Terrain in the context of "Weather"

Borders are generally defined as geographical boundaries, imposed either by features such as oceans and terrain, or by political entities such as governments, sovereign states, federated states, and other subnational entities. Political borders can be established through warfare, colonization, or mutual agreements between the political entities that reside in those areas.

Some borders—such as most states' internal administrative borders, or inter-state borders within the Schengen Area—are open and completely unguarded. Most external political borders are partially or fully controlled, and may be crossed legally only at designated border checkpoints; adjacent border zones may also be controlled. For the purposes of border control, airports and seaports are also classed as borders. Most countries have some form of border control to regulate or limit the movement of people, animals, and goods into and out of the country. Under international law, each country is generally permitted to legislate the conditions that have to be met in order to cross its borders, and to prevent people from crossing its borders in violation of those laws.

A drainage divide, water divide, ridgeline, watershed, water parting or height of land is elevated terrain that separates neighboring drainage basins. On rugged land, the divide lies along topographical ridges, and may be in the form of a single range of hills or mountains, known as a dividing range. On flat terrain, especially where the ground is marshy, the divide may be difficult to discern.

A triple divide is a point, often a summit, where three drainage basins meet. A valley floor divide is a low drainage divide that runs across a valley, sometimes created by deposition or stream capture. Major divides separating rivers that drain to different seas or oceans are continental divides.

Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation. In a broader sense, climate is the state of the components of the climate system, including the atmosphere, hydrosphere, cryosphere, lithosphere and biosphere and the interactions between them. The climate of a location is affected by its latitude, longitude, terrain, altitude, land use and nearby water bodies and their currents.

Climates can be classified according to the average and typical variables, most commonly temperature and precipitation. The most widely used classification scheme is the Köppen climate classification. The Thornthwaite system, in use since 1948, incorporates evapotranspiration along with temperature and precipitation information and is used in studying biological diversity and how climate change affects it. The major classifications in Thornthwaite's climate classification are microthermal, mesothermal, and megathermal. Finally, the Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region.

Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from soil by restricting the former term specifically to displaced soil.

Soil consists of a solid collection of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and a liquid phase that holds water and dissolved substances both organic and inorganic, in ionic or in molecular form (the soil solution). Accordingly, soil is a complex three-state system of solids, liquids, and gases. Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time. It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists regard soil as an ecosystem.

Land, also known as dry land, ground, or earth, is the solid terrestrial surface of Earth not submerged by the ocean or another body of water. It makes up 29.2% of Earth's surface and includes all continents and islands. Earth's land surface is almost entirely covered by regolith, a layer of rock, soil, and minerals that forms the outer part of the crust. Land plays an important role in Earth's climate system, being involved in the carbon cycle, nitrogen cycle, and water cycle. One-third of land is covered in trees, another third is used for agriculture, and one-tenth is covered in permanent snow and glaciers. The remainder consists of desert, savannah, and prairie.

Land terrain varies greatly, consisting of mountains, deserts, plains, plateaus, glaciers, and other landforms. In physical geology, the land is divided into two major categories: Mountain ranges and relatively flat interiors called cratons. Both form over millions of years through plate tectonics. Streams – a major part of Earth's water cycle – shape the landscape, carve rocks, transport sediments, and replenish groundwater. At high elevations or latitudes, snow is compacted and recrystallized over hundreds or thousands of years to form glaciers, which can be so heavy that they warp the Earth's crust. About 30 percent of land has a dry climate, due to losing more water through evaporation than it gains from precipitation. Since warm air rises, this generates winds, though Earth's rotation and uneven sun distribution also play a part.

Maritime transport (or ocean transport) or more generally waterborne transport, is the transport of people (passengers) or goods (cargo) via waterways. Freight transport by watercraft has been widely used throughout recorded history, as it provides a higher-capacity mode of transportation for passengers and cargo than land transport, the latter typically being more costly per unit payload due to it being affected by terrain conditions and road/rail infrastructures. The advent of aviation during the 20th century has diminished the importance of sea travel for passengers, though it is still popular for short trips and pleasure cruises. Transport by watercraft is much cheaper than transport by aircraft or land vehicles (both road and rail), but is significantly slower for longer journeys and heavily dependent on adequate port facilities. Maritime transport accounts for roughly 80% of international trade, according to UNCTAD in 2020.

Maritime transport can be realized over any distance as long as there are connecting bodies of water that are navigable to boats, ships or barges such as oceans, lakes, rivers and canals. Shipping may be for commerce, recreation, or military purposes, and is an important aspect of logistics in human societies since early shipbuilding and river engineering were developed, leading to canal ages in various civilizations. While extensive inland shipping is less critical today, the major waterways of the world including many canals are still very important and are integral parts of worldwide economies. Particularly, especially any material can be moved by water; however, water transport becomes impractical when material delivery is time-critical such as various types of perishable produce. Still, water transport is highly cost effective with regular schedulable cargoes, such as trans-oceanic shipping of consumer products – and especially for heavy loads or bulk cargos, such as coal, coke, ores or grains. Arguably, the Industrial Revolution had its first impacts where cheap water transport by canal, navigations, or shipping by all types of watercraft on natural waterways supported cost-effective bulk transport.

A landform is a land feature on the solid surface of the Earth or other planetary body. They may be natural or may be anthropogenic (caused or influenced by human activity). Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, mountains, canyons, and valleys, as well as shoreline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great oceanic basins.

Northern Bulgaria (Bulgarian: Северна България, romanized: Severna Bylgarija), also called Moesia (Bulgarian: Мизия, Mizija) is the northern half of Bulgaria, located to the north of the main ridge of the Balkan Mountains which conventionally separates the country into a northern and a southern part. Besides the Balkan Mountains, Northern Bulgaria borders the Timok River and Serbia to the west, the Danube River and Romania to the north, and the Bulgarian Black Sea Coast to the east.

Geographically, the region's terrain is relatively uniform, dominated by the hilly Danubian Plain, with some low plateaus to the east. Northern Bulgaria covers an area of 48,596 square kilometres and has a population of 2,674,347 according to the 2011 census (36% of Bulgaria's entire population), with a population density of 55 people per km². The three largest cities are Varna, Rousse and Pleven.