Global Change and Sanitation of Freshwater

The intention of this blog is to illustrate what the impacts of climate change on the hydrological cycle above the ground and their wider implications in terms of sanitation are as well as the impacts on groundwater. Climate change is deemed as having the ability to change every aspect of people's lives as well as the whole biophysical systems (Amanambu et al., 2020). But there is a global consensus now that the global climate is changing (Amanambu et al., 2020).

According to the picture below, higher evaporation, higher transpiration, less snow, and higher temperature all show signs of change in face of climate change. Indeed, in most of the academic literatures on climate change, this intensification of hydrological cycle have been noted (Creed et al., 2005), evidenced by higher temperatures driving higher evaporation and evapotranspiration, increase in precipitation and its variability (Burke and Stott, 2017), less amount of snow (Wang et al., 2015). 

Fig 1: Changes in precipitation, evaporation, transpirtion in the face of climate change

With the changes in global climate, there might be an increase in the rate of diarrheal diseases (Kolstad and Johannson, 2011). According to Carlton et al. (2015), the relationship between diarrhea caused by bacterial infections and increased temperatures is positive. However, there is a significant variation between regions, with the most serious infections taking place at tropical regions (Howard et al., 2011). In addition, WHO estimates that 48,000 diarrheal deaths would be caused in 2030 due to climate change (2014).

Moreover, the increase in temperatures would also result in significant precipitation patterns (2014), with more frequent and intense rainfall taking place in some areas then other, causing flood events (2002). Under the case of flooding, there would be no sanitation resulting in severe contamination of drinking water supplies, both those above the ground and groundwater (Cann et al., 2013). Alderman et al. (2012) found that disease epidemics are more likely to occur when there is a mass population migration caused by flooding and there was abundant evidence to show that water-related diseases surged after the flood. 

On the other hand, groundwater plays a vital role in biophysical sustainment and ensure human adaptation in times of unexpected global climate changes, especially in the current case of surface water stress in the face of increasing population and competing water uses (Amanambu et al., 2020). It is estimated that there are 1.386 billion cubic kilometres of water present on the Earth, where 97% of it is found in the ocean, with the remaining 3% found as fresh water. Most of the fresh water is present in the forms of ice and snow, while the last 30% exists as groundwater (Gleick, 1993). In this sense, we can interpret the importance of groundwater to people's lives, and ecosystem sustainment. 

With the incidence of a flood event, the groundwater supplies would be contaminated by the downward movement of faecal matter and chemical compounds (Dragoni and Sukhija, 2008). This phenomenon is most obvious in semi-arid areas where high evaporation is observed resulting in the sedimentation of salt and hence salinisation of shallow aquifers (Bighash and Murgulet, 2015). 

In conclusion, this blog focuses on the impacts brought about by climate change on the quality of surface waters and groundwater. In both cases, it is observed that the consequent changes in hydrological cycles from climate change would lead to contamination of surface waters as well as the aquifer, resulting in more diseases and deaths. 

Last but not the least, there are only two days left till the world's toilet day! It would be deeply appreciated if you could give some help to the fund-raising activity for Africa's sanitation facility construction!