LT SWAT Point Source (PS) Data Processing Toolbox

This repository contains R scripts and tools for processing point source (PS) discharge data—such as wastewater treatment plant outputs—to prepare inputs for the SWAT (Soil and Water Assessment Tool) model, specifically tailored for Lithuania's river modeling system (LRMS). The workflow focuses on data validation, pollutant load calculation, and risk assessment for water bodies.

Purpose

The purpose of this toolbox is to automate the integration of point source pollution data into the LT SWAT modeling framework and to support the assessment of the impacts of point sources on water bodies. This is part of the broader LIFE22-IPE-LT-LIFE-SIP-Vanduo project, which aims to enhance integrated water management in Lithuania.

Project Overview

• Created on: 2025-06-05
• Last Modified: 2026-04-16
• Author: Svajunas Plunge
• Email: svajunas_plunge@sggw.edu.pl

Key Features

1. Quality Assurance (QA): The ps_qa.R script is used for data validation and integrity checks to ensure point source datasets are correctly represented in LRMS.
2. Impact Analysis: ps_impacts.R calculates pollutant loads and evaluates their specific impacts on the water bodies (WB).
3. Risk Assessment: ps_risk_wb.R identifies risk WBs by comparing base and change scenarios.
4. Point Source Assessment:ps_assess.R (and related updates in ps_risk_wb.R) provides capabilities to calculate the contribution of each point source to pollutant loading in all downstream water bodies.
5. Interactive App: The ps_assess_app/ directory contains a dedicated application for the interactive assessment of point source impacts.
6. Modular Functions: : Core logic, shared utilities, and features like date filtering are maintained in function.R to ensure consistency across the toolbox.

Repository Structure

LT-SWAT-PS-Processing/
├── Data/                # Directory for storing raw and processed datasets
├── ps_assess.R          # Script for calculating point source contributions to water bodies
├── ps_assess_app/       # Source code for the interactive assessment application
├── function.R           # Collection of custom R functions used across scripts
├── ps_impacts.R         # Script for assessing environmental impacts of point sources
├── ps_qa.R              # Quality assurance and data cleaning for point source datasets
├── ps_risk_wb.R         # Water body risk assessment based on point source loads
├── update_small.R       # Utility script for updating small point source datasets
├── .Renviron            # Environment variables configuration (e.g., Postgres database connection)
├── ps_in_ltswat.Rproj   # RStudio project file for the LT-SWAT PS processing workflow
└── README.md            # Project documentation and usage instructions

Prerequisites

Software Requirements

• R (100% of the project is written in R).
• RStudio is recommended for managing the .Rproj environment.

Data Requirements

• Point source discharge datasets as required by the analysis scripts.
• A properly configured .Renviron file to define local data directories and environment settings.
• Access to a PostGres database if required for data storage and retrieval.
• LRMS (Lithuanian River Modeling System) data for integrating point source information.

Usage

1. Clone the Repository: Download or clone the ps_in_ltswat repository from GitHub.
2. Initialize Project: Open ps_in_ltswat.Rproj in RStudio to set the working directory.
3. Configure Environment: Edit the .Renviron file to specify your local file paths.
4. Load Functions: Source function.R to load the necessary utilities for the project.
5. Run Scripts:
   • Execute ps_qa.R to validate your data.
   • Use ps_assess.R or the ps_assess_app/ for data assessment.
   • Execute ps_impacts.R or ps_risk_wb.R to generate model inputs and risk reports.

Acknowledgments

This work was carried out within the LIFE22-IPE-LT-LIFE-SIP-Vanduo project (Integrated water management in Lithuania, ref: LIFE22-IPE-LT-LIFE-SIP-Vanduo/101104645), funded by the European Union LIFE program under the grant agreement No 101104645.