Landslides, a prevalent natural disaster, wreak havoc on both human lives and vital infrastructure, making them a significant global concern. Their devastating impact is immeasurable, necessitating proactive measures to minimize their occurrence. The ability to accurately forecast the severity of a landslide, including its potential fatality rate and the scale of destruction it may cause, holds tremendous potential for prevention and mitigation to reduce the risk and the damage caused by a landslide to infrastructure and life. In this study, the spatial variability in severity of landslides (in terms of mortality rates) and its dependence on various meteorological, geographical and soil composition has been attempted to be established. To do this, Ordinary Least Squares (global) and various Geographically Weighted (local) models have been employed to observe the varying relation between mortality rates and its various causative factors. Existence of geographical heterogeneity in the relationships is also investigated. The spatial pattern of landslide mortality and its associations with various causative variables in the South Asian Region are investigated and analysed. Through this, insights into targeting of prevention and mitigation measures for landslides based on a given location can be obtained by studying the various forms of heterogeneous spatial associations observed. The outcomes highlight that the local models in the form of Gaussian GWR and Poisson GWR outperform their global counterparts by a huge margin with better R2 and Adj R2 values. In comparison with Poisson GWR and Gaussian GWR, it is seen that Poisson GWR outperforms Gaussian GWR in terms of Mean Absolute Error, Mean Squared Error and Corrected Akaike Information Criterion. Furthermore, several intriguing local relationships patterns are also noted.
Equivalent black carbon (EBC) was measured with a seven-wavelength Aethalometer (AE-31) in the Urumqi River Valley, eastern Tien Shan, China. This is the first high-resolution, online measurement of EBC conducted in the eastern Tien Shan allowing analysis of the seasonal and hourly variations of the light absorption properties of EBC. Results showed that the highest concentrations of EBC were in autumn, followed by those in summer. The hourly variations of EBC showed two plateaus during 8:00-9:00 h local time (LT) and 16:00-19:00 h LT, respectively. The contribution of biomass burning to EBC in winter and spring was higher than in summer and autumn. The planetary boundary layer height (PBLH) showed an inverse relationship with EBC concentrations, suggesting that the reduction of the PBLH leads to enhanced EBC. The aerosol optical depths (AOD) over the Urumqi River Valley, derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) data and back trajectory analysis, showed that the pollution from Central Asia was more likely to affect the atmosphere of Tien Shan in summer and autumn. This suggests that long-distance transported pollutants from Central Asia could also be potential contributors to EBC concentrations in the Urumqi River Valley, the same as local anthropogenic activities.
Black carbon (BC) is a major light-absorbing component in the atmosphere and plays an important role in aerosol radiative forcing. In this study, the combination of monitoring data and the WRF-Chem model was used to study the source apportionment of BC in China during January 2017. Meanwhile, the aerosol-radiation interaction (ARI) effect of BC was also simulated. We found that the average BC/PM(2.5)ratios were 4.8%, 4.2%, and 3.8% in Shijiazhuang, Tangshan, and Beijing, respectively. The source apportionment suggested that traffic emissions played a dominant role in the BC concentration over Beijing. The traffic, residential, industrial, and power contributions accounted for 41%, 32%, 25%, and 2% of total concentration, respectively. The BC concentration in Beijing was also affected by regional transport. During January, the contributions of monthly regional transport to BC and PM(2.5)concentrations in Beijing were 41% and 49%, respectively. BC emissions decreased downward shortwave radiation (SWDOWN) at the surface, leading to a decrease in temperature. As a result, the planetary boundary layer height (PBLH) development was suppressed and the relative humidity increased. The stable meteorological conditions suppressed the dispersion of air pollutants and increased BC concentrations. Traffic emissions decreased the monthly SWDOWN by approximately 2.2 W/m(2), decreased 2 m temperature (T2) by approximately 0.1 degrees C, increased 2 m relative humidity (RH2) by approximately 0.5%, and decreased PBLH by approximately 4.4 m.