University of California, Los Angeles
October 2011
Introduction:
The Indus River Valley spans three dominant countries, China, India and Pakistan. Beginning in Indian controlled Kashmir, the Indus River runs through each country, and is mainly used by the countries of India and Pakistan (Syed). The Indus River is one of the main water sources in the region, and is used by many groups that live along the river, as well as larger cities such as Sukkur in Pakistan, which have grown immensely and require increasingly large amounts of water (William). Tensions between India and Pakistan regarding the use of the Indus River were settled with the signing of the Indus Waters Treaty in 1960. With the effects of climate change slowly unfolding, however, the tension that was once assuaged is now looming over both countries once again. This climate change has caused the rapid melting and deterioration of the glaciers that feed the river, which has in turn caused many negative changes in and around the river itself. (William).
The implications of an issue such as water tension building between India and Pakistan is one of nuclear disaster. The 1960s were a very different time period in regards to the reaches of both India and Pakistan. Today both countries are nuclear armed, and furthermore, both countries house extremely large populations. Demographers expect India's population to triple in size and Pakistan's population to increase six fold in the next fifteen years (Mauldin). While nuclear armament and use are clearly the most global detriments that can occur by the continuation of water shortage in these areas, on a micro level large economic detriments have already occurred. In Pakistan, rural towns and smaller cities have economically collapsed. Certain areas have already been abandoned by farmers and villagers due to the water flow having decreased so greatly in their area that agriculture is no longer feasible (William). In somewhat larger cities than these smaller areas, something known as water theft has started to become a profitable business. People have begun diverting and stealing water from city pipes and private residential areas in order to sell it (William).
In order to mitigate these adverse effects, we must be able to first fully address the root of the issues. The problems at hand may be known and observable to a certain extent, via the use of any sort of local census data (if available) and through water quality monitoring (where available). The most consistent and reliable data, however, is going to be procured from remote sensing and satellite imagery. Satellites with high temporal resolution and high spatial resolution allow for the monitoring of water levels in regards to anthropogenic forces, such as damming and agrarian use, as well as glacial runoff due to climate changes. Implementing these satellites such as Geoeye's IKONOS and Quickbird which have very high resolution imagery and fast temporal resolutions can allow for better assessment by the academic community. With these new technologies, we should now be able to assess to a fine accuracy the distinct change (if any) in the Indus River and its tributaries. Based on research and scholarly articles I would expect to see a stead decline in the water levels from 1979 to 2006.
Methods:
The first step in the process of observing the water level change and urban growth over the Indus Valley was to download the necessary satellite images. In order to acquire the necessary images, I had to locate sites that would relinquish the images for free. I found the Maryland Global Land Cover Facility via Google. I then downloaded an ETM + image from 2000 and 2006 and MSS image from 1979 of the necessary site area. Since the Indus River Valley spans multiple countries I had to narrow the search area to a specific region. I chose Sukkur, Pakistan for my area of interest. Sukkur serves as a perfect sample location, as it is right on the river, and has experienced many of the negative changes that I have discussed.
Once all the necessary images were downloaded, I loaded the MSS and the two ETM+ images into the ENVI software. Comparisons between the two parent images of the ETM+ were made based on scale and landmarks present between the images. However in order to fully analyze these images, an NDVI had to be created. In order to render each of these images into their own respective NDVIs, the following steps were followed. Bands 3 and 4 for each image were opened in the a 4,3,4 sequence and loaded the same way into the RGB color scheme and then loaded in separate displays. The resulting images revealed a pink coloration. Then each image was saved as an image (.jpeg) file.
*Note: Make sure to leave the image file as “full scene.”
Once the NDVI is created for both images, a change detection was applied in order to compute the differences of each area.
*Note: The NDVI final image should be in black and white while the change detection image should be blue and pink gradients.
[Fig 1. An Multispectral Scanner image taken in 1979. This image has been modified from its original image and has been transformed into an NDVI.]
The downloading of the two ETM+ images was to use in order to create a Change Detection Map. In order for this to be created accurately, I implemented images from the same satellite sensor in order to preserve spectral and spatial resolutions. In order to create the change detection, both images had to be loaded in ENVI and under Basic Tools → Change Detection → Compute Difference Map I was able to render the change detection image. Both the 2000 and 2006 ETM+ images were used to create this map.
The two parent files, 2006 and 1979, were also used to create a density slice. By implementing density slicing I was able to highlight areas in the image in order to further accentuate and show physical change. In this case, it is applied to water in order to visually show more prominently growth or decline in the river's water level. The first step to implementing a density slice is to open the saved NDVI image into ENVI and under Tools open up Color Mapping and then Density Slice. After that you will be prompted to change color values and I did so to the best of my ability using the best available color theory referenced from Google Earth.
Results:
[Fig 2. Enhanced Thematic Mapper Plus image of our region transformed into an NDVI.]
[Fig 3. An NDVI of the region of interest taken from an Enhanced Thematic Mapper Plus image.]
[Fig 4. A density slice transformation performed on the 2006 ETM+ images.]
[Fig 5. A change detection map of the Indus area that was rendered from the two parent ETM+ images. The red denotes vegetation gain while blue indicates a loss.]
The results of this procedure concluded certain specifics that are situation based in regards to certain anthropogenic forces. The Indus River clearly exhibits fluctuation in both water level and path over both the 26 year gap and the 6 year gap. The contradiction of the images is as follows: the 2006 ETM+ image shows a higher water level than the 1979 MSS image. The possible explanations for this are: While the proximate water level appears to have risen, (contradicting my initial thought) in actuality the ultimate water level of the river has decreased overall. The reason it appears to be higher in 2006 is due to an anthropogenic climate change which has caused the parent glaciers of the river to release more water than in previous years (Williams). When a comparison between the two ETM+ images is drawn, it is noticeable that 2006 appears to still have a higher water level than the comparing image (ETM+ 2000 image). However in the Change Detection Map, you will notice that there seems to be an increase in vegetation between 2000 and 2006. The red indicates an increase in vegetation whereas the blue indicated a decrease in vegetation. Since the Indus Valley is an agricultural area, we could interpret the water level fluctuation as a result of another anthropogenic force, irrigation.
Based on my analysis of water level in the Indus Valley, it seems that what appears to be a rise in water level might actually be a red herring. As anthropogenic climate change continues to accrue with heavy usage of resources that emit green house gases, the glacial water stores will continue to melt at a more rapid rate than previously recorded. This will only cause water levels to temporarily increase, allotting more water at one time to be used by us. In doing so, water stores are being hastily depleted, and the scarcity that is looming over many societies is extremely frightening. The Indus River is just one large scale example of water shortage that is resulting in extremely negative impacts. Without the proper means of conservation, water scarcity will only continue to grow as eventually branch into a global issue, especially when it occurs between countries that both have access to nuclear weapons. We can only hope that education and dissemination of information throughout areas that exhibit attributes of impending water scarcity will aid in eliminating any potential conflict.
References:
Water, Peace and Conflict Management: The Experience of the Indus and Mekong River Basins, Kirmani, Syed. Water International 1990, Vol. 15, Issue 4. Pages 200-205.
India and Pakistan as Odds Over Shrinking Indus River, William Wheeler. National Geographic October 12, 2011.
Evaluation of Alternative Solutions for Achievement of River Standard, Thomas P. Quirk and Leonard J. Eder. Water Pollution Control Federation 1970, Vol. 42, Issues 2. Pages 272-290.
Population and Population Policy in Pakistan, W. Parker Mauldin. Marriage and Family Living 1963. Vol. 25, Issue 1. Pages 62-68.
Population Growth and Food Supply Margin in Pakistan, Mohamed Ismail Siddiqi. GeoJournal 1985. Vol. 10, Issue 1. Pages 83-89.
