Use Google Scholar and search using your research topic's key words. You will find the related papers based on which you can prepare your proposal.

Try to find the research gaps reviewing those papers, set up your research questions, formulate the objectives and develop your methodology to achieve those objectives. That's it.

I agree with Sajal. There is unlikely to be a single or set of journals that adequately cover this kind of topic. Maybe also go to the most recent IPCC reports and look at their cited materials relating to drought effects associated with climate change.

For better understanding, your topic, try to find a related journal and search inside it to find papers related such as a crop science journal