抄録
In order to clarify effects of the vegetation change in the Ashio district on short-term rainfall characteristics in its surrounding region, the current study conducted statistical analysis of observation data and experimental numerical simulations of precipitation systems using a mesoscale meteorological model with past and present conditions of land cover. Results of the statistical analysis show that the frequency of short-term heavy rainfall with over 30 mmh at the stations located 10 to 30 km north of the Ashio district show a slight decrease, which is a tendency totally different from other stations in the surrounding region. On the other hand, simulation results of 61 events show that the vegetation recovery in the Ashio district can cause such a frequency decrease of rainfall due to the impact of ground roughness increase on the location and frequency of convective cloud initiation, which indicates that the result of the statistical analysis can be attributed to the vegetation recovery.
