137 Cs, , :, 137 Cs. , 137 Cs. LIU Zhi2qiang 1,2,3 YANG Ming2yi 1,2 LIU Pu2ling 1,2 TIAN Jun2liang 1,2

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1 ,23 (3) : Journal of Nuclear Agricultural Sciences : (2009) Cs 1,2,3 1,2 1,2 1,2 (1., ; 2. Π, ; 3., ) : Cs, Cs,, Cs,:, Cs ; Cs, Cs, 0125m 2 11 ;, Cs, Cs,7, : Cs ;; SAMPLING NUMBERS AND AREA FOR THE CONFIRMATION OF Cs REFERENCE INVENTORY LIU Zhi2qiang 1,2,3 YANG Ming2yi 1,2 LIU Pu2ling 1,2 TIAN Jun2liang 1,2 (1. Research Center of Soil and Water Conservation & Eco2environment, Ministry of Education, Chinese Academy of Sciences, Yangling, Shaanxi ; 2. State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water ConservationΠNorthwest Sci2Tech University of Agriculture and Forestry, Yangling, Shaanxi ; 3. Graduate School, Chinese Academy of Sciences, Beijing ) Abstract :Confirmation of the Cs reference inventory is the premise and foundation of using Cs technique to study soil erosion. However, most investigators made the Cs reference inventory using haphazard approach and lacked the uniform sampling numbers and sampling area. The sampling method of gradually increased grid density was used to study the spatial variation of Cs reference inventory on undisturbed land and cultivated land in this paper. The results indicated that Cs inventory showed spatial variation greatly on the undisturbed area. The exponential regression appeared between the number of reference points and CV. With the increasing of grid area, the coefficient of variation of Cs content displayed the increased trend. And to satisfy the required accuracy of experiment, at least 11 points should be sampled in the area of 0125m 2. However, due to long2term cultivation on crop land, the Cs content was mixed uniformly within the plough layer, and the spatial variation decreased obviously. The sampling numbers of reference points had also the exponential regression relationship with CV. At least 7 points should be sampled to reach accuracy of experiment, and the sampling numbers were not affected by sampling area. Key words : Cs reference inventory ; grid sampling ; spatial variability, Cs : : : (2006BAD09B05) : (19822),,,,, E2mail com : (19702),,,, E2mail com

2 3 Cs 483 Cs Cs,, Cs Cs Cs 50 Cs [1 ], :, [2 ] 3 Cs ; [3 ] 2,10 ; [4 ] 15, 10 Cs ; [5 ] 3, 5, 1, Theocharopoulos [6 ] 10, 34 %, ; Sutherland [7 ] 11 Cs, 1Π3 Cs, Suthealand [7 ] 75 Cs, 11 %,, Cs,Π, Cs,, Cs, Cs [8,9 ] ; Cs [10 ],,, 4 4m 2, 1 115m 2 ; 4 8m 2 4 4m 2, ( 1), 0125, Cs 32m 2 4, Cs cm [7,11,12 ], Cs, 30cm N = 2 t (, n- 1) CV,, (1) A E,1, : N ; t 95 %t ; CV ( ) ; A E (, 10 %). t CV,[ 1 ],, ;[1 ] Cs, Cs, Cs,, Cs,, 1 Cs : (1) (N :34191,E : ),,,, ; (2) (N :36156, E : ),,, : (3) (N :35122,E : ),,,, ; (4) (N : 34175,E : ),,, 60,, 2 4,4 4m 2 2 4m 2 2 2m 2 1 2m 2 1 1m m m 2 7 ; 5,5 ;,,

3 484 23, Cs, 95 % ( 10 %) 8h 3 1 Fig. 1 The sampling schematic diagram,spss Cs,,,, 40,, 300g MCA, ORTEC 8192, 66116keV Cs, Cs 311 Cs 1 Cs 1 Cs,, Walling [13 ] Cs 1,, [14 ], Cs,, Cs,;,, 113,1600m, Cs,4 Cs,,,,,,, 4 Cs Table 1 The measured and predicted data of Cs reference inventories in the different sampling sites sampling sites Tongchuan,Shaanxi Lanzhou, Gansu Yuncheng,Shanxi Tianshui, Gansu longitude ( E) latitude ( N) altitude (m) annual mean precipitaion (mm) Cs Cs reference inventory measured (Bq kg - 1 ) Cs Cs reference inventory measured (Bq m - 2 ) Cs Cs reference inventory predicted (Bq m - 2 ) Cs Cs,, Cs 1214 % 1112 %, Cs,(1) DataFit % : y = 0197 e x R 2 = 0185 n = 66 () (2) y = 0185 e x R 2 = 0185 n = 82 () (3) : y Cs; x Cs ; n Cs SPSS Cs ( 2 3), Cs N (0111, 0102) N(0112, 0103), 95 % 7 % 15 % 6 % 18 % (2) (3) 95 % , 11,

4 3 Cs Cs Fig. 2 The CV frequency distribution of Cs reference inventories in Lanzhou 3 Cs Fig. 3 The CV frequency distribution of Cs reference inventories in Tongchuan,Shaanxi 2 Cs Table 2 The relationship between CV of Cs reference inventories and the gridding area on the undisturbed land sampling sites Lanzhou,Gansu Tongchuan,Shaanxi the area of gridding(m 2 ) CV the average coefficient of variation( %) Sutherland [6 ] 11 2, Cs, 0125m 2,, Cs,, Cs 313 Cs Cs,,,, Cs, 7 % 10 % N(0107,0102) N(0110,0102) ( 4 5), 95 % 3 % 11 % 6 % 14 %, : y = e ( x x2 ) R 2 = 0186 n = 30 () y = e ( x x2 ) R 2 = 0178 n = 163 () (4) (5) : y Cs; x Cs ; n Cs (4) (5) 95 % : , 5 7 Cs 7 4 Cs Fig. 4 The CV frequency distribution of Cs reference inventories in Yuncheng, Shanxi Cs, Cs ( 3), Cs

5 486 Journal of Nuclear Agricultural Sciences 2009,23 (3) : % Cs, Cs 7 Cs, Cs, Cs : 5 Cs Fig. 5 The CV frequency distribution of Cs reference inventories in Tianshui, Gansu 3 Cs sampling sites the gridding area (m 2 ) CV the average of CV( %) 4 Table 3 The relationship between CV of Cs reference inventories and the gridding area on the cultivated land Yuncheng,Shanxi Tianshui, Gansu , Cs, Cs, : (1), Cs, Cs 1214 % 1112 % Cs 95 % Cs,11, Cs, 0125m 2, 0125m 2 11 Cs (2), Cs, Cs 7 % 10 %, [ 1 ],,,. Cs [J ].,2004,18 (5) : [ 2 ],,Walling D E. Cs [J ].,1998, 53 : [ 3 ] Ming2Yi Yang, Jun2Liang Tian, Puling Liu. Investigating the spatial distribution of soil erosion and deposition in a small catchment on the Loess Plateau of China, using Cs[J ]. Soil & Tillage Research, 2006, 87 : [ 4 ],,,. Cs (I)2 Cs[J ].,2003, 23(3) : [ 5 ],,,,. Cs [J ].,2002, 47 (3) : [ 6 ] Theocharopoulos S P, Florou H, Walling D E, Nikolaou T. Soil erosion and deposition rates in a cultivated catchment area in central Greece, estimated using the Cs technique[j ]. Soil & Tillage Research, 2003, 69 : [ 7 ] Ross A. Sutherland. Caesium2 soil sampling and inventory variability in reference locations : A literature survey[j ]. Hydrological processes, 1996, 10 :43 53 [ 8 ] Basher L R. Matthews KM. Relationship between Cs in some disturbed New Zealand mils and rainfall [J ]. Australian Journal of Soil Research, 1993, 31 : [ 9 ] Harper R J,Gilkes R J. Evaluation of the Cs techniques for estimating wind erosion losses for some sandy Western Australian soils [ J ]. Australian Journal of Soil Research, 1994, 32 : 1369 l387 [10 ] Chisto Takenaka, Yuichi Onda, Yasunori Hamajima. Distribution of cesium2 in Japanese forest soils : Correlation with the contents of organic carbon[j ]. The Science of the Total Environmental, 1998, 222 : [11 ] Nolin M C,Cao Y Z, Coote D R, Wang C. Short range variability of fallout Cs in an uneroded forest soil [J ]. Canadidan Journal of Soil Science. 1993, 73 : 38l 385 [12 ] Collins A I, Walling D E,Sichingabula H M. Using Cs measurements to quantify soil erosion and redistribution rates for areas under different land use in the Upper Kaleya River basin. southern Zambia [ J ]. Geoderma, 2001, 104 : [13 ] Walling D E, He Q. The global distribution of bomb2derived Cs reference inventories. Final Report on IAEA Technical Contract 10361Π RO2R1. University of Exeter, 2000,1 11 [14 ],,,,. Cs [J ].,2006,29 (1) :42 49