Forest fires are one of the major environmental issues globally.In Nepal,substantial amounts of forest biomass and carbon are lost due to fire.Nepal’s high value lowland forests are particularly vulnerable to fire.Ho...Forest fires are one of the major environmental issues globally.In Nepal,substantial amounts of forest biomass and carbon are lost due to fire.Nepal’s high value lowland forests are particularly vulnerable to fire.However,there are limited studies on the estimation of biomass loss and carbon emissions due to fire.Thus,this research addresses the information gap in the tropical mixed broad-leaved forests of Nawalparasi District.The forests were divided into three strata:Lower Tropical Sal Mixed Broad-leaved Forest,Hill Sal Forest and Riverine Forest,and from these four community-managed forests were selected for estimating above ground biomass.Ninety-two sample plots were set out for above ground biomass estimation in burnt and non-burnt areas.Forest fire incidences from 2001 to 2017 were acquired from the MODIS fire data.Forest biomass and carbon emissions were estimated using standard allometric equations.The fuel fraction consumed during the fire was estimated through field surveys during the forest fire season.The results show that every year,over 3158 ha of forests are burnt,resulting in some 1108 tons of carbon emissions,equivalent to approximately 4066 t CO_(2),2581 t CO and 1474 t CH4.Among the forests,the Hill Sal Forest was more vulnerable to fire.Forest management strategies,therefore,should include construction of fire lines and conservation ponds along with capacity building and raising awareness among local communities and stakeholders.展开更多
Traditional active and automated sampling of nitrogen dioxide (NO2) monitoring techniques require expensive instrumentation which is not easily adapted for large scale monitoring by resource limited countries. This pa...Traditional active and automated sampling of nitrogen dioxide (NO2) monitoring techniques require expensive instrumentation which is not easily adapted for large scale monitoring by resource limited countries. This paper presents the use of locally available relatively cheaper polyethylene tubes to be developed as passive diffusive sampler and use for monitoring of ambient nitrogen dioxide using Triethanolamine (TEA) as absorbent. After extraction with double distilled water, modified Griese-Saltzmann method is used for analysis of nitrite adduct formed due to reaction of NO2 with TEA using spectrophotometer. The results are compared with Ferm-Badge type passive samplers from IVL- Sweden and high volume sampling methods. The detection limits of the passive sampling methods were found to be suitable to be use in tested environment and precision of the method as expressed as Coefficient of variation are good enough for monitoring of NO2 in ambient air of Kathmandu. The method shows strong correlation with high volume sampler and no significant difference with Ferm-Badge—IVL samplers at p = 0.05.展开更多
文摘Forest fires are one of the major environmental issues globally.In Nepal,substantial amounts of forest biomass and carbon are lost due to fire.Nepal’s high value lowland forests are particularly vulnerable to fire.However,there are limited studies on the estimation of biomass loss and carbon emissions due to fire.Thus,this research addresses the information gap in the tropical mixed broad-leaved forests of Nawalparasi District.The forests were divided into three strata:Lower Tropical Sal Mixed Broad-leaved Forest,Hill Sal Forest and Riverine Forest,and from these four community-managed forests were selected for estimating above ground biomass.Ninety-two sample plots were set out for above ground biomass estimation in burnt and non-burnt areas.Forest fire incidences from 2001 to 2017 were acquired from the MODIS fire data.Forest biomass and carbon emissions were estimated using standard allometric equations.The fuel fraction consumed during the fire was estimated through field surveys during the forest fire season.The results show that every year,over 3158 ha of forests are burnt,resulting in some 1108 tons of carbon emissions,equivalent to approximately 4066 t CO_(2),2581 t CO and 1474 t CH4.Among the forests,the Hill Sal Forest was more vulnerable to fire.Forest management strategies,therefore,should include construction of fire lines and conservation ponds along with capacity building and raising awareness among local communities and stakeholders.
文摘Traditional active and automated sampling of nitrogen dioxide (NO2) monitoring techniques require expensive instrumentation which is not easily adapted for large scale monitoring by resource limited countries. This paper presents the use of locally available relatively cheaper polyethylene tubes to be developed as passive diffusive sampler and use for monitoring of ambient nitrogen dioxide using Triethanolamine (TEA) as absorbent. After extraction with double distilled water, modified Griese-Saltzmann method is used for analysis of nitrite adduct formed due to reaction of NO2 with TEA using spectrophotometer. The results are compared with Ferm-Badge type passive samplers from IVL- Sweden and high volume sampling methods. The detection limits of the passive sampling methods were found to be suitable to be use in tested environment and precision of the method as expressed as Coefficient of variation are good enough for monitoring of NO2 in ambient air of Kathmandu. The method shows strong correlation with high volume sampler and no significant difference with Ferm-Badge—IVL samplers at p = 0.05.
