Can we predict the hydrological impacts of changes in land use and management?
This is an important question, given the current focus on the potential of natural solutions to aid in reducing flood hazard and given concerns about future water availability for potable supply. The “Coalburn 2020 Experiment” will assess predictions of changes in streamflow associated with this felling. We invite the hydrological community to participate.
Details:
For the experiment the plan is to make predictions of the impacts of the forestry felling within the Coalburn catchment on (a) monthly water yield and (b) flood peaks. It is proposed that simulations be performed for the period 1993 to 2015 (or back to 1967 if the modeller wishes), using parameters representative of the historic land cover, with the models calibrated to produce the best fit between the measured and modelled discharge. The modellers will decide which parameters to change and assign new values (or lower and upper bounds) to these parameters to take into account the changed land use in the felled part of the catchment. Once this has been carried out then the discharge data for the four years from 2019-2022 will be made available and the modellers can assess how good their models are at predicting the effect of the felling on streamflow.
There are two things to note:
1) At Newcastle we have already run the model for the period 1993-2015 using the Shetran hydrological model and defined values for the parameters we are going to change due to the felling. These predictions were made in 2016 and can be seen on the Coalburn2020 website.
2) In order to check there is a different response in streamflow as a consequence of the felling, we have provisionally compared the annual discharge against the annual precipitation. For 2019-2021 this shows an increase in discharge compared to the pre-felling years of 2003-2015 (Figure 1). This suggests the felling has had an impact of the annual discharge.
Anyone interested in this work then please contact us. There is also the opportunity for interested groups to conduct their own field investigations at the site.