Brazil annually faces significant challenges with mass movements, particularly in areas with poorly constructed housing, inadequate engineering, and lacking sanitation infrastructure. Campos do Jordão, in São Paulo state, is a city currently grappling with these issues. This paper details a study conducted within a pilot area in Campos do Jordão, where geophysical surveys and geotechnical borehole data were integrated. The geophysical surveys provided 2D profiles, and samples were collected to analyse soil moisture and plasticity. These datasets were combined using a Cokriging-based model to produce an accurate representation of the subsurface conditions. The enhanced modelling of subsurface variability facilitates a deeper understanding of soil behavior, which can be used to improve landslide risk assessments. This approach is innovative, particularly within the international context where similar studies often do not address the complexities associated with urban planning deficits such as those observed in some areas of Brazil. These conditions, including the lack of proper sanitation and irregular housing, significantly influence the geological stability of the region, adding layers of complexity to subsurface assessments. Adapting geotechnical evaluation methods to local challenges offers the potential to increase the efficacy and relevance of geological risk management in regions with similar socio-economic and urban characteristics.
Cassiano Antonio BortolozoNoel HowleyAndy LeggTristan PryerDanielle Silva de PaulaTatiana Sussel Gonçalves MendesDaniel MetodievMarcio Roberto Magalhães de AndradeSilvio Jorge Coelho SimõesMaiconn Vinicius de MoraesMarcio Augusto Ernesto de MoraesLuana Albertani PampuchRodolfo Moreda MendesHarideva Marturano Egas
The determination of vertical component plays a fundamental role in the initial phase of engineering applications. However, its acquisition is technically and economically demanding, mainly due to the precise heights relative to a reference surface, such as the mean sea level. The Cokriging technique is a necessary input for the calculation of the vertical component of the geodetic control points measured by GNSS, and it requires less auxiliary data and uses complementary available variables for the calculation.Therefore, the main goal is to use Cokriging to establish a geoid undulation prediction model for the rural area of the canton of Guayaquil, Ecuador. Ordinary, Residual and Universal Cokriging and Kriging techniques were used to compare their results and select the best for achieving accuracy. The validation of the application techniques yielded that Universal Cokriging was the most accurate with an RMSE of 8 cm and RSR of 2 cm, obtained just with 66 samples(20% of the dataset). Furthermore, considering the comparison with other regional geoid undulation models, the proposed model increased the accuracy of the results by a ratio of 9.68 and 6.96 in relation to EGM96 and EGM08, respectively.
