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• Above ground forest biomass distribution in the landscape of Jorhat, Assam, India

  16-31

  Rashima Kachari

  Views:

  10

  This study aims to analyze the spatial and temporal variations in above-ground biomass (AGB) within the Jorhat region from 2001 to 2023. It also highlights the impacts of urbanization, physiographic characteristics, and soil types on AGB variation. In order to accurately assess landscape-level variation of biomass, a combination of field surveys, remote sensing techniques, and modelling approaches are employed in this study. Biomass estimation is difficult over large area using traditional method. The synoptic nature of satellite-based data improves the monitoring of inaccessible areas. Results show approximately 16.6% decrease in AGB, with urban and peripheral areas experiencing the most notable declines due to reduced forest cover. Physiographic analysis reveals low AGB values in marshes (13 t/ha), swamps (14 t/ha), and char lands (25 t/ha). The growth of trees is suppressed seasonal flooding in this physiography. Additionally, AGB follows an increasing trend from North to South, in alignment with the region’s elevation profile. Soils also exhibit variations in AGB, with alluvial soils supporting higher biomass compared to other soil types. Key ecological linkages and spatial patterns are highlighted in this study, laying the groundwork for more proactive and comprehensive environmental management. Finally, in a time of fast environmental change, these insights can assist stakeholders and policymakers
  in creating more evidence-based, flexible solutions to protect ecosystems.

• Reduction of environmental impacts of heat pump usage with special regard on systems with borehole heat exchangers

  66-77

  Tamás Buday

  Views:

  171

  Ground coupled heat pump systems are suitable for extracting subsurface thermal energy with low environmental impact especially regarding CO2 emission. The efficiency of such systems strongly depends on the temperature of the ambient heat (thus underground substrate). This temperature usually changes unfavourably during operation and efficiency becomes lower than the nominal value. Appropriate installation and operation cause lower temperature drop, thus higher efficiency. Consequently, it means lower electricity demand, therefore lower specific CO2 emission, more CO2 saving and lower operation costs. Quantitative analysis with 21 heat extraction models presented in the paper points out that the differences could be significant (up to 30 %), in addition using bivalent mode the environmental impact of the installation or/and operation can be reduced as well, especially using biomass firing as auxiliary heating.