Use the library catalogue to find books. Start with a keyword search. When you have found a relevant title click on the hyperlinked subjects on the catalogue record for related material.
You can also browse the shelves at the following call numbers:
304.2 Human ecology
304.28 Environmental abuse
304.6 Population
307 Communities
330.9 Economic geography
330.91 Economic geography in developing countries
333.7 Environment
551 Geology, hydrology
577 Ecology
910 Geography and travel