Temporal variation Case studies 2 Land Resources 2 Mathematics and Statistics 2 Models 2 Pollution and Degradation 2 Soil Chemistry and Mineralogy 2 Spatial variation 2 Sustainability 2 Water Resources 2 Watershed management 2 Watersheds 2 Agriculture 1 Aquatic Biology and Ecology 1 Aquatic animals 1 Aquatic plants 1 Catchment hydrology 1 Cropping systems 1 Demography 1 Ecohydrology 1 Ecological restoration 1 Ecology 1 Ecosystems 1 Erosion 1 Erosion: Soil and Water Conservation 1 Eutrophication 1 Field Crops, (New March 2000) 1 Forest plantations 1 Geological sedimentation 1 Hydrology 1