How to predict hydrological effects of local land use change:how the vegetation parameterisation for short rotation coppices influences model results

Hydrology and Earth System Sciences

F.Richter¹  C.Bernhofer¹  C.Döring¹  M.Jansen¹  O.Panferov¹  U.Spank¹ 

DOI  :  10.5194/hess-19-3457-2015

学科分类：地球科学(综合)

来源: Copernicus Publications

【 摘 要 】

Among the different bioenergy sources, short rotation coppices (SRC) withpoplar and willow trees are one of the promising options in Europe. SRC provide not only woody biomass but also additional ecosystem services.However, a known shortcoming is the potentially lower groundwater rechargecaused by the potentially higher evapotranspiration demand compared toannual crops. The complex feedbacks between vegetation cover and water cyclecan be only correctly assessed by application of well-parameterised andcalibrated numerical models. In the present study, the hydrological model system WaSim (Wasserhaushalts-Simulations-Model) is implemented for assessment of the water balance. The focusis the analysis of simulation uncertainties caused by the use of guidelinesor transferred parameter sets from scientific literature compared to"actual" parameterisations derived from local measurements of leaf area index (LAI), stomatal resistance (Rsc) and date of leaf unfolding (LU). Theanalysis showed that uncertainties in parameterisation of vegetation lead toimplausible model results. LAI, Rsc and LU are the most sensitive plantphysiological parameters concerning the effects of enhanced SRC cultivationon water budget or groundwater recharge. Particularly sensitive is thebeginning of the growing season, i.e. LU. When this estimation is wrong, theaccuracy of LAI and Rsc description plays a minor role. Our analysesillustrate that the use of locally measured vegetation parameters, likemaximal LAI, and meteorological variables, like air temperature, to estimateLU give better results than literature data or data from remote networkstations. However, the direct implementation of locally measured data is notalways advisable or possible. Regarding Rsc, the adjustment of localmeasurements gives the best model evaluation. For local and accuratestudies, measurements of model sensitive parameters like LAI, Rsc and LU arevaluable information. The derivation of these model parameters based onlocal measurements shows the best model fit. Additionally, the adjustedseasonal course of LAI and Rsc is less sensitive to different estimates forLU. Different parameterisations, as they are all eligible either from localmeasurements or scientific literature, can result in modelled ground waterrecharge to be present or completely absent in certain years under poplarSRC.

【 授权许可】

Unknown