Estimation of Aquatic Animals' Potential Habitats based on Geographical Information System.

在分析兵库县水生和湿地动物的潜在栖息地之前，我们收集了大量的评估报告、当地论文和科学出版物。淡水动物的数据库样本多达一万五千种。然后，在地理信息系统（GIS； ESRI软件）的给定尺度网格基础上，对这些水生动物的分布与现有的地质、地理、气象和植物社会学数据库进行多元回归分析。分析表明，流域面积、给定点的坡度和下游垂直断面的面积决定了溪水更替频率的时间。溪水替代量的低与泥沙等悬浮物的沉降速率有关。这层沉积物为淡水双壳类提供了适宜的栖息地，而这些双壳类又为濒危的鲤类提供了适宜的产卵物质。在兵库县，被泥土和沙子覆盖的河流流域现在是相当稀少的栖息地。这些栖息地已经被大口黑鲈和蓝鳃鱼等外来鱼类入侵。濒临灭绝的淡水鱼是双拳的情况。现在迫切需要县政府采取措施抑制这些外来物种的数量。同样的方法也适用于日本农村的火蜥蜴Kasumi。在这种情况下，由于位于山坡上的水田建设所造成的渐变斜坡的缺乏，为地下水提供了泄漏点，为这种水生动物的产卵点提供了时间池。时间池和带植被的渐变坡度两个变量的集合与该蝾螈的潜在栖息地有很强的相关性。在这种情况下，与最近的另一个合适栖息地的距离也是重要因素。此外，我们还调查了濒危鲤科鱼类栖息的泥质河段和沙质河段河道整治前后鱼类群落的差异。改造前河流结构特点是岸线复杂，存在深点，被泥质基材包裹。经过改良后，这些性状变为形状平坦、面积较浅、底质较砂。根据这种生境因子的剧烈变化，鱼类群落结构立即严格响应。我们判断这种变化将是暂时的现象。生境结构和鱼类群落的监测研究仍在继续。少

Prior to analyzing the potential habitat of aquatic and wetland animals in Hyogo Prefecture, we gathering a numerous number of assessment reports, local papers and scientific publications. The data base sample of the fresh water animals reach up to fifteen thousands. Then, we analyzed the multiple-regression between these aquatic animals distribution and the existing geological, geographical, meteorological and plant sociological database on the base of given scale grid in Geographical Information System (GIS ; ESRI soft). These analysis revealed that the area of the drainage, the gradient of given point and the area of vertical section following downstream, decides time of creek water replacement frequency. The low value of creek water replacement surely related to sedimentation rate of suspended substances such as mud and sand. This deposit layer provides the suitable habitat for freshwater bivalves, and then these bivalves provide the suitable spawning substances of endangered cypri … More nid fish such as small bitterling. In Hyogo Prefecture, the stream reach embedded by mud and sand is now quite scarce habitats. These habitats are already invaded by alien fish of largemouth bass and blue gill. The endangered freshwater fish is double punched situation. Actions depressing these alien species population by the prefectural government is urgently needed now.The same method is employed about Japanese countryside salamander, Kasumi. In this case, the lack of the gradual slope created by paddy field construction located mountain slope, provides the leak point of ground water, it making temporal pool for spawning point for this aquatic animal. The set of two variables of temporal pool and gradual slope with vegetation strongly correlated to potential habitat of this salamander. In this case, the distance from nearest another suitable habitat is also important factor.In addition, we investigated the fish communities differences between prior to and after stream channel improvement at muddy and sandy reach, where inhabited by endangered cyprinid fishes. Before improvement stream structure were characterized by, complicated shore-line, existence of deep point, and embedded by muddy substrate. After improvement these characters changed to plain shape, shallow area and sandy substrate. According to this dramatic change of the habitat factors, fish community structure strictly responses immediately. We judge this change will be temporal phenomenon. The monitoring research both habitats structure and fish communities are continued. Less