Hydrology Tool Set (HTS) includes a suite of tools that have been developed through a collaborative research effort of Canadian Rivers Institute (CRI), University of New Brunswick (UNB), Agriculture and Agri-Food Canada (AAFC) and Environment and Climate Change Canada (ECCC). The suite of hydrology tools have been developed as part of a larger research effort aimed at evaluating the impacts of agricultural production practices on groundwater and surface water quality and on the quality of downgradient aquatic ecosystems.

  The various tools included in the suite can be used for advancing the understanding of local and watershed scale hydrological processes and include algorithms for estimating 1) surface runoff and groundwater contributions to streamflow via hydrograph separation [SepHydro]; 2) potential, reference and actual evapotranspiration [ETCalc]; 3) crop water deficit and excess, irrigation requirement and its impact on aquifer storage, water budget [SWIB]; 4) water balance (e.g., snowfall, snowmelt, snowpack, soil water content, evapotranspiration, drainage, infiltration, surface runoff, etc.) [SNOSWAB]; 5) groundwater recharge [RECHARGE BUDDY]; and 6) snowfall and rainfall amounts [SNOWFALL BUDDY]. The tools included in the suite can be used in many areas of environmental research, such as the assessment of the impact of agricultural practices, urbanization, climate change, etc.

  All the tools included in HTS have been developed using several principles as follows:

  • User-friendly interface
  • Streamlined and easy to follow procedures
  • Customisable parameters
  • Minimal input data requirement
  • Required input data generally available to the public at large
  • Offer a choice of methods when possible
  • Freely available (i.e. tool available at no cost and without user registration)
  • Integrate data import and export functions as well as graphical and tabular inspection tools


  ETCalc is a tool that integrates several customizable methods for calculating daily Potential Evapotranspiration (PET), Reference Evapotranspiration (ETR) and Actual Evapotranspiration (ET) based on user provided meteorological data and crop coefficients. The tool currently integrates Penman-Monteith, Thornthwaite, Blaney-Criddle, Turc, Priestley-Taylor, Hargreaves, Jensen-Haise and Abtew empirical equations.


  SepHydro is a tool that offers several customizable digital filtering algorithms for performing hydrograph separation (or baseflow separation) and assessing surface runoff and groundwater contributions to streamflow based on user provided daily streamflow data. SepHydro currently integrates Lyne & Hollick, Chapman, Eckhardt, Pettyjohn & Henning (Fixed Interval, Sliding Interval, Local Minimum, TR-55, Szilagyi (long and short), Boughton (AWBM) and Furey & Gupta, Chapman & Maxwell separation methods.


  SWIB (Soil Water Stress, Irrigation Requirement and Water Balance) is a model that allows users to estimate daily crop / soil water stress (either as water deficit or water excess), crop irrigation requirements and the impact of irrigation on aquifer storage, as well as a series of water balance components, based on user provided daily measured soil moisture and precipitation. SWIB allows for testing irrigation scheduling and efficiency scenarios based on user-defined growing and irrigation seasons, thresholds for soil moisture and water losses.


  SNOSWAB (Snow, Soil Water and Water Balance) is an online model for estimation of daily dynamics of snow-related processes (snowfall, snow accumulation, snowmelt), soil water content and water balance components (infiltration, drainage and surface runoff) based on user provided air temperature, precipitation, rainfall and evapotranspiration. The model incorporates routines for evaluation of the effects of temperature and precipitation on snow-related processes as well as impact of freezing and low or high soil water content on the dynamics of water balance components. SNOSWAB includes calibration routines and bivariate statistics for optimization of model output.


  Groundwater Recharge Estimation Tool (RECHARGE BUDDY) is an online tool for estimation of daily groundwater recharge, groundwater discharge and change in aquifer storage based on user-provided specific yield and daily water table elevations. RECHARGE BUDDY uses an adaptation of the widely-used Water Table Fluctuation (WTF) method. RECHARGE BUDDY includes calibration routines and bivariate statistics for optimization of model output.


  Snowfall and rainfall estimation tool (SNOWFALL BUDDY) is an online tool for estimation of daily snowfall and rainfall amounts based on user-provided daily air temperature and total precipitation. SNOWFALL BUDDY estimates snowfall and rainfall as mm of water and further allows for conversion of the snowfall amount into centimeters of snow. SNOWFALL BUDDY includes calibration routines and bivariate statistics for optimization of model output.