Detecting the influence of land use changes on discharges and floods in the Meuse River Basin – the predictive power of a ninety-year rainfall-runoff relation?

摘要

Quantifying how changes in land use affect the hydrological response at theriver basin scale is a current challenge in hydrological science. A dailydischarge record (1911–2000) of the river Meuse (21 000 km2; WesternEurope) has been simulated with a semi-distributed conceptual model (HBV).The model has been calibrated and validated with a data set for the period1968–1998. In this study the performance of the model for the period priorto 1968 has been analysed. The observed and simulated discharge records arecompared in terms of annual average discharge, summer and winter averagedischarge, annual maximum daily discharge, and annual maximum 10-day averagedischarge. The results are discussed with reference to land use change (i.e. foresttype change) and shortcomings of the available precipitation anddischarge records.

The general agreement between the observed and simulated discharge recordsis good (Nash-Sutcliffe efficiency: 0.89–0.93), in particular flood volumesand the highest flood peaks are simulated well but the model has problemswith the medium floods (shape and peak value). However, there are somesystematic deviations between the observed and simulated discharges duringspecific periods. The simulation result could somewhat be improved by takingthe historical land use into consideration. But the systematicoverestimation of the discharge for the period 1933–1968 could not beattributed to observed changes in land use. It is concluded that the overallimpact of land use changes in the Meuse basin is too small to be detectedgiven the uncertainties in the available records.