Tuesday, July 31, 2018

Anke Hildebrandt's recent research

If you are interested in the hydraulics of plants, you should give a look to the recent production of Anke Hildebrandt. Her production encounter my favor since she is able to put together experimental work and theoretical work on the thermodynamics of trees. A topic on which recently I became interested in. Relevant among her production is the work on hess: A thermodynamic fomulation of root water uptake which was awarded as one of the best paper of 2017 in HESS. No more comments. Just papers to read below. 

Recent papers

Van Stan, J. T., Norman, Z., Meghoo, A., Friesen, J., Hildebrandt, A., Côté, J.-F., et al. (2017). Edge-to-Stem Variability in Wet-Canopy Evaporation From an Urban Tree Row. Boundary-Layer Meteorology, 165(2), 295–310. http://doi.org/10.1007/s10546-017-0277-7

Guderle, M., Bachmann, D., Milcu, A., Gockele, A., Bechmann, M., Fischer, C., et al. (2017). Dynamic niche partitioning in root water uptake facilitates efficient water use in more diverse grassland plant communities. Functional Ecology, 32(1), 214–227. http://doi.org/10.1111/1365-2435.12948

Metzger, J. C., Wutzler, T., Dalla Valle, N., Filipzik, J., Grauer, C., Lehmann, R., et al. (2017). Vegetation impacts soil water content patterns by shaping canopy water fluxes and soil properties. Hydrological Processes, 31(22), 3783–3795. http://doi.org/10.1002/hyp.11274

Weisser, W.W., C. Roscher, S. Meyer, A. Ebeling, G. Luo, E. Allan, H. Beßler, R. Barnard, N. Buchmann, F. Buscot, C. Engels, C. Fischer, M. Fischer, A. Gessler, G. Gleixner, S. Halle, A. Hildebrandt, H. Hillebrand, H. de Kroon, M. Lange, S. Leimer, X. Le Roux, A. Milcu, L. Mommer, P. Niklaus, Y. Oelmann, R. Proulx, C. Scherber, M. Scherer-Lorenzen, S. Scheu, T. Tscharntke, M. Wachendorf, C. Wagg, A. Weigelt, W. Wilcke, E.-D. Schulze, B. Schmid, N. Eisenhauer. Biodiversity effects on ecosystem functioning in a 14-year grassland experiment: patterns, mechanisms, and open questions. Basic and Applied Ecology, doi: 10.1016/j.baae.2017.06.002. (link)

Zimmermann, A., Voss, S., Metzger, J. C., Hildebrandt, A., & Zimmermann, B. (2016). Capturing heterogeneity: The role of a study area’s extent for estimating mean throughfall. Journal of Hydrology, 542(C), 781–789. http://doi.org/10.1016/j.jhydrol.2016.09.047

Guderle, M., D. Bachmann, A. Milcu, A. Gockele, M. Bechmann, C. Fischer, C. Roscher, D. Landais, O. Ravel, S. Devidal, J. Roy, A. Gessler, N. Buchmann, A. Hildebrandt. Dynamic niche partitioning in root water uptake facilitates efficient water use in more diverse plant communities. Functional Ecology, doi: 10.1111/1365-2435.12948. (link)

Metzger, J. C., N. Dalla Valle, T. Wutzler, J. Filipzik, R. Lehmann, M. Roggenbuck, D. Schelhorn, J. Weckmüller, K. Küsel, K. U. Totsche, S. Trumbore, A. Hildebrandt. Tracing spatial variation of canopy water fluxes to the soil with high resolution data. Hydrological Processes. doi: 10.1002/hyp.11274 (link)

Arnold, S., Attinger, S., Frank, K., Hildebrandt, A. 2016. Assessing the structural adequacy of alternative ecohydrological models using a pattern-oriented approach. Ecological Modelling 316: 52-61. doi: doi:10.1016/j.ecolmodel.2015.08.003. (link)

Hildebrandt, A. A. Kleidon and M. Bechmann. A thermodynamic fomulation of root water uptake. Hydrology and Earth System Sciences. 20: 3441-3454, doi: 10.51947hess-20-3441-2016. (link)

Milcu, A., W. Eugster, D. Bachmann, M. Guderle, Ch. Roscher, D. Landais, O. Ravel, A. Gessler, M. Lange, A. Ebeling, W. Weisser, J. Roy, A. Hildebrandt, N. Buchmann. 2015. Plant species and functional diversity increase grassland productivity-related water vapour fluxes: a combined Ecotron and modeling approach. Ecology 97(8): 2044-2054. doi: 10.1890/15-1110.1 (link)

Renner, M., S. K. Hassler, T. Blume, M. Weiler, A. Hildebrandt, M. Guderle, S. J. Schymanski, and A. Kleidon. Dominant controls of transpiration along a hillslope transect inferred from ecohydrological measurements and thermodynamic limits, Hydrology and Earth System Sciences 20: 2063-2083. doi: 10.5194/hess-20-2063-2016. (link)

Fischer, C., Tischer, J., Roscher, C., Eisenhauer, N., Ravenek, J. M., Gleixner, G., Attinger, S., Jensen, B., de Kroon, H., Mommer, L., Scheu, S., Hildebrandt, A. 2015. Plant species diversity affects infiltration capacity in an experimental grassland through changes in soil properties. Plant and Soil. 397(1): 1-16, doi: 10.1007/s11104-014-2373-5 (link)

Guderle M. and Hildebrandt A. 2015. Using measured soil water contents to estimate evapotranspiration and root water uptake profiles - a comparative study. Hydrology and Earth System Sciences. 19: 409-425. doi: 10.5194/hess-19-409-2015 (link)

Bechmann, M., C. Schneider, A. Carminati, D. Vetterlein, S. Attinger, A. Hildebrandt. 2014. Parameterizing complex root water uptake models - the arrangement of root hydraulic properties within the root architecture affects dynamics and efficiency of root water uptake. Hydrology and Earth System Sciences. 18:4189-4206. doi: 10.5194/hess-18-4189-2014 (link)

Fischer, C., C. Roscher, Jensen, N. Eisenhauer, J. Baade, S. Attinger, S. Scheu, W.W. Weisser, A. Hildebrandt. 2014. How do earthworm, soil texture and plant composition affect infiltration in managed grasslands along a plant diversity gradient? PLoS ONE9(6): e98987. doi:10.1371/journal.pone.0098987. (link)

Leimer, S., Kreutziger, Y., Rosenkranz, S., Beßler, H., Hildebrandt, A., Oelmann, Y., Weisser, W., Wirth, C. Wilcke, W., 2014. Plant diversity effects on the water balance of an experimental grassland. Ecohydrology, doi: 10.1002/eco.1464. (link)

Carminati, A., C. L. Schneider, A. B. Moradi, M. Zarebanadkouki, D. Vetterlein, H.-J. Vogel, A. Hildebrandt, U. Weller, L. Schüler, and S. E. Oswald. 2011. How the Rhizosphere May Favor Water Availability to Roots. Vadose Zone Journal 10:988. doi: 10.2136/vzj2010.0113. (link)

Kalbacher, T., C. L. Schneider, W. Wang, A. Hildebrandt, S. Attinger, and O. Kolditz. 2011. Modeling Soil-Coupled Water Uptake of Multiple Root Systems with Automatic Time Stepping. Vadose Zone Journal 10:727. doi: 10.2136/vzj2010.0099. (link)

Alexandrov, G. a., D. Ames, G. Bellocchi, M. Bruen, N. Crout, M. Erechtchoukova, A. Hildebrandt, F. Hoffman, C. Jackisch, and P. Khaiter. 2010. Technical assessment and evaluation of environmental models and software: Letter to the Editor. Environmental Modelling & Software 26:328-336. doi: 10.1016/j.envsoft.2010.08.004. (link)

Wednesday, July 25, 2018

If I was the head of my Department

I manifested to my colleague my availability to be voted for Department Head. Not an easy task indeed, and a challenge if I want to continue to do some research. However, this is the right time for doing it. In six years I will be too old to plan to for ten years in advance and the baton has to be given to others, while I will give "good advise, if I will not be able to give bad examples".
Today we are asked, the so far three candidates, to give our vision for our mandate in front  our peers and electors.
Below the above figure, you find my talk (in Italian). Have to say my opponents are good guys, and I have not problems to give up if I recognize if their will and view is better than mine.  At the end, I think one of the quality of good academics is to recognize where excellence stands. 

Monday, July 16, 2018

Towards a new SWMM, JSWMM

You want to design a storm water management system. What you usually get is a rainfall-runoff model. In this specific subfield, the model is SWMM. EPA SWMM contains many features that were implemented to simulate urban storm water depletion network. Meaning that there are specific model's parameters set for that, and that a community gathered around this tool.

However SWMM is not a system for designing sewers. Designing requires that you repeat the modeling actions several times. At the outlet of any pipe, you have to:
  • estimate the runoff under a "design rainfall" coming from some intensity-duration-frequency curves.
  • get the maximum discharge with an assigned return period (say 10 years)
  • Use simplified hydraulics for obtaining the size of the pipe apt to contain the maximum discharge
  • repeat the operation for the pipes downhill, without leaving out uphill branches.
Operation 2 above requires a search algorithm to find the rainfall duration that is responsible for the maximum discharge. The complete theory is in Rigon et al., 2011.
The point is that SWMM does not do the sequence of operation above. This is one of the reasons we implemented JSWMM. To see what it does, click on the figure.