depths were estimated by three GSA models, and finally groundwater recharge was estimated. Stratigraphy analyses revealed that besides shallow aquifers, deep confined aquifers of 5–16 m thickness exist at 54–96 m depths in the study area. Significant correlation of groundwater levels with the water levels in excavations and the ‘potential recharge’ of 1.90–2.99 cm/day from excavations indicate that the excavations can serve as promising low-cost recharge structures for augmenting groundwater resources. Nitrate concentration in the groundwater beyond maximum permissible limit at most sites renders it unsuitable for drinking purpose. Furthermore, the Hazen, Harleman, and Alyamani and Sen models yielded reasonable K values of subsurface formations. Average hydraulic conductivity and transmissivity values of the deep aquifer system vary from 3 to 129 and 27 to 1161 m2 /day, respectively, which suggest significant aquifer heterogeneity. Seasonal groundwater recharge in the study area was found to be in the range of 4.32–15.24 cm.Not Availabl