"Erosion-Productivity Impact Calculator"

Lizenz: kostenfrei

1 Abstract

EPIC (Erosion-Productivity Impact Calculator) is a mechanistic simulation model used to examine long-term effects of various components of soil erosion on crop production (Williams et al., 1983). EPIC is a public domain model that has been used to examine the effects of soil erosion on crop production in over 60 different countries in Asia, South America and Europe.

The model has several components:

  • soil erosion,
  • economic,
  • hydrologic,
  • weather,
  • nutrient,
  • plant growth dynamics and
  • crop management.

The model requires input from GRASS GIS layers. These include soil series and weather data, although the model can generate the necessary weather parameters. The model also requires management information that can be input from a text file. Currently, there are many management files that exist for EPIC and an effort is underway to catalogue these files and provide them to users. The model provides output on crop yields, economics of fertilizer use and crop values.

2 Model Objective

Assess the effect of soil erosion on productivity. Predict the effects of management decisions on soil, water, nutrient, and pesticide movements and their combined impact on soil loss, water quality, and crop yields for areas with homogeneous soils and management.

3 Model Components

Weather, surface runoff, return flow, percolation, ET, lateral subsurface flow and snow melt. Water erosion; Wind erosion; N & P loss in runoff , nitrogen leaching; Organic N & P transport by sediment; N & P mineralization, immobilization and uptake; Denitrification; Mineral P cycling; N fixation; Pesticide fate and transport; Soil temperature; Crop growth and yield for over 80 crops; Crop rotations; Tillage, Plant environment control (drainage, irrigation, fertilization, furrow diking, liming); Economic accounting; Waste management (feed yards dairies with or without lagoons).

4 Model Operation

  • Daily time step - long term simulations (1-4,000 years)
  • Soil, weather, tillage and crop parameter data supplied with model
  • Soil profile can be divided into ten layers
  • Homogeneous areas up to large fields
  • Weather generation is optional
  • Takes <1 sec./year on a Pentium machine

5 Siehe auch

6 Weblinks

Kategorien: Modelle

Letzte Änderung dieses Artikels: November 14, 2011, at 07:49 AM