As stated in the tab about the topic and the research question, the data used for this research can be divided into two groups. The one group is the data on the modelled scenarios about the discharge for the Aare catchment with its various sub-catchments. The scenarios involve 100-, 300-, 1’000-, 10’000- & 300’000-year events. For clarification, a 100-year event means that the measured, or in this case modelled, event is one of an extremity level which happens once every 100 years. Analog, this applies for the other time-period events.
The other group is the land cover data. As the data is aggregated for the entirety of the country, it was intersected with each sub-catchment to receive the exact land cover respectively. It is noteworthy that the initial data is categorised in 2 steps. The first step is a broad distinction between, settlement, agricultural land, forest and unproductive areas. The second step involves a finer distinction within the 4 main categories.
In our research, a few things regarding the data have been purposely left out. For one, the scenario for 300’000 years, was excluded. This is due to the enormous time-period. Further, it does not differ enormously from the 10’000-year scenario. And to reduce redundancy, it was decided to not involve the longest time scenario. Next, even though very detailed data on landcover was accessible, the decision was made to use to more basic distinction of the land cover. This is due to the fact that the finer distinction would overcomplicate the visualisation of the data while not baring any further or useful insight towards answering the research question.
Regarding the land cover, it becomes evident after looking at the data that in the northern parts there is more settlement area to be found while in the southern part of the Aare catchment, more unproductive area can be found. Regarding the agricultural land cover, a lot can be found in the pre-alpine regions. This applies occasionally as well as in the northern parts of the catchment/Switzerland. The forests areas are somewhat randomly distributed when it comes to the percentage of land cover within the respective sub-catchment.
It can be stated that this is what we expected to be the case for the land cover distribution within the sub-catchments and between the various sub-catchments. This is because most settlement is in Switzerland is located in a belt going from the south-west over the north-west and further to the north-east. Most cities are located in this belt such as Geneva, Lausanne, Basel, Bern, Lucerne, Zurich or St. Gallen. Some of the cities are not located within the Aare catchment, some are very close next to the catchment and some are located within (Bern, Lucerne, Zurich). The mentioned city, or rather high density settlement belt goes through the northern part of the Aare catchment. Similar was expected and is actually the case for agricultural land. This is due to the fact that in the high altitude alpine regions within the Aare-catchment there is a lack of suitable soil for agriculture due to lower temperatures and thus slower soil generation processes. That is also the reason why, there is much more unproductive area in the southern high altitude sub-catchments. Rocky mountain cliffs are common there while humus-rich soils are not.
For the discharge data, it must be stressed that these are simulations. The displayed data implies strong precipitation periods in specific regions. This does not apply consistently for those regions, since due to weather conditions variation on the specific precipitation event can be expected. What becomes visible, especially after watching the animated scenarios, is that the discharge usually peaks in more mountainous areas. Even if the final parts of the catchment (with respect to the flow direction of the water) also potentially can raise a lot, it is still less than in some mountainous sub-catchments.