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| Titel |
An Assessment of Global Net Irrigation Water Requirements from Various Water Supply Sources to Sustain Irrigation |
| VerfasserIn |
Sayaka Yoshikawa, Jail Cho, Hannah Yamada, Anupam Khajuria, Naota Hanasaki, Shinjiro Kanae |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250094249
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| Publikation (Nr.) |
 EGU/EGU2014-9649.pdf |
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| Zusammenfassung |
| Water supply sources for irrigation, such as rivers, reservoirs, and groundwater, are critically
important for agricultural productivity. The current rapid increase in irrigation water use
threatens sustainable food production. In this study, we estimated the time-varying
dependence of irrigation water requirements from water supply sources, with a particular
focus on variations in irrigation area during the period 1960–2050 using the global water
resources model, H08. The H08 model simulates water requirements on a daily basis at a
resolution of 1.0° x 1.0°. The sources of irrigation water requirements in the past
simulations were specified using four categories: rivers (RIV), large reservoirs (LR) with a
storage capacity greater than 1.0 km3, medium-size reservoirs (MSR) with storage
capacities ranging from 1.0 km3 to 3.0 M m3, and non-local non-renewable blue water
(NNBW). We also estimated future irrigation water requirements from the above four
water supply sources and an additional water supply source (ADD) in three future
simulation designs; irrigation area change, climate change, and changes in both
irrigation area and climate. ADD was defined as the difference between NNBW
in the 1990s and NNBW in the 2040s, because it was difficult to distinguish the
types of future water supply sources except for RIV. The simulated results showed
that RIV, MSR, and NNBW increased significantly through the 1960s to the early
1990s globally, but LR increased at a relatively low rate. After the early 1990s, RIV
approached a critical limit due to the continued expansion of the irrigation area.
Furthermore, MSR and NNBW increased significantly following the expansion of the
irrigation area and the increased storage capacity of the medium-size reservoirs.
After the 2020s, MSR could be expected to approach the critical limit without the
construction of medium-size reservoirs. ADD would account for 11–23% of the total
requirements in the 2040s. We found that an expansion of the irrigation areas and
climate change would considerably increase irrigation water requirements from ADD. |
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