| Based on abundant rainfall in Minjiang River Basin and frequent floods have brought great losses on agriculture production, national economy etc, the relationship between soil and water losses and rainfall characteristics was studied in four forest lands, viz. Chinese fir, enclosing and tending forest, Costarica henryi, orchard and control (bare land) in Jianou, Fujian by establishment of runoff plot. We systemically discussed the distribution of precipitation, dynamics of soil erosion in different land-use types, the relation between soil and water losses and some rainfall characteristics, such as rainfall amount, intensity, duration and prophase rainfall. Further, rainfall erosion force was discussed and regression equations between soil and water losses and rainfall characteristics were founded. Due to few detailed studies on this aspect, the ecological comparisons of soil and water loss among different utilized lands on the basis of various rainfall parameters are necessary in providing the implications for sustainable management of lands and alleviation of harms of floods in Minjiang River Basin. The results showed that:(1) Based on rainfall amount, times and types, rainfall in Minjiang River Basin could be divided into three distinct seasons, that was rainy season (from March to June) when the precipitation was great and dominating rain types were heavy rain and downpour, season influenced by typhoon storm (from July to October) which changed annually, and drought season (from November to February in next year) with little rainfall and small intensity.(2) There was significant difference in soil and water losses for various lands. Five land-use types followed annual runoff amount: the control (459.34mm) >orchard(42.26 mm) >Castanea henryi forest (25.88 mm) >enclosing and tending forest (18.90 mm) > Chinese fir forest (16.79 mm). Annual runoff coefficient for the control was 25.29%, while only 0.92% for Chinese fir forest. The corresponding sequence of soil erosion in different lands was the control (52.527 t-hm-2) >orchard (0.171 t-hm-2) >Castanea henryi forest (0.128 t-hm-2) >Chinese fir (0.029 t-hm-2) and enclosing and tending forests (0.028 t-hm-2). Especially, soil erosion modulus in the control was over 5000 t-km-2-a-1 belonging to severe soil erosion intensity, while for other land-use types, the values were all less than 200 t-km-2a-1 and fell in the range of normal erosion intensity. So lands covered with vegetation and soil and water conservation measures being made can prevent soil and water losses effectively.(3) The seasonal change of soil and water losses was evident similar to rainfall. Runoffamount in rainy season for different land-use types constituted more than 50% of annual amount, while the proportion in drought season was less than 17%. Of annual total soil loss amount, the control accounted for 60% and complex proportions for other lands. However, soil loss amounts in drought season for all lands were lowest in one year.(4) On the premise of same rain type, significant differences in soil and water losses for various land were found. In the control, even light rain could bring soil and water losses. While for orchard and Costarica henryi forest, runoff and sediment yield both reduced greatly. Regarding to Chinese fir and enclosing and tending forests with favorable vegetative coverage, minimum soil and water losses were produced even by the rainstorm.(5) Rain types had different effects on soil and water losses. Statistical analysis showed that soil loss produced by medium rain was dominated and heavy rain (or storm) was the primary rain type which could result in soil erosion. The proportions of soil and water losses caused by heavy rain (or storm) were 65%~75% and >80% respectively. There was extremely significant positive correlation between rainfall and runoff amount, while not-significant correlation between rainfall and soil loss was found.(6) Great differences in soil and water losses in studied lands were observed on the...
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