Principles:   The software shown below, consisting of mathematical (numerical, computer, simulation) models, all has the same features: -- an input menu for data handling -- a calculation phase -- an output menu for inspecting results including graphs -- a possibility to make *.prn or *.txt files for spreadsheet use Hints:   The computer programs are supposed to be self explanatory. Examples of input and output files are given.   Acknowledgement:   I acknowledge the contributions of users of the software worldwide who, through their valuable observations and suggestions, have helped to contually improve the software.                                                     Contact:   I would appreciate it to learn about your experiences. For this there is a contact form .   Click on any of the following 7 programs for more information and free downloads. Articles & manuals   Reports & cases   FAQ's & papers   Update reports   Home page

 

Programs:

CumFreq

SegReg

RainOff

EnDrain

WellDrain

SaltMod

SahysMod

CumFreq is meant for segmented cumulative frequency analysis using a breakpoint (break-point), which serves for example to study discontinuous probability distributions and return periods of hydrologic factors like rainfall, river and drain discharge, water and river level, depth or level of watertable, soil salinity, hydraulic conductivity (soil permeability for water). SegReg can be used for segmented linear regression, i.e. regression in segments, using a breakpoint (break-point) or threshold value, which serves for example to analyse the relation between plant growth or crop production in agriculture versus soil salinity and depth of watertable in agricultural land.

RainOff helps in modelling effective rainfall, recharge, water storage, runoff, drainage and discharge relations in hydrological catchment areas (watersheds) using the concept of a nonlinear reservoir. EnDrain does calculations on horizontal subsurface drainage systems in agriculture, hydraulic head, depth and level of water-table in agricultural land, and drain spacing using the energy balance of groundwater flow but also the Darcy and continuity equation (mass balance/budget of water). It includes drain entrance resistance and soil anisotropy of hydraulic conductivity (soil permeability for water), i.e. the horizontal and vertical hydraulic conductivity are different. Applicable to pipe/tile drains (drain pipes) and open ditches. WellDrain Calculates the spacing of wells, the shape, depth, and level of the watertable in vertical drainage systems using pumped wells. Like EnDrain, it permits aquifers with various different properties and, in addition, fully/partially penetrating wells.

SaltMod a mathematical, numerical simulation model describing the relations between agriculture, crop rotation, irrigation, rainfall, potential and actual evaporation (evapotranspiration), climate, hydrology, depth and level of water-table, capillary rise, deep percolation, soil salinity and subsurface drainage by drains or wells, and reuse (conjunctive use) of ground and drain water from wells. It includes farmers' responses to water logging and soil salinity. SahysMod a combination of Saltmod with a model of ground water flow and hydraulics to account for large spatial variation through a network of polygons. It includes phreatic (unconfined) aquifers as well as soil layers with slow vertical hydraulic conductivity (soil permeability for water) resulting in semiconfined (leaky) aquifers.

Click on any of the above 7 programs for more information and free downloads.