WEBVTT FILE

1
00:00:09.510 --> 00:00:10.290
~Sound of Helicopter and music in background~

2
00:00:10.290 --> 00:00:15.880
Peder Nelson: My land cover career really started in 2002…

3
00:00:15.880 --> 00:00:18.040
…with the biggest wildfire in Oregon’s history.

4
00:00:18.040 --> 00:00:20.000
And that was the Biscuit Wildfire.

5
00:00:20.000 --> 00:00:23.000
I at the time was doing botany surveys.

6
00:00:23.000 --> 00:00:29.850
And looking for rare plants or rare mushrooms. And so I was spending a lot of time out on

7
00:00:29.850 --> 00:00:36.020
On the forest, looking at and taking photos and doing the documentation that a scientist or a land manager does.

8
00:00:36.020 --> 00:00:39.470
When that fire happened, it changed everything.

9
00:00:39.470 --> 00:00:46.860
Because we all had to react to this fire that was burning up some of the places that I had literally been the day before.

10
00:00:46.860 --> 00:00:50.430
And it was mapping what was there, and what was under threat.

11
00:00:50.430 --> 00:00:57.160
But it was also mapping the effects of the fire. We needed to find a way to look across five-hundred thousand acres.

12
00:00:57.160 --> 00:01:00.740
And the only way that we could really do that was satellite data.

13
00:01:00.740 --> 00:01:05.970
If we can’t get out and actually measure every single thing, what are we missing?

14
00:01:05.970 --> 00:01:11.940
And that’s where citizen scientist can actually come in and really help traditional scientists. To better understand

15
00:01:11.940 --> 00:01:17.420
What is happening around them. But also fill in these gaps.

16
00:01:17.420 --> 00:01:20.000
~♪Music♪~

17
00:01:20.000 --> 00:01:25.380
Title: Why Observe? Land Cover

18
00:01:25.380 --> 00:01:30.280
Narrator: The Global Learning and Observations to Benefit the Environment Program

19
00:01:30.280 --> 00:01:33.150
Is an international science and education program.

20
00:01:33.150 --> 00:01:39.920
It provides students and the public with the opportunity to participate in data collection and the scientific process.

21
00:01:39.920 --> 00:01:45.440
The GLOBE Observer App, is one of the opportunities allowing citizen scientists and students to take land cover

22
00:01:45.440 --> 00:01:51.090
Observations around the world and submit them to a larger database.

23
00:01:51.090 --> 00:01:54.570
But, what exactly is land cover?

24
00:01:54.570 --> 00:01:58.380
Doctor Eric Brown de Colstoun of NASA’s Goddard Space Flight Center explains

25
00:01:58.380 --> 00:02:04.750
Eric: Land cover is really the basic form of the landscape that we have around us.

26
00:02:04.750 --> 00:02:12.540
So, whether it’s forest or a desert. But it’s really one of the components of the landscape that we can study from space.

27
00:02:12.540 --> 00:02:16.800
Narrator: Peder Nelson is a scientist who uses land cover imagery in his research.

28
00:02:16.800 --> 00:02:23.180
Peder: I am a remote sensing scientist, who studies land cover across the globe.

29
00:02:23.180 --> 00:02:31.010
I use satellite imagery to make maps of land cover. And try to quantify what covers the earth.

30
00:02:31.010 --> 00:02:38.110
Sometimes a satellite can’t see what’s happening underneath a tree canopy, or what’s happening underneath cloud cover.

31
00:02:38.110 --> 00:02:45.580
And so we really need people to go out there to take these photos and do these observations, to help fill in where a satellite can’t

32
00:02:45.580 --> 00:02:47.660
actually make some observations.

33
00:02:47.660 --> 00:02:49.590
Narrator: Just like any digital photograph

34
00:02:49.590 --> 00:02:53.730
Land cover images are made up of a series of pixels. To show what covers the Earth.

35
00:02:53.730 --> 00:02:57.900
A pixel, or picture element, is the smallest unit of a digital image.

36
00:02:57.900 --> 00:03:02.730
When combined with thousands of other pixels, a picture is formed.

37
00:03:02.730 --> 00:03:06.180
Each pixel color shown represents a land cover type.

38
00:03:06.180 --> 00:03:11.230
It’s from these pixels where ground verification, or ground-truthing, come into play.

39
00:03:11.230 --> 00:03:14.500
You see, depending on what satellite is taking images

40
00:03:14.500 --> 00:03:20.030
A pixel can cover roughly an area of thirty to five-hundred meters squared.

41
00:03:20.030 --> 00:03:26.650
For imagery captured by Landsat, a pixel is thirty meters squared. Or about the size of a baseball diamond.

42
00:03:26.650 --> 00:03:34.460
However, part of that pixel showing forest, might actually be water. Or shrubs.

43
00:03:34.460 --> 00:03:41.400
By taking land cover observations, citizen scientists can help answer these questions when it comes to land cover maps.

44
00:03:41.400 --> 00:03:47.040
Sooo, why are these land cover observations so important?

45
00:03:47.040 --> 00:03:51.080
Why are they taken in the first place?

46
00:03:51.080 --> 00:03:55.150
Eric: We also are looking at how these components are changing over time.

47
00:03:55.150 --> 00:04:01.220
So, deforestation in the Amazon or across the world. How are cities expanding?

48
00:04:01.220 --> 00:04:06.970
A lot of different things to study and really the view from space is the way we do it here at NASA.

49
00:04:06.970 --> 00:04:14.850
We have big supercomputers that simulate the physics of the atmosphere and the land. The interaction between the Earth’s

50
00:04:14.850 --> 00:04:16.190
Systems.

51
00:04:16.190 --> 00:04:23.580
It’s important to have that land cover map. It sets certain parameters.

52
00:04:23.580 --> 00:04:28.870
Those models can actually be used to look at current day conditions and weather.

53
00:04:28.870 --> 00:04:36.750
So based on these current conditions, what might the Earth look like fifty or a hundred years from now.

54
00:04:36.750 --> 00:04:46.620
There’s an element of understanding but then also being able to predict into the future, you know, what that might be like.

55
00:04:46.620 --> 00:04:49.710
What these changes may mean for us.

56
00:04:49.710 --> 00:04:54.580
Narrator: Each point shown here represents a real world measurement of environmental conditions.

57
00:04:54.580 --> 00:04:59.440
Scientists use computer models to fill in information where measurements may not exist.

58
00:04:59.440 --> 00:05:07.640
By verifying the satellite imagery and using the data for these models, scientists can predict changes in our environment more accurately.

59
00:05:07.640 --> 00:05:14.990
One of these scientists using land cover maps to track urbanization as part of her work is Doctor Amita Mehta of NASA’s Goddard Space Flight Center.

60
00:05:14.990 --> 00:05:20.940
Amita: So, urbanization changes terrain as well as characteristics of the surface itself.

61
00:05:20.940 --> 00:05:27.080
And so, impervious surfaces is what we look at when we are monitoring flooding.

62
00:05:27.080 --> 00:05:34.180
When there are, say, parking lots, cement and concrete surfaces increase. So previously, if it was farmland

63
00:05:34.180 --> 00:05:45.190
Or something which was not built, and if that is built now. That water previously that could go or percolate in the soil and in the ground

64
00:05:45.190 --> 00:05:48.620
now cannot go in and it stays there.

65
00:05:48.620 --> 00:05:51.600
Monitoring helps you to plan for it.

66
00:05:51.600 --> 00:05:59.490
If you see land cover changing, even then you know that how water’s going to flow in that region might change.

67
00:05:59.490 --> 00:06:07.630
If you have to send rescue out or you have to plan for relief activities, and if you know land cover, then you know

68
00:06:07.630 --> 00:06:11.180
Where there might be help needed.

69
00:06:11.180 --> 00:06:22.060
By using land cover maps and models that reflect changes over time, scientists can predict where flooding and other events may occur.

70
00:06:22.060 --> 00:06:29.100
With a changing climate, these predictions from models and land cover maps can help scientists better understand these changes.

71
00:06:29.100 --> 00:06:32.290
And help communities prepare for them.

72
00:06:32.290 --> 00:06:37.700
But, perhaps a more important reason as to why take land cover observations is

73
00:06:37.700 --> 00:06:43.960
You get to participate in a community of scientists, citizen scientists and students.

74
00:06:43.960 --> 00:06:50.580
Eric: So, it’s a very important component that the citizen science and students of the GLOBE Program and GLOBE Observer

75
00:06:50.580 --> 00:06:59.220
Can contribute to is by really giving us the information on the ground of what they’re seeing around them and in front of them.

76
00:06:59.220 --> 00:07:03.680
And we hope over time as well as how maybe some of these things are changing.

77
00:07:03.680 --> 00:07:07.060
Because those would be very valuable for science.

78
00:07:07.060 --> 00:07:12.480
Peder: I saw the value of having information before a hazard happens.

79
00:07:12.480 --> 00:07:18.090
Because once that fire went through an area, we can never recreate that data.

80
00:07:18.090 --> 00:07:24.570
This is all important for us to share and put together because that’s how we understand Earth as a system.

81
00:07:24.570 --> 00:07:34.080
All of these things end up affecting where we live, why we live where we do and why we make some of the choices that we do.

82
00:07:34.080 --> 00:07:39.230
Narrator: To learn more about GLOBE Observer, check out the website at observer.globe.gov

83
00:07:39.230 --> 00:07:40.928
And download the app to start taking your own observations today.