Announcements

International Conference in honor of Rien van Genuchten on the occasion of his 80^th birthday

We wish all participants of the Rien van Genuchten Conference held at Rio de Janeiro beginning of May 2025 interesting presentations and fruitful discussions. Rien, stay healthy and hope to welcome you next year at our ISMC conference in Brazil.

Featured Paper

Do you want your paper featured?

Please share your recent paper if you want to be featured in the ISMC newsletter. With your contributions, we will select one paper to be featured in every newsletter. Submission can be done here. 

Field-scale variability and dynamics of soil moisture in Southwestern Nigeria

This research leverages field-based sensors and Geographic Information Systems (GIS) to elucidate soil moisture dynamics across diverse land uses in Southwestern Nigeria, including Cocoa, Cassava, Oil Palm, and Riparian ecosystems. The study synthesizes soil moisture data and geospatial coordinates from strategically selected land covers with satellite-derived soil moisture records from NASA's Prediction of Worldwide Energy Resources (POWER) and the US Geological Survey. Through a robust analytical framework combining cross-correlation functions, wavelet analysis, and inverse distance weighting interpolation, we revealed distinct soil moisture patterns ranging from 0 to 47.9% in arable farms, 0 to 46.8% in built-up areas, 0 to 49.9% in cocoa farms, 0.2 to 49.7% in oil palm farms, and 5.6 to 94.1% in riparian vegetation. The coefficient of determination values between 0.7 and 0.97 (p ≤ 0.05) underscore the significant influence of periodic land use on soil moisture during the study period. A comparative analysis of ground-based and satellite data revealed a potential overestimation of minimum soil moisture values by 66% and an underestimation of maximum values by 4%. This investigation provides critical insights into the interplay between hydrological variables and agro-meteorological factors, informing the management and assessment of agricultural resources. More information can be found here.

Analytical model for bare soil evaporation dynamics following wetting with concurrent internal drainage

Under natural conditions, infiltrated rainwater redistributed into the soil profile, becomes partially sheltered from surface evaporative losses relative to undrained wet surfaces. Surface evaporation rates and internal drainage dynamics are both sensitive to soil hydraulic properties and initial soil hydration state. We report a novel analytical framework for quantifying surface evaporation rates with concurrent internal drainage, considering soil properties and dynamic surface evaporation resistance. Interplay among soil hydraulic properties, boundary conditions, and atmospheric demand result in nonlinear relationships between cumulative evaporative losses and initial water content. The new analytical solution shows good agreement with laboratory column experiments and literature data. Results highlight the role of soil texture on evaporative losses and the nonlinear effects of initial wetness on evaporation. The largest evaporative losses per rainfall amount are predicted for small rainfall events over initially dry loamy soils due to the detention of infiltrated rainwater near the surface for soils with large porosity and low hydraulic conductivity. The analytical framework uses readily available parameters hence can be implemented in land surface models to explicitly consider how soil properties and rainfall event size affect surface evaporation dynamics. More information can be found here.

Featured Soil Modeler (Tiago Ramos)

Agricultural water management

Tiago Ramos is a researcher at Instituto Superior Técnico (IST), the engineering school of the University of Lisbon, Portugal. He studied Agronomy at the University of Évora and completed his PhD in 2014 from Instituto Superior de Agronomia (ISA), the School of Agronomy of the University of Lisbon. His research focuses on modeling the impact of agricultural water management on soil and water resources.

- Please tell us briefly about yourself and your research interest

My research focuses on developing sustainable soil and water management practices for intensive agricultural production areas. This includes accurately estimating crop water requirements to improve irrigation water management, particularly in the complex orchard systems that dominate irrigated regions in southern Portugal. However, most of my work is dedicated to modeling soil water dynamics and solute transport to assess the impact of management practices on soil and water resources, as well as crop yields. A more recent and challenging aspect of my research has been integrating the variability of soil properties into the dynamic modeling of soil water. This requires not only the use of more complex modeling tools, specifically distributed models, but also collaboration with other disciplines, particularly geophysics and pedometrics, to create more accurate soil maps for use at both field and regional scales.

-  How did you first become interested in soil modelling and learn about ISMC?

In 2002, I began my graduation thesis in Agronomy at the Soil Science Department of the research institute under the Portuguese Ministry of Agriculture, supervised by Casimiro Martins and Maria Gonçalves. What started as a thesis project turned into a 12-year journey at the institute. As the only laboratory in Portugal dedicated to soil physics, it provided a unique opportunity to explore various methods for determining soil hydraulic properties. Over time, my work evolved into studying water and solute transport modeling in variably saturated soils at different scales. A key turning point came when Maria Gonçalves invited Jirka Šimůnek and Rien van Genuchten to conduct a HYDRUS course in Portugal, which took place in Lisbon in June 2004. Later, during my PhD under the supervision of Luis Santos Pereira, we refined our modeling skills to better describe soil and water fluxes in agricultural systems. Luis Santos Pereira was also instrumental in expanding my research network and creating opportunities to apply our work in agricultural water management, environmental mitigation, and improving the livelihoods of communities not only in Portugal but also in Brazil, China, Syria, and, more recently, West Africa. About ISMC, I first heard about it through an email exchange with Jirka Šimůnek many years ago, when he introduced me to what was then a newly formed soil modeling group and encouraged me to join. Although my involvement in their activities has been limited, I have always made an effort to stay informed about their work and attended the most recent conference in Tianjin, China.

- Can you share with us your current research focus? And, please tell us briefly how your research could contribute to ISMC Science Panel’s activities

In recent years, I have worked with Luis Santos Pereira, Hanaa Darouich, and others on various aspects of agricultural water management. This includes identifying salinization hotspots in orchard areas of southern Portugal and developing improved management practices to address this issue. Further studies have focused on evaluating the effectiveness of salinity control measures in the Hetao irrigation district in northern China, as well as assessing the feasibility of mangrove-swamp rice production in Guinea-Bissau, West Africa. Additionally, I have been collaborating with Ana Oliveira, Mohamaad Farzamian, and Ana Horta on three-dimensional modeling of soil water dynamics at different scales, taking soil variability into account.

-Please tell us how can ISMC help you advance in your career?

The ISMC provides an excellent opportunity for networking and gaining knowledge.

- What resources or skills would you recommend that early career members of ISMC should acquire? And how can ISMC help and support early career members in this regard?

The ISMC conference is one of the best events for early-career soil modelers to disseminate their work, as it attracts an audience with unmatched expertise and capability. Additionally, the ISMC organizes several highly interesting summer schools and other events, providing young members with the opportunity to interact with some of the leading experts in the field.