1. H UMAN A CTIVITIES A LTER H YDROLOGICAL C YCLE TANG QIUHONG

2. Human activities alter hydrological cycle Introduction Research area Some ideas

3. Human Domination of Earth’s Ecosystems [1] Modified from Peter M. Vitousek et al. [1] Human alteration of earth is substantial and growing.

4. (Modified from [5]) Human activities & hydrological cycle [2,3,4] 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. Land transformation Intake from river, reservoir …

5. Focus on Dissipative Flow 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] 1.Natural Dissipative flow (“without human interpose”) Spring (Modified from William M. Alley et al [6])

6. 2.Manmade Dissipative flow (“direct human interpose”) River Soil water Groundwater City irrigated land 70% of man-used water is used in agriculture [7] Use population, economic growth etc to estimate it. (about 30%) Soil water Groundwater NON-irrigated land Root zone Groundwater P E E Soil water Water content is controlled

7. Visualization (Modified from Illinois Water Resources Center (IWRC) [8] ) Runoff flow (direct): Surface runoff is lagged by ridge of field. Dissipative flow (direct): Keeping soil moist when it is dry. Human activities affect latent and sensible fluxes to the atmosphere. Feedback to atmosphere (evaporation, albedo, etc) P E Feedback

8. Human activities alter hydrological cycle Introduction Research area Some ideas

9. 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)

10. 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 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] perennial

11. Human activities alter hydrological cycle Introduction Research area Some ideas

12. Model description (  ) 1.Coupling with atmosphere 2.Physically base on Soil water model 3.Consider Groundwater 4.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 ) (FAO) Penman-Monteith equation: Soil & Vegetation Groundwater Atmosphere     

13. Model description (  )  Atmosphere-Soil interaction 1.Atmosphere model gives parameters for Penman- Monteith equation -> Evaporation (latent heat flux) 2. Atmospheric radiation -> sensible heat flux land use type  Root zone water balance Soil & Vegetation Groundwater Atmosphere      Soil water Groundwater irrigated land Soil water Groundwater NON-irrigated land Irrigation (soil moisture) PP hortonian overland flow saturation overland flow( water table rises above the land surface) Et Evapotranspiration from water table If water table depth >5m, it is zero.

14. Model description (  )  Groundwater balance Soil & Vegetation Groundwater Atmosphere      Soil water Groundwater irrigated land Soil water Groundwater NON-irrigated land River Exchange Exchange =f(water level,water table) ? depended on elevation

15. ? Model description (total) grid of large scale model Atmosphere Land surface Soil water Ground water 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].

16. Next step Specify the research area Collect dataset Coding,put it into action …… 行勝於言 Acts speak louder than words. (from Tsinghua Alumni Association Website, URL: http://www.tsinghua.org.cn/ )

17. Reference [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 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 http://www.environ.uiuc.edu/iwrc/faq.htm 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].

18. Reference (continued) [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)