XXth Conference of PhD Students and Young Scientists The location and the date of the conference virtual event – online conference, Poland, October 14-16, 2020 XXth Conference of PhD Students and Young Scientists “Interdisciplinary topics in mining and geology” continues a series of events that started in 2000 at Wroclaw University of Science and Technology. Scientific programme of the Conference focuses on three thematic panels:1. Mining Engineering: problems of securing, protecting and using remnants of old mining works, underground mining, opencast minig, processing of minerals and waste, mining machinery, mine transport, economics in mining, mining aeronautics, ventilation and air conditioning in mines,2. Earth and Space Science: geology, hydrogeology, environmental protection, extraterrestrial resources, groundwater and medicinal waters, engineering and environmental protection, geotourism,3. Geoinformation: mining geodesy, GIS, photogrammetry and remote sensing, geodata modeling and analysis.The XX Conference of PhD Students and Young Scientists was held as a virtual event, that is as a virtual, on-line conference in real-time. The reason why the Organizing Committee decided to change the traditional formula of the event to online formula was related to the concern for the health of the participants due to the COVID-19 epidemic and the internal regulations of the Rector of Wrocław University of Science and Technology regarding security measures for the organization of such events - only virtual conferences are allowed until further notice.The Organizing Committee decided to make an online conference instead of postponing the event because 2020 was the 20th anniversary year of the Conference and to maintain the tradition of annual meetings.The XX Conference of PhD Students and Young Scientists took place from 14th to 16th of October 2020 in Wroclaw, Poland. That is the organisers worked and managed the event from the Wrocław University of Science and Technology Geocentre building.The Conference was divided into 6 oral sessions (with 18 presentations) and 1 poster session (with 28 posters). The amount of time provided to one presentation was 15 minutes, after presentation there was 5 minutes available for discussion. The poster session was available throughout the event, and the posters were available for online viewing on the Conference’s website with the possibility of writing comments. Every day of the Conference one „virtual coffee break” was devoted for discussion between participants and question and answer session for the Organizers. It is also important to note that each day of the Conference begins with the presentation of Keynote Speaker: Professor Sergey A. Zhironkin (Russian Federation), Current problems and perspectives of open pit mining development in Kuzbass; Professor Isabel Fernandes (Portugal), Alkali-silica reactions in concrete: the role of engineering geosciences; Professor Jurand Wojewoda (Poland), Real curve geological surfaces: examples and implications.There were 75 registered participants: the largest number 43 from Poland; 16 from the Russian Federation; 4 from Spain; 2 from Germany, Czech Republic and Slovakia (each); as well as 1 from Austria, Portugal, Kazakhstan, USA, England and Republic of Kosovo (each).The online XX Conference of PhD Students and Young Scientists was conducted using the Zoom meeting platform with commemorative screen shots taken. By tradition two competitions, for the best oral presentation and for the best poster were held. The award for the best oral presentation was given to the team od authors C. L. Garrido, I. Morilla, R. A. Galindo (Spain), New methodology of simplified rock tests to determine bearing capacity in embankments and excavation bottoms, whereas the best poster was awarded to M. Chojwa (Poland), Influence of green areas on air temperature. The Conference was held via Zoom platform.