Hydrogeodesy: Can it help to reach the Millennium Development Goal for Water in Africa?

Norman L. Miller

IGCP 565 Fifth Annual Workshop

29-30 October 2012

Outline

1. Hydrology, Water Scarcity and MDG 7

2. Monitoring Surface Water and Groundwater Variations

3. Modeling, Assimilation, and Prediction of Water Variations

4. Water Use Efficiency Management and Education

Millennium Development Goal Target 7: Ensure Environmental Sustainability

•By 2015, halve the number of people without access to sustainable drinking water.

•WHO/UNICEF 2012: Progress on Drinking Water and Sanitation. At the end of 2010, 89% of the World’s population has adequate drinking supplies. Exceeding the MDG Target of 88%.

•However there are 783 Million People still not meeting MDG, mostly in Africa (477 Million People are in Sub-Sahara Africa).

Forty Percent of the Global Population Face Water Scarcity

Percent Water Scarcity

Annual Total Precipitation and River-Runoff In Africa

Percent Land Area Irrigated

Water Storage and Fluxes~30 percent of Freshwater Storage is Groundwater

Less than 0.8 % of the Global Water Cycle is Groundwater

But, this is a very important part of the Hydrologic Cycle !

Groundwater acts as our drought insurance

To Meet the MDG on Water, Groundwater Change Needs Monitoring

•Gravity monitoring yields total mass change

•Land Surface Modeling yields surface soil moisture content (i.e. surface water and snow storage).

•Gravity monitoring provides the residual groundwater change

African Geodetic Reference FrameGlobal GPS Network Sites in Africa

Weighing Stored Terrestrial Water by

Remote Sensed Geodesy

GRACEGravity and Climate ExperimentTwin Satellites

GRACE•Variations in Mass within the Earth

•Runoff and Groundwater Storage ChangeGRACE needs 150,000 km2 for accuracy

•Changes in Ice Mass

Mean Annual Gravity Height

From Yamamoto

Lake Victoria Drainage Basin (258000 km2) Hydrologic Modeling using Gravity Recovery

The Agreed Curve sets outflows as a function of lake level

Lake Victoria Water Level Lags Precipitation by One Month

The 1963 Lake Level Increase is Primarily due to the Phase of the IOZM (Indian Ocean Zonal Mode)

Meeting the MDG on Water

•Increased Ground truth observations to increase accuracy

•Better characterized land surface properties for improved simulation of surface water

•Water Use Efficiency and Precision Agriculture using GPS network