An approach for modelling snowcover ablation and snowmelt runoff in cold region environments

Reliable hydrological model simulations are the result of numerous complex interactions among hydrological inputs, landscape properties, and initial conditions. Determination of the effects of these factors is one of the main challenges in hydrological modelling. This situation becomes even more difficult in cold regions due to the ungauged nature of subarctic and arctic environments. This research work is an attempt to apply a new approach for modelling snowcover ablation and snowmelt runoff in complex subarctic environments with limited data while retaining integrity in the process representations. The modelling strategy is based on the incorporation of both detailed process understanding and inputs along with information gained from observations of basin-wide streamflow phenomenon; essentially a combination of deductive and inductive approaches. The study was conducted in the Wolf Creek Research Basin, Yukon Territory, using three models, a small-scale physically based hydrological model, a land surface scheme, and a land surface hydrological model. The spatial representation was based on previous research studies and observations, and was accomplished by incorporating landscape units, defined according to topography and vegetation, as the spatial model elements. Comparisons between distributed and aggregated modelling approaches showed that simulations incorporating distributed initial snowcover and corrected solar radiation were able to properly simulate snowcover ablation and snowmelt runoff whereas the aggregated modelling approaches were unable to represent the differential snowmelt rates and complex snowmelt runoff dynamics. Similarly, the inclusion of spatially distributed information in a land surface scheme clearly improved simulations of snowcover ablation. Application of the same modelling approach at a larger scale using the same landscape based parameterisation showed satisfactory results in simulating snowcover ablation and snowmelt runoff with minimal calibration. Verification of this approach in an arctic basin illustrated that landscape based parameters are a feasible regionalisation framework for distributed and physically based models. In summary, the proposed modelling philosophy, based on the combination of an inductive and deductive reasoning, is a suitable strategy for reliable predictions of snowcover ablation and snowmelt runoff in cold regions and complex environments

Gestión del agua subterránea en el centro-este de La Pampa : Una propuesta de actuación ante factores de incertidumbre hidrológica

El presente trabajo pretende introducir una discusión de una compleja situación hidrológica de la región Centro-Este de La Pampa, donde las peculiares características hidrológicas del ámbito subhúmedo-seco siempre han trasladado una situación al campo social y económico que hay que solucionar. Ante esta situación, las aguas subterráneas juegan un papel sumamente importante en estas condiciones de incertidumbre y se establecen como un recurso importante moderador en la planificación en un área de extrema fragilidad hidrológica. Por eso se pretende que, a partir del conocimiento hidrogeológico se pueda comprender y corregir la actividad socio económico de la región. Como resultado se demuestra que es posible obtener elementos de gestión en un área de extrema variabilidad hidrológica, con un factor importante de incertidumbre, a partir del conocimiento y trasladar los mismos a la actividad socio económico de la región y a su vez que sirvan como soporte para la toma de decisiones.This paper aims to introduce an analysis of a complex hydrological situation of the Central-East of La Pampa, where the peculiar hydrological characteristics of field-dry subsumed always been perceived as a serious problem that is transferred to the social and economic fields to be solve. In this situation, groundwater plays a major role in these conditions of uncertainty and constitutes a regulatory element of planning in an area of extreme fragility hydrological from knowledge, and moves them to the socio economic development of the region. As a result it is shown that it is possible to obtain management elements in an area of extreme hydrological variability, with a factor of uncertainty based on knowledge and move them to the socio economic development of the region and in turn serve as support for decision.Universidad Nacional de La Plat

Identificación y caracterización hidrológica de lagunas del noreste de la provincia de La Pampa

Fil: Dornes, Pablo F.. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Comas, Rocío N.. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Cardín, Daniel. Dirección General Catastro de La Pampa. Casa de Gobierno; ArgentinaFil: Pochetti, Roberto. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Ianni, Juan. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Kruse, Eduardo Emilio. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

Wolf Creek Cold Regions Model Set-up, Parameterisation and Modelling Summary

Non-Peer ReviewedWolf Creek Research Basin is in the Upper Yukon River Basin near Whitehorse, Yukon and is representative of headwaters in the northern Coast Mountains. It was established in 1993 to better develop northern hydrological models, and related hydrological process, ecosystem and climate science. Yukon Environment maintains Wolf Creek hydrometeorological and hydrometric stations and conducts regular snow surveys in the basin. A number of hydrological models have been tested on Wolf Creek and all have had great difficulty in simulating the cold regions hydrological processes that dominate its streamflow response to snowmelt and rainfall events. Developments in understanding hydrological processes and their interaction with terrestrial ecosystems and climate at Wolf Creek have lead to the development of the Cold Regions Hydrological Model (CRHM) by a consortium of scientists led by the University of Saskatchewan and Environment Canada. CRHM comprehensively incorporates the blowing snow, intercepted snow, sublimation, melt energetics, infiltration to frozen soils, organic terrain runoff and other cold regions hydrological phenomenon and discretizes the catchment on a hydrological response unit basis for applying water and energy balance calculations. The model is intended for prediction of ungauged basins with parameter selection from physically measurable properties of the river basin or regional transference of calibrated values. In Russia, a long tradition of cold regions hydrological research has led to the development of the Hydrograph model by the State Hydrological Institute, St. Petersburg. The Hydrograph model contains several promising innovations regarding the formation and routing of runoff, discretizes the basin using hydrological response units and addresses some (but not all) cold regions hydrological processes. Hydrograph parameter selection is made from both physically measured properties and those that are calibrated, but the calibrations can be easily regionalized. Test simulations of runoff processes using CRHM and Hydrograph for Wolf Creek Research Basin was undertaken using data archives that had been assembled and cleaned up in a related project by the University of Saskatchewan. The test simulations are a demonstration of model capabilities and a way to gain familiarity with the basin, its characteristics and data and to better compare model features. Data available included a GIS database of basin characteristics (topography and vegetation distribution) and the hydrometeorological and hydrometric observational dataset from Yukon Environment. The sub-surface hydrology presented a formidable unknown in parameterising the model. Hydrograph performed well in initial simulations of the basin hydrograph for multi-year runs. Several issues with observational data quality created substantial uncertainty in evaluating the model runs

Spatial and temporal expression of the wetlands of the Atuel and Salado rivers, La Pampa, Argentina

Los humedales son ecosistemas complejos y diversos, tanto en sus características biológicas como en los procesos físicos que determinan su funcionamiento. Su expresión varía por diversos factores, como el clima, la configuración geológica, la relación agua superficial-subterránea y el factor antrópico. El sistema en estudio se ubica en la confluencia de los ríos Atuel y Salado, en una región semiárida dentro de una extensa planicie aluvial conformada por numerosos cauces y bañados, cuyo régimen hidrológico se encuentra drásticamente modificado por acción antrópica, lo que dificulta la comprensión de su funcionamiento. El objetivo fue describir cambios en el patrón de inundación, a partir de teledetección con imágenes de satélite ópticas (Landsat 5 TM, 8 OLI y Sentinel 2A). Para el análisis de la variación espacial interanual y mensual, se utilizaron eventos y series continuas entre 1984-2017. El estudio de la interacción superficial–subterránea incluyó el análisis de caudales de entrada, del nivel freático y de su hidroquímica. Se observa una activación de los humedales cuya expansión y contracción está relacionada al régimen hidrológico de ambos ríos, con un carácter mayoritariamente influente. El flujo subterráneo muestra gradientes concordantes con la dirección de la escorrentía intermitente. Su ausencia determina un drástico deterioro de la calidad del agua subterránea. El patrón de inundación cambia de acuerdo a la magnitud de los eventos de escorrentía. Se visualiza que la sincronicidad de altos caudales en ambos ríos determina una mayor expresión areal y la salida de escurrimientos superficiales del sistema de humedales.Wetlands are complex and diverse ecosystems, both in their biological characteristics and physical processes that determine their functioning. Their expression varies according to various factors, such as weather, geological environment, relationships between surface and groundwater and anthropogenic influence. The area is located at the confluence of the Atuel and Salado Rivers, in a semi-arid region within an extensive alluvial plain with many channels and flooded areas. The hydrological regime is drastically modified by upstream uses, which complicate the understanding of its functioning. The objective of the study was to describe changes in the spatial patterns of f looded areas, based on remote sensing with optical satellite images (Landsat 5 TM, 8 OLI and Sentinel 2A). For the analysis of the inter-annual and monthly spatial variation, the events and continuous series between 1984 and 2017 were used. The surface and groundwater interaction was analyzed by comparing flows, variation of the water table and hydrochemistry. The activation of the wetlands shows an expansion and contraction related to the hydrological regime of both rivers, with a predominantly influential character. Groundwater gradients have the same direction as the surface flows. The lack of these flows drastically deteriorates chemical quality of the groundwater. The flooded pattern differs according to the magnitude of the runoff events. The synchronicity of high flows in both rivers determines the area expression of the wetlands and the surface outflow from the system.Fil: Páez Campos, Hugo Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Confluencia; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Dornes, Pablo Fernando. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; Argentin

Water budgets in ecosystems

Water is the foundation of all ecosystems, whether terrestrial or aquatic. In terrestrial ecosystems freshwater not only provides critical water supply for transpiration during plant photosynthesis and drinking water for animals, but also transports, redistributes and stores energy, nutrients and contaminants. In aquatic and snow ecosystems, water is the medium in which the ecosystem functions and so its state mediates all transactions in these systems. Ecosystems are not passive responders to water but through their structure and function can manage water and associated microclimate – forests, grasslands, organic terrain wetlands, and beaver ponds being just a few examples. This chapter will examine the surface water budget in terms of the water continuity equation as a manifestation of the hydrological cycle. To solve the continuity equation for water, the chapter will review hydrological processes and how they interact with vegetation, animals, soils, geomorphology and climate in the context of the catchment. The coupling of the mass and energy continuity equations in controlling hydrological processes will be discussed. How hydrological processes and their ecosystem interactions are managed by humans will be introduced. Then the chapter will review calculation schemes for the surface water budget via one-dimensional land surface schemes and catchment-based hydrological models, noting the data requirements, uncertainty and limitations of these models and the balance required between model complexity and physical representation of hydrology. This will give the conceptual ideas and basic mathematics of conservation laws and transport processes that form the basis of many models in the forthcoming chapters