Escenarios de Cambio Climático: Método k-NN

This briefing by the Stockholm Environment Institute describes a non-parametric statistical downscaling methodology using the k-nearest neighbors (k-NN) method to generate synthetic regional climate series for temperature and precipitation between 2020 and 2100. These series are designed to inform the Water Evaluation and Planning (WEAP) system to help water service providers and environmental agencies develop robust adaptation alternatives and vulnerability analyses for water systems.

• The k-NN method is a non-parametric statistical downscaling technique used to create synthetic climate series for temperature and precipitation from 2020 to 2100. This method is advantageous because it uses probabilistic rules that maintain attributes from historical series, capturing daily resolution climate attributes while preserving the spatial correlation of observations.
• The methodology utilizes the CMIP5 database, which includes 61 General Circulation Models (GCMs) published in 2013. Because GCMs have a spatial detail of 40–120km, which is insufficient for local water resource planning, the k-NN method downscales this data. GCMs are selected and prioritized based on their ability to represent local climate attributes across various time scales, using eight quantitative and qualitative metrics such as dry and wet day streaks.
• The k-NN process generates daily weather sequences where temperature increments are estimated by comparing the moving average of the GCM signal for a specific day against the moving average for the reference period. For precipitation, the method generates random series that preserve the joint probability of consecutive humidity states (Dry, Wet, and Extremely Wet) derived from both observed signals and GCMs.

APA

Moncada, A., Pérez, C. F., & Angarita, H. (2020). Escenarios de Cambio Climático: Método k-NN. Stockholm Environment Institute. https://www.sei.org/wp-content/uploads/2020/06/knndiscussionbrief-2.pdf

Chicago

Moncada, Angélica, Cristo Facundo Pérez, and Héctor Angarita. Escenarios de Cambio Climático: Método k-NN. Stockholm Environment Institute, 2020. https://www.sei.org/wp-content/uploads/2020/06/knndiscussionbrief-2.pdf.

Wikipedia

{{cite report |last1=Moncada |first1=Angélica |last2=Pérez |first2=Cristo Facundo |last3=Angarita |first3=Héctor |title=Escenarios de Cambio Climático: Método k-NN |publisher=Stockholm Environment Institute |date=June 2020 |url=https://www.sei.org/wp-content/uploads/2020/06/knndiscussionbrief-2.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{moncada2020escenarios, author = {Moncada, Angélica and Pérez, Cristo Facundo and Angarita, Héctor}, title = {{Escenarios de Cambio Climático: Método k-NN}}, institution = {Stockholm Environment Institute}, year = {2020}, month = jun, url = {https://www.sei.org/wp-content/uploads/2020/06/knndiscussionbrief-2.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }