IDEAS Insights Forest Management in Nepal | Page 3

Sustainable management of forests is central to Sustainable Development Goal 15.b. In
Nepal, forests account for 40% of land area. As agriculture forms the base of the Nepalese
economy, a considerable number of forest communities rely on sustainable timber
harvesting for their livelihoods. Our Mathematica model aims to measure the sustainable
extraction rate for these communities.
Additionally, Nepal is susceptible to political and economic vulnerabilities, including natural
disasters: floods, landslides, earthquakes and forest fires. The likelihood of such events
increases annually. [2] The April 2015 Nepal earthquake was the most recent example. By
modelling the impact of an earthquake on forest-dependent communities, we can
generalise this model to other countries that rely on forest industries and face earthquake
hazards in the future.

When constructing our model, the balance between complexity and practicality was a
crucial issue. The more realistic the elements included, the more complex and delicate the
model. However, more complicated models do not necessarily result in better practicability.
Indeed, interpretation of results from an overly complex model may prove difficult! We
therefore retained a realistic level of complexity by carefully selecting and calibrating
relative data and parameters.

Our model for timber harvesting may be non-linear, in which calculation and inspection of
patterns is not as straightforward as in a linear model. It is notable that chaotic behaviour –
an important indicator of volatility, with real-life implications – only occurs under non-linear
systems.
Chaotic behaviour is understated when data is approximated to a linear pattern (a
"linearized model"). We adopted a minimum-level complex model, where it is not necessary
to linearize data.
For more information about linear and non-linear models, please see the below article:

Explained: Linear and nonlinear systems