From 7b8a64b7497af9149be24e6195d9e8a80f56bad9 Mon Sep 17 00:00:00 2001 From: Lesley De Cruz Date: Thu, 10 Oct 2024 13:08:41 +0200 Subject: [PATCH] Update English pages. Add content. --- content/about-ai.en.md | 27 +++++++++++++++++++ content/about-heatisland.en.md | 47 ++++++++++++++++++++++++++++++++++ content/about.en.md | 4 +++ 3 files changed, 78 insertions(+) diff --git a/content/about-ai.en.md b/content/about-ai.en.md index 3dfa77d..fe7bf8a 100644 --- a/content/about-ai.en.md +++ b/content/about-ai.en.md @@ -2,3 +2,30 @@ title: "About - Artificial intelligence" ShowToc: true --- + +## AI for meteorology and climate adaptation + +### What is AI? + +Artificial Intelligence (AI) enables a machine to perform intelligent tasks such as planning, reasoning, predicting, and classifying. + +Machine Learning (ML) is a branch of AI in which a computer program learns from existing data to make predictions or perform tasks. For example, an ML program can recognize animals in photos by learning from existing images. + +Since 2012, AI has made a huge leap forward thanks to developments in *deep learning* (artificial neural networks with many layers), along with more powerful computers. With the power of deep learning, technologies such as self-driving cars, virtual assistants (Siri, Google Assistant, Alexa, ...), and services based on large language models, such as chatGPT, are getting better and better. AI has more and more practical applications, also in science. + +![AlphaGo, an AI developed by DeepMind, beats Lee Sedol, the world champion of Go](/assets/images/about/alphago.jpeg) + +### AI for meteorology + +Predicting the weather is challenging because many different time and spatial scales are involved. Numerical weather models solve the physical equations of the atmosphere to make a prediction. They require a lot of computing power and become less reliable for predictions far into the future. + +The finer the models, the more accurate the local predictions are, as shown in the figure below. Unfortunately, this also requires much more computing power. An alternative is to refine the models with AI. + +![The effect of resolution: Refining a temperature forecast from a lower to a higher resolution. In the right figure, you can see much more clearly the local impact on the temperature.](/assets/images/about/Knipsel.PNG) + +### Calculating the urban climate + +Cities have a unique climate due to the many buildings and streets. During the day, they store sunlight as energy, which is emitted as heat at night. This urban heat island effect means that cities are warmer at night than the surrounding rural areas. In addition, human activity locally produces extra heat (e.g., heating, cars, etc.). + +Predicting the urban climate is complex because traditional weather models usually work on larger scales. The fine urban landscape creates microclimates that can vary greatly within a city, due to local effects such as air pollution and differences in building density. This makes urban predictions challenging + diff --git a/content/about-heatisland.en.md b/content/about-heatisland.en.md index a8d11c0..11bf862 100644 --- a/content/about-heatisland.en.md +++ b/content/about-heatisland.en.md @@ -2,3 +2,50 @@ title: "About - Urban heat island" ShowToc: true --- + +### The City Has Its Own Climate + +#### What is the Urban Climate? + +In the early 19th century, London chemist Luke Howard discovered that urban climates differ from their rural counterparts. After years of measurements in and around London, he observed higher urban temperatures, especially at night and during winter. This phenomenon was later named the urban heat island effect. The urban climate, characterized by higher temperatures and lower wind speeds, has become an important research subject, especially since more than half of the world's population lives in cities. During the day, materials absorb solar radiation, and at night they release heat. However, the presence of buildings prevents this heat from escaping easily, and the lack of proper ventilation causes the heat to linger in the city. + +![On the left, you see the temperature map, and on the right, the vegetation map of New York. Areas with less vegetation tend to have higher average temperatures. Source: NASA via Wikimedia Commons](/assets/images/about/new_york_UHI.png) + +#### Measuring is Knowing + +Systematic measurements are essential to understand the urban climate and to create accurate models. These models are used for risk assessments and urban planning. Cities vary greatly: some are large, others small; some are densely built, others have many parks. It is important to monitor these variations and their urban climates. The meteorological VLINDER network provides valuable data in this regard. + +As cities expand and become more densely built, the intensity of the urban heat island effect increases, leading to rising urban temperatures. This is compounded by global climate change. Therefore, cities must take action to remain livable in the long term. + +![The VLINDER weather station at the VUB, in Etterbeek](/assets/images/about/vlinder-vub.png) + +#### Impact on Health and Comfort + +In cities like Brussels, densely built areas can be up to 10 °C warmer than the surrounding countryside on a hot night. High temperatures cause heat stress, leading to poor sleep and reduced productivity. If someone cannot cool down properly, it can result in serious health issues like strokes, kidney failure, respiratory problems, and even death. The elderly and young children are particularly vulnerable on hot days and nights. Heat-induced sleep deprivation can also lead to aggressive behavior and lower work productivity. + +Heat also increases energy consumption for cooling, which, if fossil fuel-based, contributes to greenhouse gas emissions. The heat island effect also warms urban rainwater, causing problems like algae blooms, fish deaths, and potential public health risks. + +![Anspachlaan, in the past. Source: Google Streetview](/assets/images/about/anspach_vroeger.png) +![Anspachlaan, now. Source: Google Streetview](/assets/images/about/anspach_nu.png) + +#### Greening to Cool + +Reducing paved surfaces in cities is essential for cooling, with green spaces and trees being key to mitigating heat stress. They provide cooling by creating shade and evaporating water. In comparison to asphalt and concrete, plants retain less heat, helping cool the environment faster. Plants use solar energy to evaporate water from the ground, preventing the energy from being used to heat surfaces. + +The illustration below shows the relationship between vegetation and evaporation. + +![The water cycle in urban and rural areas. Source: USEPA, 2008.](/assets/images/about/urban_rural_hydrology.jpg) + +#### Impact on Heat, Wind, and Water + +The cooling effect depends on the amount of greenery and biomass. Larger trees with dense canopies cool more effectively than smaller ones. Vegetation also reduces water runoff peaks by holding rainwater and slowly allowing it to infiltrate the ground. + +![Urban and rural environments](/assets/images/about/urban_rural.png) + +#### The Role of Water in the City + +Urban water bodies provide cooling during the day but release heat at night if the water is stagnant. Flowing water cools the surrounding area better than still water. The combination of trees and water, such as ponds and fountains, is the most effective against heat stress due to shade and cooling. + +Moreover, features like wadis—a type of natural buffer basin—help to capture rainwater and slowly allow it to infiltrate. This is important for maintaining groundwater levels during periods of drought. + +![Solutions for the urban heat island effect. Source: Wageningen University & Research](/assets/images/about/klimaatadaptatie.jpg) \ No newline at end of file diff --git a/content/about.en.md b/content/about.en.md index a54428b..a216178 100644 --- a/content/about.en.md +++ b/content/about.en.md @@ -4,10 +4,14 @@ title: "About" ## Urban heat island +Summary: The urban heat island (UHI) is a phenomenon where urban areas are warmer than their rural surroundings. This is due to the high concentration of buildings, roads and other infrastructure that absorb and retain heat. The UHI can have a significant impact on the health and well-being of urban residents, as well as on the environment. + + [More info...]({{< ref "about-heatisland.en.md" >}}) ## Artificial intelligence + [More info...]({{< ref "about-ai.en.md" >}}) ## Crowdsourced observations