M-TROPICS at UNIST and Konkuk University, South-Korea

Three researchers involved in M-TROPICS CZO went to South Korea from November 26 to December 6 within the French-Korean Campus France-funded project “Investigating fate and transport of microbial pathogens in freshwater-environment”. Emma Rochelle-Newall (IRD – iEES Paris), Olivier Ribolzi (IRD – GET), and Laurie Boithias (CNAP – GET) met Prof. Yongeun… Continue Reading

Paty NAKHLE started her PhD within M-TROPICS on pathogen bacteria transport and fate in tropical catchments

Paty Nakhle is a former student from both the Lebanese University and the Agronomy Engineering School of Toulouse (ENSAT), with a specialization in environmental science. She also hold a joint ENSAT/Paul Sabatier University master degree Ecosystèmes et Anthropisation and performed her 6-month internship at GET laboratory, where she experimentally modelled… Continue Reading

Dong Cao, Roots and Humans

A documentary film (Dong Cao, des racines & des Hommes, 9’04) featuring Jean-Luc MAEGHT (IRD) and PHAM Dinh Rinh (SFRI) has been shot within the Dong Cao catchment in Vietnam (M-TROPICS/MSEC) to highlight the long term monitoring of the CZO (climate, land use, hydrology, and soil erosion, root density, macrofauna,… Continue Reading

Vietnamese IRD partners visiting the Dong Cao CZO

Scientists from the USTH and from the Thuyloi University visited the monitored catchment of Dong Cao, northern Vietnam (M-TROPICS/MSEC). The visit was led by Rinh Pham Dinh (SFRI) and by Jean-Luc Maeght (IRD, iEES-Paris). Visiting scientists discovered the history of the research carried out on this peri-urban watershed (49.7 ha).

Soils in the critical zone

Christian Valentin (IRD) coordinated a series of 6 books at ISTE Editions about the role of soils within the critical zone, including in the tropics. Renewed interest for soils is due to the social challenges they are associated to: agricultural productions, climate and biogeochemical cycles regulation, urbanization… By locating soils… Continue Reading

Sediment delivery from tropical rivers

Lancelot Pinta defended a master degree (M2) thesis entitled “Impact of rainfall erosivity and land cover change on total organic carbon accumulation in sediments of a water reservoir in Thailand” on Thursday June 28th at Sorbonne Université (Paris). The objectives of this study were to determine, the amount of catchment-derived… Continue Reading

Fecal bacteria occurrence in tropical rivers

Floriann Langlet, a master student from the Université de Toulouse III Paul Sabatier, just finished his internship at GET laboratory. He analyzed the occurrence of bacterial pathogens along the Mekong river basin (M-TROPICS/MSEC) and found that soil type, discharge, and turbidity were among the key variables associated to E. coli… Continue Reading

Field experiment of the ANR ATCHA project

Jean Riotte (IRD-GET) and Laurent Ruiz (INRA/IRD-GET), together with M. Tripti (Post doc IISc) and Nils Dubois (M2 ISTOM), performed a field experiment within the frame of the ANR ATCHA project, aiming at assessing the fate of nitrates from irrigation by groundwater. The experiment was performed in the Berambadi catchment (M-TROPICS/BVET)… Continue Reading

Critical zone analysis with GRASS and QGIS

A book authored by Yves AUDA has been published, handling the analysis of the critical zone with open-source softwares GRASS and QGIS: field sampling, hydrological models, landscape analysis, remote sensing mapping, digital elevation models, etc. Theory and exercises are based on data from the M-TROPICS/MSEC CZO in Northern Laos, gathered… Continue Reading

The roots of the drought: Hydrology and water uptake strategies mediate forest-wide demographic response to precipitation

An inter-disciplinary team at Bengaluru’s Indian Institute of Science (IISc) studied how different tree species partition underground water resources up to 30m depth and co-existing tree species diverge in water uptake depths (M-TROPICS/BVET). Deep rooted trees turn to be more vulnerable to severe droughts than shallow rooted species : climate… Continue Reading

Processes controlling silicon isotopic fractionation in a forested tropical watershed: Mule Hole Critical Zone Observatory (Southern India)

The analyses of silicon isotopes in soil, water and plant compartments of the Mule Hole forested watershed (M-TROPICS/BVET) reveal that vegetation takes up twice more silica than first estimates using elemental mass balance. This flux is 30 times higher than the solute silica flux exported by the stream, itself resulting… Continue Reading

Linking crop structure, throughfall, soil surface conditions, runoff and soil detachment: 10 land uses analyzed in Northern Laos

In montane Southeast Asia, deforestation and unsuitable combinations of crops and agricultural practices degrade soils at an unprecedented rate. Typically, smallholder farmers gain income from “available” land by replacing fallow or secondary forest by perennial crops. The aim of this study (M-TROPICS/MSEC) was to understand how these practices increase or… Continue Reading

Impacts of teak expansion on environment and human health

Short summary of the latest research on the Houay Pano CZO (M-TROPICS/MSEC) dealing with teak expansion, the impact of understorey management on soil surface features and water infiltration, and the consequences of increased surface runoff and soil erosion on pathogens’ transport. Video (4’39) can be watched here.

REY-Th-U solute dynamics in the critical zone

Combined influence of chemical weathering, atmospheric deposit leaching, and vegetation cycling (Mule Hole watershed, South India): the source and proportion of REY, Th, and U exported by groundwater and by the ephemeral stream along with the elemental proportions passing through vegetation have been assessed in the subhumid tropical forested CZO… Continue Reading

How can we manage a resource we don’t understand?

“When John Rowell moved to India in 2012, he had a limited understanding of ‘water problems’. A chance encounter with a member of the Indo-French Cell for Water Sciences led him on a six month journey to better understand our most precious resource…” Full text can be found here.  

From shifting cultivation to teak plantation: effect on overland flow and sediment yield in a montane tropical catchment

Soil erosion supplies large quantities of sediments to rivers of Southeastern Asia. It reduces soil fertility of agro-ecosystems located on hillslopes, and it degrades, downstream, water resource quality and leads to the siltation of reservoirs. An increase in the surface area covered with commercial perennial monocultures such as teak plantations… Continue Reading

Groundwater resource vulnerability and spatial variability of nitrate contamination

Insights from high density tubewell monitoring in a hard rock aquifer: agriculture has been increasingly relying on groundwater irrigation for the last decades, leading to severe groundwater depletion and/or nitrate contamination. Understanding the links between nitrate concentration and groundwater resource is a prerequisite for assessing the sustainability of irrigated systems…. Continue Reading