1st International Congress on Environmental Modelling and Software - Lugano, Switzerland - June 2002
Keywords
solar radiation, climate data, cropsyst, crop modeling, decision support systems, ladss
Start Date
1-7-2002 12:00 AM
Abstract
Models are increasingly being used to represent land uses within decision support systems. Crop simulation models often require climate data as input variables. Whilst precipitation and temperature data are usually available, there is often a dearth of representative solar radiation data in most countries. An illustration is made of the spatial distribution of meteorological stations with records of solar radiation and / or sunshine duration in the UK. Methods are available to estimate solar radiation using meteorological data, or by conversion from sunshine duration. In the absence of site-specific data, the nearest meteorological station data is often used to run models at a particular location. The aim of this paper is to determine an appropriate source of solar radiation data, given the range of meteorological data available, for the sitespecific application of a crop model (CropSyst). Three methods of providing solar radiation data were tested: conversion from sunshine duration; the two nearest meteorological stations; and the Campbell-Donatelli model. Generic simulations of spring barley were run within CropSyst for 13 separate years, using the three sources of solar radiation data for three neighbouring locations in southern England. Crop yield output was compared with results derived from observed solar radiation. For the three locations tested, the order of most suitable data source was: conversion of sunshine duration; nearest meteorological station; and the Campbell- Donatelli model. There is a significant effect on model results arising from the data source. The results demonstrate that DSS employing crop models should use an appropriate source of solar radiation data. The results are discussed in the context of utilising CropSyst within the Land Allocation Decision Support System (LADSS), a spatial multiple-objective land-use planning tool for considering farm-scale environmental, social and economic trade-offs.
A Comparison of Methods for Providing Solar Radiation Data to Crop Models and Decision Support Systems.
Models are increasingly being used to represent land uses within decision support systems. Crop simulation models often require climate data as input variables. Whilst precipitation and temperature data are usually available, there is often a dearth of representative solar radiation data in most countries. An illustration is made of the spatial distribution of meteorological stations with records of solar radiation and / or sunshine duration in the UK. Methods are available to estimate solar radiation using meteorological data, or by conversion from sunshine duration. In the absence of site-specific data, the nearest meteorological station data is often used to run models at a particular location. The aim of this paper is to determine an appropriate source of solar radiation data, given the range of meteorological data available, for the sitespecific application of a crop model (CropSyst). Three methods of providing solar radiation data were tested: conversion from sunshine duration; the two nearest meteorological stations; and the Campbell-Donatelli model. Generic simulations of spring barley were run within CropSyst for 13 separate years, using the three sources of solar radiation data for three neighbouring locations in southern England. Crop yield output was compared with results derived from observed solar radiation. For the three locations tested, the order of most suitable data source was: conversion of sunshine duration; nearest meteorological station; and the Campbell- Donatelli model. There is a significant effect on model results arising from the data source. The results demonstrate that DSS employing crop models should use an appropriate source of solar radiation data. The results are discussed in the context of utilising CropSyst within the Land Allocation Decision Support System (LADSS), a spatial multiple-objective land-use planning tool for considering farm-scale environmental, social and economic trade-offs.
