Your search found 5 records
1 Tiwari, K.; Goyal, R.; Sarkar, A.. 2018. GIS-based methodology for identification of suitable locations for rainwater harvesting structures. Water Resources Management, 32(5):1811-1825. [doi: https://doi.org/10.1007/s11269-018-1905-9]
Rainwater ; Water harvesting ; GIS ; Remote sensing ; Surface runoff ; Drainage systems ; Estimation ; Land use mapping ; Land cover mapping ; Soil types ; Slopes ; Models / India / Rajasthan / Alwar
(Location: IWMI HQ Call no: e-copy only Record No: H048510)
(4.10 MB)
Presently, the water resources across the world are being continuously depleted. It is essential to find sustainable solutions for this shortage of water. Rainwater harvesting is one such promising solution to this problem. This paper presents a new GIS-based methodology to identify suitable locations for rainwater harvesting structures using only freely available imageries/remote sensing data and data from other sources. The methodology has been developed for the semi-arid environment of Khushkhera-Bhiwadi-Neemrana Investment Region (KBNIR) in Alwar district of Rajasthan. For identifying locations suitable for rainwater harvesting structures, the layers of surface elevation (ASTER-DEM), landuse/landcover, soil map, drainage map and depression map are used and further analyzed for their depression volume, and availability of surface runoff using Soil Conservation Service - Curve Number (SCS-CN) method. Based on the proposed criteria total seven locations were identified, out of which two locations are excellent; three locations are good, (if provisions of overflow structure are made for them) and two locations are not suitable for rain water harvesting. The total rainwater harvesting potential of the study area is 54.49 million cubic meters which is sufficient to meet the water requirements if harvested and conserved properly. This methodology is time-saving and cost-effective. It can minimize cost of earthwork and can be utilized for the planning of cost effective water resource management.
2 Sarkar, A.. 2019. Can shared standpipes fulfil the sustainable development goal of universal access to safe water for urban poor in Kenya? Water Policy, 21(5):1034-1049. [doi: https://doi.org/10.2166/wp.2019.047]
Water supply ; Sustainable Development Goals ; Water availability ; Urban areas ; Pipes ; Water management ; Infrastructure ; Households ; Informal settlements ; Willingness to pay ; State intervention ; Economic aspects ; Socioeconomic environment / Kenya / Nairobi
(Location: IWMI HQ Call no: e-copy only Record No: H049451)
(0.27 MB)
With the analyses of secondary data, the study finds that there has been a consistent increase in safe water coverage in Kenya over the years, mostly through paid common standpipes. However, primary data collected through in-depth field investigations in the Mathare slums of Nairobi reveal that the paid standpipes are overstressed and are prone to unreliable services, neglected operation and maintenance, illegal connections, water theft, unregulated and high tariffs and client favouritism on the basis of tribal affiliations. Thus, the most effective way to serve the urban poor is to increase the number of working standpipes with fixed operating schedules per day, along with strict enforcement of water tariff regulations.
3 Acharya, P.; Barik, G.; Gayen, B. K.; Bar, S.; Maiti, A.; Sarkar, A.; Ghosh, Surajit; De, S. K.; Sreekesh, S. 2021. Revisiting the levels of aerosol optical depth in South-Southeast Asia, Europe and USA amid the COVID-19 pandemic using satellite observations. Environmental Research, 193:110514. [doi: https://doi.org/10.1016/j.envres.2020.110514]
Air pollution ; Air quality ; Aerosols ; COVID-19 ; Nitrogen dioxide ; Sulphur dioxide ; Emission ; Weather data ; Wind speed ; Humidity ; Satellite observation ; Moderate resolution imaging spectroradiometer / South Asia / South East Asia / Europe / USA
(Location: IWMI HQ Call no: e-copy only Record No: H050797)
(12.20 MB)
The countries around the world are dealing with air quality issues for decades due to their mode of production and energy usages. The outbreak of COVID-19 as a pandemic and consequent global economic shutdown, for the first time, provided a base for the real-time experiment of the effect of reduced emissions across the globe in abetting the air pollution issue. The present study dealt with the changes in Aerosol Optical Depth (AOD), a marker of air pollution, because of global economic shutdown due to the coronavirus pandemic. The study considered the countries in south and south-east Asia (SSEA), Europe and the USA for their extended period of lockdown due to coronavirus pandemic. Daily Aerosol Optical Depth (AOD) from Moderate-resolution imaging spectroradiometer (MODIS) and tropospheric column density of NO2 and SO2 from Ozone monitoring instrument (OMI) sensors, including meteorological data such as wind speed (WS) and relative humidity (RH) were analyzed during the pre-lockdown (2017–2019) and lockdown periods (2020). The average AOD, NO2 and SO2 during the lockdown period were statistically compared with their pre-lockdown average using Wilcoxon-signed-paired-rank test. The accuracy of the MODIS-derived AOD, including the changing pattern of AOD due to lockdown was estimated using AERONET data. The weekly anomaly of AOD, NO2 and SO2 was used for analyzing the space-time variation of aerosol load as restrictions were imposed by the concerned countries at the different points of time. Additionally, a random forest-based regression (RF) model was used to examine the effects of meteorological and emission parameters on the spatial variation of AOD. A significant reduction of AOD (- 20%) was obtained for majority of the areas in SSEA, Europe and USA during the lockdown period. Yet, the clusters of increased AOD (30–60%) was obtained in the south-east part of SSEA, the western part of Europe and US regions. NO2 reductions were measured up to 20–40%, while SO2 emission increased up to 30% for a majority of areas in these regions. A notable space-time variation was observed in weekly anomaly. We found the evidence of the formation of new particles for causing high AOD under high RH and low WS, aided by the downward vertical wind flow. The RF model showed a distinguishable relative importance of emission and meteorological factors among these regions to account for the spatial variability of AOD. Our findings suggest that the continued lockdown might provide a temporary solution to air pollution; however, to combat persistent air quality issues, it needs switching over to the cleaner mode of production and energy. The findings of this study, thus, advocated for alternative energy policy at the global scale.
4 Sarkar, A.. 2023. Women, technology, and water: creating new waterscapes and contesting cultural norms. Journal of Water, Sanitation and Hygiene for Development, 13(1):30-38. [doi: https://doi.org/10.2166/washdev.2022.306]
Women ; Men ; Technology ; Tankers ; Water scarcity ; Water supply ; Villages ; Drinking water ; Households ; Commercialization ; Domestic water / India / Rajasthan / Barmer / Jaisalmer / Jodhpur
(Location: IWMI HQ Call no: e-copy only Record No: H051617)
https://iwaponline.com/washdev/article-pdf/13/1/30/1164339/washdev0130030.pdf
https://vlibrary.iwmi.org/pdf/H051617.pdf
https://vlibrary.iwmi.org/pdf/H051617.pdf
(0.29 MB) (300 KB)
With the analysis of primary data, the paper looks at how the adoption of new modes of water technologies and subsequent water commercialization has created new waterscapes. Water commercialization is changing cultural norms associated with water collection in the drought-prone villages of western Rajasthan. The newly introduced water tankers have selectively benefited the upper caste rich households who now buy water from the tankers at doorsteps. The majority of the poor and low caste households remain dependent on common water sources that are drying up due to neglect with the advent of water commercialization. Women from low caste poor households have to walk for long distances to fetch water in addition to doing physical labor to support family income. Though domestic water use remains a domain of woman's working space, men from high caste rich households have started fetching and storing water as it entails cash transactions.
5 Rana, B.; Parihar, C. M.; Jat, M. L.; Patra, K.; Nayak, H. S.; Reddy, K. S.; Sarkar, A.; Anand, A.; Naguib, W.; Gupta, N.; Sena, Dipaka R.; Sidhu, H. S.; Singh, R.; Singh, R.; Abdallah, A. M. 2023. Combining sub-surface fertigation with conservation agriculture in intensively irrigated rice under rice-wheat system can be an option for sustainably improving water and nitrogen use-efficiency. Field Crops Research, 302:109074. [doi: https://doi.org/10.1016/j.fcr.2023.109074]
Subsurface irrigation ; Drip irrigation ; Water-use efficiency ; Nitrogen-use efficiency ; Crop yield ; Fertigation ; Conservation agriculture ; Irrigated rice / India / Indo-Gangetic Plains / Punjab
(Location: IWMI HQ Call no: e-copy only Record No: H052334)
(1.86 MB)
Context: The rice-wheat cropping system in the Indo-Gangetic plains (IGP) of South Asia has been shown to have higher productivity. However, this benefit is offset by the unsustainable over-drafting of groundwater resources. Given the growing scarcity of water, it is imperative to investigate alternative crop establishment and irrigation methods that do not rely on the conventional puddled transplanting method (PTR). Objective: This study aims to assess the impact of combining conservation agriculture-CA with sub-surface drip irrigation-SSD referred to as CA+, at different nitrogen (N) doses on physiological performance, crop yield, irrigation and nitrogen use-efficiency, as well as farm profitability of rice in the north-western IGP of India. Method: A two-year field experiment was conducted to assess the effects of medium-term CA and the combination of CA with SSD (CA+) at three levels of N (0%, 75%, and 100% of the recommended dose), in comparison to PTR using recommended dose of nitrogen-RDN (120 kg N ha-1). Indicators of crop growth (under CA, CA+), i.e., biomass, grain yield, water-use, water-use efficiency (WUE), nitrogen-use efficiency (NUE), and economic analysis of rice production were evaluated and compared with PTR. Result: The results revealed that the PTR plots produced 15% and 11% higher grain yield than CA and CA+ systems, respectively, even at 100%RDN, due to a significantly higher number of fertile tillers. However, the application of 100%RDN and irrigation through SSD resulted in a significant increase in nitrogen uptake (4.5%) and remobilization (7.5%) into the grain compared to PTR. The CA+ plots demonstrated a reduction in irrigation water usage by 1.5 and 2 times compared to the CA and PTR systems, leading to a respective increase in WUE by 1.6% and 1.8%. PTR exhibited highest net returns, while the CA+ treatment– SSD-N100 achieved the highest benefit-cost ratio. Conclusion: The combination of CA with SSD at 100%RDN offers significant benefits, including notable water saving, improved WUE, NUE and crop yield. This integrated approach presents a promising solution to address the pressing issues of food security and sustainability arising from water scarcity and groundwater depletion in South Asia. Future implication: There is a need to increase awareness among farmers about the benefits of CA coupled with SSD i.e., CA+ , for water-intensive rice-based systems. Additionally, further research should focus on identifying ideal rice cultivars suitable for CA+ systems and determining the optimal specifications for drip lines and emitter discharge rates for diverse water-scarce agro-ecological conditions.
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