In this assignment, we are going to use satellite images from the LandSat Themat
ID: 119300 • Letter: I
Question
In this assignment, we are going to use satellite images from the LandSat Thematic Mapper to observe how the environment has changed over time. Each of the images below shows an area of desert in Al Jouf, Saudi Arabia (30N, 38.2E). Most of the area in the first image, taken in 1991, is still desert, but there are a few circular areas that appear green. These green areas are fields of crops that are being watered using center-pivot irrigation (CPI). Each field has a well in the center that is attached to a long pipe on wheels that rotates in a giant circle around the well. Sprayers hang from the pipe and water the crops. Irrigation has allowed the Saudis to grow crops in the desert. Instructions Answer the following four questions in a two-page report. Each question will be graded “credit” or “no credit” depending on your ability to answer the questions completely using scientific terms and concepts from class. Answers that do not meet criteria will receive no credit.
1. In two paragraphs, first describe what changed in this location, and then explain how these changes are likely to affect the local climate or water resources.
2. Use the satellite images to estimate the area of the center-pivot irrigation (CPI) fields in 1991, 2000, and 2004. CPI-irrigated fields appear as circles on the satellite images. Each circle covers approximately 0.166 km2 (1/6 km2 ). For this question, we will focus on the study area outlined in black in each of the three images.
a. How much land was irrigated in the black square in 1991? ________km2
b. How much land was irrigated in the black square in 2000? ________km2
c. How much land was irrigated in the black square in 2004? ________km2
3. In at least two paragraphs, explain how the changes taking place in the study area are related to an environmental issue of current importance to society.
4. Describe a step-by-step scientific procedure that would allow you to use satellite imagery to measure the amount of forest in Maryland over time. Label each step with a number (“Step 1:”). Base your procedure on the methods used in this worksheet to measure irrigated land in Saudi Arabia. 1991 2000 2004
cobo 1991 2000 2004Explanation / Answer
1. we can easily see the difference between the satellite images of 1991 , 2000 and 2004. in 1991 satellite image mot of the study area was desert but then it increaes in 2000 and more increased in 2004. these circles are represent the crops in that field and desert represented by the yellow colour in the image . we can see that density of the green circles increased continuosuly it means crops density is also increased year by year using the irrigation techniques.
these changes make possible to continuous use of irrigation technique and provide suitable environment for the crop. these crops in that area also affects the local environment. we know that plants and trees are atract the couds and make paoosibilities of the rain even plants make the temperature difference with our presence , temperature is low in the plant presence in comparison to other places where plats are not available. and these differences will increase with the increased density of the crops in that field.
2. one circle covers the area = 1/6 km2
and we are focusing on the study area outlined in black in each of the three images.
in 1991, we can see there is no circles in the black outlines area . in 2000 , we can see there is 36 circles (including black circles as well). and
in 2004 , we can see there is 133 circles (including black circles as well).
a. How much land was irrigated in the black square in 1991? ___0* 1/6 = 0_____km2
b. How much land was irrigated in the black square in 2000? ___36 * 1/6 = 6_____km2
c. How much land was irrigated in the black square in 2004? __133 * 1/6 = 23.83 / 24______km2