RT null
T1 Environmental Guidelines for Sand and Gravel Extraction Projects - Environmental Management Guidelines, No. 20
A1 United Nations Environment Programme, 
K1 river
K1 seabed resource
K1 information need
K1 environmental monitoring
K1 mining
K1 seabed mining
K1 environmental degradation
K1 sand extraction
K1 gravel extraction
YR 1990
FD 1990
LK https://wedocs.unep.org/handle/20.500.11822/29053
UL https://wedocs.unep.org/handle/20.500.11822/29053
NO The environmental impacts of sand and gravel extraction are not always readily obvious and hence have long been under-estimated. The cumulative, far-reaching effects of numerous uncontrolled operations have contributed substantially to the degradation of river and coastal ecosystems.
DS UN Environment Document Repository
RD Sep 17, 2026