Improvement of the national water balance feasibility of water balances per river basin

Transcription

1 Improvement of the national water balance feasibility of water balances per river basin Report on Grant agreement No Cor Graveland & Kees Baas By: Water Accounts / Water Statistics Eurostat: Luxembourg, 1 & 2 February 2012

2 Content Specs of the project Methodology Basic statistics needed for method Compilation along different sectors Data improvements Results Conclusions / Recommendations Discussion 1

3 Specification of the project (1) Objectives Water balance: improvement of several items: Precipitation, evapotranspiration, external inflow from upstream territories, Other flows and actual outflows ((Completion certain water types categories: with flows between different water types)) Exchange between river basins and with other territory Abstractions and discharges at 7 (sub-)rbs Distinction between Summer and Winter period Construction of stocks, ground-, surface, soil water Test: regionalization to the River Basins (RBs) Figures for 2009 Use and discuss data with water modelers for methodology, tuning and conformation 2

4 Specification of the project (2) Carried out by: Project groups Environmental Accounts Project group of Water Statistics Time-table: January 2011 February

5 Project activities Improvement of: 1. Precipitation data 2. Actual evapotranspiration 3. Actual external inflow from upstream territories 4. Other flows and actual outflows 5. Quantification of groundwater flows, incl. sea vs. neighboring countries 6. Regionalized external inflow to RB 7. Quantification of some balance items 8. Import / export of water in tap water or in products 9. Water abstraction 10. Waste water, production and discharge and reuse of water 11. ES-OECD-JQ (table 1) estimation of three major items 1. The internal flow 2. The recharge into aquifer 3. The groundwater available for abstraction 12. Groundwater, soil water stocks 13. Surface water stocks 14. Fresh water balance: flows 15. Fresh water balance: stocks 4

6 Products JQ tables 1, 1A for 2009 Break downs of JQ tables 1, 1A to: River Basin Season Refinement of JQ tables 1, 1A Abstractions Discharges Import / Export Report with description sources, methodologies, and results for Eurostat Water data for regional Water Accounts 5

7 Precipitation and Actual Evapotranspiration Precipitation (Summer 2009) Precipitation Per Grid (1*1 km) Summer 2009 Based upon precipitation radar network (KNMI) Calibrated using dozens of precipitation gauges Source: Water Watch

8 Precipitation and Actual Evapotranspiration Evaporation (soil) Transpiration (crop) Per Grid Summer 2009 Based upon satellite images Source: Water Watch

9 Precipitation and Actual Evapotranspiration (volumes) Results per (sub-)river Basin mm per year The volumes are calculated using the surface of land and of freshwater basins per River Basin area. North-sea Scheldt Rhine-West Waddensea Lake 700 IJssel Rhine-North Ems Rhine-Central Rhine-East Precipitation Actual Evapotranspiration Germany Meuse Belgium 8

10 Actual external inflow and outflow of surface water Method / processing: inventory and collection of flow data from water boards and national water authority Most files received contain daily average flow rates (m3/sec), some contain monthly flow totals. Inflow: 30 gauging stations at border locations Outflow: only to sea, in total 28 data files on 81 outlets Data were aggregated to monthly, seasonal and yearly totals (mio m3), national & per River Basin. River Scheldt (from Belgium) is not accounted for as inflow already has become marine/brackish. 9

11 Actual external inflow of fresh surface water, results Monthly inflow in Rhine RBD, mio m3, 2009 Monthly inflow in Meuse RBD, mio m3, Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec River Rhine Small rivers River Meuse Small rivers 10

12 Actual external outflow of surface water, results Monthly outflow, mio m3, per (sub-)river Basin mio m jan feb mar apr may jun jul aug sep oct nov dec Rhine-West Rhine-Central Meuse Scheldt Rhine-North Ems 11

13 Actual external inflow and outflow of surface water, overview Mio m3 / year Rhine-North Ems Rhine-Central Rhine-East Small rivers Germany: Rhine-West Scheldt Meuse Rhine: Small rivers Belgium: 327 Small rivers Germany: 981 Meuse:

14 Regionalized inflows and outflows of surface water Major transfers of fresh surface water occur between: The four sub-river Basins of Rhine: very complex From Rhine to Meuse and vice versa, in the delta area From Meuse to Scheldt, in the delta area Rhine: intern transfers (sub-rbs) are not inventoried in the project because of the numerous transfer points. For other transfers: inventory of flow rates at gauging stations at or near the transfer points. Key waterworks regarding distribution of water in Rhine-Meuse- Scheldt delta are the Haringvliet drain sluices. Diversion of river flows is often done to combat salt intrusion in the large delta area. Important water management tool 13

15 Regionalized inflows and outflows of surface water, results 2500 mio m Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Rhine to Meuse Meuse to Scheldt Regional Inflow Total Winter Summer mio m3 From Rhine to Meuse 4166,6 1848,1 2318,5 From Meuse to Scheldt 597,0 75,8 521,1 14

16 Quantification of major balance items Estimates: Internal flow Recharge into aquifer Groundwater available for annual abstraction Precipitation (1) Actual evapotranspiration (2) Internal Flow (b) (3) Actual external inflow (4) Total actual outflow (5) of which: into the sea (6) of which: into neighbouring territories (7) TOTAL FRESHWATER RESOURCES (8) [=(3)+(4)] Recharge into the Aquifer (9) Groundwater available for annual abstraction (10) 2009 mio m3 Year Summer Winter theoretical maximum

17 Import & export, 2009 Import of tapwater: 9.24 mio m3 Export of tapwater: 3.44 mio m3 Of other water : not observed, = 0 m3 Water contained by im- and export products: 45 mio m3 and 30 mio m3 respectively Im- and export of bottled water 1 mio m3 Im- and export of cross-border abstracted groundwater / surface water: not observed (source VEWIN) 16

18 Water abstractions per (sub-)river Basin, 2009 Calculated on basis of method developed in 2008 Water Grant (report Baas and Graveland, 2011). Groundwater abstraction, 2009 (sub-) River Basin Total Agriculture Industry; power plants PWS companies mio m3 Rhine 614,4 36,8 123,4 454,2 of which Rhine-North 73,2 4,1 9,3 59,7 Rhine Central 121,4 9,3 18,5 93,6 Rhine-East 188,9 19,1 36,5 133,3 Rhine-West 227,8 1,1 59,2 167,5 Ems 41,9 0,5 4,3 37,2 Meuse 334,0 38,9 53,4 241,7 Scheldt 23,9 0,9 4,2 18,7 Total 1011,2 73,9 185,3 751,9 17

19 Water abstractions per (sub-)river Basin, 2009 (2) Abstraction of surface water, 2009 (sub-) River Basin Freshwater abstracted by Marine Water Total Agriculture Industry; power plants PWS companies mio m3 Rhine of which Rhine-North Rhine Central Rhine-East Rhine-West Ems Meuse Scheldt Total freshwater

20 Discharges of wastewater and effluents UWWTP, 2009 Effluents UWWTP: yearly questionnaire of Statistics Netherlands, including x- y location of discharge Industries, power plants: data from PRTR reports, including x-y location. Work to do: estimation of discharges via combined sewer overflows and separate rainwater sewers (model is already available). Discharges to fresh surface water mio m Rhine- North Rhine- Central Rhine- East Rhine- West Ems Meuse Scheldt UWWTP Industries, cooling 19

21 Stock of fresh groundwater / soil water: Cross section off Dutch subsoil Source: KNAW: Geology of the Netherlands Groundwater in the NL (KNAW), by De Vries 20

22 Stock of fresh groundwater Chosen salinity as a threshold: (<300 mg Cl-/l (Chloride)) Calculation (solely saturated with fresh water) Soil volume Area of land Thickness of relevant soil layer ( maximum, relevant ) Upper bound of saturated zone (=groundwater table) Lower bound of groundwater column, the interface fresh / brackish groundwater (<300 mg Cl-/l) The porosity (=water content) of the total soil volume versus of the relevant fresh water column Method / approach: clear Parameterization: reasonable For 37 bln m 2, an estimate ranging from Bln m times annual abstraction National balance ((? Regionalization to the RBs?) Due to large bandwidth, annual monitoring hardly make sense Thus no opening & closing stocks.. In touch with (ground) water modelers for methodology, tuning and conformation 21

23 Stock of fresh Soil water Calculation stock of fresh water Soil volume, that carries the fresh soil water Area of land, thus with an unsaturated zone (above ground water table) Thickness of relevant soil layer: Top side of unsaturated zone of soil water column Lower bound of soil water column, the interface with the groundwater table largely determined by level of control : ( controlled level (0-1 m) vs free drainage (0-25m)) (<300 mg Cl-/l) (=groundwater table) The porosity of the relevant soil zone (water and air) Level of (un-)saturation of the pores (=water content) Method / approach: clear Parameterization: reasonable Precision: bandwidth For 37 bln m 2, a first preliminary estimate is around Bln m 3 (3 5 percent of fresh groundwater stock) National balance. Regionalization to the 7 (sub-) River Basins requires soil type Significant seasonal variation, annual monitoring requires real time monitor In touch with (ground) water modellers for methodology, tuning and conformation 22

24 Stock of fresh Surface water Salinity (<300 mg Chloride) Calculation stock of fresh surface water bodies (m3); Area of water (bodies) within the country, eventually per category of water body: (1) Average depth of the fresh water bodies within the country, eventually per water body category (m) (2) Method / approach: clear Parameterization: area good; depth within certain range Area of water: 7,2 bln m 2 Average depth differs Result in estimate of 10 Bln m 3 Only 1 percent of groundwater stock! Comparable to annual abstraction of fresh surface water (10.6 bln m3) Inflow is even 6 times as big Regionalization to the 7 (sub-) River Basins (RBs) Due to large variation, annual monitoring hardly feasible Connected to modelers and WFD people for methodology and data 23

25 Project activities: evaluated Improvement of: 1. Precipitation data 2. Actual evapotranspiration 3. Actual external inflow from upstream territories 4. Other flows and actual outflows 5. Quantification of groundwater flows, incl. sea vs. neighboring countries 6. Regionalized external inflow to RB 7. Quantification of some balance items 8. Import / export of water in tap water or in products 9. Water abstraction 10. Waste water, production and discharge and reuse of water 11. ES-JQ (table 1) estimation of three major items 1. The internal flow 2. The recharge into aquifer 3. The groundwater available for abstraction 12. Groundwater, soil water stocks 13. Surface water stocks 14. Fresh water balance: flows 15. Fresh water balance: stocks 24

26 To be completed Fresh Water balance (Table 1 extended) Not complete yet, under construction Data on abstractions, returns, imports and exports to be added in final stage of the project Estimates of discharged volumes of combined sewer overflows Not feasible Opening and closing stocks of groundwater, soil water and surface water; only estimated range Flows of Groundwater not feasible within the timing and resources of the project 25

27 Conclusions / Recommendations Sound estimate for the actual evapotranspiration is a key for a well established water balance Cooperation with external partners and experts has proven very useful for the project 26

28 Thank you for your attention! Questions? Eurostat: Luxembourg, 1 & 2 February 2012

29 Method The Netherlands: Part of 4 international river basin districts Rhine-area is split up into 4 national sub-basins 28