In this study, we first use the IMPACT-WATER model to assess the
degree of irrigation stress at the scale of individual river basins, and
then (in a sequential fashion) we embed these estimates within an
extended version of the GTAP model GTAP-BIO-W to explore how
changes in future irrigation availability for irrigation will affect crop
production, food prices, and the resultant effects of these changes on
bilateral trade patterns (Fig. A1). (Note that irrigation availability is
defined as the share of potential irrigation demand realized through
actual consumption, and it is estimated using the 1951-2000
monthly climatology representing average climate condition over
that period.) Compared with previous studies, our approach allows
for new interactions across sectors, which includes inter-sectoral
linkages through intermediate inputs and competition for land,
water, labor, capital and energy. Moreover, the model we proposed
has the special advantage of analyzing bilateral trade flows and
providing macro-economic impacts of irrigation shortfalls.