Abstract. Future changes in the climate system could have significant impacts on the
natural environment and human activities, which in turn affect changes in
the climate system. In the interaction between natural and human systems
under climate change conditions, land use is one of the elements that play
an essential role. On the one hand, future climate change will affect the
availability of water and food, which may impact land-use change. On the
other hand, human-induced land-use change can affect the climate system
through biogeophysical and biogeochemical effects. To investigate these
interrelationships, we developed MIROC-INTEG-LAND (MIROC INTEGrated LAND
surface model version 1), an integrated model that combines the land surface
component of global climate model MIROC (Model for Interdisciplinary
Research on Climate) with water resources, crop production, land ecosystem,
and land-use models. The most significant feature of MIROC-INTEG-LAND is
that the land surface model that describes the processes of the energy and
water balance, human water management, and crop growth incorporates a land
use decision-making model based on economic activities. In MIROC-INTEG-LAND,
spatially detailed information regarding water resources and crop yields is
reflected in the prediction of future land-use change, which cannot be
considered in the conventional integrated assessment models. In this paper,
we introduce the details and interconnections of the submodels of
MIROC-INTEG-LAND, compare historical simulations with observations, and
identify various interactions between the submodels. By evaluating the
historical simulation, we have confirmed that the model reproduces the
observed states well. The future simulations indicate that changes in
climate have significant impacts on crop yields, land use, and irrigation
water demand. The newly developed MIROC-INTEG-LAND could be combined with
atmospheric and ocean models to develop an integrated earth system model to
simulate the interactions among coupled natural–human earth system
components.