Climate change impacts on the Wabash watershed in Indiana

Wabash Watershed and Global Warming

Global warming is the gradual increase in the average temperatures of Earth caused by an increase in Greenhouse Gases (GHG) in Earth's atmosphere. An unprecedented increase in GHG has induced the warming up of Earth. Since global warming impacts entire biosphere and ecosystems, watersheds are also distorted through warming of climate. The paper defines watersheds, their role in ecosystem, and explanation of changes that have taken place in Wabash watershed. Wabash watershed is composed of smaller watersheds such as Upper Wabash Watershed, Lower Wabash, Little Wabash Watershed, Middle Wabash-Busseron, and Middle Wabash-Little Vermilion Watershed. Human agency has caused the global warming to increase over a period of last two decades, though its signs are obvious much before that. Increases in average lower temperatures, precipitation, and stream runoff are some evident outcomes of global warming. Wildlife, water resources, agriculture, and human health will have an adverse impact in Wabash watershed area due the climatic warming phenomenon.

Introduction

The unprecedented increase in human population and resulting economic activity has taken place at the cost of unsustainable use of natural resources. Water is one such natural resource that has been impacted by this activity. A watershed is such basin like geographical area in which all water, whether under it or flowing above, is drained to same low-lying area. In fact watersheds range from largest to smallest of sizes. Wesley Powell defines watershed a 'bounded hydrologic system' in which all species, humans as well as animals, are make one community based on water source. Watersheds do not have definitive shape or size, they cross cities, states, and even national boundaries. Wabash watershed is also one of the largest watersheds of State of Indiana whereby the watershed covers the cities of Muncie, Bloomington, Lafayette, Wabash valley, Anderson and Terre Haute. Wabash River is the main tributary in which the water of Wabash watershed flows, that in turn drains into the Ohio River.

Recreation, wildlife maintenance, and natural resources availability are all dependent on areas that form the watersheds (Gregersen, Ffolliott & Brookes, 2008). The essay is composed of five parts including the introduction. Part II will describe the watersheds and their relationship with our ecosystem. Evidence of global warming and resulting impact on watersheds will be highlighted in section II. Section III will highlight the Wabash watershed area with respect to change in biosphere of area. Evapotranspiration, surplus/deficit conditions and runoff/stream flow will also be highlighted. Section IV will describe the role human agency plays in distorting the environment. This section also highlights the potential impact of global warming in Wabash area with a succinct discussion on improvement measures being initiated. The report will conclude by stating the implications of study and reporting the lessons learned.

Watersheds and relationship with Global warming

In order to maintain the effectiveness of our natural ecosystems, plentiful drinking as well as agricultural water is made available through watersheds. In total Wabash watershed is composed of following smaller watersheds. Upper Wabash Watershed, Lower Wabash, Little Wabash Watershed, Middle Wabash-Busseron, and Middle Wabash-Little Vermilion Watershed. Since human use of land and water impacts the way that watersheds holds and disseminate the water, the issue of managing watersheds has come in limelight due to the phenomenon of 'global warming'. Excessive erosion due to de-forestations, un-sustainable water use, water pollution, and increase in downstream sedimentation has caused irreparable damage to watersheds. The gradual warming of climate, with rise in average temperatures of Earth is known as global warming. Stream discharge is main feature of watersheds that impacts all the downstream populations. Global warming causes increase in stream discharge, thus making the watersheds become detrimental to ecosystem itself during the rainy season (McCabe & Wolock, 1999). The Intergovernmental Panel on Climate change presented its fourth assessment report in which it was conceded that 0.74 "C increase in global average temperature had been recorded in period during past 100 years. The ice cover in great lakes of Midwestern region, of which Wabash watershed is part of, is observed to have got uncovered since 1970 to 2010 from being 90% to 50% respectively.

Run off and annual temperatures increase

The data of annual average temperatures in the Wabash Valley indicate that there is an increase in the temperature since 1980. From being 61.5°F in 1980, the temperature has got raised to 63.5°F, a net increase of 2°F over a period of 10 years. The annual runoff in the area also represents an increase from 12 inches in 1963 to 17 inches in 1984. The last reported year 1991 had 22 inches of annual runoff in the area whereas in 1987 it was only approximately 5 inches. This abrupt but gradually increasing runoff will result in increased stream discharge. Early snow melting is also an outcome of increase in average annual temperatures, both lower and higher end temperatures. Westerling, Hidalgo, Cayan & Swetnam (2006) conducted an investigation regarding wildfires in the Western part of the U.S. And concluded that rather than land use, the wildfires were associated to early snow melting and increased temperatures in summers and spring. The climatic changes have induced the natural catastrophes in many regions of the world. Flash floods in Queensland in Australia as well as in Brazil and China in recent years have raised the issue on a worldwide scale. The U.S. is not the only causality of such unprecedented change in climate. More temperatures in summer coupled with less precipitation in summer is an anticipated outcome in years to come, those around 2050-2080 (Karl, Melillo and Peterson, 2009).

The accelerated cycle of precipitation and runoff will result in an increased flow into the oceans of the world. The global warming will as well induce the glacial melting and combination of both these factors will result in increasing the level of oceans. It has also been reported by some researchers that 18% more water was fed into oceans in 2006 as compared to 1994 due to the fast melting of polar ice and increased river flow in oceans. On an annual basis, the increment of ocean water is reported to be at 1.5%. Increased disparity in different regions with respect to the amount of rainfall that is received is also a main issue in the problem caused by global warming and unsustainable use of water. The increase in precipitation is more in tropical regions that already have adequate water reserves in form of rivers, lakes, and sea. On the other hand, the regions with less water supply are having increased number of droughts. Ths, as a result a vicious circle of flash floods and droughts have already been observed in many regions of the world. The evaporation-precipitation cycle has got intensified over the period of last few decades and is likely to remain same in the years to come. The fresh water from watersheds and other water reservoirs such as lakes, rivers and oceans is evaporated fast to cause more rainfall in short periods of time. Thicker clouds are formed due to fast evaporation process which results in heavier downpour as the cycle matures. The total water flowing from continents into the oceans is now being recorded by latest technology employed by NASA and European observatories rather than isolated scientists doing the research. The precipitation and evaporation record of Midwestern regions of the U.S. displays that increased water went into the oceans and more snow got melted in early spring as compared to the previous years.

Human agency and environment

Humans make choices for their survival as well as creating a more plentiful world for themselves. This includes an increased and unsustainable use of natural as well as manmade resources. Human agency has impact on vegetation, soil, animals, and environment around us. Forests and naturally occurring vegetation is the first causality of human agency. While not replacing the impacted forests with equal vegetation, the large forest lands are turned into barren lands. Grazing has been restricted due to industrial economies and production of all commodities in very large quantities. The human agency on water system of the world is most evident in the degradation of major watersheds of which Wabash watershed is a small instance. The deliberate modification of rivers, building of concrete dams, riverside embankments, and water channel modifications, all are a few examples of human intervention that have caused distortion in the ecosystem (Goudie, 2005). Water channel modification to increase the flow of water is a double edged sword, firstly it disrupts fauna development, and secondly it expedites water flow in flood seasons.

Conclusion

The human intervention could not have been avoided during the long course of history of mankind as man is bound to interact with its environment. However, this interaction and agency could have been more sustained. The people of Wabash watershed may experience adverse impact of global warming in the years to come. The potential impact of such warming of temperatures and associated climatic changes will increase human health issues, negatively impact the water resources, and adversely affect the agricultural and related ecosystem. Heat related deaths, pollution and worsening of air quality, increase in ticks and mosquitos are least negative impact and result in diseases such as West Nile virus. Reduced availability of water in summers, increase in flood related damage, and heavy downpour are the obvious results of life long human agency. Seemingly, the global warming is empirically verified and evidently causing serious impacts on Wabash area. Though, it is not possible to reverse the impact human have created, however it is appropriate to exercise restraint in human activity that adversely effects the ecosystem, specifically the watersheds throughout Midwestern regions. Public health as well as the quality of life in cities of Midwestern states will get affected due to global warming. Three heat waves are estimated to take place each year in the region. Such statistics will have potential implications on governments and people upon the way they conduct activity in cities and rural areas. Though governments have started taking the issue more holistically, a significant modification in human agency pattern is not expected immediately. The research will interest more effort to be put in gauging the impact that distortion of watersheds in Wabash has created.