1 00:00:00,272 --> 00:00:02,190 (light music) (aircraft motor buzzing) 2 00:00:02,190 --> 00:00:03,773 [Manuel Razo] Flooding is a serious problem 3 00:00:03,773 --> 00:00:04,606 here in the state of Texas; 4 00:00:04,606 --> 00:00:06,610 we experience various types of flooding. 5 00:00:06,610 --> 00:00:10,600 So, one way that we want to really represent that 6 00:00:10,600 --> 00:00:12,100 and address some of those issues 7 00:00:12,100 --> 00:00:15,130 is through providing mapping services statewide, 8 00:00:15,130 --> 00:00:17,130 and we want to use accurate data. 9 00:00:17,130 --> 00:00:20,300 And so, in order to do that, we use the lidar data, 10 00:00:20,300 --> 00:00:22,330 and that provides a really detailed 11 00:00:22,330 --> 00:00:24,183 representation of the terrain. 12 00:00:24,183 --> 00:00:25,520 (motor rumbling) 13 00:00:25,520 --> 00:00:27,500 We need to have this up-to-date, 14 00:00:27,500 --> 00:00:30,880 accurate depiction of what the flood risk is, 15 00:00:30,880 --> 00:00:32,880 and that's through up-to-date science. 16 00:00:32,880 --> 00:00:36,370 And we need that lidar data to better understand that. 17 00:00:36,370 --> 00:00:38,120 [Joey Thomas] Lidar data creates 18 00:00:38,120 --> 00:00:39,778 a very detailed representation 19 00:00:39,778 --> 00:00:41,670 of the earth's surface. 20 00:00:41,670 --> 00:00:44,103 Lidar stands for light detection and ranging. 21 00:00:45,700 --> 00:00:48,400 Typically, there is a laser and a sensor 22 00:00:48,400 --> 00:00:50,600 mounted to the bottom of a plane. 23 00:00:50,600 --> 00:00:53,610 And as the plane flies over the surface of the earth 24 00:00:53,610 --> 00:00:55,720 or the area you're surveying, 25 00:00:55,720 --> 00:00:58,710 it pulses a laser at hundreds of thousands 26 00:00:58,710 --> 00:01:00,230 of times a second. 27 00:01:00,230 --> 00:01:02,900 What is measured is the time it takes for the pulse 28 00:01:02,900 --> 00:01:06,290 to hit the ground and return to the sensor 29 00:01:06,290 --> 00:01:07,910 on the bottom of the plane. 30 00:01:07,910 --> 00:01:11,660 And using that time lapse, they can calculate 31 00:01:11,660 --> 00:01:14,110 what the distance from the plane to the earth is. 32 00:01:15,050 --> 00:01:18,670 The final data set produced by a lidar acquisition 33 00:01:18,670 --> 00:01:21,820 can give you information about anything 34 00:01:21,820 --> 00:01:23,450 on the earth's surface. 35 00:01:23,450 --> 00:01:26,620 So, because you can filter out portions of the point cloud, 36 00:01:26,620 --> 00:01:28,680 such as vegetation and buildings, 37 00:01:28,680 --> 00:01:31,400 you're left with just the ground surface. 38 00:01:31,400 --> 00:01:34,080 And that surface can be used to more accurately 39 00:01:34,080 --> 00:01:37,460 represent flooding and flood modeling 40 00:01:37,460 --> 00:01:40,120 and doing the baseline engineering required 41 00:01:40,120 --> 00:01:42,400 for FEMA floodplain mapping. 42 00:01:42,400 --> 00:01:44,120 [Manuel Razo] So, in order for the flood planners 43 00:01:44,120 --> 00:01:47,720 to be able to identify areas that need mitigation, 44 00:01:47,720 --> 00:01:50,200 they need that updated science. 45 00:01:50,200 --> 00:01:54,012 And through the lidar, it provides the data that we need 46 00:01:54,012 --> 00:01:57,010 to go in there and do the modeling 47 00:01:57,010 --> 00:01:59,363 and identify the flood risk areas. 48 00:02:00,210 --> 00:02:03,070 Older floodplain maps were derived off 49 00:02:03,070 --> 00:02:07,640 of the old U.S. Geological Survey 30-meter 50 00:02:07,640 --> 00:02:10,330 or 10-meter digital elevation models. 51 00:02:10,330 --> 00:02:12,240 It was a representation of the terrain, 52 00:02:12,240 --> 00:02:14,780 but it was a 30- by 30-meter grid. 53 00:02:14,780 --> 00:02:18,070 Where now, we use a 1-meter by 1-meter grid 54 00:02:18,070 --> 00:02:19,120 to represent the terrain. 55 00:02:19,120 --> 00:02:22,620 So, it's a lot more detailed and accurate. 56 00:02:22,620 --> 00:02:25,730 It gives us that real detailed picture of the terrain 57 00:02:25,730 --> 00:02:29,170 to understand where the high spots and the low spots are. 58 00:02:29,170 --> 00:02:31,310 And you know, the low spots tend to be the ones 59 00:02:31,310 --> 00:02:33,690 that are more susceptible to flooding. 60 00:02:33,690 --> 00:02:36,260 As the state grows, we get more development; 61 00:02:36,260 --> 00:02:37,520 we get more people moving in, 62 00:02:37,520 --> 00:02:39,430 which we're seeing right now. 63 00:02:39,430 --> 00:02:42,030 We can get that lidar, and it will be reflective 64 00:02:42,030 --> 00:02:44,690 of what's happening on the ground 65 00:02:44,690 --> 00:02:46,890 so that we can better model and better understand 66 00:02:46,890 --> 00:02:48,436 what's going to happen during a flood. 67 00:02:48,436 --> 00:02:50,777 (plane engine rumbling)