Using of regional hydrological modelling under data and water scarcity conditions in Peruvian Pacific catchments for the implementation of operational runoff indices
Abstract
In a context of water scarcity in Peruvian Pacific catchments added to the paucity of data availability, we propose a methodology which provides new perspectives for freshwater availability estimation as a base reference for unimpaired conditions in the 1970-2010 period.
To represent the multi-decadal behaviour of freshwater runoff along the region, a regional runoff analysis is proposed based on hydrological modelling at annual and monthly time step for unimpaired conditions over the whole 1970 − 2010 period. Differential Split-Sample Tests are used to assess the hydrological modelling robustness of the GR1A and GR2M conceptual lumped models, showing a satisfactory transposability from dry to wet years inside the thresholds defined for Nash-Sutcliffe and bias criteria . This allowed relating physical catchment characteristics with calibrated and validated model parameters, thus offering a regional perspective for dryland conditions in the study area (e.g. the anticlockwise hysteresis found for seasonal precipitation-runoff relationship) as well as the impacts of climate variability and catchment characteristics. Under those considerations, a regional discharge of 709 m3/s to the Pacific Ocean from the arid Peruvian Pacific region is estimated with a significant increasing trend of about 43 m3/s/decade over the last four decades (1970− 2010). Based on our regional hydrological modelling approach, which allowed describing the unimpaired runoff variability, the Peruvian National Service of Meteorology and Hydrology (SENAMHI) is implementing a downscaled runoff gridded product at sub-basin scale. Among other operational purposes, this product will be applied to characterize hydrological indices for droughts. This offers a great perspective for surveying water deficit in this region which only benefits from 2% of the total national available freshwater while they concentrate almost 50% of the population of the country.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H11N1715R
- Keywords:
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- 1809 Desertification;
- HYDROLOGY;
- 1812 Drought;
- HYDROLOGY;
- 1833 Hydroclimatology;
- HYDROLOGY;
- 1834 Human impacts;
- HYDROLOGY