Nivelare

Nivelare is the process of determining a horizontal reference plane and measuring vertical differences between points. In surveying, civil engineering, and cartography, it is used to establish elevations, transfer them from benchmarks to construction sites, and create reliable topographic models. The term comes from the Romanian root nivel, meaning level, with the -are suffix indicating the action or process.

Most commonly, differential leveling is employed. A leveling instrument (optical or digital level) is set up on a stable tripod and used with a graduated staff to read height differences between benchmarks. Trigonometric leveling uses vertical angles and known distances to compute altitudes. Modern practice may supplement traditional leveling with GNSS/GPS and barometric methods, though these are typically used for broader altitude reference rather than precise local leveling.

The standard workflow starts with selecting a reference benchmark of known elevation, mounting the instrument, and taking a series of forward and backward readings to minimize errors. The differences are accumulated to determine elevations at required points. Results are adjusted for instrument line of sight, staff readings, and refraction effects when high precision is needed.

Applications include the setting of building foundations, road and bridge construction, drainage and irrigation projects, earthworks, and topographic surveying for maps and geographic information systems. Accurate nivelare requires well-maintained equipment, stable setups, proper training, and adherence to surveying standards.

History notes that leveling techniques evolved from basic sighting to modern optical and digital instruments, enabling reliable vertical control in large engineering projects.