A Tool in R for Easy Hydroclimatic Calculations

Current hydrological and climatological data volume requires using a programming language to automate calculations. This work introduces an open package written in R language named hydRopclim, which seeks to help with monthly data exploration and visualization through six valuable functions in the hydro climatological field. Based on original methods developed and published in previous works, these functions were tested in arid, semi-arid, and mountainous regions such as the Peruvian Pacific coast and Andean mountains. However, most of them can be applied in other areas of the world. The package covers the six following functionalities: (a) Evaluation and correction of monthly TRMM grid-point precipitation; (b) NCEP NCAR grid-point temperature through a multiplicative model validated with root mean square error, correlation coefficient, and linear adjustment slope (Condom et al. in Hydrol Process 25:1924–1933, 2011; Rau et al. in Spatio-temporal analysis of monthly temperature in the mountainous regions of Peru. An approach for NCEP NCAR Reanalysis data correction, 2013); (c) Estimation of a monthly runoff index for ungauged watersheds through the GR2M model (Rau et al. in Hydrol Process 33:20–35, 2019); (d) Estimation of hydroclimatic seasonal indices as those of El Niño phenomenon and visualization of their running correlations with in-situ data (Bourrel et al. in Hydrol Process 29:1252–1266, 2015); (e) Evaluation and spatial visualization of k-means clustering validated by the silhouette analysis (Rau et al. in Int J Climatol 37:143–158, 2017); (f) Hydroclimatic change analysis and the impact of climate and human activities validated with the statistical adjustment of a Budyko model (Rau et al. in Theor Appl Climatol 134:139–153, 2018).