Precipitation records from 15 weather stations in the arid and semiarid regions in the Yellow River Basin of China were used to validate the CLIGEN weather generator.Daily records of 41 years from 15 stations were used to evaluate the generator.Generally,the performance of the CLIGEN generator is better in semiarid regions than in the arid regions.Results show that the generator was successful in modeling the means of the total of the annual,monthly and daily precipitation,the monthly probabilities of wet and dry days,and the variability of daily,monthly and annual precipitation.Mean absolute relative errors for simulating daily,monthly and annual precipitation across 15 stations were 2.1%,2.4% and 2.4% for the means and 3.6%,4.1% and 15.9% for the standard deviations,respectively.The relative error for the standard deviation of annual precipitation was relative high.Thus,the improvements of precipitation occurrence are expected.Mean absolute relative errors for the all-time maxima of daily,monthly and yearly precipitation were 5.2%,17.3% and 11.1%,respectively.Most of the maxima values across these stations were overestimated.It may lead to overestimation of runoff and sediment yield by the soil erosion models such as WEPP using the precipitation patterns generated by the CLIGEN model.The validation of the parameters of storm events such as storm duration and peak rain density are needed to conduct by using the pluviograph data.
[1] BannayanM, CroutN M J, Hoogenboom G. App lication of the CERES2Wheatmodel forwithin-season p rediction ofwinter wheat yield in the United Kingdom[J]. Agronom y Journal, 2003, 95 (1): 114-125.
[2] Hartkamp A D, White J W, Hoogenboom G. Comparison of three weather generators for crop modeling: A case study for subtrop ical environments[J]. Agricultural System s, 2003, 76 (2): 539-560.
[3] Kittel T G F, Rosenbloom N A, Royle J A, et al. VEMAP phase-bioclimatic database. I. Gridded historical (20 th century) climate formodeling ecosystem dynamics across the conterminous USA [J]. Clim ate Research, 2004, 27 (2): 151-170.
[4] Pickering N B, Stedinger J R, Haith D A. Weather input for nonpoint source pollution models[J]. Journal of Irrigation and D rainage, 1988, 114: 674-690.
[5] SemenovM A, Porter J R. Climatic variability and the modeling of crop yields[J]. Agricultural and ForestM eteorology, 1995, 73 (3-4): 265-283.
[6] Richter G M, Semenov M A. Modelling impacts of climate change on wheat yields in England and Wales: Assessing drought risks[J]. Agricultural System s, 2005, 84 (1): 77-97.
[7] Riha S J, WilksD S, Simoens P. Impact of temperature and p recip itation variability on crop model p redictions[J]. Clim at2 ic Change, 1996, 32 (3): 293-311.
[8] WeissA, Hays C J, Won J. Assessing winter wheat responses to climate change scenarios: A simulation study in the US Great Plains[J]. Clim atic Change, 2003, 58 (1-2): 119-147.
[9] Zhang X C, LiuW Z. Simulating potential response of hydrology, soil erosion, and crop p roductivity to climate change in Changwu tableland region on the Loess Plateau of China[J]. Agricultural and ForestMeteorology, 2005, 131 (3-4): 127-142.
[10] Mearns L O, Rosenzweig C, Goldberg R. Mean and variance change in climate scenarios: Methods, agricultural app lica2 tions, and measures of uncertainty[J]. Clim atic Change, 1997, 35 (4): 367-396.
[11] ElshamyM E, Wheater H S, GedneyN, et al. Evaluation of the rainfall component of a weather generator for climate impact studies[J]. Journal of Hydrology, 2006, 326 (1-4): 1-24.
[12] 高彦春,王长耀. 水文循环的生物圈方面(BAHC计划)研究进展[J]. 地理科学进展, 2000, 19 (2): 97～103. [GAO Yan-chun, WANG Chang-yao. Biospheric aspects of hydrological cycle: BAHC p lan and its research p rogress. Progress in Geography, 2000, 19 (2): 97-103.]
[13] 吴金栋,王馥棠. 随机天气模型参数化方案的研究及其模拟能力评估[J]. 气象学报, 2000, 58 (1): 49 ～59. [WU Jin-dong, WANG Fu-tang. Study on the parameters p rogram of a stochastic weather generator and evaluation of its simula2 tion. Acta Meteorologica S inica, 2000, 58 (1): 49-59.]
[14] 张东,张万昌. SWAT2000 气象模拟器的随机模拟原理、验证与改进[J]. 资源科学, 2004, 26 (4): 28～36. [ZHANG Dong, ZHANGWan-chang. Stochastic simulation theory, validation and imp rovement for SWAT 2000 climate simulator. Resources Science, 2004, 26 (4): 28-36.]
[15] 缪驰远,何丙辉,陈晓燕,等. WEPP模型中的CL IGEN 与BPCDG应用对比研究[J]. 中国农学通报, 2004, (6) . [MIAO Chi-yuan, HE Bing-hui, CHEN Xiao-yan, et al. Study on the app lication and contrast of CL IGEN and BPCDG in WEPP model app lication. Chinese Agricultural Science B ulletin, 2004, (6) .]
[16] 廖要明,张强,陈德亮. 中国天气发生器的降水模拟[J]. 地理学报, 2004, 59 (5): 689 ～698. [LIAO Yao-ming, ZHANG Qiang, CHEN De-liang. Precip itation simulation in China with a weather generator. Acta Geographica S inica, 2004, 59 (5): 689-698.]
[17] 杨文峰,陈德亮,胡春娟. 天气发生器对陕西降水的模拟[J]. 陕西气象, 2005, (5): 5-7. [YANGWen-feng, CHEN De-liang, HU Chun-juan. Simulation on p recip itation in Shaanxi p rovince by weather generator. Journal of ShaanxiMeteorology, 2005, (5): 5-7.]
[18] Luo Y, Shen Z R, Zeng SM. Risk Analysis ofDisease Ep idemics onWheat by Simulation Studies[J]. Agricultural System s, 1993, 43 (1): 67-89.
[19] 马晓光,沈佐锐. 随机天气发生器的可视化编程及其将来在农业生态学上的应用[J]. 中国农业科学, 2002, 35 (12): 1473～1478. [MA Xiao-guang, SHEN Zuo-rui. Visual p rogramming stochastic weather generator and its app lica2 tions to ecological study in future. Scientia Agricultura S inica, 2002, 35 (12): 1473-1478.]
[20] 史婉丽,杨勤科,穆婉红. 随机气候生成器在黄土高原的适用性检验[J]. 中国水土保持科学, 2006, 4 (2): 18～23. [SH IWan-li, YANG Qin-ke, MU Wan-hong. App licability test of CL IGEN in Loess Plateau. Science of Soil and W ater Conservation, 2006, 4 (2): 18-23.]
[21] 张光辉. CL IGEN天气发生器在黄河流域的适应性研究[J]. 水土保持学报, 2004, 18 (1): 175～178, 196. [ZHANG Guang-hui. Adap tability of climate generator of CL IGEN in Yellow River Basin. Journal of Soil and W ater Conservation, 2004, 18 (1): 175-178, 196.]
[22] NicksA D, Gander G A. CL IGEN: A weather generator for climate inputs to water resource and othermodels[A]. In: Proceedings of the 5 th International Conference on Computers in Agriculture[C]. St. Joseph, Michigan, 1994. 3-94.
[23] Baffaut C, NearingM A, Nicks A D. Impact of CL IGEN parameters on WEPP2p redicted average annual soil loss[J]. Transactions of the ASAE, 1996, 39 (2): 447-457.
[24] Yu B. Adjustment of CL IGEN parameters to generate p recip itation change scenarios in southeastern Australia[J]. CATE2 NA , 2005, 61 (2-3): 196-209.
[25] ElliotW J, Arnold C D. Validation of the weather generator CL IGEN with p recip itation data from Uganda [J]. Transac2 tions of the ASAE, 2001, 44 (1): 53-58.
[26] Zhang X C, Garbrecht J D. Evaluation of CL IGEN p recip itation parameters and their imp lication onWEPP runoff and ero2 sion p rediction[J]. Transactions of the ASAE, 2003, 46 (2): 311-320.
[27] Johnson G L, Hanson C L, Hardegree S P, et al. Stochastic weather simulation: Overview and analysis of two commonly used models[J]. Journal of Applied M eteorology, 1996, 35 (10): 1878-1896.
[28] Arnold C D, ElliotW J. CL IGEN weather generator p redictions of seasonalwet and dry spells in Uganda[J]. Transactions of the ASAE, 1996, 39 (3): 969-972.
[29] WilksD S, Wilby R L. The weather generation game: A review of stochastic weathermodels[J]. Progress in Physical Ge2 ography, 1999, 23 (3): 329-357.
