TITLE:
Average Rainfall Estimation: Methods Performance Comparison in the Brazilian Semi-Arid
AUTHORS:
Fernando D. Barbalho, Gabriela F. N. da Silva, Klebber T. M. Formiga
KEYWORDS:
Average Rainfall; Interpolation Techniques; Multiquadric Equations; Reciprocal Distance Squared Method; Semiarid Rainfall; Thiessen’s Method
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.2,
February
25,
2014
ABSTRACT: Considering the rainfall’s importance in hydrological
modeling, the objective of this study was the performance comparison, in
convergence terms, of techniques often used to estimate the average rainfall
over an area: Thiessen Polygon (TP) Method; Reciprocal Distance Squared (RDS)
Method; Kriging Method (KM) and Multiquadric Equations (ME) Method. The
comparison was done indirectly, using GORE and BALANCE index to assess the
convergence results from each method by increasing the rain gauges density in a
region, through six scenarios. The Coremas/Mae D’água Watershed
employed as study area, with an area of 8385 km2, is situated
on Brazilian semi-arid. The results showed the TP, as RDS and ME techniques to
be employed successfully to obtain the average rainfall over an area,
highlighting the MEM. On the other hand, KM, using two variograms models, had
an unstable behavior, pointing the prior study of data and variogram’s choice
as a need to practical applying.