Precipitation trends analysis by Mann-Kendall test: a case study of Paraíba, Brazil

Abstract

This work aimed to select semivariogram models to estimate trends in monthly precipitation in Paraiba State-Brazil using ordinary kriging. The methodology involves the application of geostatistical interpolation of precipitation records of 51 years from 69 rainfall stations across the state. Analysis of semivariograms showed that specific months had a strong spatial dependence (Index of Spatial Dependence - IDE < 25%). The trends were subjected to the following models: circular, spherical, pentaspherical, exponential, Gaussian, rational quadratic, K-Bessel and tetraspherical. The best fit models were selected by cross-validation and Error Comparison Index (ECI). Each data set (month) had a particular spatial dependence structure, which made it necessary to define specific models of semivariogram in order to enhance the adjustment of the experimental semivariogram. Besides, the monthly trend map was plotted to justify the chosen models.

Impacts of atmospheric CO2 increase and Amazon deforestation on the regional climate: A water budget modelling study

“…The Mann–Kendall test is an important parameter for detection of significant trends, and therefore, this test was applied for precipitation, temperature and moisture balance (incoming—outgoing in the red rectangle; Figure 1) variables. The method as well as the equations were described by Xavier et al (2020). The vertically integrated moisture transport was calculated by: where the Qu and Qv represent the zonal and meridional wind components, g is the acceleration due to gravity, p 0 is the surface pressure level and pt is the upper domain pressure level (500 hPa was used) and q is the specific humidity.…”

“…The Mann-Kendall test is an important parameter for detection of significant trends, and therefore, this test was applied for precipitation, temperature and moisture balance (incoming-outgoing in the red rectangle; Figure 1) variables. The method as well as the equations were described by Xavier et al (2020). The vertically integrated moisture transport was calculated by:…”

Precipitation Trends in the Ganges-Brahmaputra-Meghna River Basin, South Asia: Inconsistency in Satellite-Based Products

“…Various statistical methods such as parametric, non-parametric, and Bayesian methods have been used to detect trends. Many researchers have used the Mann-Kendall test to estimate precipitation trends in different parts of the world [2,4,21,[25][26][27]. A Mann-Kendall trend test is a non-parametric test which Mann [28] and Kendall [29] used to identify trends in time series data.…”