5 th AGILE Conference on Geographical Information Science, Palma (Balearic Islands, Spain) April 25 th- 27th 2002
The Concept and Implementation of the Monitoring Networks for Surface Waters: A Case Study of Estonia Antti Roose Institute of Geography, University of Tartu Ülikooli 18, 50090 Tartu, Estonia e-mail:
[email protected] Abstract. The implementation and enforcement of European Community Directives in the field water policy requires complete monitoring programme, preliminary investigations and surveys. The national implementation will vary from county to country, in particular in the accession states. In Estonia, the concept of monitoring is developed to provide a sufficient number and plausible distribution of stations. The network of monitoring is designed depending on international or trans-boundary obligations and on the degree of the present national coverage. The task of ensuring good status of surface waters requires additional set of sites in the sensitive areas on the local level. 60 monitoring points of rivers, 25 rivers of biological monitoring, 30 points in the large lakes and 26 points in the small lakes are selected for the monitoring programme to achieve adequate classification of water bodies consistent with the normative definitions. Indicator mapping gives the efficient output for the dissemination.
Introduction The requirements of EC directives set new standards for environmental monitoring. On the other hand, standard procedures, routines and stability should be kept at the appropriate level to serve time series approach for the interregnum. In essence, the monitoring network can be optimised in both spatial and temporal scales. Appropriate data density and quality, efficient sampling strategies, rotational principle of monitoring activities are challenging for many projects in the monitoring programme. Monitoring does not have to be observation per se, but certainly it carries purpose of describing the ecological status of the water body, dissemination of information for water management and raising environmental awareness for public. Following these objectives, integration of different monitoring environments and methodologies in different scales and sampling frequencies could create knowledge surplus and the substantial increase of efficiency in the information management, avoiding overload and enormous quantities of low quality data. The evaluation requires the synthesis of local spatio-temporal variability and modelling of controls and responses, causes and effects. For the purpose of management, monitoring is a about making a decision on available evidence and with a cost structure for errors rather than in demonstration of an impact in a very conclusive and comprehensive manner. Initial analyses do not address uncertainty issues.
Still, misconceptions surround the use of spatial analysis in the environmental studies, including monitoring, and there is a need to understand local variations in more complex relationships. The risk of violating the characteristic scales of disturbance and resistance increases using powerful tools of data handling and analysis. The present paper describes the spatial concept of monitoring objectives and network planning, based on the Estonian case. The approach is advocated, how sensitive monitoring might be to selection of network and of sampling strategy, which refers to the spatial extent and temporal frequency over which the monitoring is conducted.
Implementation of monitoring network The national authorities assisted by academic institutions and expert groups are to develop a proposal on the legal and technical implementation of the water quality objectives and monitoring in surface waters in accordance with the Directives of the European Union. Comprehensive changes are required in the water management and monitoring, new quality standards are set up. The plan requires the preparation of a concept for the monitoring of the quality of surface waters. Several topical and methodological issues are included in the discussion: hydrochemistry, hydrobiology, operational activities, all of them having the strong spatial focus. The discussed subject requires to harmonise the Community legislation, in particular the provisions of Council Decision 77/795/EEC (exchange of information), Council Directive 76/464/EEC (dangerous substances) and their daughter directives, Council Directive 91/271/EEC, completed 98/15/EEC (urban waste water treatment), Council Directive 91/676/EEC (nitrates), Council Directive 76/160/EEC, (Bathing Water), Council Directive 75/440/EEC (surface waters for drinking water abstraction), Council Directive 78/659/EEC (freshwater fish).
1
5 th AGILE Conference on Geographical Information Science, Palma (Balearic Islands, Spain) April 25 th- 27th 2002
Estonia began accession negotiations with the European Union in 1998, the environmental negotiation chapter has been provisionally closed in June. Based on the conclusions of the screening and negotiations, Estonia is prepared to adopt and to implement the acquis with respect to the environment in full on the date of accession, with the exception of the some country-specific items. Among other tasks the implementation of nitrogen compounds vulnerable zones action programme, monitoring of discharge of dangerous substances into surface water and enforcing of adequate groundwater protection measures are most capacious areas of the European harmonization in Estonia. While the actual models and up-to-date reporting depend upon data availability, monitoring as a strategic instrument is to be designed and adjusted to satisfy public need for effective, appropriate environmental action. The structure of the monitoring of the surface waters includes four sub-programmes: the chemical monitoring of rivers, the biological monitoring of rivers, monitoring of big lakes and monitoring of small lakes. The projectbased approach serves as the methodological framework. As the initial criteria for the survey of waters, a threshold value for river basin is 10 km² and for the lake 0.5 km². According to the Acquis Estonia shall ensure the establishment of monitoring programmes in order to establish a coherent and comprehensive overview of water status within each of nine adopted River Basin Districts in Estonia. Monitoring programmes for surface waters covers the volume and level or rate of flow and survey of the ecological status and the chemical status, but it has to be elaborated for the ecological potential. General requirements on the monitoring network distribute the network as the surveillance set and an operational set. In addition, there is also need to establish a programme of investigative monitoring to survey basins of uncertain impact in more detail or due to the accident pollution. The present national monitoring network for the surface waters is laid down in the Estonian Water Act as amended in 2001. The surveillance monitoring and operational monitoring of the water status should be carried out on the basis of an appropriately modified national monitoring network adopted by the Monitoring Council of the Ministry of Environment. Monitoring points on surface waters are divided into 3 categories from a legal and institutional point of view: 1. National monitoring set: representative and reference points, including also transboundary monitoring points by international agreement. 2. Local monitoring set, indicating the anthropogenic pressure. 3. Company set, indicating the pollution loads. According to the EUROWATERNET 60 national river points are distributed into four categories: background (9), representative (51), force (32) and impact (12). The efficiency of selection is indicated by the multifunctionality of points. The aim is that modified monitoring network would provide for a sufficient number, and plausible distribution, of points to monitor surface water bodies, in total 1.3 stations per 1000 km2 . The network of national monitoring points is presented in the attached map as Figure 1. In addition, the monitoring network of above listed Directives is given as Figure 2.
Figure 1. Estonian National Monitoring Network of Surface Waters
2
5 th AGILE Conference on Geographical Information Science, Palma (Balearic Islands, Spain) April 25 th- 27th 2002
The surveillance monitoring network According the framework, the surveillance monitoring network will comprise national monitoring points as these reflect the long-term changes, in addition supplemented by information on human impacts. The surveillance set establishes the basis for the operational monitoring programme, which is partly carried out by local authorities and companies.
Figure 2. Monitoring Network - Accession Requirements according to EU Directives and National Environmental Chapter of Adoptation of the Acquis The framework criteria adopted by the national legislation requires additional 14 points, altogether 40 for surveillance monitoring. Secondly, all monitoring points determined under the Information Exchange Decision 77/795/EEC and the requirements of the European Environmental Agency. Monitoring points for trans-boundary water bodies were selected in Lake Peipsi, in the Narva River and in the Latvian borders (Convention of the protection and use of trans-boundary watercourses and international lakes (1992), Convention of environmental impact assessment in a cross-border context (1991), Convention of cross-border effect of industrial accidents (1992)). Monitoring points for trans-boundary water bodies of smaller sub-basins were selected in case of mining area along the Russian border. The monitoring points were established on the bigger tributaries and in critical sub-basins. The Estonian islands are not appropriately represented in the network.
Another question is about the frequency of monitoring (Sheppard, Charles 1999). Principally, frequencies shall be chosen so as to achieve an acceptable level of confidence and precision. As a rule, it means testing 12 times per year. Several minor rivers are tested bimonthly. According to the EUROWATERNET monitoring programme for small lakes is supplemented by 18 lakes in comparison with existing network. The criteria of selection is the following: a) reference areas, b) lakes and water reservoirs near settlements, c) more wide geographical distribution, d) in case insufficient investigation (halotrophic and water reservoirs).
The operational monitoring network The monitoring network for operational monitoring shall be designed on the basis of the results of surveillance monitoring. Monitoring points on water bodies at risk from significant point source pressures is the first priority. Secondly, to assess the impact of these pressures as a whole the pollution clusters are subject to monitor. Third, monitoring points on water bodies at risk from significant diffuse point source pressures need to be considered. The selection and application of these monitoring points depends on comprehensive investigation and on river basin management plans.
3
5 th AGILE Conference on Geographical Information Science, Palma (Balearic Islands, Spain) April 25 th- 27th 2002
Sensitivity analysis Sensitivity analysis as applied here is a structured framework for evaluating environmental monitoring network against multiple criteria. This study defines the spatial sensitivity of monitoring network by categories and sites, exploring how effective and informative is monitoring network. Set of indicator variables is chosen for water monitoring. Data is examined in order to select: •
optimal points to monitor
•
optimal indicators to monitor
•
optimal frequency and seasonal distribution for sampling
•
testable hypothesis and statistical methods
The identification of system change due to an impact consists of two phases: detecting a significant change and identifying the change if any with the putative cause. The development of new network requires spatial analysis of selected monitoring data, which demonstrates perturbation in various magnitudes of impacts. Assessment requires the calculation of the magnitudes of changes. The method of testing for differences for this study was ttest and analysis of variance (ANOVA), taken p < 0.05. Time series were decomposed into a year-to-year variation. The test was carried out by means of a qualitative assessment based on a spatial analysis. Special attention was paid to the comparable density and location of local monitoring points for the distribution of monitoring points within hydrographic sub-basins with similar structures of distortion from human activity. Indicator mapping In this application, the paper focuses on assessment of water quality, river monitoring is selected for sensitivity analysis. The surface-water-quality assessment sub-programme is designed to describe the status and trends in the surface water resources and to provide a understanding of the natural and human factors that affect the quality of resources. Sampling is conducted in 60 important rivers. The most powerful layers, or indicative variables are identified and pre-selected by spatial variability. This quality standard includes only the physicchemical and a few planctic quality indicators of the water. Three indicators, biological oxygen demand (BOD7 ), total nitrogen (TN) and total phosphorus (TP) are included at the river monitoring in this study (Table 1). The indexation of rivers and lakes based on new standards uses spatial modelling techniques (Figure 3). Table 1. Number of rivers according to the quality standards. Indicator
I class J
II class J
III class J
IV class K
V class L
BOD7
Excellent 46
Good 12
Satisfactory 1
Bad 0
Very bad 0
TN
22
17
10
3
5
TP
17
21
12
5
4
4
5 th AGILE Conference on Geographical Information Science, Palma (Balearic Islands, Spain) April 25 th- 27th 2002
Figure 3. Classification of the Water Status by Total Nitrogen in 2000 The rationale for such case study is for purposes of setting monitoring network. The combination of surveillance monitoring and operational monitoring in a course of national network is proposed. The specific requirements are laid by the Directives for the urban waste water treatment, abstraction of drinking water from bodies of surface waters and bathing waters and vulnerable zones (Figure 2). This may create overlapping and further spatial analysis using overlay, distance and proximity functions. It is far better to consider the coverage of stations across an entire territory than to select sites based solely on individual merit. As the Water Framework Directive focuses on effect of human pressures the monitoring stations should be located near to important pollution areas, such as larger cities and outlets of larger catchments. A serious limitation of the implementation and achieving good quality is the fixed point distribution of test sites. Adequately, the approach of the hierarchical structures and continuous surveying needs to be applied in the monitoring of water systems.
References Council Decision 77/795/EEC of 12 December 1977 establishing a common procedure for the exchange of information on the quality of surface fresh water in the Community. Council Directive 76/464/EEC of 4 May 1976 on pollution caused by certain dangerous substances discharged into the aquatic environment of the Community. Directive of the European Parliament and of the European Council 2000/60/EC establishing a framework for Community action in the field of water policy. Sheppard, Charles R. C, 1999. How Large should my Sample be? Some quick guides to sample size and the power of tests. In: Marine Pollution Bulletin Vol. 38, 6. pp 439-447.
5
