苏北海堤主要防护林类型的防护效益研究

Study on the Benefit of the Main shelterforest types on Seawalls in Jiangsu Province

定位观测分析结果表明：森林植被可有效地减低地表径流量，无林区地表径流量（径流系数为２１．９４％）分别比柳杉、水杉和刺槐林高５３．３３％，４３．８５％和３３．５５％。落叶期水杉和刺槐林地表径流量比柳杉林高３０％～５０％，而盛叶期水杉林地表径流量和柳杉林相近，但比刺槐林地减低２０％～３０％。森林对地表径流过程的影响，主要表现在减洪和滞洪方面，盛叶期柳杉和水杉林地表径流峰值比对照区减低７０％～８０％，刺槐林比对照区减低４０％～５０％，并能在不同程度上推迟产流和洪峰到来时间。在深入分析降水特性因子与地表径流量关系基础上，给出了各地段地表径流量回归估计模型，经误差检验估计精度达８０％以上。

The paper mainly studiesthe realationship between the quantity of surface runoff and their influential factors in the main shelter-forest types on seawalls in Jiangsu Province.It is shown by the results that forest vegetation has great function on decreasing the quantity of sur-face runoff.Conserastion plot has greater surface runoff quantity.Its surface runoff coefficient(21.9%)is bigger than that of chinese cryptomeria,water fir and black locus by 53.33%,43.58%adn 33.55%. The monthly surface runoff quantity of each forest types increases with thesame mouth s precipitation quantity.During deciduous period,surface runoff quantities of bothwater fir's and black locus sare greater than that of chinese cryptomerias by 30%～50%, Butduring growing peried,the surface runaff quantity of water fir is nearly the same as that of chi-nese cryptomeria. Both of their surface runoff quantity are biger than that of black locus's.Forest s niain influences are on decreasing the pick quantity of surface runoff and putting off picktime of surface runoff. Both chinese cryptomeria forest and water fir forest could decrease thepick quantity of surface runOff by 70%～80%,and the black Iocus forestcould reduce it by 40%～50%.soil characteristics,espeially the soil permenating capability and the depth of tight soil layercan also innuence the quantity of surface runoff greatly.In this paper,some regression medelsshovving the relationships between the surface runoff and rainfall characteristics in different areasare established.