## 2 Materials and Methods
### Case Study
These results are correlated with sedimentation dating studies carried out in the Hanabanila reservoir, which also show the mouth of the River Negro sector as the source of the most significant contribution of sediments to the reservoir [140]. The integration of the results with this third technique (IH) facilitated a more accurate identification of significant differences between the evaluated sources, enabling their differentiation and providing substantial support for the identification study of sediment contributions (as demonstrated by the FingerPro model through the discriminant analysis conducted on the selected tracers in the investigation). The integrated application of isotopic and nuclear techniques also permitted the incorporation of the FP technique into the hydrogeological study of the case study to analyze mixtures. The water contributions within the River Hanabanila sector were analyzed from five wells (3, 4, 7, 8, 9) as potential sources. The mixing point was taken at the discharge point of sector II, and a similar tracer was used as in the previous analysis (chemical macro-components, isotopes, and physical-chemical), as illustrated in Figure 4.  
Figure 4: Water sampling points (wells) were selected in the sector of the sub-basin for River Hanabanila. In the initial data evaluation, the range test excluded two tracers (total dissolved solids and electric conductivity) suitable for inclusion in the study. The LDA revealed notable distinctions between the evaluated sources and identified partial overlap for wells 7 and 8. The distinct contributions associated with groundwater at the discharge point of the Hanabanilla sector were identified. The wells with the highest contribution, which approaches 75%, are wells 3 and 4 (situated more than 9 km away) and well 9, which account for 25%. The integrated application of isotopic and nuclear techniques (FRN, FP, HI), developed in this study case, enabled a comparison of results, thus identifying the limitations of their individual use and the significant potential of the results provided with their use in an integrated manner (Figure 5). The analysis of soil and water degradation phenomena must consider the various aspects associated with soil redistribution, sedimentation processes, and their relationship with water dynamics. The integrated use of these techniques can significantly enhance the characterization of water and land degradation phenomena, allowing us to evaluate their impacts and formulate strategies for sustainable water and land management. As illustrated in Figure 5, the sediment contributions for the Rio Hanabanilla sub-basin revealed the forestry sector as the primary source (50%), followed by subsistence crops (40%), and, finally, coffee (10%). The goodness of fit for the mixing model was 0.91, indicating a strong correlation between the observed and predicted values. In the case of the Rio Charco Azul sub-basin, forestry (50%) and subsistence crops (40%) are also primary land uses contributing sediment, while fruit trees (10%) represent the last significant source. The goodness of fit was 0.86. The sedimentation rates associated with each sediment core at the discharge points of each sub-basin within the dam were evaluated. The highest rates were observed in core III (0.24 g/cm\({}^{2}\)), followed by core IV (0.21 g/cm\({}^{2}\)). The lowest values were observed in cores II and I, with rates of 0.16 and 0.15 g/cm\({}^{2}\), respectively. These findings are corroborated by the aforementioned analysis of source contributions at the reservoir's final discharge point, which highlights the significance of the Rio Negro and Charco Azul sub-basins as primary sediment sources. Figure 5: Summary of results with the integrated application of isotopic and nuclear techniques.