The rapid and significant expansion of urban areas is observed worldwide; however, considerable differences are detected within the characteristics of the process. The rural–urban fringe is changing most dynamically from the aspect of land use and this tends to be relevant in the case of post-socialist cities in Central Europe even with a stagnating or decreasing population. Debrecen (Hungary) and its hinterland adequately represent the migration trends of Hungarian cities and the great administrative area provided wide intra-urban suburbanization processes. The current study put the emphasis on the analysis of the spatial pattern of built-up areas and the distribution of residents. In order to discover the processes of the post-socialist transition period, detailed point layers were created to illustrate every built-up parcel in the rural–urban fringe of Debrecen (for the years 1980, 2000, and 2020). The most important characteristics were discovered with the help of GIS methods—Kernel-density, grid pattern analysis of the object density, and analysis of land cover/land use changes using Corine Land Cover Change (CLCC) databases. The dynamic and extended expansion of built-up areas was seen until 2000, in which the outskirts (including hobby gardens) densified spectacularly. The urban sprawl has been less intensive since the millennium and the increase in built-up areas has become more concentrated. As a consequence of the transition period, extended territories—primarily the least dense parts of the rural–urban fringe—are faced with the disappearance of buildings due to agricultural cultivation reasons.

Climate change plays a pivotal role in the hydrological dynamics of tributaries in the upper Blue Nile basin. The understanding of the change in climate and its impact on water resource is of paramount importance to sustainable water resources management. This study was designed to reveal the extent to which the climate is being changed and its impacts on stream flow of the Gumara watershed under the Representative Concentration Pathway (RCP) climate change scenarios. The study considered the RCP 2.6, RCP 4.5, and RCP 8.5 scenarios using the second-generation Canadian Earth System Model (CanESM2). The Statistical Downscaling Model (SDSM) was used for calibration and projection of future climatic data of the study area. Soil and Water Assessment Tool (SWAT) model was used for simulation of the future stream flow of the watershed. Results showed that the average temperature will be increasing by 0.84 °C, 2.6 °C, and 4.1 °C in the end of this century under RCP 2.6, RCP 4.5, and RCP 8.5 scenarios, respectively. The change in monthly rainfall amount showed a fluctuating trend in all scenarios but the overall annual rainfall amount is projected to increase by 8.6%, 5.2%, and 7.3% in RCP 2.6, RCP 4.5, and RCP 8.5, respectively. The change in stream flow of Gumara watershed under RCP 2.6, RCP 4.5, and RCP 8.5 scenarios showed increasing trend in monthly average values in some months and years, but a decreasing trend was also observed in some years of the studied period. Overall, this study revealed that, due to climate change, the stream flow of the watershed is found to be increasing by 4.06%, 3.26%, and 3.67%under RCP 2.6, RCP 4.5, and RCP 8.5 scenarios, respectively.

Climate change and its impact on surface runoff in the upper Blue Nile basin and sub-basins have been widely studied in future climate projections. However, the impact on extreme flow events of rivers is barely investigated discretely. In this paper, the change in temperature and rainfall under the Representative Concentration Pathway (RCP) highest emission scenario (RCP 8.5) and its impact on the high flow and low flow simulated by the Soil and Water Assessment Tool (SWAT 2012) in major watersheds of the Lake Tana Basin has been evaluated by comparing the baseline period (1971–2000) with the 2020s (2011–2040), 2050s (2041–2070), and 2080s (2071–2100). The high flows of watersheds were selected by the Annual Maximum Series (AMS) model, whereas the low-flow watersheds were selected by the 7-day sustained mean annual minimum flow method. The result showed that the highest change in maximum temperature ranged from 2.93 °C to 5.17 °C in monthly time scales in the 2080s. The increment in minimum temperature is also more prominent in the 2080s and it is expected to rise by 4.75 °C. Inter-annual variability of the change in rainfall has shown increasing and decreasing patterns. The highest increments are expected by 22.37%, 25.58%, and 29.75% in the 2020s, 2050s, and 2080s, respectively, whereas the projected highest decrease in rainfall dictates the decrease of 6.42%, 7.11%, and 9.26% in 2020s, 2050s, and 2080s, respectively. Due to changes in temperature and rainfall, the low flow is likely to decrease by 8.39%, 8.33%, 6.21%, and 5.02% in Ribb, Gumara, Megech, and Gilgel Abay watersheds, respectively, whereas the high flow of Gilgel Abay, Megech, Gumara, and Ribb watersheds are expected to increase by 13.94%, 12.16%, 10.90%, and 10.24%, respectively, every 30 years.

Changes in land use were studied in 2 km wide peri-urban open spaces of seven small Hungarian towns as part of a RENATUR Interreg Europe (2019–2023) project. The aim of the project is to present best practices related to the sustainable and wise use of the peri-urban open spaces of small European towns. The rate and tendencies of conversion from one land use type to another were evaluated on the basis of a comparison of Corine Land Cover and Land Cover Change databases from 1990, 2000 and 2018. Land use changes in the study areas in different time periods were studied for which the Corine categories were aggregated. Subsequently, there were field verification surveys carried out between March and June of 2021. Most significant changes—due to the significant increase of built-up areas—were found in the case of the towns that were developed to form the suburbs of Debrecen, the core settlement of their region with a population of 200,000. In the case of settlements further away from the major city, the population is either stagnating or decreasing, and the size of built-up areas hardly increases. In the case of cities that are surrounded by high-quality chernozem soils with profitable agriculture, large-scale arable lands have become dominant in the border zones of the settlements, as the spatial extent of gardens, orchards and grasslands has decreased. Highly diverse and mosaic land use (dominated by small plots) is not characteristic anywhere.

Climate change plays a pivotal role in the hydrology of tributaries in the upper Blue Nile basin. This study was designed to reveal the extent to which climate change impacts on stream flow of the Gumara watershed under the Representative Concentration Pathway (RCP) climate change scenario. The study considered the RCP 2.6, RCP 4.5 and RCP 8.5 scenarios using the second generation Canadian Earth System Model (CanESM2). The Statistical Downscaling Model (SDSM) was used for calibration and projection of future climatic data of the study area. Soil and Water Assessment Tool (SWAT) model was used for simulation of the future stream flow of the watershed. Result showed that the average temperature will be increasing by 0.84oC, 2.6oC and 4.1oC in the end of this century under RCP 2.6, RCP 4.5 and RCP 8.5 scenarios respectively. The change in monthly rainfall amount showed a fluctuating trend in all scenarios but the overall annual rainfall amount is projected to increase by 8.6%, 5.2% and 7.3% in RCP 2.6, RCP 4.5, and RCP 8.5 respectively. Overall, this study revealed that, due to climate change, the stream flow of the watershed is found to be increasing by 4.06%, 3.26%, and 3.67% under RCP 2.6, RCP 4.5 and RCP 8.5 scenarios respectively.

Laser scanning is a promising relatively new technology of land surveying and has different contributions to research areas and practical applications. We performed a review based on query terms in the Scopus database. We determined the number of papers where the laser scanning was the technique of the survey and refined the results with the aerial (ALS) and terrestrial (TLS) laser scanning methods, and the urban and vegetation searching terms. Results showed that geosciences had a 30-40% ratio within the scientific papers using LiDAR. TLS had larger relevance related to ALS considering the total number of research papers, urban application and vegetation analysis in urban environment. We analysed the current status of the technology and discussed the underlying possible causes.