Abstract
We used the new process-based, tracer-aided ecohydrological model EcH(2)O-iso to assess the effects of vegetation cover on water balance partitioning and associated flux ages under temperate deciduous beech forest (F) and grassland (G) at an intensively monitored site in Northern Germany. Unique, multicriteria calibration, based on measured components of energy balance, hydrological function and biomass accumulation, resulted in good simulations reproducing measured soil surface temperatures, soil water content, transpiration, and biomass production. Model results showed the forest "used" more water than the grassland; of 620 mm average annual precipitation, losses were higher through interception (29% under F, 16% for G) and combined soil evaporation and transpiration (59% F, 47% G). Consequently, groundwater (GW) recharge was enhanced under grassland at 37% (similar to 225 mm) of precipitation compared with 12% (similar to 73 mm) for forest. The model tracked the ages of water in different storage compartments and associated fluxes. In shallow soil horizons, the average ages of soil water fluxes and evaporation were similar in both plots (similar to 1.5 months), though transpiration and GW recharge were older under forest (similar to 6 months compared with similar to 3 months for transpiration, and similar to 12 months compared with similar to 10 months for GW). Flux tracking using measured chloride data as a conservative tracer provided independent support for the modelling results, though highlighted effects of uncertainties in forest partitioning of evaporation and transpiration. By tracking storage-flux-age interactions under different land covers, EcH(2)O-iso could quantify the effects of vegetation on water partitioning and age distributions. Given the likelihood of drier, warmer summers, such models can help assess the implications of land use for water resource availability to inform debates over building landscape resilience to climate change. Better conceptualization of soil water mixing processes and improved calibration data on leaf area index and root distribution appear obvious respective modelling and data needs for improved simulations.
| Original language | English |
|---|---|
| Pages (from-to) | 2174-2191 |
| Number of pages | 18 |
| Journal | Hydrological Processes |
| Volume | 33 |
| Issue number | 16 |
| Early online date | 19 Jun 2019 |
| DOIs | |
| Publication status | Published - 30 Jul 2019 |
Bibliographical note
ACKNOWLEDGMENTSThe authors would like to acknowledge research funding from the European Research Council (project GA 335910 VeWa). M. Maneta acknowledges support from the U.S. National Science Foundation (project GSS 1461576). C. S. is grateful to the Leibniz IGB Berlin for a Senior Research Fellowship. We also thank Umweltbundesamt (UBA) for providing the climate data.
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available from the corresponding author upon reasonable request.
Keywords
- forest hydrology
- ecohydrology
- tracers
- tracer-aided models
- CARBON
- CLIMATE-CHANGE
- TRANSPIRATION
- VARIABILITY
- LAND-USE CHANGE
- STORAGE DYNAMICS
- GLOBAL SYNTHESIS
- PANOLA MOUNTAIN
- LEAF-AREA INDEX
- VEGETATION
Access to Document
- Ecohydrological modelling with EcH2O‐iso to quantify forest and grassland effects on water partitioning and flux ages
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