Upload date
All time
Last hour
Today
This week
This month
This year
Type
All
Video
Channel
Playlist
Movie
Duration
Short (< 4 minutes)
Medium (4-20 minutes)
Long (> 20 minutes)
Sort by
Relevance
Rating
View count
Features
HD
Subtitles/CC
Creative Commons
3D
Live
4K
360°
VR180
HDR
8,246 results
For an introductory college-level physical geology class: a review of how groundwater contributes to freshwater supplies, how it ...
53,881 views
2 years ago
"Groundwater is a valuable natural resource that must be protected from groundwater depletion (declining level) and chemical ...
5,385 views
3 years ago