Role of neotectonics and climate in development of the Holocene geomorphology and soils of the Gangetic Plains between the Ramganga and Rapti rivers

1994 ◽  
Vol 94 (1-2) ◽  
pp. 129-151 ◽  
Author(s):  
Pankaj Srivastava ◽  
B. Parkash ◽  
J.L. Sehgal ◽  
Sudhir Kumar
Keyword(s):  
2021 ◽  
Author(s):  
Mohd Usman Khan ◽  
Nachiketa Rai ◽  
Mukesh Kumar Sharma

<p>As contamination in groundwater has been reported from various regions of the Indian subcontinent but no data related to heavy metal contamination of groundwater has been reported for the Bahraich area in the Indo-Gangetic plains. We report the first dataset on arsenic contamination and groundwater hydrogeochemistry, in Bahraich. This includes concentrations of heavy metal such as As, Mn, and Fe, along with major cations (Na<sup>+</sup>, K<sup>+</sup>, Ca<sup>2+</sup>and Mg<sup>2+</sup>) and anions (F<sup>-</sup>, Cl<sup>-</sup>, NO<sub>3</sub><sup>-</sup>, SO<sub>4</sub><sup>2-</sup> and PO<sub>4</sub><sup>3-</sup>), and dissolved organic carbon (DOC), along with various physico-chemical parameters such as EC, pH, and Eh from samples collected during two extensive field campaigns conducted during pre-monsoon, and post-monsoon seasons respectively. The combined use of geochemical modeling and multivariate statistical approaches such as principal component analysis (PCA) and correlation analysis (CA) suggest several processes affecting the geochemistry of groundwater including the lithological characteristics of aquifers and anthropogenic activities.</p><p>The groundwater of the study area predominantly belongs to the Ca-Mg-HCO<sub>3</sub> type hydrochemical facies. HCO<sub>3</sub><sup>−</sup>/Na<sup>+</sup> and Ca<sup>2+</sup>/Na<sup>+</sup> signatures of groundwater indicate the influence of silicate weathering and carbonate dissolution processes with the insignificant role of evaporate dissolution mechanism. As concentration was found to range from 0.6 μg/L to ~100 μg/L with almost 40% of the collected samples exceeding the WHO defined limit of 10 μg/L for drinking water. 70 % of the groundwater samples were found to have very high Fe concentrations exceeding the WHO guideline of 0.3 mg/l in drinking water. Mn concentrations in the groundwater samples were relatively low with only ~10 % of the samples exceeding the WHO defined limit for Mn (400 μg/L). The majority of the groundwater samples were found to be anoxic in nature showing low NO<sub>3</sub><sup>−</sup> & SO<sub>4</sub><sup>2-</sup> concentrations, high Fe & Mn and DOC concentrations, and negative Eh values.</p><p>Results from this study show that the reductive dissolution mechanism of iron oxyhydroxide is the dominant mechanism responsible for arsenic release in groundwater of the region, ruling out any role of sulfide oxidation and alkali desorption.</p><p> </p><p> </p>


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Yonggang Liu ◽  
Ming Zhang ◽  
Zhengyu Liu ◽  
Yan Xia ◽  
Yi Huang ◽  
...  
Keyword(s):  

2022 ◽  
Vol 3 ◽  
Author(s):  
Anjana Chaudhary ◽  
Pragya Timsina ◽  
Bhavya Suri ◽  
Emma Karki ◽  
Akriti Sharma ◽  
...  

While there are numerous studies that explore the agronomic and the economic benefits of Conservation Agriculture in South Asia, only few studies have explored the farmers' experiences and the drivers of its adoption. This study aims to learn directly from current users through exploration of their decision processes, evaluations, and experiences in extrapolating the concept for the broader scaling of Conservation Agriculture across the Eastern Gangetic Plains (EGPs) of South Asia. We analyzed a total of 57 qualitative and semi-structured individual interviews with the farmers who are currently implementing Conservation Agriculture practices across six locations. These farmers faced a variety of hurdles including hesitation in accepting and adopting the technology, technical performance challenges, information gaps, and subsidy/project dependence. To overcome these, respondents adopted various strategic approaches such as assuming the role of an educator by sharing their knowledge with other farmers in the community, changing mindsets for stover retention, adoption through self-investment, and opting for communal purchase of machinery to reduce project dependence. This led farmers to identify a range of benefits including improved socio-economic condition, increased respect in the community, and increased free time to pursue diverse interests and opportunities. Additionally, strengthened information networks such as improved interpersonal connection with agricultural universities, government extension systems, and local farmers groups have positively enhanced the uptake, allowing them to overcome further limitations. These findings provide novel learnings on how farmers overcome nine key friction points, and what this means for increasing the farmer uptake of new practices across the region, which are crucial for successful future interventions as implemented by the government and development organizations.


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