 |
| Titel |
Assessing the changes of groundwater recharge / irrigation water use between SRI and traditional irrigation schemes in Central Taiwan |
| VerfasserIn |
Shih-Kai Chen, Cheng-Shin Jang, Cheng-Bin Tsai |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250102816
|
| Publikation (Nr.) |
 EGU/EGU2015-2217.pdf |
|
|
|
|
|
| Zusammenfassung |
| To respond to agricultural water shortage impacted by climate change without affecting rice
yield in the future, the application of water-saving irrigation, such as SRI methodology,
is considered to be adopted in rice-cultivation in Taiwan. However, the flooded
paddy fields could be considered as an important source of groundwater recharge in
Central Taiwan. The water-saving benefit of this new methodology and its impact on
the reducing of groundwater recharge should be integrally assessed in this area.
The objective of this study was to evaluate the changes of groundwater recharge/
irrigation water use between the SRI and traditional irrigation schemes (continuous
irrigation, rotational irrigation). An experimental paddy field located in the proximal
area of the Choushui River alluvial fan (the largest groundwater pumping region in
Taiwan) was chosen as the study area. The 3-D finite element groundwater model
(FEMWATER) with the variable boundary condition analog functions, was applied in
simulating groundwater recharge process and amount under traditional irrigation
schemes and SRI methodology. The use of effective rainfall was taken into account or
not in different simulation scenarios for each irrigation scheme. The simulation
results showed that there were no significant variations of infiltration rate in the
use of effective rainfall or not, but the low soil moisture setting in deep soil layers
resulted in higher infiltration rate. Taking the use of effective rainfall into account, the
average infiltration rate for continuous irrigation, rotational irrigation, and SRI
methodology in the first crop season of 2013 were 4.04 mm/day, 4.00 mm/day and 3.92
mm/day, respectively. The groundwater recharge amount of SRI methodology was
slightly lower than those of traditional irrigation schemes, reducing 4% and 2%
compared with continuous irrigation and rotational irrigation, respectively. The
field irrigation requirement amount of SRI methodology was significantly lower
than those of traditional irrigation schemes, saving 35% and 9% compared with
continuous irrigation and rotational irrigation, respectively. The SRI methodology
significantly improved water-saving benefit compared with the disadvantage of
reducing groundwater recharge. The results could be used as a basis for the relevant
government agency to formulate the integral water resource management strategies in this
area.
Keywords: SRI, Paddy field, Infiltration, Groundwater recharge |
|
|
|
|
|
|