Ask HN: Can you recommend any niche hackathons tackling interesting problems?

Hi, recently failed entrepreneur here, thinking about my next project. I have a lot of ideas, but many are not necessarily tied to a real problem and I know enough now to want to start with an impactful problem with real demand.

As I looked around, it occurred to me that many hackathons actually supply great problem statements.

A good example is U.S State Department's "Fish Hackathon", which partnered with dozens of fisheries, environmental organizations, and governments to summarize the biggest problems in the fishing industry. Take a look at the problem statement around 'ghost gear' for example - https://goo.gl/YshXQZ

It's a great problem statement that clearly captures the level of impact from both a financial and environmental perspective and also identifies the stakeholders looking for a solution. Along with the problem statement, there is a listing of relevant resources, a few solution ideas and contact info for various people at these organizations.

Other good examples include NASA's space apps challenge (2017.spaceappschallenge.org) which compiled incredible lists of datasets for important problems tied to UN's adopted sustainable development goals and Bangledesh's hackathon (https://goo.gl/LA6Sao) which lists the 10 biggest problems facing the country along with domain experts willing to help for each problem.

Defining a great problem statement is a very important first step to a successful project. Reading the problem statements of these hackathons has been eye opening for me. I've found a dozen interesting hackathons and I'm looking for more.

So I'm here to ask if anyone can recommend more hackathons with good problem statements. If I find enough, I'd be happy to compile them into a free resource for other makers/entrepreneurs.