Opportunities for Development of a Global Water Information

Opportunities for Development of a Global Water Information System David R. Maidment, University of Texas at Austin • Definition of an information system • Data required • Functionality and training • Example: GIS Hydro ‘ 97 link

Definition of an Information System • Data is a sampled view of the world • Functions operate on the data • Users interact with the data through the functions Information System Users Functions Data World

Functions Required • Viewing the data (graphs and maps)link • Presentation of results (reports, visual aids) • Interpretation of data (queries and simple data arithmetic) • Analysis (macro script invoked from a GUI button or menu bar) • Modeling (programming language: Fortran, C, C++)

Data Required • Climate (grids of precipitation, temperature, radiation, humidity, wind, vapor pressure) link • Water (runoff, groundwater, water use, dams) • Terrain, streams, basins (DEMs) • Soils (soil water properties) • Land use and land cover • Political boundaries and land features • Population and demography

Time, Space and Variables N = Time Units M = Spatial Units L = Variables Dimensionality = LMN (if within GIS, LMN < 10 million

Climate Data • Global data: mean annual and monthly values on 2. 5´ (5 km) to 0. 5° (50 km) grids • National and local data: time series from gages • Blending of global data grids with national time series at gages + Global National

Available Climate Grids • • Legates-Willmott global climatology Hutchinson grids for Africa, Australia, …. IIMI project at Utah State University GPCC - Global Precipitation Climatology Center NASA surface radiation budget ISLSCP (research data) UNEP GRID FAO Climwat (point data)

Water Data • Runoff data. Monthly and daily gaged streamflow (Global Runoff Data Center) • Water use data (AGL project at FAO) • Dams (UNESCO inventory georeferenced at the University of New Hampshire) • Access and distribution of raw data? • Dissemination of statistics (mean monthly and annual flows, flow duration curve)

Terrain, Streams, Basins • GTOPO 30 - 30” Digital Elevation Model of earth (USGS & UNEP) link • Streams - Digital Chart of the World (1: 1 M scale) • Basins - 5 -level Pfaffstatter basins available for North America, Africa, … link • Blending of global and local data (river valleys)

Soils • FAO Digital Soil Map of the Earth is the basic source (1: 5 M scale) • Needs addition of soil water properties (soil water holding capacity, saturated conductivity, …. ) • Link soil texture to standard tables of soil water properties classified by texture • Create monthly soil water balance link

GH-Soilwater: Soil Water Balance Module Precipitation Temperature Evaporation Net Radiation Runoff Water Holding Capacity

GH-Soilwater GH-Runoff Calibrating Soil Water Balance using a Runoff Map Runoff (mean annual) Soilwater (mean monthly) P E W Q

Land Use and Land Cover • Land cover assessment of earth being done at US Geological Survey using NDVI (Normalized Difference Vegetation Index), a measure of greenness of vegetation • Link greenness to rate of evapotranspiration • Use Soil water balance to produce a Famine Early Warning System • Linking land use and water pollution
![GH - Loads: Pollution Loading Module Load [Mass/Time] = Runoff [Vol/Time] x Concentration [Mass/Vol] GH - Loads: Pollution Loading Module Load [Mass/Time] = Runoff [Vol/Time] x Concentration [Mass/Vol]](http://slidetodoc.com/presentation_image_h2/83fee19d57a1f6947cb23f612c7a4166/image-14.jpg)
GH - Loads: Pollution Loading Module Load [Mass/Time] = Runoff [Vol/Time] x Concentration [Mass/Vol] Precip. Runoff DEM Land. Use Accumulated Load EMC Table Load Concentration

GH - Loads: Pollution Loading Module EMC Table

Other Data Sources • Political Boundaries (national and provincial) • Cities and Roads • Population distribution - global demography project at Univ. of California, Santa Barbara, yields provincial level population data and 5’ gridded population of the earth

Digital Atlas of the World Water Balance, Version 1. 0 • Based on FAO/UNESCO Water Balance of Africa Project • gridded mean monthly climate data for continents on 0. 5° cells, some runoff data, • lessons in English, French, Spanish, (Portuguese) link • three training courses during last year (Rabat, Cairo, Dar Es Salaam)

Dissemination of Information • Using html on the world wide web – http: //www. ce. utexas. edu/prof/maidment link • Using html on CD-ROMs link • Training courses in countries link • Virtual course taught on internet and by CDROMs (Fall semester, 1998) • Paper-based materials

Conclusions • Significant opportunity for an FAO effort on global data synthesis • Produce data bases by region (perhaps add Latin America to present emphasis on Africa) • Share data with countries, provide training and applications to typical problems • Encourage insertion of national data into a global system
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