Materials and Objects Library
Materials and Objects Library
The Materials and Objects Library is the central application to manage the different ENVI-met database tables ranging from building materials over soil profiles up to pollutant sources.
The Materials and Objects Library offers a distinct overview and easy access to data stored on your system and helps you to view, edit and add datasets. For a basic overview over the ENVI-met database concept, see The ENVI-met Database System
Working with the Materials and Objects Library
Below you find a list of the parameters that can be changed in the Materials and OBjects Library.
Albedo/Reflection
A dimensionless parameter from 0 to 1. It describes how much shortwave radiation that hits this material is reflected. If the albedo is 0.5, then 50% of the shortwave radiation is reflected.
Absorption
This is the fraction of the incoming shortwave radiation absorbed by the material. It is also dimensionless and goes from 0 to 1.
Transmittance/Transmission
Another dimensionless parameter from 0 to 1 describing the fraction of shortwave radiation that can pass through the material without being absorbed or reflected. It is usually only used for glass-like materials or simple plants.
Important Note
Albedo/Reflection, Absorption and Transmittance/Transmission must add up exactly to 1.
Leaf Area Index [m² / m²] (LAI)
The LAI represents the total leaf surface area per unit of ground area (m² of leaves per m² of ground). It indicates how much vegetation covers a surface, affecting shading, evapotranspiration, and overall microclimate conditions.
Leaf Area Density [m² / m³] (LAD)
The LAD describes the amount of leaf surface area in a given volume of air, usually measured in square meters of leaf area per cubic meter of space (m²/m³). Higher LAD values indicate denser foliage, which influences shading, wind flow, and evaporation in a microclimate. * Note for Simple Plants: Regardless of height, each simple plant is made up of 10 sections in which the LAD can be changed. This ensures that you can define the plant as close as possible.
Emissivity
Emissivity is a measure of how well a material releases heat as infrared radiation. A surface with high emissivity (close to 1.0), like asphalt (~0.90) or matte-painted walls (~0.85), efficiently radiates heat and cools down quickly. In contrast, materials with low emissivity, such as polished aluminium (~0.05) hold onto heat longer or reflect more energy. This property plays a key role in how surfaces affect temperature in a microclimate.
Heat Conductivity [W / mK]
The Heat Conductivity describes how well a material transfers heat—high conductivity materials like metal (e.g., aluminium ~200 W/mK) quickly transfer heat, while low conductivity materials like insulation foam (~0.03 W/mK) slow down heat flow.
Volumetric Heat Capacity [m³ / K] ** 10^6
The Volumetric Heat Capacity describes how much energy (in Joule) is needed to increase the temperature of a cubic meter of that material by 1 °C.
Specific Heat Capacity [J / kg * K]
A measure of how much energy (in Joule) is needed to increase the temperature of one kilogram of the material by 1 °C.
Density [kg / m³]
Describes how much a cubic meter of that material weighs.
Surface is irrigated
Keeps the humidity of that profile constant to represent irrigation.
z0 Roughness Length
It describes at which height the wind speed is reduced to 0 due to the roughness of the chosen soil profile
Hydraulic Conductivity
Hydraulic Conductivity at Water Saturation describes how easily water moves through a fully saturated material, with higher values indicating faster water flow (e.g., sand has high conductivity, while clay has low conductivity and concrete has no conductivity).
Water content at saturation [m³(Water / m³(Soil)]
A measure that describes how much water in m³ is in one m³ of soil at the saturation point.
Water content at field capacity [m³(Water / m³(Soil)]
A measure that describes how much water in m³ is in one m³ of soil at field capacity.
Water content at wilting point [m³(Water / m³(Soil)]
A measure that describes how much water in m³ is in one m³ of soil at the wilting point of plants.
CO2 Fixation Type
A tag that refers to the photosynthetic pathway a plant uses to absorb and process carbon dioxide. The fixation type is either C3 or C4.
Plant height [m]
Defines the height of the simple plant in meters.
Root Zone Depth [m]
Defines how far the roots of a plant reach into the ground, given in meters.
Root Area Density [m² / m³] (RAD)
The RAD describes the amount of root surface area in a given volume of soil, usually measured in square meters of root area per cubic meter of space (m²/m³).
Daily Traffic Value (Veh / 24h)
Number of vehicles that pass in a 24-hour span.
Contribution of Vehicle Category to overall traffic
Each category is given in percent.
Please note, that 3DPlants are also a part of the database system, but due to their complexity, they are managed in the Tree Library application.