I would suggest you topics related to water resource and its management. This is not a new topic but a topic of very importance. U would have read about the water scarcity and almost at the verge of extinction in South African city which is not too far for us. So if u can contribute something useful in this field ( not just as literature) it will be quite appreciable.
Dear Koneru, the natural resource management is a wider umbrella where all the possible topics can be embedded, however, it is vital what are your topics, just giving a point for debate may not serve the purpose. You should contemplate what actually you would like to focus upon and what are the priority objectives of your research; that also includes the physiographic and demographic area of your research, etc.