Estimation of efficiency of the modern and planning optimal network of seismic stations within the Vietnam territory

Efficiency of the modern network of seismological observations in Vietnam is estimated, and an optimal design of planning network, consisted of 14 seismic stations is proposed. At the same sensitivity of network, but with a less number of stations, the new network would enable to determine hypocenter parameters in a more precise at a more uniform distribution of errating band within observation area.     

Reproducibility of a regional geological map derived from geochemical maps, using data mining techniques: with application to Chungbuk province of Korea

Interpolated geochemical maps contain problems of sample catchments and vacant sample areas. However, the resemblance of these maps with regional geological maps implies that there are strong correlations between them. A conceptual model of the geological units from multivariate chemical elements is constructed by decision tree technique. The reproducibility of the geological map with the conceptual model is about 80% in the Chungbuk province map of Korea. Statistical uncertainties indicate that rock units could be predicted reasonably well by decision tree if the geological map polygon is big enough. Misinterpreted points are due to interpolation problems between samples from adjacent rock units and from different sample catchments. In the Chungbuk example, the latter is less significant. The size of the map polygon is one of the most critical factors, and a polygon size greater than 50 km² is reliable for such analyses for the Chungbuk example. Combined lithologies in a single mapping unit are not critically affected by decision tree prediction.     

Novel Extreme Learning Machine-Multi-Verse Optimization Model for Predicting Peak Particle Velocity Induced by Mine Blasting

Natural Resources Research - Peak particle velocity (PPV) is an important criterion for assessing the risk level of ground vibration induced by mine blasting. Based on this criterion, many efforts...     

Multipurpose agroforestry as a climate change resiliency option for farmers: an example of local adaptation in Vietnam

Increasing frequency, intensity and duration of severe weather events are posing major challenges to global food security and livelihoods of rural people. Agriculture has evolved through adaptation to local circumstances for thousands of years. Local experience in responding to severe weather conditions, accumulated over generations and centuries, is valuable for developing adaptation options to current climate change. This study aimed to: (i) identify tree species that reduce vulnerability of cropping systems under climate variability; and (ii) develop a method for rapidly assessing vulnerability and exploring strategies of smallholder farmers in rural areas exposed to climate variability. Participatory Rural Appraisal methods in combination with Geographical Information Systems tools and statistical analysis of meteorological data were used to evaluate local vulnerability to climate change and to investigate local adaptation measures in two selected villages in Vietnam, one of the countries most vulnerable to climate change. The low predictability of severe weather events makes food crops, especially grain production, insecure. This study shows that while rice and rain-fed crops suffered over 40 % yield losses in years of extreme drought or flood, tree-based systems and cattle were less affected. 13 tree species performed well under the harsh local climate conditions in home and forest gardens to provide income, food, feed and other environmental benefits. Thus, this research suggests that maintenance and enhancement of locally evolved agroforestry systems, with high resilience and multiple benefits, can contribute to climate change adaptation.