Vineesh V, Geography

Weighted Overlay is a widely used spatial decision-making technique in Geographic Information Systems (GIS). It functions as an analytical method that balances multiple spatial factors by assigning relative importance to each variable. Essentially, it integrates scientific reasoning with logical evaluation to determine the suitability of locations for specific purposes. In simple terms, Weighted Overlay is a method that combines several spatial raster layers. Each layer represents a different factor influencing the decision-making process. Before integration, the values of each raster layer are standardized to a common evaluation scale, typically ranging from 1 to 5 or 1 to 9. Subsequently, each layer is assigned a weight based on its relative importance. The final suitability value for each cell is calculated by summing the weighted contributions of all layers. The conceptual formula can be expressed as: Final Suitability Value = (Layer 1 × Weight 1) + (Layer 2 × Weight 2) + ... + (La...

Conceptual diagram of a braided river and its stratigraphic deposits. Zones of thread confluence and thread splitting, shown by blue arrows, facilitate the formation, accretion, and deformation of bank-attached and mid-channel bars. Within a larger channel-belt sand body, bar deposits can be stratigraphically preserved as packages characterized by sigmoidal bar clinothems that accrete in the direction of bar growth and downlap (e.g., blue arrows in cross-stream stratigraphic view) onto older deposits

Folding and Faulting

💡Anticipatory action is the smart way to provide humanitarian assistance for forecastable events, ahead of the shock. 🚀 When a pre-agreed forecast threshold is crossed, a set of pre-agreed and pre-financed humanitarian interventions is triggered. Acting before the event protects lives, livelihoods, and dignity. 🤝 Anticipatory action is interwoven with other humanitarian approaches and with climate and development efforts. It builds on early warnings, early action, climate adaptation, and disaster preparedness.

Disaster Risk Management 

Climate change does not remove cold weather: it changes how it behaves. As global temperatures rise, winters are milder on average and snow cover is declining. Yet warming also alters atmospheric dynamics, sometimes increasing winter disruption. Key mechanisms include: 🌀 Polar vortex shifts – when weakened or displaced, it can amplify jet stream swings and push Arctic air south. 💧 More atmospheric moisture – warmer air and oceans fuel heavier snow, sleet, or freezing rain when cold air is present. ⚖️ Competing effects – reduced temperature contrasts can weaken storms, while extremes may intensify. The result: fewer cold events overall, but potentially sharper impacts when they occur. Understanding this complexity strengthens forecasting, early warnings, and preparedness.

Time scale 

Biome and temperature 

The history of Geographic Information Systems (GIS) is rooted in early efforts to understand spatial relationships and patterns, long before the advent of digital computers. While modern GIS emerged in the mid-20th century with advances in computing, its conceptual foundations lie in cartography, spatial analysis, and thematic mapping. Early Roots of Spatial Analysis (Pre-1960s) One of the earliest documented applications of spatial analysis dates back to  1832 , when  Charles Picquet , a French geographer and cartographer, produced a cholera mortality map of Paris. In his report  Rapport sur la marche et les effets du choléra dans Paris et le département de la Seine , Picquet used graduated color shading to represent cholera deaths per 1,000 inhabitants across 48 districts. This work is widely regarded as an early example of choropleth mapping and thematic cartography applied to epidemiology. A landmark moment in the history of spatial analysis occurred in  1854 , when  John Snow  inv...