This study investigates intra-crustal variability across the Indus–Ganges–Brahmaputra (IGB) foreland–Himalayan system through integrated analysis of gravity and seismicity data. Satellite-derived free-air gravity anomalies (− 350 to 650 mGal) and earthquake data (M ≥ 5.0) from the ISC-EHB catalogue (1990–2023) are used to constrain lithospheric structure. A series of 15 regional gravity profiles ( 650 km length) were modelled to derive crustal architecture and Moho depth variations across the foreland–orogen transition. Our modelling reveals significant lateral heterogeneity in Moho geometry beneath the Greater Himalaya and highlights a spatial clustering of seismicity that correlates with these structural gradients. We interpret these robust structural features to reflect variable crustal thickness and differential tectonic loading along the arc, suggesting that inherited crustal heterogeneities strongly influence strain localisation. While these gravity-seismicity observations are consistent with a preferred tectonic model involving crustal shortening, flexural loading, and localised uplift (such as a pop-up mechanism for the Shillong massif), they also establish a broader regional-scale framework to test alternative evolutionary scenarios. Ultimately, these findings provide critical, observation-based constraints on lithospheric-scale deformation processes and lateral variability across the Indo-Eurasian collision zone.
Urban areas are increasingly exposed to extreme heat conditions due to rapid urbanization, climate change, and the intensification of the Urban Heat Island (UHI) effect. Accurate characterization of the urban radiation environment is therefore essential for supporting climate-responsive urban planning and sustainable landscape design. This study presents a high-resolution microscale assessment of the spatial and temporal distribution of mean radiant temperature (Tmrt) in a representative urban district of Balçova, İzmir, Türkiye, using unmanned aerial vehicle (UAV)-derived spatial data and the Solar and LongWave Environmental Irradiance Geometry (SOLWEIG) model implemented within the Urban Multi-scale Environmental Predictor (UMEP) framework in QGIS. High-resolution Digital Surface Models (DSM) and Digital Elevation Models (DEM) were generated from UAV photogrammetry and integrated with hourly meteorological observations, including air temperature, relative humidity, and wind speed, obtained from the Turkish State Meteorological Service for 10 June 2023 Hourly meteorological observations corresponding to 10 June 2023 were obtained from the Turkish State Meteorological Service (TSMS). The SOLWEIG model was employed to simulate hourly mean radiant temperature, shadow distribution, wall characteristics, and sky view factor (SVF), enabling detailed evaluation of radiation exposure across a microscale urban environment. The simulation results demonstrate substantial spatial variability in mean radiant temperature associated with urban morphology. Areas characterized by taller buildings, greater shading intensity, and reduced sky exposure consistently exhibited lower Tmrt values throughout the daytime, whereas open paved surfaces with high sky visibility experienced considerably greater radiative heat loads. The generated shadow and SVF maps further reveal the dominant influence of building geometry and vegetation on modifying local radiation conditions. Rather than directly evaluating human thermal comfort indices such as Physiological Equivalent Temperature (PET) or Universal Thermal Climate Index (UTCI), this research focuses specifically on the radiative component governing outdoor thermal environments through high-resolution Tmrt modelling. The findings demonstrate that integrating UAV-derived three-dimensional urban morphology with physically based radiation modelling provides an effective framework for identifying localized heat exposure patterns and supporting evidence-based urban climate adaptation strategies. The proposed methodology offers a practical, open-source, and transferable workflow for microscale urban radiation assessment in climate-sensitive cities while providing valuable spatial information for future thermal comfort analyses and urban design applications.
Hydrogeological dynamics in multi-aquifer systems under varying climatic conditions and human extractions are difficult to analyse. In West Bengal, India, rapid socio-economic growth, urbanization, and agricultural demands have caused significant, undocumented fluctuations in groundwater levels across unconfined and confined systems. This study investigates long-term temporal variations in the Groundwater Table (GWT) and Piezometric Surface (PS) across four distinct geo-hydrological zones in West Bengal. It evaluates the forecasting performance of three statistical models, e.g., Holt’s Linear Exponential Smoothing, Exponential Triple Smoothing (AAA ETS), Autoregressive Integrated Moving Average (ARIMA). It also assesses inter-period changes (1970–2009 vs. 2010–2020), seasonal recharge behaviour, and head differences (H=GWT-PS). AAA and ARIMA models demonstrated superior, highly competitive performance, with an average difference of less than 1.2
In January 2023, two earthquakes with magnitudes of MN 5.4 and MN 5.9 occurred in the Khoy region of West Azarbaijan Province, followed by numerous aftershocks. Analysis of this aftershock sequence provides valuable insights into the local tectonic framework. Since the Khoy earthquakes in January 2023 occurred near the Iran–Turkey border, seismic data were integrated from seismographic stations in Iran, and neighboring countries to ensure comprehensive coverage and improve location accuracy. In this study, the Khoy aftershock sequence was relocated employing both the single-event location approach and the double-difference relocation algorithm. The relocated aftershocks delineate a NW–SE–trending seismic zone approximately 20 × 10 km2 in extent. Analysis of the temporal and spatial patterns indicates that seismicity migrated southeastward over a period of three months. Cross-sectional profiles reveal that focal depths increase toward the northeast, suggesting a northeast-dipping fault plane. The results indicate that the Firoraq Fault, a branch of the Gilatu–Siahcheshmeh–Khoy fault system, was the causative structure responsible for the January 2023 Khoy earthquakes and their associated aftershocks.
