| dc.description.abstract | Due to greenhouse effect, the gradual increase of temperature has been
found to be an important factor changing the global climate. The possible
outcomes of climate change will be the increase of precipitation, surface runoff,
and evapotranspiration, the decrease of soil moisture, and the high frequency of
extreme weather events, such as floods and droughts. However, the results at a
global scale may not reflect the outcome in regional scale, or in an even smaller
scale like the island of Taiwan. Therefore, it is worthwhile studying the effect
of climate change on the hydrologic cycle in Taiwan.
In order to effectively estimate the impact of climate change on land
hydrology in Taiwan, a simple water balance model is developed to account for
precipitation, evapotranspiration, surface runoff, and groundwater infiltration of
the land hydrologic cycle. Under different climate change scenarios, it is
applied to access the impacts of climate change on these land hydrologic
processes. Daily temperature and precipitation are major input data required
for this study, while landuse conditions is used to account for land surface
roughness. A total of nine climate change scenarios is applied to project
possible climate variations in the future.
Under current climate condition, the mean annual precipitation is around
928 billion tons, evapotranspiration is 314 billion tons, surface runoff is 414
billion tons, and groundwater infiltration is 200 billion tons in Taiwan. The
simulation results indicate that: Although predictions by different GCMs or
region climate model are different, the trend of more extreme precipitation and
surface runoff can be seen in most cases. Since groundwater infiltration is
closely related to evapotranspiration, surface runoff, and rainfall, the amount of
groundwater infiltration in Taiwan has a great possibility to gradually decrease
under the impact of climate change. | en_US |