Tag Archives: model

New algorithms for hydrological parameters optimization

In addition to the SCE-UA (Shuffled Complex Evolution – University of Arizona), used for the optimization of the hydrological parameters in RS MINERVE, two new algorithms have been implemented: the “Uniform Adaptive Monte Carlo” and the “Coupled Latin Hypercube and Rosenbrock”

The Uniform Adaptive Monte Carlo (UAMC) algorithm is based on the Monte Carlo experiments that rely on repeated random sampling but has been modified in order to iteratively adjust the solution space.
The algorithm randomly launches a collection of simulations (block) and finds the better results in the solution space. Afterwards, the solution space is adjusted and a new group of simulations starts. The process is repeated until the optimization converges to the best set of parameters.

The Coupled Latin Hypercube and the Rosenbrock algorithm, generates a powerful tool for optimization of complex problems. This combined algorithm can discretize a wide domain and then narrow your search to smaller sectors. Scanning of the space of possible solutions is performed by the Latin Hypercube. This algorithm allows pseudo-statistical sampling conditioned by the previous calculated solutions. The Latin hypercube is an evolution of the Monte Carlo method, with more homogeneous samples achieved with fewer samples. An important advantage of this method is that the dimension of the problem is defined by the division of the latin hypercube and not by the number of parameters.
The best results from samples become the starting points required for Rosenbrock algorithm. The advantage of this subroutine calculation lies in the speed to obtain near optimal values. This algorithm is based on a gradient search, adjusting axis changes based on the direction of maximum enhancement, thus reducing the number of evaluations of the objective function.

More details in the technical manual.

 

Potential Evapotranspiration calculation

RS MINERVE currently offers the possibility to calculate the Potential Evapotranspiration (ETP) values from different methods when no ETP data is available.

The 4 implemented ETP methods are :

  • Turc: calculation of ETP depending on the global radiation Rg (based only on latitude and longitude) and temperature
  • McGuinness: method depending on Rg (based only on latitude and longitude) and temperature
  • Oudin: a french method depending on the extra-terrestrial radiation Re (based only on latitude) and T
  • A uniform ETP

The value of global radiation Rg is a monthly averaged value which depends on the latitude and longitude of the hydrological model.   These Rg data were obtained from the Surface meteorological and Solar Energy (SSE) web portal, sponsored by the NASA’s Applied Science Program (http://eosweb.larc.nasa.gov/sse).

Rg data takes into account 22 year monthly average (July 1983 – June 2005). The latitude and the longitude values indicate the lower left corner of a 1×1 degree region. Negative values are south and west; positive values are north and east. Boundaries of the -90/-180 region are -90 to -89 (south) and -180 to -179 (west). The last region, 89/180, is bounded by 89 to 90 (north) and 179 to 180 (east). The mid-point of the region is +0.5 added to the latitude/longitude value. These data are regional averages, not point data.

The value of extra-terrestrial radiation Re is directly computed based on the latitude of the hydrological model and parameters such as sun-earth distance and solar declination.

For more information, please refer to the RS MINERVE Technical Manual.

 

New object “Structure efficiency”

The recently published version of RS MINERVE (1.1.0) offers a new object, developed by Hydro10 Association, named Structure efficiency. With a simple efficiency coefficient, it allows computing effects of discharge losses in a structure such a canal or a pipe (Output = Input * Efficiency_coefficient).

Users can now model, for example, losses in an irrigation canals network. By changing the coefficients of all Structure efficiency objects in only a few clicks, assessment of losses reduction in the network can now easily be performed.

The developments achieved in 2014 (Consumer, Hydropower, Structure efficiency, etc), trends to easily understand and improve water management to end users.

Hydropower modeling

The new hydropower “object” of RS MINERVE computes the net height and the linear pressure losses, providing energy production values and total income based on turbine performance and sale price of energy. This new object is very useful for evaluating hydropower plants benefits depending on hydro-meteorological scenarios or on different hydropower schemes. More details in the technical manual.

Water consumption in RSM models

A new object Consumer is added to RS Minerve to model the agricultural, municipal (including domestic) or industrial water use.
The Consumer calculates the water use as well as the downstream hydrograph. If the water demand exceeds the water supply, the water shortfall is calculated for the simulation period.
More details in the technical manual.

New hydrological models

RS MINERVE simulates the formation of free surface run-off flow and its propagation. The tool is based on object-oriented programming and allows hydrologic and hydraulic modeling according to a semi-distributed conceptual scheme. In addition to particular hydrologic processes such as snowmelt, glacier melt, surface and underground flow due to infiltration, hydraulic control elements, for example gates, spillways, diversions, junctions, turbines and pumps are also incorporated.
The previous list of hydrological models (Snow, Glacier, GR3, SWMM, GSM and SOCONT) is extended with the models HBV (“Hydrologiska Byråns Vattenbalansavdelning”), GR4J (“Génie Rural à 4 paramètres Journalier”) and SAC-SMA (“Sacramento Soil Moisture Accounting”).

Welcome post

A software, a blog for communicating, people for discussing… Welcome to the new blog created by the Association Hydro10 for supporting and sharing knowledge about the free hydrological – hydraulic software RS MINERVE.
The development of this software started in 2012 thanks to motivated people wanting to propose a hydrologic – hydraulic tool capable of dealing with hydrological issues in natural or equipped basins.
The software RS MINERVE is available from January 2013 and is already used in some projects in Switzerland, France, Spain, Nepal, Tunisia, Peru… and that is just the beginning.
Please join us to discuss all engineering, hydrologic, hydraulic issues and to take advantage of this new software.