Impact of Watershed Geomorphic Characteristics on the Energy and Water Budgets

Abstract The GEOtop model makes it possible to analyze the short- and long-term effects of geomorphic variation on the partitioning of the lateral surface and subsurface water and surface energy fluxes. The topography of the Little Washita basin (Oklahoma) and of the Serraia basin (Trentino, Italy) have been used as base topographies from which virtual topographies with altered slopes and elevations have been created with corresponding modifications of the soil thickness and the extension of the channel network, according to applicable geomorphological theories, in order to quantify the contribution of these topographic features to the spatial and temporal variability of energy and water fluxes. Simulation results show that both a more extended channel network and more accentuated slopes cause an increase in the discharge balanced by a diminution of the evapotranspiration. The diminution of the latent heat flux is balanced by the increase in the sensible heat flux. Net radiation shows a minor sensitivity to topography. Evaporative fraction, on the contrary, is shown to be strongly dependent on geomorphic characteristics. The results confirm the importance of including an adequate treatment of topography in large-scale land surface models

Co-designing built interventions with children affected by displacement (DeCID)

Displacement is at a world record high as a result of persecution, conflict, violence, and human rights violations. Children make up around half of the refugee population worldwide, and 40% of the 80 million displaced people globally. Approximately two-thirds of displaced people live in urban areas, the large majority in developing countries (UNHCR 2020). The quality of spaces available to children has an important impact on child development and wellbeing as it affects a number of children’s rights including play, health, safety and learning. The DeCID handbook was born out of a lack of practical guidelines for co-designing built interventions with children affected by urban displacement. It was created by a mixed team of practitioners and academics from different disciplines, and via a research process involving interviews and thematic discussions with varied related practitioners. This handbook aims to raise the number and quality of built interventions that have been co-designed with children affected by displacement in the urban context: ultimately advancing their wellbeing. It provides practical insights regarding interventions that put children’s wellbeing first, and at the intersection of participatory design, forced displacement, and the urban context

Performance of site-specific parameterizations of longwave radiation

In this work 10 algorithms for estimating downwelling longwave atmospheric radiation (L↓) and 1 for upwelling longwave radiation (L↑) are integrated into the JGrass-NewAge modelling system. The algorithms are tested against energy flux measurements available for 24 sites in North America to assess their reliability. These new JGrass-NewAge model components are used (i) to evaluate the performances of simplified models (SMs) of L↓, as presented in literature formulations, and (ii) to determine by automatic calibration the site-specific parameter sets for L↓ in SMs. For locations where calibration is not possible because of a lack of measured data, we perform a multiple regression using on-site variables, i.e. mean annual air temperature, relative humidity, precipitation, and altitude. The regressions are verified through a leave-one-out cross validation, which also gathers information about the possible errors of estimation. Most of the SMs, when executed with parameters derived from the multiple regressions, give enhanced performances compared to the corresponding literature formulation. A sensitivity analysis is carried out for each SM to understand how small variations of a given parameter influence SM performance. Regarding the L↓ simulations, the Brunt (1932) and Idso (1981) SMs, in their literature formulations, provide the best performances in many of the sites. The site-specific parameter calibration improves SM performances compared to their literature formulations. Specifically, the root mean square error (RMSE) is almost halved and the Kling–Gupta efficiency is improved at all sites. Also in this case, Brunt (1932) and Idso (1981) SMs provided the best performances. The L↑ SM is tested by using three different temperatures (surface soil temperature, air temperature at 2 m elevation, and soil temperature at 4 cm depth) and model performances are then assessed. Results show that the best performances are achieved using the surface soil temperature and the air temperature

ALCUNE CONSIDERAZIONI DELLA SOCIETÀ IDROLOGICA ITALIANA SULLA GRAVE SICCITÀ DELL’ESTATE 2022

La siccità che ha colpito il nostro Paese fin dall’inizio del 2022, ha posto all’attenzione della popolazione, at- traverso i media, un tema che i gestori delle risorse idriche, i tecnici e i ricercatori hanno ben presente, ma che non aveva ancora suscitato adeguato interesse nel dibattito politico. L’articolo del Ministro della Transizione Ecologica, Roberto Cingolani, pubblicato sul Corriere della Sera lo scorso 11 luglio, è un utile stimolo, per amministratori e politici, ad affrontare il tema della scarsità di risorse idriche e delle misure necessarie per mi- tigare l’impatto dei fenomeni siccitosi

The design, deployment, and testing of kriging models in GEOframe with SIK-0.9.8

This work presents a software package for the interpolation of climatological variables, such as temperature and precipitation, using kriging techniques. The purposes of the paper are (1) to present a geostatistical software that is easy to use and easy to plug in to a hydrological model; (2) to provide a practical example of an accurately designed software from the perspective of reproducible research; and (3) to demonstrate the goodness of the results of the software and so have a reliable alternative to other, more traditional tools. A total of 11 types of theoretical semivariograms and four types of kriging were implemented and gathered into Object Modeling System-compliant components. The package provides real-time optimization for semivariogram and kriging parameters. The software was tested using a year's worth of hourly temperature readings and a rain storm event (11 h) recorded in 2008 and retrieved from 97 meteorological stations in the Isarco River basin, Italy. For both the variables, good interpolation results were obtained and then compared to the results from the R package gstat

On Hack\u27s Law

Hack\u27s law is reviewed, emphasizing its implications for the elongation of river basins as well as its connections with their fractal characteristics. The relation between Hack\u27s law and the internal structure of river basins is investigated experimentally through digital elevation models. It is found that Hack\u27s exponent, elongation, and some relevant fractal characters are closely related. The self-affine character of basin boundaries is shown to be connected to the power law decay of the probability of total contributing areas at any link and to Hack\u27s law. An explanation for Hack\u27s law is derived from scaling arguments. From the results we suggest that a statistical framework referring to the scaling invariance of the entire basin structure should be used in the interpretation of Hack\u27s law

Estimating the water budget components and their variability in a pre-alpine basin with JGrass-NewAGE

The estimation of water resources at basin scale requires modelling of all components of the hydrological system. Because of the great uncertainties associated with the estimation of each water cycle component and the large error in budget closure that results, water budget is rarely carried out explicitly. This paper fills the gap in providing a methodology for obtaining it routinely at daily and subdaily time scales. In this study, we use various strategies to improve water budget closure in a small basin of Italian Prealps. The specific objectives are: assessing the predictive performances of different Kriging methods to determine the most accurate precipitation estimates; using MODIS imagery data to assist in the separation of snowfall and rainfall; combining the Priestley-Taylor evapotranspiration model with the Budyko hypothesis to estimate at high resolution (in time and space) actual evapotranspiration (ET); using an appropriate calibration-validation strategy to forecast discharge spatially. For this, 18 years of spatial time series of precipitation, snow water equivalent, rainfall-runoff and ET at hourly time steps are simulated for the Posina River basin (Northeast Italy) using the JGrass-NewAGE system. Among the interpolation methods considered, local detrended kriging is seen to give the best performances in forecasting precipitation distribution. However, detrended Kriging gives better results in simulating discharges. The parameters optimized at the basin outlet over a five-year period show acceptable performances during the validation period at the outlet and at interior points of the basin. The use of the Budyko hypothesis to guide the ET estimation shows encouraging results, with less uncertainty than the values reported in literature. Aggregating at a long temporal scale, the mean annual water budget for the Posina River basin is about 1269 ± 372 mm (76.4%) runoff, 503.5 ± 35.5 mm (30%) evapotranspiration, and −50±129−50±129 mm (−−4.2%) basin storage from basin precipitation of 1730 ± 344 mm. The highest interannual variability is shown for precipitation, followed by discharge. Evapotranspiration shows less interannual variability and is less dependent on precipitation

Evaluation of the morphological quality index in the Cordevole river (Bl, Italy)

The European Union (EU) Water Framework Directive (WFD, 2000/60/EC), which came into force in Italy under Decree Law no. 152 of 3rd April 2006, has as its objectives the protection and improvement of aquatic ecosystem status, promoting the sustainable use of water resources and mitigating the effects of floods and droughts. According to this Directive, the ecological classification of a watercourse should be considered in addition to physical-chemical and biological aspects of its hydromorphological condition, in order to define the deviation of the present condition from a pre-defined reference state. The Italian National Institute for Environmental Protection and Research has promoted a methodology called IDRAIM for the hydromorphological analysis of streams. This is an integrated approach aimed at implementing both WFD and EU Flood Directives (2007/60/EC). In this paper, we describe the application of the morphological quality index (MQI) protocol, which is part of the IDRAIM, used for evaluating the morphological quality of the Cordevole River, Province of Belluno, northeastern Italy. General settings and segmentation of the water network through the use of semi-automatic GIS techniques were presented. The MQI data derived from the application of 28 indicators in 42 reaches were then analysed. Most (48%) of the analysed reaches have a good quality status; 38% have a moderate quality status and poor morphological conditions (14%) are due to the presence of artificial elements and to the limited connectivity between hill-slopes and the river corridor

WATZON: the Italian network of ecohydrology and critical zone observatories

The Italian initiative WATZON (WATer mixing in the critical ZONe) is a network of instrumented sites, bringing together six pre-existing long-term research observatories monitoring different compartments of the Critical Zone - the Earth's permeable near-surface layer from the tops of the trees to the bottom of the groundwater. These observatories cover different climatic and physiographic characteristics over the country, providing information over a climate and eco-hydrologic transect connecting the Mediterranean to the Alps. With specific initial scientific questions, monitoring strategies, databases, and modeling activities, the WATZON observatories and sites is well representative of the heterogeneity of the critical zone and of the scientific communities studying it. Despite this diversity, all WATZON sites share a common eco-hydrologic monitoring and modelling program with three main objectives: 1) assessing the description of water mixing process across the critical zone by using integrated high-resolution isotopic, geophysical and hydrometeorological measurements from point to catchment scale, under different physiographic conditions and climate forcing; 2) testing water exchange mechanisms between subsurface reservoirs and vegetation, and assessing ecohydrological dynamics in different environments by coupling the high-resolution data set from different critical zone study sites of the initiative with advanced ecohydrological models at multiple spatial scales; 3) developing a process-based conceptual framework of ecohydrological processes in the critical zone to translate scientific knowledge into evidence to support policy and management decisions concerning water and land use in forested and agricultural ecosystems. This work provides an overview of the WATZON network, its objectives, scientific questions, and data management, with a specific focus on existing initiatives for linking data and models based on WATZON data