As one of the most severe and high-impact weather phenomena, tornadoes their long-term frequency trends have received lots attention from both scientific community public. Here, we show that over last six decades (1954–2018), U.S. (E)F1 a statistically significant upward trend but (E)F2–E)F4 downward based on solid analyses three independent methods robust verifications reported tornado data us...

The Souss-Massa region in southwestern Morocco is characterized by a semi-arid climate with high variability rainfall. Frequent droughts and flash flood events combined overexploitation of water resources recent decades have had significant impact on the human security economy which mainly based agriculture, tourism fishery. For better management extreme under changing climatic conditions, stud...

Ganga River basin, being the largest river basin in India, adheres with its social and spiritual importance for country. Although many studies have been conducted on however, trend observed flow sediment yield has scarcely studied. Alteration pattern transport rivers brings remarkable impact geomorphology entire ecosystem of region. The present paper attempts to identify trends terms annual max...

This article discusses such a phenomenon as electronic commerce. Basic concepts with the study of their history are given. The prerequisites for emergence e-commerce in two types considered: economic and technical support. Each type background is described separately, table was made about functions Internet at various stages business cycle. We learned detailed development e-commerce. It studied...