Geographic segmentation, spatial dependencies, and evaluation of the relative position of rain-gauges based on gridded data of mean monthly precipitation: application in Nigeria
| Autor: | Dimitris Papamichail, G. O. Awe, Vasileios Aschonitis, Kleoniki Demertzi, T. P. Abegunrin, Giuseppe Castaldelli |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
010504 meteorology & atmospheric sciences
principal component analysis 0208 environmental biotechnology evaluation of rain-gauge network Iso-Cluster analysis maximum likelihood classification principal component analysis terrain segmentation Elevation terrain segmentation Ambientale evaluation of rain-gauge network 02 engineering and technology 01 natural sciences 020801 environmental engineering Latitude Position (vector) Principal component analysis Segmentation Spatial variability Precipitation maximum likelihood classification Longitude Cartography 0105 earth and related environmental sciences Water Science and Technology Mathematics Iso-Cluster analysis |
| Popis: | The aim of the study is to present a combination of techniques for (a) the spatiotemporal analysis of mean monthly gridded precipitation datasets and (b) the evaluation of the relative position of the existing rain-gauge network. The mean monthly precipitation (P) patterns of Nigeria using ∼1 km2 grids for the period 1950–2000 were analyzed and the position of existing rain-gauges was evaluated. The analysis was performed through: (a) correlations of P versus elevation (H), latitude (Lat) and longitude (Lon); (b) principal component analysis (PCA); (c) Iso-Cluster and maximum likelihood classification (MLC) analysis for terrain segmentation to regions with similar temporal variability of mean monthly P; (d) use of MLC to create reliability classes of grid locations based on the mean clusters’ characteristics; and (e) analysis to evaluate the relative position of 33 rain-gauges based on the clusters and their reliability classes. The correlations of mean monthly P versus H, Lat, Lon, and PCA highlighted the spatiotemporal effects of the Inter Tropical Discontinuity phenomenon. The cluster analysis revealed 47 clusters, of which 22 do not have a rain-gauge while eight clusters have more than one rain-gauge. Thus, more rain-gauges and a better distribution are required to describe the spatiotemporal variability of P in Nigeria. |
| Databáze: | OpenAIRE |
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