The role of citizen science in hydrology: a review of the lack of hydrological data

From the last post, I brought up the idea that citizen science helps empower local communities in through their participation in data collection. What I did not mention was mobilising non-experts in the field of hydrology helps battle against the dearth of data on water resources ever since the 1970s, especially in the developing countries. Tanzania, according to the map producing by Wold Meteorological Organisation (WMO) (Figure 1), only have 1-50% of reporting rates. Additionally, the density of stations are clearly much sparse in comparison to those in Europe. This shows the importance of community monitoring schemes in Tanzania.

Areas with little data available often are the ones that suffer from poor management. With more data to better assessment the current hydrological conditions and project future scenarios, these areas will have the greatest potential for improvement through better mitigation and adaptation schemes (Walker et al 2016). Although there are data available from General Circulation Model (GCM), Regional Circulation Model (RCM) and reanaylsis rainfall product, the quality of the data is often hampered by the lack of observational data and thus modelling results suffer from inaccuracy and greater uncertainty (Symeonakiset al., 2009). Through community-monitoring schemes, it is possible to make up for the lack of formally measured data and provide a cheap but valuable source of hydrological time series data.

The lack of sub-Saharan Africa (SSA) hydrological data

In terms of rainfall, according to Washington et al (2006), on average there is only one met station every 26000km2. The density will need to increase by 8-fold to reach the WMO’s minimum recommendation. Many other studies (Pitman 2011; Washington et al., 2004) also pointed out that precipitation data had suffered greatly from the decreasing investment in the maintenance of weather stations. With the lack of maintenance, the number and density of rain gauges decreased quickly after 1970 (Willmott et al., 1994).

In terms of river discharge, only 2/5 of the river gauging stations around the world are functioning after 2003 (Tourian et al 2013) and this is due to the sharp decline in functioning river gauging stations is SSA (Walker et al 2016). Many experts believe that there is a dire need to better maintain and build more river gauging stations (Owor et al., 2009; Taylor et al., 2009).

For data on groundwater and hydrogeology, the situation is slightly different in the sense that there is no such sharp decline in data volume as there has been little historical observation in the first place! The understandings of aquifer and recharge mechanisms are often overlooked but are of significant importance for agricultural sectors in Africa in the future, especially under climate change where precipitation become more intense and uncertain (MacDonald et al 2012). 

Most existing data came from deep abstraction boreholes rather than the hand dug wells that are used daily by people in rural areas. More information and consistent time series data on the shallow hydrogeology, aquifer characteristics, recharge rates, flow regime and water quality of SSA is needed.

Given the current situation, we are indeed in need of greater hydrological data collection and one way to achieve this is through community monitoring schemes. However, as with any other form of citizen science, their validity is often called into question. Next week, I will discuss whether hydrological data collected by non-experts are useful in water resource assessment and management.