Introduction
The Aral Sea is located in Kazakhstan and Uzbekistan nations which were parts of former Soviet Union. It is historically a saline lake in the center of a huge, flat desert basin. It is a primary example of dynamic surroundings. In 1960, it was the Earth's fourth largest lake; the size of the entire Southern California. Furthermore, it occupies 26,250 square miles, just about two hundred times bigger than the Salton Sea (Zavialov. 15).
The Aral Sea drying-up, the dust and salt laden air, have had a negative effect on the health of animals, people, as well as the plant life. The introduction of insect repellent into the cotton and rice fields, and the leakage of the remains back into the rivers have largely polluted the water for people living along the banks of the tributary flowing into the Sea. This has further irritated people's health. Ailments like cancer, tuberculosis and anemia as well as allergies are common. Many kids are born with imperfection. Ever since, the first project was put into practice, there has been a constant increase in viral hepatitis, typhoid fever, throat cancer, and TB in many areas. It is as high as three times the nationwide average. All of these grievance can be accredited either to the decrease in quantity and quality of water resultant from the drying up of Aral Sea.
The devastation of the Aral Sea ecosystem has been severe and sudden. Starting from 1960s, agricultural demands have destitute this large Central Asian salt lake of sufficient water to sustain it, and it has contracted rapidly. Kazakhstan, Uzbekistan, and other Central Asian nations use this water to produce cotton and other export crops, in the wake of widespread ecological consequences, including loss of fish, soil and water contamination, and dangerous intensities of polluted airborne dregs. It is generally settled that the present situation is unsustainable, although the poverty and export reliance of the Central Asian nations have halted real action, and the sea goes on shrinking. Currently, there are efforts aimed at reduction of minerals and blowing salts emanating from exposed sea beds. Possible solutions include construction of dikes to control and restrict water flows diverted from irrigation.
In order to Save the Aral Sea International Fund Aral Sea (IFAS) was created, with organizations like International Coordination Water Commission and Catchment Water Management Units on Sirdariya and Amudariya as subordinates. The scheme worked out by IFAS has been backed by UNDP, World Bank and Global Environmental Foundation.
Methods
Study Area : Our project landcover data is for Aral Sea and surrounding of Kazakhstan and Uzbekistan agriculture areas. Aral Sea is one of the four largest lakes in the world and it is approximately 26,300 square miles in between Kazakhstan and Uzbekistan. Since 1960s Soviet Union started the project irrigation of water from lake and it makes to shrink of water level in Aral Sea. There have three sections that sea survives today, which are Northern Sea in Kazakhstan, the Central Sea, and the Western Sea mostly located in Uzbekistan. The Landsat images from 1989 and 2010 had shown a significant amount of the loss of water.
Moreover, the surrounding of Aral Sea region is an agricultural area. The climate is continental and landscape is a semi-desert.
Data:
We collected Ladnsat 4-5 TM and Landsat 4-5 MSS images from September 1989 and September 2010 in path 161 and Row 29 from the USGS Global Visualization Viewer. Secondly we downloaded the images from Global Land Cover Facility(GLCF) for Uzbekistan’s agricultural areas. The images were utilized into ENVI program to use bands 3 and 4 which as the red and infrared bands. We utilized a 1989 TM image and 2000 ETM image to make a agricultural area with colors by NDVI. The NDVI shows the vegetation of the area in Aral Sea. NDVI shows “greenness” around the landscape desert. We transfixed our images into NDVI within the ENVI program to create the maps concluded needed for the project. These images clearly show the sea's surface before and after. In addition, we captured three different times of the Aral Sea’s surface from the Google Earth.
Results
From Google Earth. The Figures below show the results and their differences from 1973, 1999 until 2011.
The two images show the great difference between the area from 1989 and to 2010. This shows that the amount of water in the area has decreased enormously from a big amount or a big body of water to a small body of water as we have seen in Figure 3.
The figure above shows the Abstraction of water from 1957 up to 2000. It shows that the abstraction of water has drastically changed from a steady growth scenario that was the expected level for 2000 and the now expected result of a stable level demand and an optimistic scenario. The images show that the Aral Sea has changed from a large area to a small are of the abstraction of water.
By using NDVI from 1989 TM and 2000 ETM images from satellites, I was able to figure out how agriculture which cotton and soil health got decreased. I decided to use images under band 4, 3, 4 to make NDVI. By looking at density slice value, we could figure out which portion got changed by several years. This is highly important to make sure that we know the areas and the portions that has changed drastically or slowly.
It is historically a saline lake in the center of a huge, flat desert basin. It is a primary example of dynamic surroundings. In 1960, it was the Earth's fourth largest lake; the size of the entire Southern California.
In terms of the brightness, greenness and wetness transformation we can see that the change that has occurred in the area is a bad change.
This might be due to the fact that the Aral Sea is in itself a problematic state.
Discussion
For our project, there has been much imagery published by the USGS Global Visualization Viewers. USGS Global Visualization Viewers contains pictures that show change in the Aral Sea at different times. It especially had good sources of data that were exactly what we were looking for, data that compared the area by time difference. It was easy to determine onshore and offshore lines by the pictures. It clearly showed different sides of the sea water level decreased and which side was deep and left water. Water was dried up in the south basin first, and north basin still contained water.
Global Land Cover Facility created landscape imageries to determine the agriculture area. We search a Uzbekistan and Kazakhstan for agricultural. After we used ENVI to change the colors, agricultural area around the Aral Sea was clearly identified.
It was most difficult in this study to seek the data at the Global Land Cover Facility (GLCF). There were no specific data for the Aral Sea basin. We had to search the country around the sea to find images one by one. Our study area was divided to four basins: northern, southern, eastern, and western basins. The GLCF mostly contained separate basins instead of a whole picture of the sea. The images that separate the parts of basin were harder to use to explain the problem.
We compared to other studies of the Aral Sea, and it is apparent that research and data gathering has happened for a long time. The researchers would have spent a lot of time to figure out the problem and data for the area. However, most people addressed causes of Aral Sea water conflict. However, we tried to correlate the water conflicts with agricultural characteristics.Future Research
We are not satisfied of our work because we had some trouble in the beginning obtaining high-resolution imagery for the area. We tried to find the best images for our study from the USGS Global Visualization Viewers and the Global Land Cover Facility websites. If we were to further our research, we would use new images that showed the Aral Sea because the Kazakhstan government has started a project to raise the Aral Sea’s water level.
Reference
1) Campbell, Robert Wellman, ed. 2001. “Aral Sea, Central Asia: 1964, 1973, 1987, 1999.” Earthshots: Satellite Images of Environmental Change. U.S. Geological Survey. http://earthshots.usgs.gov. This article was released 14 February 1997 and revised 14 August 2000 and 14 August 2001.
2) “ARAL SEA.” EDSserver. UCSD. Web. 01 Dec. 2011. http://visearth.ucsd.edu/VisE_Int/aralsea/index.html.
3) “NGM Blog Central – Aral Sea Change – National Geographic Magazine – NGM.com. “National Geographic Magazine – Blog Central. National Geographic, 29 Dec. 2010. Web. 01 Dec. 2011. <http://blogs.ngm.com/blog_central/2010/12/aral-sea-change-html>.
4) “World of Change: Shrinking Aral Sea : Feature Articles. “NASA Earth Observatory: Home. NASA Earth Observatory, 25 Aug. 2000. Web. 01 Dec. 2011. <http://earthobservatory.nasa.gov/Features/WorldOfChange/aral_sea.php>.
5) Zavialov, Peter: ㅊ. New York. Springer, 2005
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