The HC-LAC: a Platform for Modeling Hydrology and Climate Change in Latin America and the Caribbean
Abstract
This platform, called the Hydrology and Climate Change in Latin America and The Caribbean, or "HC-LAC", is an integrated quantitative simulation of hydrology and climate change. The HC-LAC is composed of two principal components: the Analytical Hydrography Dataset (AHD) and an enhanced version of the Generalized Watershed Loading Function (GWLF). The AHD is a spatially explicit surface water data layer of Central and South America derived from digital elevation data from the Shuttle Radar Topography Mission (SRTM) and modified by the USGS to provide more accurate flow between cells in the raster data. For the LAC area, AHD consists 230, 000 catchments and stream segments with an average area of 100 km2 and length of 10 km, respectively. The AHD data structure is patterned after the US National Hydrography Dataset Plus (NHDPlus), thus providing a proven structure for flexible data integration and analyses necessary for spatial models like the HC-LAC. The structure of the AHD enables the implementation of water balance modeling and general routing of flows through the stream network thus supporting a range of environmental models. GWLF is applied on each AHD catchment which is characterized by multiple land use and soil type. The response of each land use in a given catchment is modeled separately in generating stream flow as well as recharge to soil storage. The stream flows generated from each catchment are routed through stream networks, providing total flow at any point in the stream network. A pilot implementation of the HC-LAC was established for the Rio Grande basin in North West Argentina (drainage area 6,700 km2). The model was parameterized and calibrated using readily available data. Three stream flow time series were generated using a reference climate case and two climate change projections. The reference case was based on historical records and assumes no climate change. The two climate change projections were generated using the IPCC "A2" high emissions scenario with two general circulation models: the UKMO Hadley CM3 (used frequently in Argentina) and the CSIRO Mk3 (the "dry" scenario used by World Bank) for the period 2012-2060. The three stream flow time series were used to calculate unmet water demand for urban water supply and irrigation, taking into account various measures to adopt to climate change. The HC-LAC was also used to generate a complete surface flow database for the Rio Grande basin, which is proving useful for analysis of a variety of current and future water resource management issues by the local governmental agencies.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2013
- Bibcode:
- 2013AGUSM.H41A..03M
- Keywords:
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- 1807 HYDROLOGY / Climate impacts;
- 1805 HYDROLOGY / Computational hydrology;
- 1833 HYDROLOGY / Hydroclimatology