Probability density function
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines probability density function (PDF) as: ‘The mathematical function that describes the relative chance of observing values of a continuous variable. For example, a probability density function could describe the chance that the measured river flow could equal a certain value (for example 100 m³/s), or the chance that a single culvert has a certain percentage blockage.’
Climate Change 2021, The Physical Science Basis, published by the Intergovernmental Panel on Climate Change in 2021, states: ‘A probability density function is a function that indicates the relative chances of occurrence of different outcomes of a variable. The function integrates to unity over the domain for which it is defined and has the property that the integral over a sub-domain equals the probability that the outcome of the variable lies within that sub-domain. For example, the probability that a temperature anomaly defined in a particular way is greater than zero is obtained from its PDF by integrating the PDF over all possible temperature anomalies greater than zero. Probability density functions that describe two or more variables simultaneously are similarly defined.’
[edit] Related articles on Designing Buildings
- Berm.
- Bund.
- CIRIA.
- Culvert.
- Flood.
- Probability.
- River.
- Screen.
- Swales.
- Watercourse.
- Watercourse screen.
Featured articles and news
Homes, landlords. tenants and the new housing standards
What will it all mean?
The Architectural Technology podcast: Where it's AT
Catch-up on the latest episodes.
Edmundson Apprentice of the Year award 2026
Entries now open for this Electrical Contractors' Association award.
Traditional blue-grey slate from one of the oldest and largest UK slate quarries down in Cornwall.
There are plenty of sources with the potential to be redeveloped.
Change of use legislation breaths new life into buildings
A run down on Class MA of the General Permitted Development Order.
Solar generation in the historic environment
Success requires understanding each site in detail.
Level 6 Design, Construction and Management BSc
CIOB launches first-ever degree programme to develop the next generation of construction leaders.
Open for business as of April, with its 2026 prospectus and new pipeline of housing schemes.
The operational value of workforce health
Keeping projects moving. Incorporating unplanned absence and the importance of health, in operations.
A carbon case for indigenous slate
UK slate can offer clear embodied carbon advantages.
Costs and insolvencies mount for SMEs, despite growth
Construction sector under insolvency and wage bill pressure in part linked to National Insurance, says report.
The place for vitrified clay pipes in modern infrastructure
Why vitrified clay pipes are reclaiming their role in built projects.
Research by construction PR consultancy LMC published.
Roles and responsibilities of domestic clients
ACA Safety in Construction guide for domestic clients.
Fire door compliance in UK commercial buildings
Architect and manufacturer gives their low down.