## 4 Conclusions  
The study demonstrated changes in land use and land cover patterns and water quality standards in the MRW from 2005 to 2018. It is possible to observe changes in land cover such as the reduction in native vegetation, as well as a decrease in livestock and an increase in agricultural plantations. Additionally, there was variability in the quantity of wetland areas in the MRW, characterizing multi-year cycles of drought and flood. Water quality parameters such as BOD, DO, pH, and Turbidity as well as the WQI, remained within the permissible reference limit for classification in Class 2, except for Thermotolerant Coliforms and Total Phosphorus, which showed values above the allowed range. The study also revealed a trend of increasing BOD values, indicating a higher input of organic matter into the water bodies of the basin, although, in all the studied Influence Areas, the WQI was considered \"GOOD\" or \"EXCELLENT\". This indicates, overall, satisfactory levels of water quality for the basin. On the other hand, although Total Phosphorus exceeded the allowed limit, there was a gradual decreasing trend over the study period.  
When analyzing correlations in the MRW, it was observed that when using a general approach for the entire basin, the indices showed low correlation. However, when correlations were analyzed by Influence Area (sub-basins), the correlation values increased, both for positive and negative correlations, indicating that policies for water quality management can be developed in terms of sub-basins, smaller planning units.  
Comparing the behavior of water quality parameters concerning the wetland areas of the MRW, there is a significant improvement in WQI, and for Thermotolerant Coliforms and Turbidity. However, there is a downward trend in DO values in wetland areas and an increase in BOD. For pH, it is observed that values tend to increase, making the water more alkaline, rarely exceeding the range of 7.5. Regarding TP, TN, and TS, it was found that the values showed variability over the years, with periods of increase or decrease. Considering the climatic seasonality in the wetland areas of the MRW, it was observed that  
Figure 17: Spatial variation of the Water Quality Index (WQI) at the monitoring stations of the Pantanal (IA07, IA14, IA15, IA16, IA17).  
DO, Turbidity, and WQI values are higher in the driest times of the year, and COD, TN, and TP presented higher concentrations in the rainy season.  
Wetland areas play important hydrological and ecological functions for flora and fauna, and especially for the water quality of the region. They are effective in the removal, storage, and cycling of nutrients, such as nitrogen and phosphorus, as well as improving and controlling quality parameters downstream. Therefore, they are highly relevant areas for defining strategies for watershed management and conservation, environmental protection, and the provision of ecosystem services.  
Conceptualization, F.J.C.M.F. and W.d.S.C.; methodology, F.J.C.M.F. and W.d.S.C.; formal analysis, C.S.C.C.; investigation, F.J.C.M.F. and W.d.S.C.; resources, F.J.C.M.F.; data curation, W.d.S.C.; writing--original draft preparation, L.R.R. and C.S.C.C.; writing--review and editing, L.R.R. and C.S.C.C.; visualization, F.J.C.M.F.; supervision, F.J.C.M.F.; project administration, F.J.C.M.F.; funding acquisition, F.J.C.M.F. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Ministerio Publico Estadual Do Mato Grosso do Sul (MPMS) \"State Public Ministry of Mato Grosso do Sul\", through the project Centro Integrado de Protezao e Pesquisa Ambiental (CEIPPAM) \"Integrated Center for Environmental Protection and Research\".  
Not applicable.  
Data Availability Statement: Data are contained within the article.