MATHEMATICAL
BALANCE
MODELS FOR MONITORING
T H E S T A T E OF L A K E B A I K A L YU. A. A N O K H I N Natural Environment and Climate Monitoring Laboratory, USSR State Committee f o r Hydrometeorology and Control o f Natural Environment, USSR Academy o f Sciences
Abstract. The global cycles of man-produced pollutants entering the natural environment are reflected
in changes of pollutant cycles, even in background regions. The system of mathematical balance simulation models of inorganic pollutant distribution and circulation (some heavy metals and pesticides included in the priority list for integrated background monitoring) has been developed for the Lake Baikal drainage basin. The system consists of the following units: (1) inventory and classification of regional sources of pollutants entering the atmosphere, natural waters and soils; (2)computation of the global atmospheric transfer and depositions; (3)regional spreading with atmospheric fluxes and deposition onto the underlying surfaces; (4)transport with waterflows feeding Lake Baikal; (5) transport with the lake currents and balance in the lake. The models developed have enabled improvement of existing programmes and systems of observations, in particular to substantiate the large-scale snow sampling and analysis network, and to develop the programme of integrated surveys of the state of Lake Baikal. Since 1981 these actions have been included in the operational network observations within the Lake Baikal Monitoring System.
1. Introduction
Analysis of observation data of the environment in the Lake Baikal basin [1, 12, 15] over many years has allowed us to conclude that the pollutant levels in cis-Baikal environmental compartments are extremely low and characterize the global background pollution of the biosphere [12, 20]. However, man-made pollutants, such as heavy metals and pesticides, entering the environment as by-products of the world's economic activities, are involved in global cycles which, even in clean regions, may lead either to the origin of new regional cycles (if such substances as DDT are considered) or to a change in the historical pattern of geochemical cycles (in the case of heavy metals). Balance mathematical models are an efficient instrument for studying these phenomena. For the Lake Baikal basin, a system of balance (statistical and simulation) mathematical models [1, 2, 3] of the distribution and circulation of inorganic pollutants, included in the list of priority pollutants for integrated background monitoring, has been developed [12]. These mathematical models make up one of the components of the integrated system of Lake Baikal regional monitoring, which consists [1, 4, 5] of the following subsystems: (1) observations, (2) modelling and data assessment, and (3) prediction of man-induced changes in the environment [3]. One of the basic features of this system is an interactive adjustment of the observations to data processing and analysis for assessing and predicting the state of the environment. Therefore, the system of observations should yield data fit for solving problems of balance compilEnvironmental Monitoring and Assessment 11: 315-325, 1988. 9 1988 Kluwer Academic Publishers. Printed in the Netherlands.
316
Vt;. A, ANOKHIN
ation (assessment and prediction), while the mathematical models used for this purpose largely depend on the operational capabilities of the system of observations. At the same time, these models predetermine the organization and program of observations and the set of data collected. The creation and improvement of the observation system, definition of its structure and functional interactions among its elements, is a complicated, continuous process governed by such factors as the set goals, information consumers, material and financial resources [12]. Elaboration and improvement of the software system (the creation of a set of simulation mathematical models, in particular) is not a simple process, but is being developed with time [5]. The simple but by no means trivial truth is that these processes are closely interconnected. Below, this interconnection is illustrated by the creation and improvement of the systems of observations of the state of Lake Baikal, in particular, of the pollutant content including heavy metals and pesticides in the components of the environment, on the one hand, and required software development - statistical and simulation (dynamic) mathematical models of circulation of these pollutants in the environment - on the other.
2. System of Observations Observations of probable man-induced effects of local, regional and global factors on the ecosystem of Lake Baikal have been developed on the basis of classical ecological-limnological studies by B. I. Dybovsky, A. V. Voznesensky, G. Yu. Vereshchagin and M. M. Kozhov [1, 23]. According to the decisions of the CPSU Central Committee and the USSR Council of Ministers of 1972 and 1987 on the preservation and management of the natural resources of the Lake Baikal basin, the USSR State Committee for Hydrometeorology and Control of Natural Environment (Goskomgidromet) has established a special service of observations, data analysis and evaluation for the control and prediction of the state of Lake Baikal, i.e. a monitoring system [12]. This service operates on the basis of local network subdivisions and institutions of the Goskomgidromet with the participation of the concerned ministries and agencies, and yields regular information on the pollutant levels in surface water, air and precipitation, soils (both in impact and background regions of the Baikal area), and on the state of these environmental compartments. Physical, chemical and hydrobiological (for Lake Baikal and its tributaries) indices being recorded, as well. This information is used by economic, planning and other institutions. Figure 1 schematically shows this system of observations. The hydrochemical, hydrological and hydrobiological regimes of the Lake are monitored along a reference cross-section by 205 stations at 5 strata (including the benthic layer) for 4 different hydrological and hydrobiological characteristics of Lake Baikal. To control the chemical run-off from rivers in the basin, observations of the water composition in their estuarine parts are carried out (Figure 1). At each control site, the water
MATHEMATICAL BALANCE MODELS FOR MONITORING THE STATE OF LAKE BAIKAL
Types
of
317
observations:
- special water surveys in t h e regions of possible anthropo] genic effect
9
- of
water
pollution
- of water and pollution
9
- of
precipitation
- of
soils
- of the snow composition
Fig. 1.
atmosphere
cover
chemical
System of Observations of the chemical state of the environment in the region of Lake Baikal.
quality is defined by indices characterizing the content of oxygen, oxidizable and non-oxidizable organic substances, biogenic elements, mineral and suspended substances, oil products, trace elements (including a number of heavy metals) and pesticides.
318
YU. A. ANOKHIN
Monitoring of the atmospheric input of pollutants into Lake Baikal includes observing the chemical composition of precipitation and dry deposition (Figure 1). The described system is a necessary informational basis for modelling development, complication of balances and prediction of the state of the lake.
3. System of Mathematical Balance Simulation Models Basing on the balance approach and information from the above described system of observations, we have produced a set of models describing the arrival, distribution and circulation of pollutants in the Lake Baikal environment. The principles of modelling, as well as the structure and interconnections between individual models of this system, have been described in [3, 12, 16, 23]. At present, these models are being improved. Note, that not all of them have been elaborated in detail. However, it should be emphasized that the synthesis of the whole system has allowed us to understand better a rather complex model system ('the Lake Baikal Region'), to reveal the weak points of the observation system and to specify the ways and means of improving the regional system of monitoring. One of the most important of the accepted modelling principles is the principle of module (block) construction of the whole system of models when it consists of sectors and subsectors relatively independent and simply combined into a single whole. This enables us to modify individual parts of the system with no essential transformations of other parts. The elaborated system consists of the following modules: (1) inventory (census) of sources of pollutant arrivals in the regional atmosphere (including interregional and global transport), onto the underlying surface, and into the water streams of the Lake Baikal basin. (2) Modules of pollutants spreading with atmospheric fluxes. Estimation of the spatial-temporal pattern of pollutant distribution, estimation of fluxes of pollutant removal from the atmosphere to the underlying surface, including the water area of Lake Baikal, and their distribution over the underlying surface, are based on the data of pollutant sources, on meteorological data on wind field and precipitation. (3) Module of the release of contaminants from the soil (underlying surface) to adjacent water flows, the atmosphere; absorption by biota is possible. (4) Module of the arrival of contaminants at Lake Baikal with river waters. (5) Module of the spatial-temporal pattern of contaminant distribution in Lake Baikal. The data of the source inventory module, the estimates of arrival of pollutants from the atmosphere and via river waters, as well as information on the lake hydrology and the behaviour of pollutants in the lacustrine ecosystem, are used to identify 'effect' zones of individual sources, and to reveal the distribution of pollutant concentrations all over the water area of the lake. (6) Module of prediction. Using possible scenarios of the economic development of the region and changes in the intensity of intraregional sources, as well as of possible increases in interregional and global transport, variant estimates are made
MATHEMATICAL BALANCE MODELS FOR MONITORING THE STATE OF LAKE BAIKAL
319
of possible changes in the levels of pollutant content in the environmental components of Lake Baikal. 4. Interrelations between the Processes of Improving the Systems of Observations and Mathematical Back-up
Synthesis of the above described model system and analysis of the thus-obtained results has allowed us to substantiate the necessity of essential broadening and integration of the observation system. Therefore, beginning with 1981, the Monitoring Laboratory (LAM) with the participation of other institutions of the Goskomgidromet, the USSR Academy of Sciences, the RSFSR Ministry of Higher Education, and other ministries, have been undertaking integrated research on regional balances of pollutants and studying the state of the environment in the Lake Baikal basin. Main attention has been paid to the content of heavy metals, pesticides, oil products, sulphur compounds and other pollutants in the air and precipitation, benthic deposits in the water of the lake and its tributaries, in soil, hydrobionts (phyto-, zooplankton, fish, seal), in vegetation, and tissues of some terrestrial animals. Pursuing this goal, snow sampling is carried out annually between March and April by helicopters along profiles (Figure 2) covering vast territories of the Baikal area, including hardly accessible mountainous regions. Parallel to the snow sampling, is the sampling of under-ice water from the lake and its tributaries. In addition to that, each August the hydrochemical regime of the waters in the northern Baikal area and the content of the above-mentioned pollutants in the main abiotic and biotic components of the environment are investigated according to the 'Complex' program, using research vessels of the Goscomgidromet, the Scientific Research Institute of Biology at Irkutsk University and the Institute of Ecotoxicology under the Ministry of Forests and Paper Industry of the USSR. At the same time, the hydrobiological and microbiological regime of the water area, the content of the pollutants in the surface water, soil, vegetation and animals in the cis-Baikal area are studied. To obtain reliable information, intercalibration of the analytical methods and procedures has been performed, and statistical data quality control implemented during envisaged parallel observations and measurements [14]. The studies performed have allowed us to elaborate an informational system on the state of Lake Baikal [13]. Practical use of the system has given the following theoretical and applied results. Elaboration and utilization of statistical models for analyzing geochemical data sets, characterizing the regime of Lake Baikal for the period 1965-1984, as well as information on the background content of trace elements, including a number of heavy metals, have enabled us to establish lognormal distribution of concentration occurrence and to compute pattern parameters. The established distributions characterize the natural state of the waters in Lake Baikal, which has been forming during the period of its evolution, and present unique 'laws of nature' of Lake Baikal. Since it takes Lake Baikal hundreds of years to turn over
320
Vu. A. ANOKHIN
Helicopter
Fig. 2.
Flight
Sections
Scheme of water and snow sampling. Test-field 'Complex': 1. The Rel river - the U.Angara river; 2. Cape Elokhin-Dabsha-cape Pokoiniki-cape Orlovy; 3. Cape Oblom - cape Krestovy.
its entire volume of water [12, 18, 19], distribution parameters are stable in time. Figure 3 shows histograms of distributions and their approximation by the lognormal law for concentrations of sulphates and mercury in the water of Lake Baikal using the results of a recent survey. Knowledge of lognormal distributions has ensured specification of reserves of various substances in the water and enabled us to formulate new approaches to assessing the effect of additional pollutants [12, 18]. The results of the studies have shown the absence of statitstically important differences in the values of hydrochemical indices and concentrations of pollutants in the water of Lake Baikal in various background regions of its water area. At the same time, some significant differences in the studied indices have been revealed and parameters of their correlational links between background areas and some areas of natural oil and gas occurrence have been calculated.
MATHEMATICAL
BALANCE
MODELS
FOR MONITORING
THE STATE OF LAKE BAIKAL
321
:~ (C) O,Z O,"~
jl~ = 1 . 5 7
~
= 0.3
C = 5.05
/I
= 2.3
i iphat e-ion
O,I
. . . . .
6
7
8
9
concentration
L
C
(mg/l)
~(c)
mercury
./~ = -1o6 6"= 0.7
0,4
~
0,8
c
concentration (mkg/l)
Fig. 3. Normalizedhystograms of distributions and their approximationby the lognormal law.
The mentioned circumstances are of essential significance for characterizing the ecology of the lake. The use of the information system has shown that the hydrochemical regime of the background areas of Lake Baikal (consequently, of the lake as a whole), does not undergo any induced changes associated with anthropogenic factors. This agrees with the results of 30 years of observations, carried out by researchers from various institutions. Also defined is the trace-element composition of precipitation, water of the lake and its important tributaries- Selenga, Upper Angara, Barguzin [1, 6, 14, 15]. Some of these data are given in Table I, indicating the high quality of the lake water. Composition of snow-melt water in the region is generally the same as in other clean regions of the world [17]. Finally, the studies performed have allowed us to define the current balance of a number of substances, including heavy metals and pesticides in the natural environment of the lake basin. As an illustration, on the basis of published data [21, 22] we shall cite the results obtained on mercury and DDT. The balance scheme is described by an usual system of first-order kinetic equations
322
YU. A. ANOKHIN
dQ
--
dt
=AQ+S,
(1)
where Q is the vector of the content of the studied substance in environmental compartments, S is the vector of substance arrival, and A is the matrix of transition coefficients. TABLE I Concentrations of macrocomponents (mg/1) and trace elements (~tcg/1) in the water of Lake Baikal, Selenga river and snow melt water Index
Lake Baikal
Selenga river
Snow water
Macrocomponents: Total mineral substances Suspended matter Dissolved oxygen Hydrocarbonates Sulphate Chloride
91 1.1 11.3 63 5.6 0.8
110 4 9.1 88 10 1.6
23 12.1 -16 4.6 --
Trace elements: Mercury Lead Zinc Cadmium Copper
0.25 0.35 8.1 0.03 1.4
0.32 0.30 27 0.05 2.1
0.37 0.65 17 0.20 2.6
The results of model (1) calculation of mercury concentrations in environmental compartments of the Lake Baikal basin performed with the use of data from [11, 22], are given in Table II (observational data are shown for comparison). Table II shows that the calculated results agree well with the data of observations, which indicated that the model structure and its parameters have been correctly chosen. On the other hand, this also indicates sufficient reliability of observational data, since they meet the balance scheme (1). These data confirm that, in terms of TABLE II Calculated stationary and measured mercury concentrations in various environmental compartments Components
Soil, ixcg/kg Vegetation, I~cg/kg River water, ng/1 Lake water, ng/l
Concentration
Source
Calculated
Observed
0.04 0.03 0.30 0.2
0.009--0.03 0.002-0.02 0.32 0.05-0.2 0.25 0.05-0.35
our data our data our data [22] [6] our data
MATHEMATICAL BALANCE MODELS FOR MONITORING THE STATE OF LAKE BAIKAL
323
the levels of mercury content in environmental compartments the Lake Baikal basin refers to clean background regions of the world [19]. In contrast to mercury, of which the contribution of natural sources is significant, DDT is exclusively a product of anthropogenic activity. The data collected on the adverse effect of DDT on animals and man, are known to have led to the banning of this substance in many countries of the world, including the USSR (in 1970). However, DDT continues to be used in other countries on a limited scale (or sometimes intensively in a group of developing countries), because of the lack of other, less dangerous but more expensive pesticides, and insufficient knowledge of DDT distribution mechanisms in the environment and of possible implications of its use. DDT is known not to have ever been used in the Lake Baikal basin. However, owing to global atmospheric transport from countries where it is used, this substance enters the natural environment of the lake basin together with precipitation and subsiding dust. This has enabled us to instrumentally prove the presence of DDT in many objects of the basin's natural environment [1, 7]. Certainly, DDT levels are extremely low, but our aim is to estimate the current DDT balance (in connection with its global arrival to the environment) and to substantiate monitoring. The results of model calculations of DDT concentrations (together with its metabolites) in the components of the Baikal natural environment are presented in Table III. Observational data are cited for the sake of comparison and the data from [8, 10] have been used for calculations. Comparison of estimated and observed concentrations (Table III) allows us to draw conclusions on the satisfactory quality of the elaborated model and on the reliability of observational data. T A B L E III Estimated stationary and measured D D T concentrations (together with its metabolites) Component
Concentration
Source
Estimates
Measurements
15 13
26 16
[21] [21]
10 7
17 10
[7] [7]
Soil: Air - dry samples ixcg/kg Lake tributaries ng/l
Vegetation: Air dry samples ~tcg/kg Lake water, ng/1
The obtained results show that the observed DDT concentrations in the objects of the environment characterize the biosphere pollution and are stipulated by global atmospheric transport of DDT from those countries where it is used.
324
YU. A. ANOKHIN
5. Conclusion
Anthropogenic pollutants entering the environment are involved in global cycles, which is reflected in a change in the cycles of these substances, even in clean regions. The system of mathematical balance simulation models of the distribution and circulation of inorganic pollutants (of a number of heavy metals and pesticides), included into the priority list for integrated background monitoring, has been developed for the Lake Baikal basin. It includes the following blocks (modules): (1) inventory and classification of regional sources emmitting the above-mentioned substances to the atmosphere, natural waters and soils; (2) estimation of the atmospheric transport, fall out and depositions on the underlying surface; (3) release from the soil; (4) transport by water runoffs - tributaries of Lake Baikal; (5) transport by currents, and balance in Lake Baikal; (6) prediction. This system of models has been used for the analysis and estimation of the current state of Lake Baikal and long-term prediction of possible changes for the prospect of 25 to 30 years. Analysis of the spatial-temporal series of observations in the period 1965-1984 has shown that the hydrochemical regime of the lake remains in its natural state, while the content of heavy metals and pesticides in the water of the lake is extremely low, characterizing their global background level, and is mainly explained by historically formed geochemical conditions of the basin (for metals) or large-scale interregional and global atmospheric transport (for pesticides). Balance and prediction estimations by means of a specially elaborated mathematical model of the atmospheric transport have shown that neither a considerable increase of heavy metals nor significant reduction of DDT and its metabolite content in the water of Lake Baikal are to be expected during two or three nearest decades, in spite of the global rise of heavy metals in the atmosphere and a decrease of global DDT arriving at the lake. It is also important that the elaborated models have enabled us to improve existing programs and systems of observations, in particular, to substantiate the large-scale network of snow sampling and analysis, and to work out a program of integrated syrveys of the state of Lake Baikal. Beginning with 1981, these studies have been included into the routine network observations within the framework of the monitoring system of Lake Baikal.
References (all in Russian) [1] Anokhin, Yu. A.: 1984, 'Integrated Background Monitoring of Lake Baikal: Present State and Prospects', in Background Monitoring of Environmental Pollution, L., Gidrometeoizdat, 132-144. [2] Anokhin, Yu.A.: 1977, 'System-dynamicApproach to Definition of the Admissible Load of Pollution of the Natural Environment and Substantiation of Monitoring', in Monitoring the State of the Natural Environment, Proceedings of the 1st Soviet-UK Symposium, L., Gidrometeoizdat, 96-115. [3] Anokhin, Yu. A. and Izrael, Yu. A.: 1975, 'System Analysis and Simulation Mathematical Modelling as Methodological Basis of Definition of Admissible Loads of Anthropogenic Pollutions of the Environment - Regional Approach', in Comprehensive Analysis of the Environment, Proceedings of the USSR-USA Symposium, L., Gidrometeoizdat, 68-83.
M A T H E M A T I C A L BALANCE MODELS FOR M O N I T O R I N G T H E STATE OF LAKE BAIKAL
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[4] Anokhin, Yu. A. and Ostromogilsky, A. Kh.: 1986, 'Integrated Regional Monitoring of Lake Baikal', in Research on Environmental Pollution and its Effect on the Biosphere, L., Gidrometeoizdat, 73-86. [5] Anokhin, Yu, A. and Ostromogilsky, A. Kh.: 1982, 'Mathematical Models in the System of Integrated Monitoring', in Process Modelling in Natural and Economics Systems, Novosibirsk, Nauka (Sib. Br.), 152-160. [6] Belova, N.I.: 1984, 'Distribution of Trace Elements in the Water of Lake Baikal', in Monitoring of Background Environmental Pollution, L., Gidrometeoizdat, 2, 144-156. [7] Bobovnikova, Ts. I.: 1986, 'Problems of Environmental Pollution by Organochlorine Compounds due to Their Transport in the Atmosphere on a Planetary Scale', in Monitoring of Background Environmental Pollution, L., Gidrometeoizdat, 3, 113-119. [8] Bobovnikova, Ts. I., Virchenko, Ye. P., and Malakhov, S. G.: 1982, 'Estimation of Some Elements of the Global Balance of Organochlorine Pesticides in Natural Environment', in Integrated Global Monitoring of Environmental Pollution, Proceedings of the 2nd Internatinal Symposium. L., Gidrometeoizdat, 230-238. [9] Vizhensky V.A., Petrukhin, V. A., and Ostromogilsky, A. Kh.: 1985, 'Lead and Cadmium in Lake Baikal', Paper presented at the MAB Conference, Yalta. [10] Anokhin, Yu. A. et al.: 1978, 'Global DDT Balance in the Biosphere', Obninsk, VNIlGMIWDC, 40. [11] Anokhin, Yu. A. et al.: 1978, 'Global Balance of Mercury in the Biosphere', Review, Obninsk, 44. [12] Izrael, Yu. A.: 1984, 'Ecology and Control of the State of the Environment'. M., Gidrometeoizdat, 560. [13] Kozhova, O. M. et al.: 1982, 'Information Basis of Ecological Monitoring of Lake Baikal', in Ecological Problems in Pribaikalye, Irkutsk, 41-44. [14] Anokhin, Yu. A., Ostromogilsky, A. Kh., Poslovin, A. L. and Belova, N. I.: 1986, 'To the Problem on Estimation of Information Quality on Background Content of Mineral Substances in the Air, Snow Cover and Natural Waters', in Monitoring of Background Environmental Pollution. L., Hydrometeoizdat, 3, 138-149. [15] Izrael, Yu. A. et al.: 1981, 'Comprehensive Analysis of the Environment and Substantiation of Monitoring in the Region of Lake Baikal', in Comprehensive Analysis of the Environment, Proceedings of the 4th Soviet-American Symposium. L., Hydrometeoizdat, 43-60. [16] Filippova, L. M. et al.: 1982, 'Integrated Background Monitoring of the Environment on Lake Baikal: Objectives and Goals, History and Prospects', in Integrated GlobalMonitoring of Environmental Pollution, Proceedings of the 2nd International Symposium. L., Hydrometeoizdat, 78-85. [17] Ostromogilsky, A. Kh. et al. : 1981, 'Microelements in the Atmosphere of the Background Regions of Land and Sea, A Review', Obninsk, 41 p. [18] Anokhin, Yu. A., Belova, N. I., Ostromogilsky, A. Kh., and Poslovin, A. L.: 1984, 'Estimation and Prediction of the State of the Environment in the Problems of Integrated Background Monitoring in the Region of Lake Baikal', in Problems of Background Monitoring of the State of the Environment, CMEA GEMS. L., Hydrometeoizdat, 2, 176-185. [19] Anokhin, Yu. A., Belova, N. I., Ostromogilsky, A. Kh., and Poslovin, A. L.: 1982, 'Assessment and Prediction of the State of the Baikal Area in the Problems of Integrated Monitoring', in Ecological Problems in Pribaikalye, lrkutsk, 53-56. [20] Rovinsky, F. Ya., Filippova, L. M., and lzrael, Yu. A.: 1977, 'Background Monitoring: Regional and Base-line Stations, Biosphere Reserves', in Monitoring of the State of Natural Environment, Proceedings of the Ist Soviet/U.K. Symposium. L., Hydrometeoizdat. [21 ] Afanasyev, M. I. et al. : 1984, 'Background Content of Organochlorine Compounds and 3,4-benzpyrene in Natural Media. Communication 2', in Monitoring of Background Environmental Pollution. L., Hydrometeoizdat, 2, 35-48. [22] Yushkan, E. I., Chicheva, T. B., and Lavrentyeva, E. B.: 1984, 'Background Content of Lead, Mercury, Arsenic and Cadmium in Natural Media. Communication 2', in Monitoring of Background Environmental Pollution, L., Hydrometeoizdat, 2, 17-35. [23] Filippova, L. M., Anokhin, Yu. A., Ostromogilsky, A. N., Izrael, Yu. A., and Matveev, A. A.: 1982, 'Lake Baikal Integrated Background Monitoring. Objectives, Goals, History and Prospects', Environmental Monitoring and Assessment 2, 403-4 17.
BALANCE
MODELS FOR MONITORING
T H E S T A T E OF L A K E B A I K A L YU. A. A N O K H I N Natural Environment and Climate Monitoring Laboratory, USSR State Committee f o r Hydrometeorology and Control o f Natural Environment, USSR Academy o f Sciences
Abstract. The global cycles of man-produced pollutants entering the natural environment are reflected
in changes of pollutant cycles, even in background regions. The system of mathematical balance simulation models of inorganic pollutant distribution and circulation (some heavy metals and pesticides included in the priority list for integrated background monitoring) has been developed for the Lake Baikal drainage basin. The system consists of the following units: (1) inventory and classification of regional sources of pollutants entering the atmosphere, natural waters and soils; (2)computation of the global atmospheric transfer and depositions; (3)regional spreading with atmospheric fluxes and deposition onto the underlying surfaces; (4)transport with waterflows feeding Lake Baikal; (5) transport with the lake currents and balance in the lake. The models developed have enabled improvement of existing programmes and systems of observations, in particular to substantiate the large-scale snow sampling and analysis network, and to develop the programme of integrated surveys of the state of Lake Baikal. Since 1981 these actions have been included in the operational network observations within the Lake Baikal Monitoring System.
1. Introduction
Analysis of observation data of the environment in the Lake Baikal basin [1, 12, 15] over many years has allowed us to conclude that the pollutant levels in cis-Baikal environmental compartments are extremely low and characterize the global background pollution of the biosphere [12, 20]. However, man-made pollutants, such as heavy metals and pesticides, entering the environment as by-products of the world's economic activities, are involved in global cycles which, even in clean regions, may lead either to the origin of new regional cycles (if such substances as DDT are considered) or to a change in the historical pattern of geochemical cycles (in the case of heavy metals). Balance mathematical models are an efficient instrument for studying these phenomena. For the Lake Baikal basin, a system of balance (statistical and simulation) mathematical models [1, 2, 3] of the distribution and circulation of inorganic pollutants, included in the list of priority pollutants for integrated background monitoring, has been developed [12]. These mathematical models make up one of the components of the integrated system of Lake Baikal regional monitoring, which consists [1, 4, 5] of the following subsystems: (1) observations, (2) modelling and data assessment, and (3) prediction of man-induced changes in the environment [3]. One of the basic features of this system is an interactive adjustment of the observations to data processing and analysis for assessing and predicting the state of the environment. Therefore, the system of observations should yield data fit for solving problems of balance compilEnvironmental Monitoring and Assessment 11: 315-325, 1988. 9 1988 Kluwer Academic Publishers. Printed in the Netherlands.
316
Vt;. A, ANOKHIN
ation (assessment and prediction), while the mathematical models used for this purpose largely depend on the operational capabilities of the system of observations. At the same time, these models predetermine the organization and program of observations and the set of data collected. The creation and improvement of the observation system, definition of its structure and functional interactions among its elements, is a complicated, continuous process governed by such factors as the set goals, information consumers, material and financial resources [12]. Elaboration and improvement of the software system (the creation of a set of simulation mathematical models, in particular) is not a simple process, but is being developed with time [5]. The simple but by no means trivial truth is that these processes are closely interconnected. Below, this interconnection is illustrated by the creation and improvement of the systems of observations of the state of Lake Baikal, in particular, of the pollutant content including heavy metals and pesticides in the components of the environment, on the one hand, and required software development - statistical and simulation (dynamic) mathematical models of circulation of these pollutants in the environment - on the other.
2. System of Observations Observations of probable man-induced effects of local, regional and global factors on the ecosystem of Lake Baikal have been developed on the basis of classical ecological-limnological studies by B. I. Dybovsky, A. V. Voznesensky, G. Yu. Vereshchagin and M. M. Kozhov [1, 23]. According to the decisions of the CPSU Central Committee and the USSR Council of Ministers of 1972 and 1987 on the preservation and management of the natural resources of the Lake Baikal basin, the USSR State Committee for Hydrometeorology and Control of Natural Environment (Goskomgidromet) has established a special service of observations, data analysis and evaluation for the control and prediction of the state of Lake Baikal, i.e. a monitoring system [12]. This service operates on the basis of local network subdivisions and institutions of the Goskomgidromet with the participation of the concerned ministries and agencies, and yields regular information on the pollutant levels in surface water, air and precipitation, soils (both in impact and background regions of the Baikal area), and on the state of these environmental compartments. Physical, chemical and hydrobiological (for Lake Baikal and its tributaries) indices being recorded, as well. This information is used by economic, planning and other institutions. Figure 1 schematically shows this system of observations. The hydrochemical, hydrological and hydrobiological regimes of the Lake are monitored along a reference cross-section by 205 stations at 5 strata (including the benthic layer) for 4 different hydrological and hydrobiological characteristics of Lake Baikal. To control the chemical run-off from rivers in the basin, observations of the water composition in their estuarine parts are carried out (Figure 1). At each control site, the water
MATHEMATICAL BALANCE MODELS FOR MONITORING THE STATE OF LAKE BAIKAL
Types
of
317
observations:
- special water surveys in t h e regions of possible anthropo] genic effect
9
- of
water
pollution
- of water and pollution
9
- of
precipitation
- of
soils
- of the snow composition
Fig. 1.
atmosphere
cover
chemical
System of Observations of the chemical state of the environment in the region of Lake Baikal.
quality is defined by indices characterizing the content of oxygen, oxidizable and non-oxidizable organic substances, biogenic elements, mineral and suspended substances, oil products, trace elements (including a number of heavy metals) and pesticides.
318
YU. A. ANOKHIN
Monitoring of the atmospheric input of pollutants into Lake Baikal includes observing the chemical composition of precipitation and dry deposition (Figure 1). The described system is a necessary informational basis for modelling development, complication of balances and prediction of the state of the lake.
3. System of Mathematical Balance Simulation Models Basing on the balance approach and information from the above described system of observations, we have produced a set of models describing the arrival, distribution and circulation of pollutants in the Lake Baikal environment. The principles of modelling, as well as the structure and interconnections between individual models of this system, have been described in [3, 12, 16, 23]. At present, these models are being improved. Note, that not all of them have been elaborated in detail. However, it should be emphasized that the synthesis of the whole system has allowed us to understand better a rather complex model system ('the Lake Baikal Region'), to reveal the weak points of the observation system and to specify the ways and means of improving the regional system of monitoring. One of the most important of the accepted modelling principles is the principle of module (block) construction of the whole system of models when it consists of sectors and subsectors relatively independent and simply combined into a single whole. This enables us to modify individual parts of the system with no essential transformations of other parts. The elaborated system consists of the following modules: (1) inventory (census) of sources of pollutant arrivals in the regional atmosphere (including interregional and global transport), onto the underlying surface, and into the water streams of the Lake Baikal basin. (2) Modules of pollutants spreading with atmospheric fluxes. Estimation of the spatial-temporal pattern of pollutant distribution, estimation of fluxes of pollutant removal from the atmosphere to the underlying surface, including the water area of Lake Baikal, and their distribution over the underlying surface, are based on the data of pollutant sources, on meteorological data on wind field and precipitation. (3) Module of the release of contaminants from the soil (underlying surface) to adjacent water flows, the atmosphere; absorption by biota is possible. (4) Module of the arrival of contaminants at Lake Baikal with river waters. (5) Module of the spatial-temporal pattern of contaminant distribution in Lake Baikal. The data of the source inventory module, the estimates of arrival of pollutants from the atmosphere and via river waters, as well as information on the lake hydrology and the behaviour of pollutants in the lacustrine ecosystem, are used to identify 'effect' zones of individual sources, and to reveal the distribution of pollutant concentrations all over the water area of the lake. (6) Module of prediction. Using possible scenarios of the economic development of the region and changes in the intensity of intraregional sources, as well as of possible increases in interregional and global transport, variant estimates are made
MATHEMATICAL BALANCE MODELS FOR MONITORING THE STATE OF LAKE BAIKAL
319
of possible changes in the levels of pollutant content in the environmental components of Lake Baikal. 4. Interrelations between the Processes of Improving the Systems of Observations and Mathematical Back-up
Synthesis of the above described model system and analysis of the thus-obtained results has allowed us to substantiate the necessity of essential broadening and integration of the observation system. Therefore, beginning with 1981, the Monitoring Laboratory (LAM) with the participation of other institutions of the Goskomgidromet, the USSR Academy of Sciences, the RSFSR Ministry of Higher Education, and other ministries, have been undertaking integrated research on regional balances of pollutants and studying the state of the environment in the Lake Baikal basin. Main attention has been paid to the content of heavy metals, pesticides, oil products, sulphur compounds and other pollutants in the air and precipitation, benthic deposits in the water of the lake and its tributaries, in soil, hydrobionts (phyto-, zooplankton, fish, seal), in vegetation, and tissues of some terrestrial animals. Pursuing this goal, snow sampling is carried out annually between March and April by helicopters along profiles (Figure 2) covering vast territories of the Baikal area, including hardly accessible mountainous regions. Parallel to the snow sampling, is the sampling of under-ice water from the lake and its tributaries. In addition to that, each August the hydrochemical regime of the waters in the northern Baikal area and the content of the above-mentioned pollutants in the main abiotic and biotic components of the environment are investigated according to the 'Complex' program, using research vessels of the Goscomgidromet, the Scientific Research Institute of Biology at Irkutsk University and the Institute of Ecotoxicology under the Ministry of Forests and Paper Industry of the USSR. At the same time, the hydrobiological and microbiological regime of the water area, the content of the pollutants in the surface water, soil, vegetation and animals in the cis-Baikal area are studied. To obtain reliable information, intercalibration of the analytical methods and procedures has been performed, and statistical data quality control implemented during envisaged parallel observations and measurements [14]. The studies performed have allowed us to elaborate an informational system on the state of Lake Baikal [13]. Practical use of the system has given the following theoretical and applied results. Elaboration and utilization of statistical models for analyzing geochemical data sets, characterizing the regime of Lake Baikal for the period 1965-1984, as well as information on the background content of trace elements, including a number of heavy metals, have enabled us to establish lognormal distribution of concentration occurrence and to compute pattern parameters. The established distributions characterize the natural state of the waters in Lake Baikal, which has been forming during the period of its evolution, and present unique 'laws of nature' of Lake Baikal. Since it takes Lake Baikal hundreds of years to turn over
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Vu. A. ANOKHIN
Helicopter
Fig. 2.
Flight
Sections
Scheme of water and snow sampling. Test-field 'Complex': 1. The Rel river - the U.Angara river; 2. Cape Elokhin-Dabsha-cape Pokoiniki-cape Orlovy; 3. Cape Oblom - cape Krestovy.
its entire volume of water [12, 18, 19], distribution parameters are stable in time. Figure 3 shows histograms of distributions and their approximation by the lognormal law for concentrations of sulphates and mercury in the water of Lake Baikal using the results of a recent survey. Knowledge of lognormal distributions has ensured specification of reserves of various substances in the water and enabled us to formulate new approaches to assessing the effect of additional pollutants [12, 18]. The results of the studies have shown the absence of statitstically important differences in the values of hydrochemical indices and concentrations of pollutants in the water of Lake Baikal in various background regions of its water area. At the same time, some significant differences in the studied indices have been revealed and parameters of their correlational links between background areas and some areas of natural oil and gas occurrence have been calculated.
MATHEMATICAL
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:~ (C) O,Z O,"~
jl~ = 1 . 5 7
~
= 0.3
C = 5.05
/I
= 2.3
i iphat e-ion
O,I
. . . . .
6
7
8
9
concentration
L
C
(mg/l)
~(c)
mercury
./~ = -1o6 6"= 0.7
0,4
~
0,8
c
concentration (mkg/l)
Fig. 3. Normalizedhystograms of distributions and their approximationby the lognormal law.
The mentioned circumstances are of essential significance for characterizing the ecology of the lake. The use of the information system has shown that the hydrochemical regime of the background areas of Lake Baikal (consequently, of the lake as a whole), does not undergo any induced changes associated with anthropogenic factors. This agrees with the results of 30 years of observations, carried out by researchers from various institutions. Also defined is the trace-element composition of precipitation, water of the lake and its important tributaries- Selenga, Upper Angara, Barguzin [1, 6, 14, 15]. Some of these data are given in Table I, indicating the high quality of the lake water. Composition of snow-melt water in the region is generally the same as in other clean regions of the world [17]. Finally, the studies performed have allowed us to define the current balance of a number of substances, including heavy metals and pesticides in the natural environment of the lake basin. As an illustration, on the basis of published data [21, 22] we shall cite the results obtained on mercury and DDT. The balance scheme is described by an usual system of first-order kinetic equations
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YU. A. ANOKHIN
dQ
--
dt
=AQ+S,
(1)
where Q is the vector of the content of the studied substance in environmental compartments, S is the vector of substance arrival, and A is the matrix of transition coefficients. TABLE I Concentrations of macrocomponents (mg/1) and trace elements (~tcg/1) in the water of Lake Baikal, Selenga river and snow melt water Index
Lake Baikal
Selenga river
Snow water
Macrocomponents: Total mineral substances Suspended matter Dissolved oxygen Hydrocarbonates Sulphate Chloride
91 1.1 11.3 63 5.6 0.8
110 4 9.1 88 10 1.6
23 12.1 -16 4.6 --
Trace elements: Mercury Lead Zinc Cadmium Copper
0.25 0.35 8.1 0.03 1.4
0.32 0.30 27 0.05 2.1
0.37 0.65 17 0.20 2.6
The results of model (1) calculation of mercury concentrations in environmental compartments of the Lake Baikal basin performed with the use of data from [11, 22], are given in Table II (observational data are shown for comparison). Table II shows that the calculated results agree well with the data of observations, which indicated that the model structure and its parameters have been correctly chosen. On the other hand, this also indicates sufficient reliability of observational data, since they meet the balance scheme (1). These data confirm that, in terms of TABLE II Calculated stationary and measured mercury concentrations in various environmental compartments Components
Soil, ixcg/kg Vegetation, I~cg/kg River water, ng/1 Lake water, ng/l
Concentration
Source
Calculated
Observed
0.04 0.03 0.30 0.2
0.009--0.03 0.002-0.02 0.32 0.05-0.2 0.25 0.05-0.35
our data our data our data [22] [6] our data
MATHEMATICAL BALANCE MODELS FOR MONITORING THE STATE OF LAKE BAIKAL
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the levels of mercury content in environmental compartments the Lake Baikal basin refers to clean background regions of the world [19]. In contrast to mercury, of which the contribution of natural sources is significant, DDT is exclusively a product of anthropogenic activity. The data collected on the adverse effect of DDT on animals and man, are known to have led to the banning of this substance in many countries of the world, including the USSR (in 1970). However, DDT continues to be used in other countries on a limited scale (or sometimes intensively in a group of developing countries), because of the lack of other, less dangerous but more expensive pesticides, and insufficient knowledge of DDT distribution mechanisms in the environment and of possible implications of its use. DDT is known not to have ever been used in the Lake Baikal basin. However, owing to global atmospheric transport from countries where it is used, this substance enters the natural environment of the lake basin together with precipitation and subsiding dust. This has enabled us to instrumentally prove the presence of DDT in many objects of the basin's natural environment [1, 7]. Certainly, DDT levels are extremely low, but our aim is to estimate the current DDT balance (in connection with its global arrival to the environment) and to substantiate monitoring. The results of model calculations of DDT concentrations (together with its metabolites) in the components of the Baikal natural environment are presented in Table III. Observational data are cited for the sake of comparison and the data from [8, 10] have been used for calculations. Comparison of estimated and observed concentrations (Table III) allows us to draw conclusions on the satisfactory quality of the elaborated model and on the reliability of observational data. T A B L E III Estimated stationary and measured D D T concentrations (together with its metabolites) Component
Concentration
Source
Estimates
Measurements
15 13
26 16
[21] [21]
10 7
17 10
[7] [7]
Soil: Air - dry samples ixcg/kg Lake tributaries ng/l
Vegetation: Air dry samples ~tcg/kg Lake water, ng/1
The obtained results show that the observed DDT concentrations in the objects of the environment characterize the biosphere pollution and are stipulated by global atmospheric transport of DDT from those countries where it is used.
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YU. A. ANOKHIN
5. Conclusion
Anthropogenic pollutants entering the environment are involved in global cycles, which is reflected in a change in the cycles of these substances, even in clean regions. The system of mathematical balance simulation models of the distribution and circulation of inorganic pollutants (of a number of heavy metals and pesticides), included into the priority list for integrated background monitoring, has been developed for the Lake Baikal basin. It includes the following blocks (modules): (1) inventory and classification of regional sources emmitting the above-mentioned substances to the atmosphere, natural waters and soils; (2) estimation of the atmospheric transport, fall out and depositions on the underlying surface; (3) release from the soil; (4) transport by water runoffs - tributaries of Lake Baikal; (5) transport by currents, and balance in Lake Baikal; (6) prediction. This system of models has been used for the analysis and estimation of the current state of Lake Baikal and long-term prediction of possible changes for the prospect of 25 to 30 years. Analysis of the spatial-temporal series of observations in the period 1965-1984 has shown that the hydrochemical regime of the lake remains in its natural state, while the content of heavy metals and pesticides in the water of the lake is extremely low, characterizing their global background level, and is mainly explained by historically formed geochemical conditions of the basin (for metals) or large-scale interregional and global atmospheric transport (for pesticides). Balance and prediction estimations by means of a specially elaborated mathematical model of the atmospheric transport have shown that neither a considerable increase of heavy metals nor significant reduction of DDT and its metabolite content in the water of Lake Baikal are to be expected during two or three nearest decades, in spite of the global rise of heavy metals in the atmosphere and a decrease of global DDT arriving at the lake. It is also important that the elaborated models have enabled us to improve existing programs and systems of observations, in particular, to substantiate the large-scale network of snow sampling and analysis, and to work out a program of integrated syrveys of the state of Lake Baikal. Beginning with 1981, these studies have been included into the routine network observations within the framework of the monitoring system of Lake Baikal.
References (all in Russian) [1] Anokhin, Yu. A.: 1984, 'Integrated Background Monitoring of Lake Baikal: Present State and Prospects', in Background Monitoring of Environmental Pollution, L., Gidrometeoizdat, 132-144. [2] Anokhin, Yu.A.: 1977, 'System-dynamicApproach to Definition of the Admissible Load of Pollution of the Natural Environment and Substantiation of Monitoring', in Monitoring the State of the Natural Environment, Proceedings of the 1st Soviet-UK Symposium, L., Gidrometeoizdat, 96-115. [3] Anokhin, Yu. A. and Izrael, Yu. A.: 1975, 'System Analysis and Simulation Mathematical Modelling as Methodological Basis of Definition of Admissible Loads of Anthropogenic Pollutions of the Environment - Regional Approach', in Comprehensive Analysis of the Environment, Proceedings of the USSR-USA Symposium, L., Gidrometeoizdat, 68-83.
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[4] Anokhin, Yu. A. and Ostromogilsky, A. Kh.: 1986, 'Integrated Regional Monitoring of Lake Baikal', in Research on Environmental Pollution and its Effect on the Biosphere, L., Gidrometeoizdat, 73-86. [5] Anokhin, Yu, A. and Ostromogilsky, A. Kh.: 1982, 'Mathematical Models in the System of Integrated Monitoring', in Process Modelling in Natural and Economics Systems, Novosibirsk, Nauka (Sib. Br.), 152-160. [6] Belova, N.I.: 1984, 'Distribution of Trace Elements in the Water of Lake Baikal', in Monitoring of Background Environmental Pollution, L., Gidrometeoizdat, 2, 144-156. [7] Bobovnikova, Ts. I.: 1986, 'Problems of Environmental Pollution by Organochlorine Compounds due to Their Transport in the Atmosphere on a Planetary Scale', in Monitoring of Background Environmental Pollution, L., Gidrometeoizdat, 3, 113-119. [8] Bobovnikova, Ts. I., Virchenko, Ye. P., and Malakhov, S. G.: 1982, 'Estimation of Some Elements of the Global Balance of Organochlorine Pesticides in Natural Environment', in Integrated Global Monitoring of Environmental Pollution, Proceedings of the 2nd Internatinal Symposium. L., Gidrometeoizdat, 230-238. [9] Vizhensky V.A., Petrukhin, V. A., and Ostromogilsky, A. Kh.: 1985, 'Lead and Cadmium in Lake Baikal', Paper presented at the MAB Conference, Yalta. [10] Anokhin, Yu. A. et al.: 1978, 'Global DDT Balance in the Biosphere', Obninsk, VNIlGMIWDC, 40. [11] Anokhin, Yu. A. et al.: 1978, 'Global Balance of Mercury in the Biosphere', Review, Obninsk, 44. [12] Izrael, Yu. A.: 1984, 'Ecology and Control of the State of the Environment'. M., Gidrometeoizdat, 560. [13] Kozhova, O. M. et al.: 1982, 'Information Basis of Ecological Monitoring of Lake Baikal', in Ecological Problems in Pribaikalye, Irkutsk, 41-44. [14] Anokhin, Yu. A., Ostromogilsky, A. Kh., Poslovin, A. L. and Belova, N. I.: 1986, 'To the Problem on Estimation of Information Quality on Background Content of Mineral Substances in the Air, Snow Cover and Natural Waters', in Monitoring of Background Environmental Pollution. L., Hydrometeoizdat, 3, 138-149. [15] Izrael, Yu. A. et al.: 1981, 'Comprehensive Analysis of the Environment and Substantiation of Monitoring in the Region of Lake Baikal', in Comprehensive Analysis of the Environment, Proceedings of the 4th Soviet-American Symposium. L., Hydrometeoizdat, 43-60. [16] Filippova, L. M. et al.: 1982, 'Integrated Background Monitoring of the Environment on Lake Baikal: Objectives and Goals, History and Prospects', in Integrated GlobalMonitoring of Environmental Pollution, Proceedings of the 2nd International Symposium. L., Hydrometeoizdat, 78-85. [17] Ostromogilsky, A. Kh. et al. : 1981, 'Microelements in the Atmosphere of the Background Regions of Land and Sea, A Review', Obninsk, 41 p. [18] Anokhin, Yu. A., Belova, N. I., Ostromogilsky, A. Kh., and Poslovin, A. L.: 1984, 'Estimation and Prediction of the State of the Environment in the Problems of Integrated Background Monitoring in the Region of Lake Baikal', in Problems of Background Monitoring of the State of the Environment, CMEA GEMS. L., Hydrometeoizdat, 2, 176-185. [19] Anokhin, Yu. A., Belova, N. I., Ostromogilsky, A. Kh., and Poslovin, A. L.: 1982, 'Assessment and Prediction of the State of the Baikal Area in the Problems of Integrated Monitoring', in Ecological Problems in Pribaikalye, lrkutsk, 53-56. [20] Rovinsky, F. Ya., Filippova, L. M., and lzrael, Yu. A.: 1977, 'Background Monitoring: Regional and Base-line Stations, Biosphere Reserves', in Monitoring of the State of Natural Environment, Proceedings of the Ist Soviet/U.K. Symposium. L., Hydrometeoizdat. [21 ] Afanasyev, M. I. et al. : 1984, 'Background Content of Organochlorine Compounds and 3,4-benzpyrene in Natural Media. Communication 2', in Monitoring of Background Environmental Pollution. L., Hydrometeoizdat, 2, 35-48. [22] Yushkan, E. I., Chicheva, T. B., and Lavrentyeva, E. B.: 1984, 'Background Content of Lead, Mercury, Arsenic and Cadmium in Natural Media. Communication 2', in Monitoring of Background Environmental Pollution, L., Hydrometeoizdat, 2, 17-35. [23] Filippova, L. M., Anokhin, Yu. A., Ostromogilsky, A. N., Izrael, Yu. A., and Matveev, A. A.: 1982, 'Lake Baikal Integrated Background Monitoring. Objectives, Goals, History and Prospects', Environmental Monitoring and Assessment 2, 403-4 17.
