黑龙江省降雨侵蚀力的变化规律

Variation characteristics of rainfall erosivity in Heilongjiang Province

利用黑龙江省16个气象站1960—2000年日降雨量资料,采用日降雨量侵蚀力模型计算降雨侵蚀力,对黑龙江省降雨侵蚀力变化规律及其与降雨量的关系进行分析。结果表明:1)黑龙江省1960—2000年年降雨侵蚀力、年降雨量、侵蚀性降雨量都呈升高的趋势,年降雨侵蚀力、年降雨量和侵蚀性降雨量变化速率分别为1.47 MJ.mm/(hm2.h.a)、0.29 mm/a和0.35 mm/a;2)黑龙江省16个气象站中有11个气象站降雨侵蚀力倾向率为正值,牡丹江降雨侵蚀力升高幅度最大,为15.6 MJ.mm/(hm2.h.a),有5个气象站的倾向率为负值,其中齐齐哈尔降雨侵蚀力降低幅度最大,为-16.8 MJ.mm/(hm2.h.a);3)16个气象站除哈尔滨、克山、呼玛、通河外,侵蚀性降雨时间变化对侵蚀性降雨量变化的作用大于侵蚀性降雨强度变化对侵蚀性降雨量变化的作用,显示大部分站点侵蚀性降雨量变化主要由侵蚀性降雨时间变化引起的。研究结果可为土壤侵蚀预报以及水土保持规划与决策提供依据。

We analyzed the relationship between change characteristics of rainfall erosivity and precipitation using daily rainfall data during 1960 to 2000 from 16 weather stations in Heilongjiang Province. The results indicate that： trend of annual rainfall erosivity from 1960 to 2000 is increasing, as same as trend of annual precipitation and trend of erosive precipitation, however, the changes are not significant. The annual rainfall erosivity, annual precipitation and erosive precipitation increase with rate of 1.47 MJ.mm/（hm^2·h·a） , 0.29 mm/a, 0.35 mm/a from 1960 to 2000, respectively. There are eleven weather stations that the rates of the tendency are positive, the annual rate of the tendency of rainfall erosivity increase largestly in Mudanjiang, which rate is 15.6 MJ·mm/（ hm^2· h· a） ; while there are five weather stations that the rates of the tendency are negative, the annual rate of the tendency of rainfall erosivity decrease the minimum in Qiqihaer, which is - 16.8 MJ-mm/（ hm^2· h· a）, all sites＇ changes are not reach significant level. Apart from （Harbin, Keshan, Huma, Tonghe） , the impact of the changes of frequency of erosive rainfall on the changes of erosive rainfall is greater than the impact of the intensity of erosive rainfall on the changes of erosive rainfall in these 16 weather stations. The results can provide a basis for the prediction of soil erosion and planning and decision-making for soil and water conservation.