Analysis of change between the mapping of heat/fresh islands 2013-2014 and 2020-2022

Maps of the analysis of change between * [mapping of heat/freshness islands 2020-2022] (https://www.donneesquebec.ca/recherche/dataset/ilots-de-chaleur-fraicheur-urbains-et-ecarts-de-temperature-relatifs-2020-2022) * and * [mapping of heat/freshness islands using 2013-2014 data] (https://www.donneesquebec.ca/recherche/dataset/ilots-de-chaleur-fraicheur-urbains-et-ecarts-de-temperature-relatifs-2013-2014) * across all major urban centers by two methods, i.e.

- The map of the __Difference between temperature differences in °C (* [2020-2022] (* 2020-2022] (https://www.donneesquebec.ca/recherche/dataset/ilots-de-chaleur-fraicheur-urbains-et-ecarts-de-temperature-relatifs-2020-2022) * minus * [2013-2014] (https://www.donneesquebec.ca/recherche/dataset/ilots-de-chaleur-fraicheur-urbains-et-ecarts-de-temperature-relatifs-2013-2014)*)__), which is calculated at the pixel level and produced at the scale of the ecumene of Quebec (2016 census, 167,764 km2). The temperature difference is the difference in temperature in the city compared to a nearby wooded area. A positive value of the difference in temperature differences represents an increase in the temperature difference in 2020-2022 compared to 2013-2014, a negative value represents a decrease in the temperature difference in 2020-2022 compared to 2013-2014.

- The map of __Change in the SUHII Index between 2020-2022 and 2013-2014 (%) __, which represents the percentage of change in the *Surface Urban Heat Island Intensity* (SUHII) Index between the two years. This map covers the extent of * [2021 census population centers] (https://www150.statcan.gc.ca/n1/pub/92-195-x/2021001/geo/pop/pop-fra.htm) * () * (CTRPOP) with at least 1,000 inhabitants and a density of at least 400 inhabitants per km2 to which a 2 km buffer zone is added and the values are calculated at the scale of the * [dissemination island] (https://www150.statcan.gc.ca/n1/pub/92-195-x/2021001/geo/db-id/db-id-fra.htm) * of Statistics Canada. The SUHII index highlights areas with a higher heat island intensity, by calculating a weighted average from the temperature difference classes, giving more weight to the hottest classes. Index change values below 100% represent a decrease in the intensity of UHIs in 2020-2022 compared to 2013-2014. Values greater than 100% represent an increase in UHI intensity between 2013-2014 and 2020-2022. Values around 100% correspond to an absence of change. The temperature difference classes were produced by the k-means algorithm, which takes into account the distribution of temperature difference values in a population center in a given year. The limits of temperature difference classes may therefore differ between the two years, which will influence the variation value of the SUHII index.

For more details on the creation of the various maps as well as their advantages, limitations and potential uses, consult the * [Technote] (https://www.donneesquebec.ca/recherche/dataset/analyse-de-changement-ilots-chaleur-fraicheur-et-indice-intensite-ilots-chaleur-urbains/resource/021c5399-a7b3-4b02-a753-39dda706ab27) * (simplified version) and/or the * [methodological report] ( https://www.donneesquebec.ca/recherche/dataset/analyse-de-changement-ilots-chaleur-fraicheur-et-indice-intensite-ilots-chaleur-urbains/resource/ef7e3450-9347-4051-b3bb-bedcba3c0d92) * (full version).

The production of this data was coordinated by the National Institute of Public Health of Quebec (INSPQ) and carried out by the forest remote sensing laboratory of the Center for Forestry Education and Research (CERFO), funded under the * [2013-2020 Climate Change Action Plan] (https://www.environnement.gouv.qc.ca/changementsclimatiques/plan-action.asp) * of the Quebec government entitled Le Québec en action vert 2020. 
**This third party metadata element was translated using an automated translation tool (Amazon Translate).**

Organization: Government and Municipalities of Québec | Gouvernement et municipalités du Québec