Related by context. Frequent words. (Click for all words.) 68 salination 64 Soil erosion 59 eutrophication 59 soil erosion 58 siltation 58 sedimentation 57 desertification 57 salinity 55 desiccation 54 silting 54 environmental degradation 54 deltaic 54 irrigated agriculture 54 acidification 54 river deltas 54 degradation 54 saltwater intrusion 53 Melting glaciers 53 ecological degradation 52 rampant deforestation 52 nutrient runoff 52 overfishing pollution 52 biodiversity hotspot 52 overexploitation 51 habitat degradation 51 bioaccumulation 51 nitrification 51 ecological 51 prolonged droughts 51 urbanization 51 depletion 51 riparian vegetation 51 Poyang Lake 51 habitat fragmentation 51 hydro electric dams 51 deplete oxygen 51 headwater 51 silts 50 wetland ecosystems 50 groundwater extraction 50 Stormwater runoff 50 glacial melt 50 hydrological cycle 50 Desertification 50 sediment runoff 50 Omo River 50 Severe drought 50 Polluted 50 biodiversity 50 periodic droughts 49 upwellings 49 aridity 49 toxic algae blooms 49 fertile soils 49 bilharzia 49 Salinity 49 seagrasses 49 biota 49 saturated soils 49 acidifying 49 erosion 49 glaciers melt 49 groundwater recharge 49 species extinctions 49 Urbanization 49 glacier melt 48 subsidence 48 fluvial 48 rapid urbanization 48 groundwater aquifers 48 thawing permafrost 48 submergence 48 nutrient loading 48 aquatic ecosystem 48 Evaporation 48 freshwater ecosystems 48 anoxia 48 Acidity 48 hydrological 48 glacial retreat 48 overgrazing 48 Xijiang River 48 deglaciation 48 arid lands 47 transboundary 47 biogeochemical 47 irrigated crops 47 Rapid urbanization 47 arable lands 47 lowland flooding 47 soil fertility 47 hydrology 47 alkalinity 47 oxygen depletion 47 Potable water 47 shoreline erosion 47 frequent droughts 47 silt 46 Dongting Lake 46 groundwater pumping 46 landlessness