A Preliminary Assessment of the “Undercatching” and the Precipitation Pattern in an Alpine Basin

Abstract

Gauges modify wind fields, producing important systematic errors (undercatching) in the measurement of solid precipitation (Ps), especially under windy conditions. A methodology that combines geostatistical techniques and hydrological models to perform a preliminary assessment of global undercatch and precipitation patterns in alpine regions is proposed. An assessment of temperature and precipitation fields is performed by applying geostatistical approaches assuming different hypothesis about the relationship between climatic fields and altitude. Several experiments using different approximations of climatic fields in different approaches to a hydrological model are evaluated. A new hydrological model, the Snow-Témez Model (STM), is developed including two parameters to correct the solid (Cs) and liquid precipitation (Cr). The procedure allows identifying the best combination of geostatistical approach and hydrological model for estimating streamflow in the Canales Basin, an alpine catchment of the Sierra Nevada (Spain). The sensitivity of the results to the correction of the precipitation fields is analyzed, revealing that the results of the streamflow simulation are improved when the precipitation is corrected considerably. High values of solid Cs are obtained, while Cr values, although smaller than the solid one, are also significant.

Analysis of the Potential Ompact of Climate Change on Climatic Droughts, Snow Dynamics and the Correlation between Them

“…Climate change models forecast more extreme climate conditions in the future (especially in arid and semi-arid regions) with reductions in precipitation and increases in temperature, which is expected to drastically modify the hydrological regime, affecting both surface and groundwater supplies. Alpine systems in semi-arid regions are highly sensitive to climate change, since the hydrological cycle is significantly influenced by snow dynamics (influenced by precipitation and temperature regimes) [12,13,14,15]. For this reason, the assessment of hydrological droughts associated with snow dynamics is essential to determine the possible impact on water resources.…”

Impact Assessment of Gridded Precipitation Products on Streamflow Simulations over a Poorly Gauged Basin in El Salvador

“…Furthermore, rain gauges are not always accurate devices for measuring real precipitation. Specifically, disparities between the measurements and real values of precipitation may be caused by the effects of wind above the gauge orifice, flaws in the rain gauge installation, losses by wetting and evaporation on the inside walls of the rain gauge, and other random and systematic errors [4,5]. Therefore, there is an evident need to enhance data collection and/or explore more accurate alternatives to ground-based data from rain gauges.…”

Estimation of the Monthly Dynamics of Surface Water in Wetlands from Satellite and Secondary Hydro-Climatological Data

“…These variables can provide valuable information to complete the data obtained from satellites. Regression models based on different explanatory variables have been used successfully to estimate different climatic and hydrological variables (e.g., precipitation [28], temperature [29], and snow depth and snow water equivalent [30]).…”