A Dissipative Hydrological Model for Oasis in Arid Area

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A Dissipative Hydrological Model for Oasis in
Arid Area

• TANG, Qiuhong
• Oki/Kanae Lab.
• The University of Tokyo
• 2003-11
• IHWR, Tsinghua Univ.
• 2003-06

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About the model

• Background

• Water Salt Balance Model
• World Bank projects in Tarimu River
• I developed the model by making the water cycle
  relations more reasonable ,
• adding the soil water module,
• putting it into action.

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About the model

• A model for arid area

• The key of sustainable development of arid area
  is water resources. A model for arid area will do
  favor for water resources management.
• There are lots of famous conceptual hydrological
  model such as Standford, Sacramento, Tank These
  models can work well at humid area.

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Water cycle in river basin

• A model focus on dissipative flow

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River basin in arid area
PltltE
PgtE
watershed
a mountainous area
plain area
RFA (Runoff flow area)
DFA (Dissipative flow area )
The region, a lake or a stream,a waterway,a
reservoir supplies to water, or a lake or a
stream,a waterway,a reservoir receives runoff
which originates from precipitation.
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Difference between dissipative flow model and
runoff model

• Research area is arid area .
• Usually, a dissipative flow model need not a
  module to simulate runoff, but it need a
  dissipative flow module.
• Human activities(irrigation, pumping
  groundwater,..) must be considered.
• Evaporation should been calculated more
  precisely. (soil water, crop, irrigation,
  management level)

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Profile of water cycle in DFA
Precipitation
Irrigated crop
Non-Irrigated crop
Lowland
Naked land
River
Reservoir
channel water
drainage
Groundwater exchange
River seepage
Agriculture area
Non-agriculture area
Water surface

• River is the main water supplier.
• The transfer between atmospheric moisture,
  surface water, soil water and groundwater is very
  complex, and the dissipative flow is
  distinguished.

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Water decentralization in DFA
River
inflow
outflow
seepage
channel
channel
Spring/well
Irrigated crop
Non-Irrigated crop
Reservoir
drainage
Groundwater flow
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Framework of the model
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Framework of the model
Atmosphere
Soil water
Groundwater
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Framework of the model
1
2
3
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1. Agriculture area module

• I,P irrigation water, precipitation
• EU,EM evaporation of Up-Soil layer and Down-Soil
  layer
• EGgroundwater supplying soil water
• FWMseepage water to Down-Soil layer
• FGWseepage water to groundwater
• IGWgroundwater from river, reservoir,
• IIGgroundwater exchange between Agriculture area
  and Non-agriculture area
• DR drainage

E EUEM
Up-Soil
Down-Soil
Groundwater
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Ea Evaporation Ability

• Let evaporation ability be Ea, potential
  evaporation be Ep, crop coefficient be Kc, then
  EaEpKc
• Ep(FAO, Penman-Monteith )
• Kc

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EEUEM
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EGgroundwater to Down-Soil layer
Phreatic water evaporation
E0 Water surface evaporation
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DRdrainage
Field
Drain

• We assume it is Dupuit flow, and use the Dupuit
  equation

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2. Non-agriculture area module
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Non-agriculture area Evaporation
E0
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3. Groundwater Exchange System
Type1
Type3
Type2
Type

• Also we assume it is Dupuit flow, and use the
  Dupuit equation to estimate groundwater exchange

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Applications of Model

• Based on the research on the pilot area of Akesu
  River basin oasis in northwest China, I will
  introduce the development and application of the
  dissipative hydrological model for arid oasis.
• Both the evaporation in agriculture area and in
  non-agriculture area as well as groundwater
  exchange from Jan 1999 to Dec 2002 in Akesu River
  basin oasis are calculated by the model.

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Research area
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Sketch of Research Area
Xiehela
Shaliguilanke
Alaer
Area 12,000km2 Precipitation
30-90mm/year Water-surface evaporation
1100-1300mm/year
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Sketch of riverway
Legend
Station
Reservoir
Riverway
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Comparison of the simulated and recorded
hydrograph at Xidaqiao Station
Comparison of the simulated and recorded
hydrograph at Yimapaxia Station
Comparison of the simulated and recorded
hydrograph at Alaer Station
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Water table
Comparison of the simulated and observed water
table at Unit 3
Comparison of the simulated and observed water
table at Unit 4
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Result main water cycle
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Result
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Summary

• Out of the results in Akesu river basin, we can
  draw conclusion that the model works well in
  Akesu river basin which is a representative plain
  oasis in arid area, and more applications of the
  model in northwest China may be possible.

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Further Research

• The model, based on a typical DFA, focus on
  dissipative flow, runoff flow is simplified. How
  to establish a model which focus on both
  dissipative flow and runoff flow?
• The groundwater exchange system is complex, and
  it is hard to distribute groundwater to land
  types.
• It is hard to ascertain some parameters, such as
  drainage coefficient and channel coefficient.
• A model system is required.
• My colleagues are employing the model to other
  basin (Hetianhe river, Weiganhe river, Kai-konghe
  river )in Xinjiang. I will develop the model
  according to the applications.

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Unit 1

• nextunit2

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Unit 2
nextunit3
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Unit 3
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Unit 4
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Unit 5
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Unit 6
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Programming language Delphi 5.0 Database MS
SQL Server 2000 Operating system Windows 2000 /
Windows XP