Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Master → Nouvelle Zélande → Meteorological Drought Projections for New Zealand Using CMIP5 Data

Auckland University of Technology (2017)

Meteorological Drought Projections for New Zealand Using CMIP5 Data

Dhanapal Sagadevan, Komala

Titre : Meteorological Drought Projections for New Zealand Using CMIP5 Data

Auteur : Dhanapal Sagadevan, Komala

Université de soutenance : Auckland University of Technology

Grade : Master of Computer and Information Sciences 2017

Résumé partiel
Droughts are one of the most damaging natural hazards, and anthropogenic climate change will continue to impact drought sensitive sectors such as primary production, industrial and consumptive water users. Drought monitoring and early warnings are essential for the development of mitigating strategies. The overall aim of this thesis is to develop a methodology to project droughts and its severity in the future through a multi-scenario and multi-model approach using the latest Coupled Model Intercomaprison Project Phase5 (CMIP5) models. All sixteen regions of New Zealand are included in the analysis. To achieve the above objective, the analysis was initially carried out to select the most applicable meteorological drought index – Standardised Precipitation Index (SPI) for New Zealand. Temporal changes in historic rainfall variability and the trend of SPI were investigated using non-parametric trend techniques to detect wet and dry periods across the regions of New Zealand. The first part of the analysis was carried out to determine annual rainfall trends using Mann-Kendall (MK) and Sen’s slope tests for the sixteen regions with long historical records (109 years) of the data set. For SPI trend analysis, it was observed that, results obtained showing significant trends ; direction of SPI trends were similar to annual precipitation (downward and upward trends). In addition, the rate of occurrence of drought events were examined in the temporal trends. The fact that all regions showed positive slopes indicated that the intervals between events were becoming longer and the frequency of events was temporally decreasing. From the SPI trends, it was also observed that some of the regions over New Zealand will face more dry periods leading to increased drought occurrence. Information similar to this would be very important to develop suitable strategies to mitigate the impacts of future droughts. This main objective of this thesis is to assess the drought projections for the regions of New Zealand using General Circulation Models (GCMs) under two emission scenarios – Representative Concentration Pathways (RCP4.5) and RCP8.5 for three future periods (2010-2039, 2040-2069, 2070-2199). Drought severity and spatial extent are analysed for 12-month (SPI12) events.

Mots clés : CMIP5 ; Drought ; Trend ; Projections ; New Zealand


Version intégrale (4,3 Mb)

Page publiée le 7 avril 2020