Monday, July 31, 2017

Projecting Climate Change Impacts on Water Resources in Regions of Complex Topography: A Case Study of the Western United States and Southern California

This is the talk given by Jeremy Pal (GS) in Trento on July 26, 2017. He talked about the impact of climate change and  land use on California water resources. Actually the work he presented is part of the awarded Master Thesis of Brianna Pagàn (see last slides).
The talk presents in a plane way the issue related to water resources management of South California, Los Angeles area. It then uses an impressive set of modeling tools to pass from climate and land use changes to water availability. You can enjoy the video and get the slides too.
Here it is the abstract of the talk:
The Western United States and California have a greater potential vulnerability to climate change impacts on water resources due to a heavy reliance on snowmelt driven streamflow. California, the most agriculturally productive and populous region in the United States, depends on a complex and extensive water storage and conveyance system to supply water primarily for irrigation, municipal and industrial use and hydropower generation. This study provides an integrated approach to assess the impacts of climate change on the hydrologic cycle and extremes for all Southern Californian water supply basins:  Owens Valley, Mono Lake, Colorado River, Sacramento River, San-Joaquin River, and Tulare Lake basins. An 11-member ensemble of coupled atmosphere-ocean global climate models is first dynamically downscaled using a regional climate model and then statistically downscaled to force a hydrological model resulting in 4-km high-resolution output for the Contiguous United States. Greenhouse gas concentrations are prescribed according to historical values for the period 1976-2005 and to the IPCC Representative Concentration Pathway 8.5 for the near term future period 2021-2050. Precipitation is projected to remain the same or slightly increase by mid-century; however, rising temperatures result in a repartitioning of precipitation type towards more rainfall and therefore a reduced snowpack and earlier snowmelt. In addition to these hydrological changes, daily annual maximum runoff and precipitation events are projected to significantly increase in intensity and frequency such that future return periods change to become substantially more common. More specifically, the current daily annual maximum runoff 10-, 25-, and 50-, and 100-year events are projected to become approximately two to ten times more likely in the future. Furthermore, annual cumulative runoff volumes are projected to increase for high flow years and in contrast decrease for low flow years reducing the reliability of the system. While the escalating likelihood of drought reduces water supply availability, earlier snowmelt and significantly more intense winter precipitation events increases flood risk requiring winter releases from reservoirs for flood control purposes. All of these factors, coupled with projected increases in population, are likely to decrease supply during the higher demand drier months necessitating multiyear storage solutions for urban and agricultural regions as well as improved infrastructure and measures for flood control.

Wednesday, July 26, 2017

The post-contemporary flood forecasting systems

This is the presentation that has been held at University of Calabria in Cosenza, July 27, 2017. The presentation builds upon several other presentation present in this blog, and discusses the issue of designing a modern flood forecasting system. Actually I distinguish post-modern, contemporary and post-contemporary systems. Of the latter a short manifesto is given.
Clicking on the figure above the reader can access the first (Italian) version of the presentation. The English version can be seen and downloaded at this link. Once downloaded, the pdf contains links to publication and other relevant presentations. With respect to the Italian version, the English version contains a few small variations. One, in particular, was suggested by Daniela Biondi. She suggested that in my Manifesto for the post-contemporary flood forecasting systems, I should add the estimation of errors in forecasting. Suggestion that I fully endorse.

Friday, July 21, 2017


I found this nice paper on Jackknife, worth to read. Easy also to understand the differences between the jackknife technique and the leave-one-out one.
You can click on the knife to download it. 

Tuesday, July 18, 2017

Hydrological Extremes and Human Societies

This presentation is part of the summer school “Hydrometeorological extremes: processes, models and human impacts”  just held at Cagliari University this July 12-16. It is a school well organised by Roberto Deidda and became over the year a standard appointment fo my Ph.D. students. This year, among the lecturer there was Giuliano di Baldassarre (GS, RG) who covered the topic on Hydrological Extremes and Human Societies. Unfortunately I could not have been present at his lecture, but I've got his slides (and the permission to publish them).  You can find them below, by clicking on the figure. 
He also suggested some readings related to the talk:

Bianchizza, C., & Frigerio, S. (2013). Domination of or Adaptation to Nature ? A lesson we can still learn from the Vajont. Italian Journal of Engineering Geology and Environment, 6, 523–530.

Delle Rose, M. (2012). Decision-making errors and socio-political disputes over the Vajont dam disaster. Disaster Advances, 5(3), 144–152.

Di Baldassarre, G., Martinez, F., Kalantari, Z., & Viglione, A. (2017). Drought and flood in the Anthropocene: feedback mechanisms in reservoir operation. Earth System Dynamics, 8(1), 225–233.

Di Baldassarre, G., Viglione, A., Carr, G., Kuil, L., Yan, K., Brandimarte, L., & Blöschl, G. (2015). Debates-Perspectives on socio-hydrology: Capturing feedbacks between physical and social processes. Water Resources Research, 51(6), 4770–4781.

Montanari, A., Young, G., Savenije, H. H. G., Hughes, D., Wagener, T., Ren, L. L., et al. (2013). “Panta Rhei—Everything Flows”: Change in hydrology and society—The IAHS Scientific Decade 2013–2022. Hydrological Sciences Journal, 58(6), 1256–1275.

Sunday, July 16, 2017

Iowa and operational hydrology

Or operational hydrology in Iowa. I do not know if I like the name, because it usually distinguished, since Sacramento model, models that work but kind of far from the edge of research. Obviously this was due to the fact that having a model running every day faces issues that researchers of my type seldom love, like dealing with unreliable data sets, managing, in any case huge amount of data, calibration of parameters, and, more recently, data assimilation. This obviously has to be done routinely, with no loss of forecasting, when it is easy not to have data, and so on. So the focus of these systems was (is) operativity and having reliable results with unreliable tools (an not, like I do, improving the tools).
Among the various experience I saw around the world, The Iowa's one, is remarkable, because never forgot the most recent research, thanks to the effort of Ricardo Gutierrez Mantilla (GS), and Witold Krajesky (GS).
Ricardo, which whom I share a paper, was so kind to show me what he is doing with all the group of people in Iowa in the recent EGU meeting in Wien, and I was surprised by the quality of the results he has, and the quality of the overall system. One remarkable fact is also the this system is, certainly based on the knowledge of current literature but, originally developed and different from any other. He finally sent to me the couple of his presentation that I (under his permission) am sharing with who is interested. 

Click on the figures to access the presentations. 

A recent publication about the systema was published on BAMS: Witold F. Krajewski, Daniel Ceynar, Ibrahim Demir, Radoslaw Goska, Anton Kruger, Carmen Langel, Ricardo Mantilla, James Niemeier, Felipe Quintero, Bong-Chul Seo, Scott J. Small, Larry J. Weber, and Nathan C. Young, Real-Time Flood Forecasting and Information System for the State of Iowa, Real-time flood forecasting and information system for the State of Iowa, Bull. Am. Meteorol. Soc., doi:10.1175/BAMS-D-15-00243.1, 2017.

Here you can find the  IFC official website.
Here a link to the Iowa Flood Information System (IFIS) which is the platform they use to disseminate flood related information


Wednesday, July 12, 2017

Open call for a master course in High Performance Computing applied to Hydrological Modeling.

Dear all, I would like to advertise an unique opportunity for bright and motivated young people interested in both hydrology and learn on high-performance scientific computing.
The HPC-Tres program (see is just ready to open a call four (4) fellowship to attend the master in HPC ( and work on a thesis on earth science computational project.

One of these four project is dedicated to the development of high-performance parallel code for hydrological modelling, thanks to the cooperation among EURAC Bolzano , OGS (Istituto Nazionale di Oceanografia e Geofisica Sperimentale and MHPC Master in High Scientific Computing

This is a great chance for a young graduated student to become an HPC professional and at the same time give an important contribution to advanced scientific packages.
One of the goals of the thesis is to make the hydrological model GEOtop (see also here) run in parallel and increase its speed and overall performance. See “Line C7. Development of a High Performance hydrological model” in the attached document.

To apply for the fellowship is mandatory to apply to the MHPC as well

Deadline has been updated to the 17 of July, see here:

Please do not hesitate to contact Giacomo Bertoldi for any further information on this.

Please circulate this opportunity among young and motivated collaborators interested in spending 12 month between Trieste and Bolzano fully paid to attend the master and work on HPC hydrological modelling.

Ing. Giacomo Bertoldi, Ph.D.

EURAC research

Istituto per l'ambiente alpino

Viale Druso 1, I-39100 Bolzano

t +39 0471 055 314
f +39 0471 055 399

Line C7. Development of a High Performance hydrological model

The GEOtop hydrological scientific package is an integrated hydrological model that simulates the heat and water budgets at and below the soil surface. It describes the three-dimensional water flow in the soil and the energy exchange with the atmosphere, considering the radiative and turbulent fluxes. Furthermore, it reproduces the highly non-linear interactions between the water and energy balance during soil freezing and thawing, and simulates the temporal evolution of snow cover, soil temperature and moisture. The core components of the package were presented in the 2.0 version (Endrizzi et al, 2014), which was released as Free Software Open-source project. However, despite the high scientific quality of the project, a modern software engineering approach was still missing. Such weakness hindered its scientific potential and its use both as a standalone package and, more importantly, in an integrate way with other hydrological software tools. In this research line we ail to concentrate software re - engineering efforts to create a robust and stable parallel scientific software package open to the hydrological community, easily usable by researchers and experts, and interoperable with other packages. The overall goal of the activity is to eventually reach a robust and stable software project that manages in a flexible way a complex state-of-the-art hydrological model like GEOtop and integrates it into wider workflows.

Monday, July 10, 2017

A look back to go forward with JGrass-NewAGE

Let's give a look to the last two papers to delineate what is missing. They are all about the use of the JGrass-NewAGE system.

The key aspect of the whole treatment of the water budget is the closure strategy based on the Budyko hypothesis. This has been obtained by a suitable adaptation of the previous Adige-Hymod component that has to be futher cleaned: closing the budget in this way should become more easy and "normal”.  Notably, the method implies that we cannot easily account for cc, unless we let TB increase or decrease with time. However, there is no clear way to obtain this sliding TB from cc simulations.
Another aspect that distinguishes Pp is the use of MODIS for assessing the snow cover. That method would require a better definition, and a standardization of procedures which, again, is missing.
A weak point of this procedure is that ET does not depends on soil cover  characteristics. These characteristics have to be introduced appropriately, for instance giving plants' properties, which include foliage and some plants and roots dimensions which  affect water flows.

Other questions  involve the amount of simplification made when considering an HRU as the basic unit, and how a forcing attributed to a single point (inside a HRU) is representative of the variability of the whole area. Esemplificative is the case of the ET response, obtained by a single point or a small group of points inside the HRU and not by processing all the points. 
With respect to this, the original (version 0) of JGrass-NewAGE was more farsighted by introducing the  energy index calculator components. This OMS component was set to estimate the ratio of radiation received a single pixel inside the basin in a prescribed amount of time (i.e. a month, a year) with respect to a reference pixels. Then, when working in “real time” this factor was used to estimate (approximately) the radiation of the whole HRU on the basis of the single estimate of the reference point and saving, therefore, a lot of computational time. This type of simplifications should/could be reintroduced back again and used when relevant (for instance in Pp this should have been irrelevant for temperature, since its small variation inside each HRU). 

Besides what already said for the Pp that is valid also for BNp, there is to talk, for this paper, about satellite data. All the procedures to obtain those data were performed by using R scripts which are not reproducible and/or not well designed and/or not designed to be available to third parties. To make that research really sparkling, it would be necessary that those scripts and procedures would become real OMS components to be connected with the other ones that constitutesthe core of the paper.

The second point, obviously, is the use of very large HRU that was made: more than 400 square kilometers each on average (not so big, just as large as a square of 20 times 20 km). Therefore the arguments used in Pp, where HRU are of a few kilometers estension, are much more important here: how the sub grid variability of forcings like radiation affects the final results ?
Another aspect not well investigated is how the routing scheme used  affects the results. Clearly in a so large basin, this has to be investigated more thoroughly. Our tools have several routing schemes, including an integrator of a 1d de Saint-Venant equation. Using them could have some importance for the final assessment of our work.

Beyond this, another question arises: can we use those data and those results (in Pp and BNp) as benchmarks for future develpments of our system ? If not, this would be a big wound in our claim to do replicable research.

So, Let's get our sleeves back.