One way to estimate future hydrological regimes is to find evidence of representative periods in the past. In this study a first step is taken in the historical-hydrological modeling for the catchment area of the Drentsche Aa. Policies in this area aim for higher baseflow and lower peak discharge levels that fit a more natural historical situation. By adapting the existing model to a historical scenario of around 1900, it is possible to estimate the hydrological consequences of a more natural, cultural-historical representation of the landscape. Model results show that, with the same meteorological conditions, the evaporation in the situation of 1900 is about 17% lower than in 2000. Besides this, the drainage in 1900 was limited due to fewer and shallower watercourses. This has as a consequence that in 1900 groundwater levels are higher and the superficial drainage of groundwater is larger. Discharge levels at several return periods are (substantially) higher than in 2000. The question is therefore to what extent the pursuit of a historical landscape image of 1900 will result in lower peak discharge levels and reduced flooding in the catchment area. The differences between 1900 and 2000 are greater than the differences between 2000 and the expected climate scenario of 2050 (WH scenario). This is striking and suggests that in the last 100 years the changes in the hydrological regime are larger than the expected changes for the coming decades. It is worthwhile to simulate other historical scenarios, representative of a more natural design, to create a variety of landscape compositions and their representative hydrological regimes.
|Translated title of the contribution||Historical hydrological modelling of the Drentsche Aa river system with respect to future water management|
|Number of pages||15|
|Journal||Stromingen : vakblad voor hydrologen|
|Publication status||Published - 2019|