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Climate Impacts On Water Quality And Ecosystem Environmental Sciences

Essay add: 14-11-2017, 10:46   /   Views: 1

Potential impacts of climate change on water quality and ecosystem, as a newly emerged issue and challenge, is of great concern by scientists. Climate change can alter water temperature and hydrological regimes and thus influence the water quality and ecosystem. In addition, it has also been recognized that water quality and ecosystem can be significantly impacted by climate change under the condition of human activities. However, scientific researches and practices are still facing big challenges in these issues because of their complexity and uncertainty. This paper reviews some recent studies on this topic, and then illustrates about some water management strategies. The objective of present study is expected to give directions for future relevant researches.

Nowadays, more and more scientists increasingly get attention to "greenhouse" effect. It has influenced freshwater globally, which due to the CO2 are emitted continuously to the atmosphere (Lenihan et al. 2008). Further, global climate change is likely to have significant effects on the hydrological cycle globally as well. The hydrological cycle will be strengthened, with more evaporation and more precipitation. Meanwhile, some studies have showed that due to the precipitation will be distributed around the globe unequally, some parts of the world may see significant reductions in precipitation (Arnell 1999). Moreover, climate change can have far reaching consequences for water resources, water quality, and ecosystem (Arnell 2003, Hejzlar et al. 2003, Webb et al. 2003, Hiscock et al. 2004, Moss et al. 2003, Sommer et al. 2004, Wilby et al. 2006). Strong relationship of climate-water quality was found between air and water temperature and nutrient concentration. The precipitation also appeared to exert a significant influence on water quality, which is less direct than influence of air temperature. Changes in water quality are also subject to storms, snowmelt, and periods of elevated air temperature or drought effects, which may exceed the thresholds of ecosystem tolerance, and thus lead to aquatic ecosystem degradation. In addition to ecosystem degradation, continued climate stress would also lead to chronic water quality changes (Murdoch and Baron 2000).

Although, climate change impacts on water availability and hydrological risks have been studied, the consequences on water quality and ecosystem are just beginning to be studied (Delpla et al. 2009). Moreover, climate change is increasingly recognized as an important factor, influencing water quality and the structural properties of aquatic ecosystems (Law et al. 2009). However, the impact mechanisms of climate change on water quality and ecosystem are still not fully understood. While, to solve the impact of climate change on the water resource, water quality, and freshwater ecosystem, the water resources management are the key challenges. The present paper provides a review of potential impacts of climate change on water quality and ecosystem, mainly including the overview of global researches on this issue, based on studying previous studies, which have been studied about climate change impact on water quality and ecosystem, to illustrate the way how to manage the water resource and what will be done in the future study.

Potential climate change impacts on water quality and ecosystem

As above mentioned, the impacts of climate change on hydrology have been studied broadly (Middelkoop et al. 2001). However, the focus of past studies has been on water quantity influences (flooding and droughts) rather than on changes in water quality. Nowadays, the potential influences of climate change on surface water quality and ecosystem have been acknowledged increasingly (Murdoch and Baron 2000, Whitehead et al. 2009). Kundzewicz et al. (2007) pointed out in his paper that the IPCC Fourth Assessment Report was just beginning to consider the impacts of climate change on water quality, but still not in great detail. Moreover, the EU Euro-limpacs Project, for example, is investigating the impacts on water quality and ecosystem of rivers, lakes and wetlands across Europe (Battarbee et al. 2008).

Some previous studies have indicated that water quality can be directly affected through several climate related mechanisms on both short and long term (Park et al. 2009). These include impacts of air temperature increase, as well as changes in hydrological factors, such as precipitation change on hydrology (Murdoch and Baron 2000, Muttiah and Wurbs 2002). Muttiah and Wurbs (2002), for example, found that average temperature and precipitation in the USA both increased during the 20th century, mostly due to an increase in intense rainstorms. In addition, due to water temperature are in close equilibrium with air temperature, air temperature is a key variable affecting water temperature in most biological systems, strongly influencing water chemistry, and biochemical reactions (Blenckner et al. 2007, Malmaeusa et al. 2006). There is another example, Tibby and Tiller (2007) analyzed over 15 year of water quality monitoring data from three lakes from Western Victoria, Australia, and their relationship with climate change. They found that there are strong relationship between climate change and water quality in these lakes of varied size and salinity. All of these just suggest one thing that water quality changes caused by any climate change will have ecological and socio-economic impacts that may affect the management of water resources eventually.

Besides, the extreme events, such as floods and droughts, also may modify water quality through direct impacts of dilution or concentration of dissolved substances. More intense rainfall and flooding could result in increased loads of suspended solids and contaminant fluxes associated with soil erosion and sediment transport from the land (Longfield and Macklin 1999, Lane et al. 2007). Lower flows imply smaller volume for dilution and higher nutrients concentrations which will increase organic pollutant concentrations with increased biological oxygen demand (BOD), and hence lower dissolved oxygen (OD) concentrations in water (Prathumratana et al. 2008). Furthermore, drought-rewet cycles may also impact water quality as is enhances decomposition and flushing of organic matter into water (Evans et al. 2005).

Here, as above mentioned, the impacts of climate change on water quality and ecosystem are getting more attention. However, there are still some issues need to be improved in the future. The key problem is still a lack of information about the impacts of climate change on water quality and ecosystem, and most adaptations proposed before are idealistic or impracticable. At present, the alternative way that thinking about the management of water quality and ecosystem might be a better way to reduce the impact of climate change.

Water quality and ecosystem management

Despite it is a fact and inevitable that climate change can change water quality and ecosystem significantly, human activities is no doubt contributing much more impacts than climate changes (Moore et al. 1997, Xia and Zhang 2008). Thus, the positive management may minimize some climate-change impacts on aquatic ecosystems. In order to deal with the climate changes that is happening now and to ready for those are likely to happen in the future. The water quality and ecosystem management plan is required to implement. Specific and practical management options also should be chosen for different regions.

To avoid adverse impacts of climate change on aquatic ecosystems, the adaptive water management should be taken into account simultaneously (Pahl-Wostl 2007). In many areas the available water is polluted and hence connot be used for many purposes or requires expensive treatment. Therefore, the most important and well known method to protect aquatic ecosystems is to reduce contaminant levels (Xie et al. 2004). Thus, the pollution sources should be restricted strongly. Adaptation options should also improve the ability to moderate, deal with and take advantage of the consequences of climate change (Pahl-Wostl 2007). Moreover, because of uncertainty of future climate variability, management strategies should be built in flexibility to ensure that current strategies are consistent with future climate monitoring (Pahl-Wostl 2007). Besides, relevant education and training can raise awareness and encourage more people to pay attention to this issue, which will enhance the adaptability regarding about climate change.

Conclusion

It is proved that water quality and ecosystem can be impacted significantly by climate change. However, scientific works on this issue are very limited. More and deeper researches and practices should be conducted in the near future.

For future studies, long-term monitoring in different regions is still required. More efforts should be taken to separate the impacts of climate change from human activities, although it is complicated. While, to get a better understanding of the issue, it is suggested to give more information about the alteration mechanisms of hydrological regimes by climate change. Finally, specific and practical adaptive management should be proposed to decision-makers.

Article name: Climate Impacts On Water Quality And Ecosystem Environmental Sciences essay, research paper, dissertation