MODELLING MEAN SURFACE TEMPERATURE OF NIGERIA USING GEOSTATISTICAL APPROACH

ABSTRACT

Understanding spatial variability of mean surface temperature (MST) of Nigeria is necessary for ecological restoration and national planning toward effects of unstable climate conditions. This study developed models for MST derived from two geosta- tistical procedures and Multiple Linear Regression (MLR) using measurements of monthly MST in Nigeria.The two geostatistical approaches were Ordinary Kriging (OK) and Regression Kriging (RK).The Ordinary kriging (OK) was developed in two dimensions with isotropy and in three dimensional plane with anisotropy and regression kriging (RK) that employed both correlation with independent variables and spatial autocorrelation simultaneously. Four statistics were considered to evalu- ate the performance of the approaches used. For the fitted MLR model, some of the predictors were significant at p-value of 0.05 with R2 equal to 88 percent. The one- leave-out cross-validation indicated that RK produced minimum errors compared to OK model . The OK with zonal anisotropic shown that the spatial continuity in the directions of North and North East were stronger than the directions of East and South East. The kriging weights for OK and RK were similar as shown in  the maps.The RK model outperformed the OK and the MLR and was therefore recommended for Long term prediction of mean Surface Temperature of Nigeria