Groundwater 50 Aquatic ecology-- Fresh water ecology-- Pond ecology-- Limnology (biology)-- groundwater ecology 49 Aquatic ecology-- Fresh water ecology-- Pond ecology-- Limnology (biology)-- groundwater ecology-- Periph 32 Hydrogeology 16 Groundwater flow 11 Hydrology 6 Geochemistry 4 Groundwater hydrology 4 Water chemistry 4 Arsenic 3 Customary law 3 Drainage 3 Groundwater ecology 3 Groundwater exploitation 3 Indigenous peoples 3 Irrigation water 3 LAW / General 3 Land degradation 3 Legal polycentricity 3 Soil remediation 3 TECHNOLOGY & ENGINEERING / Environmental / Water Supply 3 Tsunami 3 Water harvesting 3 Water quality management 3 Water-supply, Agricultural 3 Wells 3 Adivasis 2 Agricultural development 2 Avalanches 2 Building sites 2