帕默尔旱度模式的进一步修正

为了正确评估干旱，根据帕默尔旱度模式的思路和1986年安顺清等人修正的帕默尔旱度模式，我们以济南、郑州和太原3站逐年逐月气温和降水等作为基本资料（1961～2000年），以哈尔滨、佳木斯、呼和浩特、沈阳、北京、固原、西安、汉中、青岛、德州、运城、长沙、武汉、南昌、杭州、福州、广州、昆明、南宁、成都和贵阳21个站的有关资料（1961～2000年）为权重因子修正资料，并且在计算可能蒸散时选用了FAO推荐的彭曼-蒙蒂斯公式。另外0～20 cm和20～100 cm土层的土壤田间有效持水量根据我国测定的资料和土壤特性确定，对帕默尔旱度模式进行了进一步修正。利用此模式计算了我国北方地区139个站点（1961年1月～2000年12月）的帕默尔指数值。将计算的帕默尔指数值与一些文献记载的实际旱涝灾情相对照进行验证，表明进一步修正的帕默尔旱度模式能较为准确地评估旱涝情况，适合应用于我国

The Farther Modification of Palmer Drought Severity Model

To evaluate the ravages of a drought, a farther modified Meteorological Drought Severity Model for China was developed based on the Palmer Drought Severity Model and the modified Palmer Drought Severity Model corrected by An Shunqing etc. The monthly temperature and precipitation data at Jinan, Zhengzhou and Taiyuan (1961—2000) were used as basic data and relevant data gained at other 21 stations (Harbin, Jiamusi, Hohhot, Shenyang, Beijing, Guyuan, Xian, Hanzhong, Qingdao, Dezhou, Yuncheng, Changsha, Wuhan, Nanchang, Hangzhou, Fuzhou, Guangzhou, Kunming, Nanning, Chengdu and Guiyang) to obtain the weighing coefficient. The potential evapotranspiration for an individual month was computed by the Penman-Monteith equation commended by FAO. The available soil moisture in both layers (0—20 cm, 20—100 cm) was determined by the soil moisture data and the soil characters. The monthly Palmer Drought Index was computed at 139 stations of North China from 1961 to 2000. Comparing the computed Palmer Drought Index with the situation of drought and waterlog recorded in some documents, it is found that the farther modified Palmer Drought Severity Model can reflect the severity of meteorological drought or waterlogging comparatively and is applicable for China.