Browsing by Author "Pandey, P."

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Assessment and monitoring of land degradation using geospatial technology in Bathinda district, Punjab, India
(Copernicus GmbH, 2018) Ahmad, N.; Pandey, P.
Land degradation leads to alteration of ecological and economic functions due to a decrease in productivity and quality of the land. The aim of the present study was to assess land degradation with the help of geospatial technology - remote sensing (RS) and geographical information system (GIS) - in Bathinda district, Punjab. The severity of land degradation was estimated quantitatively by analyzing the physico-chemical parameters in the laboratory to determine saline or salt-free soils and calcareous or sodic soils and further correlating them with satellite-based studies. The pH varied between 7.37 and 8.59, electrical conductivity (EC) between 1.97 and 8.78dS m 1 and the methyl orange or total alkalinity between 0.070 and 0.223 (HCO3 )g L 1 as CaCO3. The spatial variability in these soil parameters was depicted through soil maps generated in a GIS environment. The results revealed that the soil in the study area was exposed to salt intrusion, which could be mainly attributed to irrigation practices in the state of Punjab. Most of the soil samples of the study area were slightly or moderately saline with a few salt-free sites. Furthermore, the majority of the soil samples were calcareous and a few samples were alkaline or sodic in nature. A comparative analysis of temporal satellite datasets of Landsat 7 ETM+ and Landsat 8 OLI-TIRS of 2000 and 2014, respectively, revealed that the water body showed a slight decreasing trend from 2.46km2 in 2000 to 1.87km2 in 2014, while the human settlements and other built-up areas expanded from 586.25 to 891.09km2 in a span of 14 years. The results also showed a decrease in area under barren land from 68.9847km2 in 2000 to 15.26km2 in 2014. A significant correlation was observed between the digital number (DN) of the near-infrared band and pH and EC. Therefore, it is suggested that the present study can be applied to projects with special relevance to soil scientists, environmental scientists and planning agencies that can use the present study as baseline data to combat land degradation and conserve land resources in an efficient manner. ? Author(s) 2018.
Geospatial technology applied to spatiotemporal assessment of Harike Wetland, Punjab
(Blackwell Publishing, 2017) Bhardwaj, A.; Najar, G.N.; Pandey, P.
The Harike Wetland situated in Punjab is a Ramsar site and a wetland of national importance. The present study was undertaken to assess the spatiotemporal dynamics of the wetland on the basis of geospatial technology and ground-based studies. Landsat images for the years 2002 and 2014 were acquired from the United States Geological Survey and classified digitally to generate landuse/land cover maps involving four classes (water, grassland (including water hyacinth), agriculture, built-up (settlement), barren land). The total area of the Harike Wetland was found to be 8023.68?ha. Water sampling at eleven sites was carried out and evaluated for physicochemical parameters. The water quality at several sampling points was found to be severely degraded. Change detection analysis revealed the submerged area (area under water) and grassland (including water hyacinth) had decreased over the past 12?years, whereas that area under agriculture and built-up land has increased, indicating a shrinkage in the total wetland area. The present study also indicated that the near-infrared band is a good indicator of water quality parameters, as indicated by the significant positive correlation between the near-infrared band and relevant water parameters. Because the wetland is important from both an ecological perspective and economic perspective, regular monitoring is recommended, for which geospatial technology has proven to be very useful. ? 2018 John Wiley & Sons Australia, Ltd
Spatial trends of surface urban heat island in Bathinda: a semiarid city of northwestern India
(Institute for Ionics, 2021-10-25T00:00:00) Kaur, R.; Pandey, P.
The rising global temperature coupled with the urban heat island has considerable adverse impacts on urban inhabitants and ecological integrity. An attempt has been made in the present study to monitor the surface urban heat island effect for the Bathinda District of Punjab, India. The surface urban heat island effect was monitored for the period of 5�years (2015�2019) using Landsat 8 OLI/TIRS data. The surface temperature distribution pattern was investigated by spatial extension and statistical analysis of land surface temperature dataset. The spatial autocorrelation among the data was analyzed using Moran�s Index and Getis-Ord Gi* statistics. Besides, the impact of land use land cover on land surface temperature was examined using correlation, covariance and multivariate analysis between land surface temperature and spectral indices. The results revealed that the vegetated and water surfaces accounted for low surface temperature (19.98�30.45��C), while built-up areas with high temperature (26.47�44.01��C) had amplified the heat island effect. The spatial autocorrelation with Moran�s Index (above 0.5) confirmed the spatial clustering with low p values (< 0.001) and high z values (> 2.58). Further, the hot spot analysis validated that the higher-temperature pixels lie in urban areas with dense infrastructure, while vegetated areas exhibit clusters with low-temperature values. Hence, the study inferred the occurrence of surface urban heat island with the urban heat island index of 0.7�1 for the urban cluster. The correlation between spectral indices and land surface temperature urges the need of adequate urban planning with vital urban greening, in order to achieve the urban sustainable development goals. Graphic abstract: [Figure not available: see fulltext.] � 2021, Islamic Azad University (IAU).
A spatio-temporal water quality assessment of the Beas and Sutlej Rivers at the Harike Wetland: A Ramsar site in Punjab, India
(Blackwell Publishing, 2017) Najar, G.N.; Bhardwaj, A.; Pandey, P.
Lakes play a vital role in regulating water storage, flow of river water, and ultimately maintaining a balanced ecosystem. Spatial and temporal variations in physicochemical parameters of water in Harike Wetland, a Ramsar site in the northwestern state of Punjab, India, were studied. This study was conducted on a monthly basis from January to December 2015. The water quality was studied at ten locations from sites 1 to 10 upstream, central and downstream from Harike Lake for ten physicochemical parameters, including temperature, pH, electrical conductivity, turbidity, dissolved oxygen concentration biological oxygen demand, nitrate and phosphate concentrations and salinity. The findings of this study revealed that, except for temperature and pH, all parameters exhibited relatively higher values for the Sutlej River, compared with the Beas River, with sampling sites 5 to site 7 exhibiting intermediate results. The mean seasonal temperature variations ranged from 16.9 to 26.6??C, the pH from 7.7 to 8.2, electrical conductivity from 223 to 303??S cm?1 and TDS concentration from 148.7 to 180.4?ppm. Correlation analysis was conducted to assess the relations between the variables. The electrical conductivity exhibited a high positive correlation with salinity and biological oxygen demand, whereas it correlated negatively with the dissolved oxygen concentration. Box?and whisker plots were also plotted for the study results to better examine the data distribution. ? 2017 John Wiley & Sons Australia, Ltd