Table A.1.

Methods used and uncertainties associated with reconstruction of radiation exposure rates for different areas and time periods.

Area of interest	Period of coverage	Method	No of grids	GSD
Roofs of ChNPP	3 August 1986–30 September 1986	Kriging	1	2.2
	1 October 1986–19 April 1987	Kriging	1	2.3
	20 April 1987–17 May 1987	Kriging	1	2.3
	18 May 1987–14 July 1987	Kriging	1	3.0
	15 July 1987–31 December 1987	Kriging	1	2.0
	01 January 1988–31 December 1990	Empirical formula	-	2.0
The main buildings of ChNPP	26 April 1986–1 December 1986	4-D interpolation	-	3.7
	2 December 1986–31 December 1990	Empirical formula	-	4.8
Industrial site of the ChNPP	26 April 1986–1 October 1986	Kriging	17	2.8
	2 October 1986–31 December 1987	Kriging and trend function	2	3.3
	1 January 1987–31 December 1990	Empirical formula	-	3.3
4-km zone around the ChNPP	26 April 1986–4 August 1986	Kriging	4	3.0
	5 August 1986–1 February 1987	Extrapolation using multiple regression	-	4.3
	2 February 1987–31 December 1990	Empirical formula	-	4.3
30-km zone around the ChNPP	26 April 1986–12 September 1986	Kriging	25	2.6
	13 September 1986–31 December 1987	Deposition density	-	1.7
	1 January 1988–31 December 1990	Deposition density and kriging	5	1.7
70-km zone around the ChNPP	26 April 1986–31 December 1987	Kriging	14	2.7
	1 January 1988–31 December 1990	Deposition density and kriging	5	2.7