Survey research of on regeneration of the abolished rivers in the Tokyo ward

在本研究中，我们根据东京都区废弃河流的实际情况，对再生条件和修复技术进行了研究。至于东京都区的小河，大正时期约80%的河流距离被废除。至于废河的上游空间，3/4被分流到道路上。至于较低的空间，大约60%被转移到下水道。此外，被覆盖的河流约占整个河流的30%。覆水河道的上部空间中，33%被用作绿色道路和公园，67%被用作道路和住宅用地。根据断面形式将被覆盖的河流的下部空间分为四个的结果是，具有覆盖层的雨水下水道沟或统一下水道沟占90%或更多。作为复盖河流再生的条件，我们选择了以下三个因素：足够宽度的绿色道路或公园，确保水量，蓄水设施的管理。以桃园川为例，探讨了利用雨水的复盖川修复技术。以Rakanji河为例，我们考虑了覆盖河流的恢复技术，使用泉水。

In this research, after being based on the actual condition of the abolished rivers in the Tokyo ward, we performed examination of the conditions for regeneration and the restoration technique.1. As for the minor river in a Tokyo ward part, about 80 percent of the river distance of the Taisho term was abolished. As for the up space of an abolition river, 3/4 was dive diverted to a road. As for lower space, about 60 percent was diverted to a sewer. Moreover, the covered river formed about 30 percent of the whole.2. As for the up space of a covered river, 33% was used as a green way and a park, 67% was used as a road and housing site.3. As a result of classifying the lower space of a covered river into four according to a cross-sectional form, the rainwater sewer ditch or the unification sewer ditch, that has overburden, account for 90% or more.4. As conditions for the covered river regeneration, we picked out following three factors ; a sufficient width of a green way or a park, securing the volume of water, management of water storage facility.5. Taking Momozono River for instance, we considered the restoration technique of the covered river, using rainwater.6. Taking Rakanji River for instance, we considered the restoration technique of the covered river, using springwater.