DISTRIBUTION AND EVOLUTION OF ALLUVIAL FANS IN TROPIC AND TEMPERATE HUMID REGIONS

其中菲律宾129条，台湾71条，日本490条，千岛群岛南部2条，波兰66条，扇形面积大于2千米/平方千米的河流有扇形河流占流域面积超过100千米/平方千米的河流的比例，菲律宾为20.3%，台湾为58.0%，日本为25.9%，200千米/平方千米以上的为9.4%，台湾为70.4%，日本为24.5%，波兰为20.0%。基于Ohmori(1978)在日本山区的方法。扇形河流占流域面积大于100 km2的河流的比例为：早、早亚段为0.0%，中小亚段为5.7%，中大亚段为22.8%，晚亚段为47.6%。地形起伏率随山地发育阶段的推进而变化。高地貌比的流域具有更陡峭的河床坡度，容易使扇子携带更大的砾石绕过山谷河口。基于Great…更广义的权重和气候条件下的高频分布，得出了200 km~2以上流域冲积扇分布的主导因素是气候条件。沉积环境和地貌比率也是重要因素。菲律宾西部的气候条件比北海道和日本西部更合适，这一事实推测，干燥和潮湿的气候条件对球迷来说是有利的。菲律宾东部最不利的条件是热带气候和常年降雨条件下粗料产量低，冲积扇面积随着山脉发育阶段的推进而增加，特别是在菲律宾、台湾和日本，冲积扇面积随着山脉发育阶段的推进而增加。菲律宾有44条河流，台湾有48条河流，日本有37条河流，在发育亚阶段较老的中山或晚期的山前平原上形成了扇形。流域面积与扇面面积的相关系数台湾为0.855，日本为0.680，菲律宾为0.734。在台湾和菲律宾，温度和降水量被认为在冰期和间冰期发生了变化，在日本也是如此，但数量不应该对碎片供应量产生重大影响。菲律宾的球迷面积是日本的110%到120%，台湾是日本的120%到160%。与台湾相比，菲律宾热带地区由于粗料生产较差，风机较小，但与日本相比，由于降水丰富和流量大，风机较大。较少

There are 129 rivers in Philippines, 71 ones in Tiawan, 490 ones in Japan, 2 ones in southern Kuril Islands, 66 ones in Poland, that have fans of over 2km^2. The ratios of rivers with fans to rivers whose drainage basins are more than 100km^2 are 20.3% in Philippines, 58.0% in Taiwan, and 25.9% in Japan, whereas the ratios in area over 200km^2 are 9.4% in Philippines, 70.4% in Taiwan, 24.5% in Japan, and 20.0% in Poland.The development stages of moutains were estimated in Taiwan and Philippines, based on the method of Ohmori(1978) in Japanese mountains. The ratios of rivers with fans to rivers whose drainage basins are more than 100km^2 are 0.0% in the earliest and early substage, 5.7% in younger middle one, 22.8% in older middle one, and 47.6% in later ones. Relief ratios with the advance of the develoment stage of mountains. Drainage basins with high relief ratios have steeper river-bed gradients, and are apt to make fans to carry larger gravel around valley mouths.Based on the great … More generalized weight and the high frequency in the categoty of climatic conditions, it is concluded that the dominating factor for the distribution of alluvial fans indrainage basins larger than 200km^2 is the climatic conditions. Sedimentary environments and relief ratios are also important factors. The fact that West Philippines has more suitable conditions than those in Hokkaido and West Japan os presumed that the climatic conditions with dry and wet seasons are advantage for fans. East Philippines has most unfavorable conditions due to poor coarse-material production under tropical climate and perennial rainfall.Alluvial fan areas increase with the advance of the development stage of mountains, specially from younger middle substage to older one, and from older one to later substage in Philippines, Taiwan, and Japan.There are 44 rivers in Philippines, 48 ones in Taiwan, and 37 ones in Japan, that have formed fans in the plains at the front of the mountains whose development substage are older middle or later. The correlation coefficients between drainage basin areas and fan areas are 0.855 in Taiwan, 0.680 in Japan, and 0.734 in Philippines. In Taiwan and Philippines, the temperature and amount of precipitation are considered to have been changed through the Glacial stage and the Interglacial stage as well as in Japan, but the quantative are not supposed to have drastically affected that the amount of debris supplies. The fan areas in Philippines are 110 to 120% and those in Taiwan are 120 to 160% as large as those in Japan. The fans in tropical Philippines are small due to poor production of coarse materials as compared with those in Taiwan, but are large owing to abundant precipitation and high discharge in comparison with Japan. Less