Document

HUMAN ACTIVITIES ALTER
HYDROLOGICAL CYCLE
TANG QIUHONG
Human activities alter hydrological cycle
• Introduction
• Research area
• Some ideas
Human Domination of Earth’s Ecosystems[1]
Modified from Peter M. Vitousek et al.[1]
Human alteration of earth is substantial and growing.
Human activities & hydrological cycle[2,3,4]
(Modified from [5])
Land transformation
Intake from river, reservoir …
• Most of human activities that alter rainfall-runoff flow
is unconscious.
• The actions people manage water resources are the
actions people try to influence dissipative flow.
Focus on Dissipative Flow
1.Natural Dissipative flow (“without human interpose”)
Spring
(Modified from William M. Alley et al [6])
• Flow or seepage to ‘lowland’ because of hydraulic
head without human interpose
• To simulate NDF we need know groundwater, elevation
well. But “the inability to describe heterogeneity in aquifer
characteristics is a fundamental problem in groundwater
hydrology and will continue.”[6]
2.Manmade Dissipative flow (“direct human interpose”)
70% of man-used water is used in agriculture[7]
Soil water
Soil water
City
River
Groundwater Groundwater
irrigated land NON-irrigated land
Use population, economic growth etc to estimate it . (about 30%)
P
E
E
Soil water
Soil water
Water content is controlled
Root zone
Groundwater
Visualization
(Modified from Illinois Water Resources Center (IWRC) [8])
Runoff flow (direct):
Surface runoff is lagged by
ridge of field.
Feedback
E
P
Dissipative flow (direct):
Keeping soil moist when it
is dry.
<indirect>
Human activities affect
latent and sensible fluxes
to the atmosphere.
Feedback to atmosphere
(evaporation, albedo, etc)
Human activities alter hydrological cycle
• Introduction
• Research area
• Some ideas
Scale
• We need to incorporate the mechanics of soil
moisture redistribution, and this demand us to
predicate the response of this system on a timescale
not long.
• Type of soil and vegetation should be specified (We
need to consider groundwater because a shallow water table
provides moisture for the soil and vegetation and such acts as
a source term for evapotranspiration to the atmosphere[9]. Of
cause, because of the inability to know spatial heterogeneity,
we should simplified it ). This limits the spatial scale.
• Research area: a catchment (Yellow River)
• Timescale: month (timestep: days/hours)
Why We Choose Yellow River
We should choose a river basin in semiarid area.
arid area: no efficient runoff flow(e.g. Tarimu River )
humid area: dissipative flow is not remarkable
perennial
perennial
Fig 1. Comparison between precipitation of 1998 and perennial in Yellow River[10]
Fig 2. Comparison between streamflow of 1998 and perennial in Yellow River [10]
Human activities alter hydrological cycle
• Introduction
• Research area
• Some ideas
Model description()
1.
2.
3.
4.
Coupling with atmosphere
Physically base on Soil water model
Consider Groundwater
Watershed-scale
 Horizontal boundary conditions
Given by a large scale model (GCM or a nested grid
model) (pressure, humidity, temperature, wind
gradients …)
 Internal Cycle (Timestep: hours or less?)
To calculate (atmosphere radiation, wind speed,
pressure, humidity, temperature, and precipitation)


Atmosphere


Soil & Vegetation

Groundwater
(FAO) Penman-Monteith equation:
Model description()
 Atmosphere-Soil interaction
1.Atmosphere model gives parameters for PenmanMonteith equation -> Evaporation (latent heat flux)
2. Atmospheric radiation -> sensible heat flux


Soil & Vegetation

 Root zone water balance
P
Et
Soil water
Groundwater
irrigated land
P
hortonian overland flow
Soil water
Groundwater
NON-irrigated land

Atmosphere
land use type
Irrigation
(soil moisture)

Groundwater
saturation overland flow( water table rises
above the land surface)
Evapotranspiration from water table
If water table depth >5m, it is zero.
Model description()
 Groundwater balance
Soil water

Soil water

Exchange
Groundwater Groundwater
irrigated land
River
Atmosphere
NON-irrigated land
Exchange =f(water level,water table) ?
depended on elevation


Soil & Vegetation

Groundwater
embankment
Model description(total)
grid of large scale model
Atmosphere
Land surface
Cycle in atmosphere (interaction)
Penman-Monteith equation (no data)
Groundwater (initial water table)
given by repeatedly running the model (not sure)
Riverway storage (including reservoir, lake)
we should give a simple operation rule on it[12].
Soil water
Ground water
Next step
Specify the research area
Collect dataset
Coding ,put it into action
……
(from Tsinghua Alumni Association Website, URL: http://www.tsinghua.org.cn/ )
行勝於言
Acts speak louder than words.
Acknowledge
Some of the ideas come from reference [9] and [12]. Also I would like to appreciate my
supervisor Dr. HU Heping in Tsinghua University, Beijing China for references [2][3][4].
Reference
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[1] Vitousek et al., Human Domination of Earth's Ecosystems, Science 1997 277: 494-499
[2] 干旱区平原绿洲耗散型水文模型—— I：模型结构,胡和平,汤秋鸿, 田富强, 水科学进展
（已接受）(in Chinese)HU Heping, TANG Qiuhong, and TIAN Fuqiang. A Dissipative
Hydrological Model for Arid Plain Oasis, I: Model Structure, Advance in water science, (in
press)
[3] 干旱区平原绿洲耗散型水文模型—— II：模型应用,汤秋鸿, 田富强,胡和平, 水科学进展
（已接受）(in Chinese)TANG Qiuhong, TIAN Fuqiang, and HU Heping. A Dissipative
Hydrological Model for Arid Plain Oasis, II: Applications of Model, Advance in water science,
(in press)
[4] 基于散耗流的流域水文模型研究, 胡和平,汤秋鸿, (in Chinese, English version is under
construction) HU Heping, TANG Qiuhong. A Study of Hydrological Model Based on
Dissipative Flow, (personal document).
[5] The Environment in Tokyo - Aquatic Environment 2/2. URL:
http://www.kankyo.metro.tokyo.jp/kouhou/english2001/we_2.htm
[6] Alley et al., Flow and Storage in Groundwater Systems, Science 2002 296: 1985-1990
[7] Human Appropriation of Renewable Fresh Water ,Sandra L. Postel, Gretchen C. Daily,
and Paul R. Ehrlich , Science 9 February 1996; 271: 785-788 (in Reports).
[8] Website of Illinois Water Resources Center (IWRC) URL:
http://www.environ.uiuc.edu/iwrc/faq.htm
Reference (continued)
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[9] York, J. P., M. Person, W.J. Gutowski and T. C. Winter, 2002: Putting aquifers into
atmospheric simulation models: An example from the Mill Creek Watershed, northeastern
Kansas. Adv. Wat. Res., 25, 221-238.
[10] 黄河水资源公报, 水利部黄河水利委员会 (in Chinese) Bulletin of Yellow River water
resources, Yellow River Conservancy Commission, ministry of water resources of the
People’s Republic of China.
[11] Gutowski, W. J., C. J. Vorosmarty, M. Person, Z. Otles, B. Fekete and J. York, 2002: A
Coupled Land-Atmosphere Simulation Program (CLASP). J. Geophys. Res., 107 (D16),
4283,10.1029/2001JD000392
[12] Chong LI, Dawen YANG, Guangheng NI and Heping HU, 2004: Simulation of irrigation
consumption in the Yellow River basin using a distribution hydrological model. (in press,
personal communication)

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