What is "benefit"?

Hello this is Risako from Kawasaki lab!

Our group had a field trip to Ishikari river basin, Hokkaido as Tunyu already introduced :)

The history of Ishikari river improvement dates back to the Meiji era when Japanese government tried to "develop" the land of Hokkaido where Ainu had lived with the river for a long time in a way that adapted their way of life to recurrent flooding. Ainu, indegenious people based in Hokkaido, once made a living with hunting and gathering enjoying the river's abundant resources, such as Salmon. Japanese settlers, however, relied heavily on rice cultivation. This way of life required permanent settlements near the river and the conversion of the region’s wetlands into farmland.

Construction of shortcut channels along the Ishikari River began reducing the flooding-prone area significantly. These projects also contributed to a substantial increase in agricultural yield in Ishikari region by improving drainage and drying our wetlands.

As one of our research interest stays in the spillover effects of flood control investment, let's think about how we can measure the benefit of the project. 

One simple way is to calculate the monetary value of properties that had once been unprotected but now protected. However, since most area of Ishikari flood plain consists of agricultural land, the avoided economic loss might not be enough to say that the "benefit" outweigh the costs though there is not yet such calculation published in the region. 

But...

Aren’t agricultural products essential to Japan’s food security and people’s lives, even if their monetary value is relatively small?

Were the benefits for Japane's development also benefits for Ainu?

What environmental value was lost because of these projects?

How should we evaluate the benefits of avoided losses when flood-control projects themselves encourage people to settle in hazard-prone areas, potentially creating new risks?

I believe that the meaning of "benefit" changes depending on who you are, how you see the world, and what you value. Although this is such difficult topic to do research on, our group will continue to working toward a more resilient and just society.