Présentations Colloques

Flash Poster
8.05
Session 8.05: Karst aquifers
Fournier Matthieu
An experimental lab approach of morphogranulometry on suspended particle matter to identify particle transfer properties in karst aquifer
Morphometry of particles is widely use in sedimentology to identify source-to-sink transport, sedimentation mechanisms and different sedimentary stocks. Usually, morphometry analysis is used on centimetric to millemetric quartz grains. But in hydrogeology, suspended particle matters (SPM) are mostly micrometric. Currently, morphometry analysis is realized by scanning electron microscope coupled to image analysis in order to measure various size and shape descriptors on particles like flatness, elongation, circularity, sphericity, fractal dimension. This technique is complex and take a big time. Moreover, transport processes of SPM in karst aquifer are very variable in time due to hydrological changes and complex recharge conditions. So, in order to measure the morphometry parameters of SPM during karst flash floods, it’s necessary to develop an easy, quick and exhaustive method.**The aim of this study is to present the first results of an experimental lab approach of morphometry analyses of SPM in order to identify transfer properties and sedimentary stocks of different particles recovery in karst springs. A morphogranulometer (CCD cam coupled to peristaltic pump) is used to measure different artificial and natural stocks of particles (different size, shape, nature, origin). From the measurements, the parameters allowing the identification of the different stocks are known by statistical analyses. Then, mixes of different particles stocks have been realized in order to verify the capability of the morphogranulometer to identify the particles of the stocks.**These results show the capability of this approach to identify the different stocks of sediments by morphogranulometry and offer the perspective to use this method in continuous at karst springs.**
France