History 14 Sedimentary basins 10 Dissertations, Academic (Ph.D) 7 Irrigation methods 7 Water 7 Watershed management 7 Climatic changes 6 Seed Science and Technology 6 Environmental management 5 Microbiology 5 Sedimentation and deposition 5 Sedimentology 5 Sprinkler irrigation 5 Water resources development 5 Biology 4 Check basin irrigation 4 Hydrology 4 Oceanography 4 Plate tectonics 4 River basin management 4 Water management 4 Water rights 4 Water-supply 4 Agriculture 3 Archaeology 3 Basins (Geology) 3 Biodiversity 3 Biodiversity conservation 3 Computer security 3 Economics 3