Présentations Colloques

Poster
6.03
Session 6.03: Innovative tools to improve understanding of groundwater recharge processes
Jarkko Okkonen
Infiltration and potential recharge of esker aquifer in Central Finland - observation and simulation of daily soil moisture and temperature profile
Objectives- In sustainable groundwater usage, prediction of recharge with a numerical models are of high importance because it will be used in optimizing groundwater pumping rates of an aquifer. In cold snow dominated regions, as in Finland, understanding the soil moisture and temperature dynamics affects the development of soil frost that controls snowmelt runoff, infiltration and recharge in winter periods. This study was initiated to investigate the performance of integrated hydrology model, ParFlow, in simulating soil moisture and temperature profile and daily recharge rate in esker aquifer in Karhinkangas in Central Finland. The goal is to represent the intra-annual and inter annual recharge rates that are the basis of sustainable pumping rates. **Desing and methodology- Soil water content and temperature was measured hourly at several depths. The groundwater depth and temperature was measure daily from the borehole located 2 meters from the soil monitoring station and the climate data was obtained around 5 km from the soil station. The modeling domain is from the ground surface to bedrock. **Original data and results- Soil moisture and temperature measurements from the ground surface to the depth of 2 meters are used to calibrate the numerical model. Groundwater level measurements are used to check the response of modeled groundwater level. Climate data (precipitation and temperature) are used as input data to the model. The goal is to simulate snow accumulation, snow melt, evpotranspiration and incorporate these in to this modeling study. The common land use model (CLM) that has been integrated to ParFlow wil be tested. The role of freeze and thaw cycles to hydraulic conductivity will be also discussed based on the simulation results.**Conclusions- The implications of this study will be accurate representation of groundwater recharge rate that may change intra-annual and inter-annually. This research will give a firsthand information of groundwater recharge rates to water company management, policy makers and environmental agencies which role is to assess sustainable groundwater pumping rates in the Karhinkangas groundwater area.**
Finland