Seasonal Estimation ofWater Deficit for Irrigation
and Introduction of CREST project

AGATA, Yasushi (Musiake-Herath-Oki Labo / CREST)/Tan, Guoxing (Shibasaki Labo)

What is CREST?
Research BackgroundResults and Discussion

CREST
Core Research for
Evaluational Science and Technology「戦略的基礎創造研究推進事業」in Japanese

A Big Research Program under JST

(Japan Science and Technology Corporation,
科学技術振興事業団)

Assembly of Major Research Topic
Currently begin paid intensive attention

Research Fields(領域) in CREST
・たんぱく質の構造・機能と発現メカニズム
・免疫難病・感染症等の先進医療技術
・情報社会を支える新しい高性能情報処理技術
・水の循環系モデリングと利用システム
・物理的手法を用いたナノデバイス等の創製
・化学・生物系の新材料等の創製・生命活動のプログラム
・生体防御のメカニズム・量子効果等の物理現象
・単一分子・原子レベルの反応制御
・極限環境状態における現象
・高度メディア社会の生活情報技術
・電子・光子等の機能制御
・分子複合系の構築と機能・ゲノムの構造と機能・脳を知る（脳の機能）
・脳を守る
・脳を創る
・環境低負荷型の社会システム
・地球変動のメカニズム・内分泌かく乱物質
・資源循環・エネルギーミニマム型システム技術
・生物の発生・分化・再生
・植物の機能と制御

・Many programs in bio-tech,nano-tech, IT andenvironmental science…
Among them

“水の循環系モデリングと利用システム”“Comprehensive IT
System for understanding
Real Global Water Cycle”
・Manager : Prof. Musiake
・Contains some projects

Projects under Prof. Musiake'sProgram(領域) ・Six project on atom. science,
人間活動を考慮した世界水循環・水資源モデル
階層的モデリングによる広域水循環予測
黄河流域の水利用・管理の高持続性化
北東アジア植生変遷域の水循環と生物・大気圏の相互作用の解明
社会変動と水循環の相互作用評価
モデルの構築湿潤・乾燥大気境界層が降水システムに与える影響の解明と降水予測精度の向上

water resource, ecology,social science on water use…
Among them

“人間活動を考慮した世界
水循環・水資源モデル”“Global Water Resource
Modeling with Reference
to Human activities”
・Leader : Prof. Oki
・Researchers from various field・Many PDFs, including myself

Current Global Water Resource
Assessment
Done by 0.5deg x 0.5deg grid , Annual Value
Water Supply: our original method
Climate Data + Hydrological Simulation
 "natural" river flowWater Demand: two ways

Simple Method (conventional , “ver.1”)
 National Statistics + Population Grid +Agriculture Grid Data

Process-based Modeling (recent job by Dr.Tan, “ver.2a”)
 Using EPIC for agriculture water use

Both estimations are done independently

As the first step

Water Supply
How much water
can be potentiallyused?
River Discharge Blue=wet→←River Disc. per capita
Red=poor in water

Water Demand – ver.1
How much water is necessary for human society?

←Total Demand
Blue=much water needed

Water Demand per capita→
Red=much water neededWater Demand in two ways
Demand per capita←Simple method(ver.1)

Process-based agriculture
model, EPIC→(ver.2a)Water Stress
Necessary water / Available water (base: ver. 1 demand)
Red = more risky←Scenario 1

All river water can be used

Scenario 2→
No water from upstream canbe used

Unexamined issues
For futureHigher temporal resolution
 Data limitation : discussion based on annual value

have been common
 What-if estimated by monthly?
Process-based modeling of demand Partly done for agriculture

Today’sTopic

Interactive modeling between supply model anddemand model
constrains

Water Supply
Model

Water Demand
Model
Change"natural"stateEvolution of modeling~Oct. 2001
(already in paper)

Current

Water Supply
Estimate

Water Demand(independent)
Estimate

Water Supply
Modelconstrains

Water Demand
Modelconstrains

FutureWater Supply
Model

Water Demand
Model
Change"natural"stateModel connection : schematic chart
Food Production(Shibasaki) Hand- Water Cycle(Musiake-Oki)

Crop
Yield
Food
EconomyIrrigationwater
demandshake

Available
Water
Water Stress
Assessment

Agriculture
Model

Water Cycle
ModelCommon Data
Land Topo- PopuEcoWeather
SoilPlantnomy
Use graphy lation

Etc.

Water Stress Assessment inmonthly temporal scale
Why monthly?
Water should exists at the right time Annual value assessment :may fail to detectseasonal water deficit

Irrigation water demand byModel(EPIC)

Estimated Annual Total Irrigation DemandIrrigation water deficit
RiverDischarge – Irrigation : Red = water deficit

Irrigation demand by EPIC
There are two estimates"Maximum" irrigation use Potential irrigation use withoutwater resource constrains"Real" irrigation use
 Constrained by available water amount

How they are different?
Constraints:When, where?
Maximum irrigation demand→Irrigation demand by EPIC (2)"Maximum" minus "Real" : Red=water deficits in some season

E U.S.
DeccanDeccan High
Spring Water Use is strictly limited
Irrigation > in-situ Available water
Contribution of river flow?
 Modeling Error?
Future Issue!
Eastern US
Constant limitation
But summer water shortage may damage
agriculture (soybean and wheat) there→Also effects Japanese economy!

Concluding Remarks
Process Model allows us to investigate
high temporal resolution feature of water resource
Like spatial high-resolution analysis done in last year,
temporal high-resolution assessment may give us
a new point of view on global water resource
However, interactive modeling is necessary
especially for Asia
All datasets and results have been alreadypublished :http://hydro.iis.u-tokyo.ac.jp/GW/