Richard Gosling [Dingwall, UK]
Richard Morris
Scottish Environment Protection Agency (SEPA)1
R. D. Gosling
1 richard.gosling@sepa.org.uk. Scottish Environment Protection Agency. Graesser House, Fodderty Way, Dingwall, IV15 9XB. ++44 1349 860393
2 richard.morris@sepa.org.uk. Scottish Environment Protection Agency. Clearwater House, Heriot-Watt Research Park, Edinburgh, EH14 4AP. ++44 131 449 7296
Introduction
In the European context, Scotland has an abundant water resource, with high rainfall and low evapotranspirative losses resulting in a reliable supply of high quality raw water. For key water resource users, such as the hydropower and public water supply sectors, the combination of ample water resource allied to high topographic gradient is beneficial and, as such, the more mountainous regions of the Scottish Highlands and Islands have attracted development recently. Indeed, in the last decade, there has been a large expansion in the development of small to medium size (<1 MW) run-of-river hydropower schemes with attractive subsidies available for the generation of renewable energy to assist Scotland's aim of reducing carbon emissions by 42% of 1990 levels by 2020. At the same time, Scotland's public water supplier, Scottish Water, is undertaking a large investment programme to improve resilience of supply and ensure future compliance with environmental regulations. However, in many of the highland and island regions in Scotland where water resource development is attractive or improvements are required, water resource assessment is a challenge due to large hydrometerological variability and, typically, lower flow and rain gauge density within the monitoring network. In turn, decision-making on potentially costly improvements to water supply resilience, hydropower development and environmental flow provision can be vulnerable to a lack of confidence in the evidence base.
In order to meet the requirements of both the European Union's Water Framework (European Commission 2000) and Floods (European Commission 2007) Directives, the Scottish Environment Protection Agency has developed its hydrometric network over the last decade to attempt to address issues of network coverage in regions where, historically, the drivers for monitoring did not exist. At the same time, a programme of rationalistion has been undertaken to minimise monitoring effort at sites where added information value has been deemed to be low.
Methods
This paper presents a novel method for evaluating the information held within the existing hydrometric archive to support water resource assessments using a multiple index approach. Network density, catchment typology, hydrometric quality and data demand are used as factors to evaluate information value. In addition, cross-correlation of time series data between sites across the network is used to evaluate the degree of independence of site data sets.
Results and Discussion
The analysis is used to consider how changes in legislative drivers such as the Water Framework Directive and the Climate Change (Scotland) Act (Scottish Parliament 2009) have changed the nature of the demand for data from the hydrometric network. An evaluation is made on the impact of the recent network development upon the water resource evidence base in areas of high demand for flow information to determine whether these changes in demand have been addressed.
Conclusion
By evaluating the increase in information of a number of scenarios to address gaps in evidence, it is demonstrated that this approach can support the network development decision-making process for current data demand and assist in providing some resilience to changing drivers in the future.
1. European Commission (2000). Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. European Commission. Brussels, Luxembourg.
2. European Commission (2007). Directive 2007/60/EC of the European Parliament and of the Council of 23 October 2007 on the assessment and management of flood risks. European Commission. Brussels, Luxembourg
3. Scottish Parliament (2009). Climate Change (Scotland) Act 2009 (asp12). Scottish Parliament. Edinburgh