Abstract: Nitrogen saturation has become one of the serious issues in the field of forest environment. The watershed protection forests located in the downwind hinterland of Tokyo Metropolitan Area are believed to be facing nitrogen saturation. In this study, we carefully focus on the balance of nitrogen between load and runoff. Annual nitrogen load via atmospheric deposition was estimated to 461.1 t-N/year in the upper reaches of the Kanna River. Annual nitrogen runoff to the forested headwater stream of the Kanna River was determined to 184.9 t-N/year, corresponding to 40.1% of the total nitrogen load. Clear seasonal change in NO3-N concentration was still observed. Therefore, watershed protection forest of the Kanna River is most likely to be in Stage-1 on the status of nitrogen saturation.
Abstract: On March 11, 2011, the Great East Japan Earthquake occurred off the coast of Sanriku, Japan. It is important to build a sustainable society through the reconstruction process rather than simply restoring the infrastructure. To compare the goals of reconstruction plans of quake-stricken municipalities, Japanese language morphological analysis was performed by using text mining techniques. Frequently-used nouns were sorted into four main categories of “life”, “disaster prevention”, “economy”, and “harmony with environment”. Because Soma City is affected by nuclear accident, sentences tagged to “harmony with environment” tended to be frequent compared to the other municipalities. Results from cluster analysis and principle component analysis clearly indicated that the local government reinforces the efforts to reduce risks from radiation exposure as a top priority.
Abstract: The balance between nitrogen loading and runoff in the
forested headwater streams of the Kanna River was estimated to
elucidate the current status of nitrogen saturation in a forested
watershed. NO3-N concentration in the study area was far higher than
the average value in Japan. Estimated nitrogen runoff accounted for
55–57% of nitrogen loading; suggesting that the forest-s nitrogen
retention capacity is most likely in decline. Since the 1970s, Japan-s
forestry industry has been declining due to the decrease in lumber
demand and increase in cheap imported materials. Thus, this decline
will contribute significantly to further reducing nitrogen saturation in
forest ecosystems.
Abstract: A long-term campaign for monitoring the
concentration of atmospheric Particulate Matter (PM) was conducted
at multiple sites located in the center and suburbs of the Tokyo
Metropolitan Area in Japan. The concentration of fine PM has shown a
declining trend over the last two decades. A positive matrix
factorization model elucidated that the contribution of combustion
sources was drastically reduced. In Japan, the regulations on vehicle
exhaust emissions were phased in and gradually tightened over the last
two decades, which has triggered a notable reduction in PM emissions
from automobiles and has contributed to the mitigation of the problem
of fine PM pollution.
Abstract: On March 11, 2011, the East coast of Japan was hit by
one of the strongest earthquakes in history, followed by a devastating
tsunami. Although most lifelines, infrastructure, and public facilities
have been restored gradually, recovery efforts in terms of disposal of
disaster waste and revival of primary industry are lagging. This study
presents a summary of the damage inflicted by the earthquake and the
current status of reconstruction in the disaster area. Moreover, we
discuss the current trends and future perspectives on recently
implemented eco-friendly reconstruction projects and focus on the
pro-environmental behavior of disaster victims which is emerging as a
result of the energy shortage after the earthquake. Finally, we offer
ideas for initiatives for the next stage of the reconstruction policies.