This book constitutes selected, revised and extended papers of the 7th International Conference on Geographical Information Systems Theory, Applications and Management, GISTAM 2021, held in April 2021, and 8th International Conference on Geographical Information Systems Theory, Applications and Management, GISTAM 2022, held in April 2022. Due to the COVID-19 pandemic both conferences were held online. The 4 revised full papers presented at GISTAM 2021 were carefully reviewed and selected from the 44 submissions, and 3 papers presented at GISTAM 2022 were selected from the 27 submissions. The papers are centered on urban and regional planning; water information systems; geospatial information and technologies; spatio-temporal database management; decision support systems; energy information systems; GPS and location detection.