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