GIS-based construction of baseline climatologies for the Mediterranean using terrain variables

Climate Research

Maureen D. Agnew¹  Jean P. Palutikof¹ 

关键词: Temperature;    Precipitation;    Regression;    Terrain;    Kriging;   

DOI  :  10.3354/cr014115

来源: Inter-Research Science Publishing

【 摘 要 】

ABSTRACT: A GIS-based method for constructing high-resolution (in space) maps of mean seasonal temperature and precipitation is developed for the Mediterranean Basin. Terrain variables and geographical location are used as predictors of the climatevariables at all points on a grid with a 1 km resolution, using a regression-based approach. Variables used for model development include: longitude, latitude, elevation, distance from the nearest coast, direction to the nearest coast, slope, aspect, andthe ratio of land to sea within given radii. Seasonal mean temperature and precipitation data, for the observation period 1952 to 1989, were assembled from 248 temperature sites and 285 precipitation sites in order to initialise the regression model.Temperature data from 36 stations and precipitation data from 35 stations were retained for model validation. Climate surfaces were constructed using the regression equations, and refined by kriging the residuals from the regression model and subtractingthe result from the predicted Œobservation¹ surface. Latitude, elevation and distance from the sea are found to be the most effective predictors of local seasonal climate. Validation determined that regression plus kriging predicts mean seasonaltemperatures with a coefficient of determination (R²), between the expected and observed values, of 0.87 (summer) and 0.97 (winter), and mean seasonal precipitation with an R² of 0.46 (autumn) and 0.94 (summer). A simple regressionmodel without kriging yields less accurate results in all seasons except for the temperature data in spring.

【 授权许可】

Unknown