Quantification of Water, Energy and Material Cycles in an Afforested Watershed of Chamaecyparis Obtuse in Kyushu and Those Public-Benefit-Functions.

在日本九州大学森林Kasuya研究林的Ochozu实验流域，研究了长尾草（Chamaecyparis Obtusa）造林流域的水、能量和物质循环。(1)径流结果估算出地表径流与地下径流之间的阈值为7.6mm的流域蓄水量，大致相当于主要水文活动区的厚度。采用简单遗传算法和模糊线性回归对存储函数模型参数进行优化搜索。采用存储型半分布参数模型TOPMODEL对长期和短期径流进行了估计。在流域尺度上，河岸带地下水位对径流现象具有一级控制作用。坡面上次表层土壤含水量也与流量有关，说明坡面、河岸带和河流之间存在水文耦合，发生了降雨事件。(2)叶面蒸腾速率的测定结果叶面蒸腾速率的测定结果叶面蒸腾速率的测定结果表明，叶面蒸腾速率的测定对叶面蒸腾速率和叶面蒸腾速率的测定结果表明，叶面蒸腾速率的测定至少需要20个样品。杉木树液流测量结果表明：1)虽然单株树液流的绝对速度不同，但其日变化规律基本一致；2)单株树蒸腾速率随着胸径的增大而增大，这是由于边材面积和树液通量密度的增加。两层槽模型较好地估计了流域径流和蒸散发的季节变化。(3)物质循环结果研究表明，为了合理估算流域养分平衡，排放是不可避免的，并评价了小草津流域总氮（T-N）和总磷（T-P）的输出通量均超过输入通量。由于大部分磷以颗粒形式输送，即使是最适用的养分负荷评价方法L-Q法也低估了T -P负荷。少

Water, energy and material Cycles in an Afforested Watershed of Chamaecyparis Obtusa were investigated in the Ochozu Experimental Watershed in Kasuya Research Forest of Kyushu University Forest in Kyushu, Japan.(1)Results on runoffThe threshold between overland flow and subsurface runoff was estimated to be basin storage of 7.6mm that is approximately equivalent to the thickness of major hydrological activity zone. Parameters for the Storage Function Model were optimally searched by simple genetic algorithm and fuzzy linear regression. Both long-term and short-tem runoffs were estimated by TOPMODEL, a storage-type semi-distributed-parameter model. Ground water level in the riparian zone was a first-order control on the runoff phenomenon at the basin scale. The soil moisture content of the upper subsurface in the slope also related to the discharge, which implies that hydrological coupling among the slope, the riparian zone and the stream occurred the rain events.(2)Results on evapotran … More spirationStatistical analysis on the sampling numbers of sapwood for the appropriate application of Granier method, a sapflow measurement method, showed that at least 20 samples are required for the measurement of sapflow for Cryptomeria japonica and Chamaecyparis obtusa. The results of sapflow measurement of Chamaecyparis obtusa showed that 1) although the absolute velocities of individual sapflow varied, the their diurnal variations were almost identical, 2) transpiration rate from a single tree was increased with DBH due to increase both in sapwood area and the sap flux density. Two layers tank model well estimated the seasonal changes of runoff and evapotranspiration of the watershed.(3)Results on material cyclesWe showed that discharge is inevitable to estimate nutrient balance of watershed appropriately, and evaluated that output fluxes of both total nitrogen (T-N) and total phosphorus (T-P) exceeded the input fluxes in the Ochozu Watershed. Since most of phosphorus was transported in the form of particulate, even L-Q method, most applicable method to evaluate nutrient load, underestimated the T -P load. Less