Applications database and GIS for extracting data from TRMM precipitation, specialized by hydrographic basins.

Applications database and GIS for extracting data from TRMM precipitation, specialized by hydrographic basins.
G.S. Souza¹, P. Zeilhofer¹
(1) Federal University of Mato Grosso, Brazil ([e-mail], [e-mail]).

Abstract: Studies of rainfall and its distribution in space and time are important for the sustainable management of natural resources. This study presents computational tools that can assist in extracting and synthesizing spatio-temporal precipitation time series from the 3B42 product of the Tropical Rainfall Measuring Mission (TRMM). Generated since 1998 in a three hour temporal resolution and a spatial resolution of 0.25 °, sets of this product integrate terabytes of data that are available by default in binary format, Network Common Data Form
(HDF) or NetCDF, which makes its manipulation and analysis in spreadsheets, statistical and
Geographic Information Systems (GIS) programs difficult. The applications presented here are based on NetCDF files, which are available for download by the National Aeronautics and
Space Administration (NASA) a matrix (http://disc2.nascom.nasa.gov/dods/3B42_V7_daily).
In the first step processing, the NetCDF file is transformed from a platform independent
PythonTM script in a table csv format, containing attributes like date/time, latitude, longitude and precipitation. This table is directly replicable in a Management System Database (DBMS) in our case open source PostgreSQL application with its PostGIS extension. The PostgreSQL
/ PostGIS application also provides a pre-formatted table to represent the relative percentage of TRMM cells inside reference spatial units such as watershed boundaries, municipalities etc. In a pilot application, these percentages have been generated from a GIS software, using
Thiessen polygons for spatial interpolation. Users can then perform queries which allow to synthesize the original data according to these spatial units for custom temporal