Student: Laurel Garrett
Graduation date: May 2016
Type: Concentration (single major)
Date approved: November 2013
The large-scale manipulation of rivers to maximize the utility of flow is radically changing the way we interact with water and how water interacts with the biotic systems surrounding it. These processes of management including damming, canalizing, straightening, and diverging water for irrigation are becoming increasingly implemented in areas that are facing rapid industrialization and large projected economic growth. My area of interest includes Vietnam and other Southeast Asian countries, places that are affected by monsoons, where seasons of intense rainfall contrast seasons of dryness. This unique pattern changes many hydrologic processes. The classic monsoon region extends from approximately 30°N to 30°S across Asia and Africa, although other places experience monsoon conditions as well, albeit at a smaller scale (Rowe 2011). I intend to start my research with this classic monsoon region and then look at how river management differs in, for example, the Southwest United States Monsoon. The study of this area will include an abroad trip to Vietnam, where I hope to observe the monsoon season and some of the processes of river management. Relevant environmental themes include are land change and land use in response to infrastructure placed on major rivers, agriculture and food, and climate change. Since the flow of rivers is so connected to people’s daily lives and the economic health of the region, I think this will be a very dynamic and interesting region to study.
One possible situated context is in the Mekong Delta, where canals and dykes control the flow of water and a huge percentage of the regions water usage goes to agricultural and aquaculture production. Some actors include rice and shrimp farmers, boatmen, and groups within the hydraulic bureaucracy that considerably shapes hydraulic infrastructure on water resources (Evers, Benedikter 2009). Evers describes South Vietnam as a “Hydraulic Society,” whose water landscape is tightly wound in the culture, livelihood, economy, and politics of the region. The region produces half of the countries food volume (Ka¨ko¨nen 2008), so fluctuations in productivity due to weather variability have large impacts on food security. Weather variability, either from climate change or monsoonal fluctuations in rainfall, can lead to significant decreases in rice productivity (Nhan 2011). Rice cannot be grown higher on the delta during monsoon season because of the extreme and prolonged flooding. However, downstream agriculture is reliant on high level of precipitation during the monsoon season to be able to grow rice. The extensive canals in the delta are prone to tidal flooding, which increases the acidity of the soils. Downstream during the dry season, the soil becomes too saline for rice and the area is converted to shrimp farming. Decisions about the rice crop each year are based on calculations that consider rainfall, weather forecast, and the amount of water in irrigation canals. Most farmers dig small channels to divert excess water but the Vietnamese government is investing heavily in developing irrigation systems for the whole delta. The management of the canals is primarily for maintaining agricultural productivity of the Mekong Delta. In contrast, upstream regions generally deal with different types of surface water manipulation. In Malaysia, in the Cameron Highlands, the Batang Padang catchment houses three major dams that can generate 262 MW of hydropower. Sediment that is naturally carried with the current is deposited before the dam. This sediment buildup in the Batang Padang Catchments is drastically affecting storage. At the dam’s commissioning in 1963, the live storage was 4.7 m3, by 1999 this was reduced to 1.4m3. Sediment buildup can have disastrous effects including increased risks for flooding, dam failure, and decreased in energy production (Luis et al. 2013). All of which affect rural communities in the region, as well as downstream towns and cities. Studies like “Probable Maximum Precipitation (PMP) over mountainous region of Cameron Highlands- Batang Padang Catchment of Malaysia” are crucial in looking at the adequacy of spillway capacities with high levels of rainfall. Climate change modeling in Monsoon regions predicts the Asian Monsoon having an earlier onset and longer duration, meaning more runoff into rivers and into dam storage (Zhang 2012). Changes to the monsoon season will also affects how water behaves during the dry season. Both of these situated contexts are examples of human-driven land use change stimulated by industrialization and intensification of agriculture. Increasing the amount of infrastructure on a river, whether for irrigation or energy, can have many positive as well as negative outcomes both upstream and downstream. Looking at the oversights and shortcomings of older infrastructure, it is clear that careful consideration of all actors and hydrologic processes must be taken into account before river flow management occurs.
- Descriptive: What hydraulic infrastructure is currently being used, both upstream and downstream, on major rivers in monsoon regions and what plans are there for future river management? What contemporary debates are there surrounding surface water manipulation and who is involved in these debates?
- Explanatory: How does the monsoon season affect hydrologic processes? How do these changes in the hydrologic cycle affect infrastructure like dams, canals, and irrigation infrastructure?
- Evaluative: How can surface water manipulation like dams, canals, and diverging water for irrigation, benefit or cost a region? Are there adverse effects to increased management?