Natural Hazards - Lightning, a climate-related highly localized natural phenomenon, claims lives and damage properties. These losses could only be reduced by the identification of active seasons... 相似文献
In this study, three approaches namely parallel, sequential, and multiple linear regression are applied to analyze the local air quality improvements during the COVID-19 lockdowns. In the present work, the authors have analyzed the monitoring data of the following primary air pollutants: particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO). During the lockdown period, the first phase has most noticeable impact on airquality evidenced by the parallel approach, and it has reflected a significant reduction in concentration levels of PM10 (27%), PM2.5 (19%), NO2 (74%), SO2 (36%), and CO (47%), respectively. In the sequential approach, a reduction in pollution levels is also observed for different pollutants, however, these results are biased due to rainfall in that period. In the multiple linear regression approach, the concentrations of primary air pollutants are selected, and set as target variables to predict their expected values during the city's lockdown period.The obtained results suggest that if a 21-days lockdown is implemented, then a reduction of 42 µg m−3 in PM10, 23 µg m−3 in PM2.5, 14 µg m−3 in NO2, 2 µg m−3 in SO2, and 0.7 mg m−3 in CO can be achieved. 相似文献
In this study, the aerosol behavior during two contradictory events, i.e., dust storm (DS) and Diwali (DW) has been studied over Jaipur. The aerosol particle number concentration shows distinct features between DS and DW events. The total ANC was found minimum during DS while maximum during DW. The 24 h mean of total ANC was 9.15 × 104 (±7.71 × 104) and 5.38 × 105 (±3.73 × 105 particles/l) during DS and DW, respectively. The total ANC increases from 7.78 × 104 to 5.32 × 105 and 3.52 × 105 to 1.70 × 106 particles/l in 24 h during DS and DW, respectively. In DS, the ANC in coarse mode (2 < particle diameter < 20 μm) is significantly high while in DW, the ANC in fine mode (0.3 < particle diameter < 2 μm) exhibits higher concentration. During dust episode, a significant change in ANC (3.0 × 103 to 1.12 × 105 particles/l) was observed for the particle of size range in 2.0–20 μm with a slight increase in particles number concentration (7.48 × 104 to 4.20 × 105 particles/l) in 0.3–2.0 μm range is also observed. During DS, the fine and coarse mode particles increased 4.61 and 36.44 times while during DW, it increased 3.83 and 0.95 times, respectively. The relatively high particle levels during DW are attributed for two reasons: local emissions due to burning of fire crackers and meteorological conditions, i.e., low wind speeds and low mixing-layer heights lead to relatively high particle concentrations.
Agrarian patterns in mountain ecosystems have seen a considerable change in the past decades with a vast proportion of the population abandoning traditional agriculture and diversifying their livelihood options, primarily through out-migration. This trend is especially common amongst the subsistence based family-farming communities in developing countries. This study aims at assessing methods of livelihood diversification and factors influencing farm-exit in Central Himalayan villages of Uttarakhand, India, while trying to understand local perspectives on challenges in pursuing agriculture as a viable livelihood option. We collected qualitative and quantitative data from 951 households across 60 villages evenly distributed across six hill districts of Uttarakhand, using key-person interviews and household surveys. The results of the study highlight that farm-exit is significantly influenced by livelihood diversification, number of migrants, number of female family members, and availability of irrigation facilities. In general, perception of the respondents towards agriculture as a viable livelihood option is rather unenthusiastic, with 87% of the respondents citing human wildlife conflict as the main challenge in pursuing farming, amongst several other challenges. Diversification is an integral component of present rural economy with 80.13% of the total population dependent on more than one source of income, to maintain their livelihoods. However, there is no statistically significant influence of livelihood diversification on annual income of the household. If agro-based entrepreneurial ventures are to be promoted in the region there is an urgent need for timely introduction of radical policy, institutional, and land-reforms. Economic uplifting of the local population through such efforts can also be a possible solution to the growing trends of out-migration in the state. 相似文献
The Indian Thar Desert is one of the smallest and most densely populated deserts of the world but due to its geographical location it has high avian and plant diversity. Nearly 300 bird species have been identified. A 649-km long irrigation canal, the Indira Gandhi Nahar Project (IGNP), is changing the ecology of the Thar by bringing water to arid areas. Beside the main canal, nearly 8000 km of distribution channels have been built. A massive afforestation scheme along the canal has attracted many new animal and bird species. Expansion of agriculture, overgrazing by livestock, change in cropping pattern, development of seepage wetlands and introduction of exotic plants have greatly affected desert birds such as the endangered Great Indian BustardArdoetis nigriceps, the migratory Houbara BustardChlamydotis undulataand the endemic White-browed BushchatSaxicola macrorhyncha, while some species such as Common CraneGrus grusand Demoiselle CraneGrus virgoare spreading along the canal. This paper discusses the change brought about in the birdlife of the Thar by the development of IGNP and recommends urgent conservation measures. 相似文献