tikatuwq - Water Quality Assessment and Environmental Compliance in Brazil

Tools to import, clean, validate, and analyze freshwater quality data in Brazil. Implements water quality indices including the Water Quality Index ('WQI'/'IQA') using the weighted geometric mean following 'CETESB' methodology, an independent engine reproducing the 'IQA' of the Minas Gerais water agency 'IGAM' (a documented reproduction, not endorsed by the agency), paired comparison of 'IQA' engines with compare_iqa(), the Trophic State Index ('TSI'/'IET') after Carlson (1977) <doi:10.4319/lo.1977.22.2.0361> and Lamparelli (2004) <https://teses.usp.br/teses/disponiveis/41/41134/tde-20032006-075813/publico/TeseLamparelli2004.pdf>, and the National Sanitation Foundation Water Quality Index ('NSF WQI', Brown (1970)). The package also checks compliance with Brazilian standard 'CONAMA' Resolution 357/2005 <https://conama.mma.gov.br/?id=450&option=com_sisconama&task=arquivo.download> including the legal frequency rule (Art. 15, 80% conformity over six or more samples per year), and provides seasonal analysis with regional flow-season calendars, pollutant load computation, exceedance probability estimation, 'IET' visualization, and multivariate 'PCA' tools for routine monitoring workflows. The example dataset ('wq_demo') is a real subset from 'INEMA' monitoring data from a river in Bahia, Brazil (2020-2024).