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Multi-scale geospatial agroecosystem modeling: a case study on the influence of soil data resolution on carbon budget estimates.

Authors :
Zhang X
Sahajpal R
Manowitz DH
Zhao K
Leduc SD
Xu M
Xiong W
Zhang A
Izaurralde RC
Thomson AM
West TO
Post WM
Source :
The Science of the total environment [Sci Total Environ] 2014 May 01; Vol. 479-480, pp. 138-50. Date of Electronic Publication: 2014 Feb 19.
Publication Year :
2014

Abstract

The development of effective measures to stabilize atmospheric CO2 concentration and mitigate negative impacts of climate change requires accurate quantification of the spatial variation and magnitude of the terrestrial carbon (C) flux. However, the spatial pattern and strength of terrestrial C sinks and sources remain uncertain. In this study, we designed a spatially-explicit agroecosystem modeling system by integrating the Environmental Policy Integrated Climate (EPIC) model with multiple sources of geospatial and surveyed datasets (including crop type map, elevation, climate forcing, fertilizer application, tillage type and distribution, and crop planting and harvesting date), and applied it to examine the sensitivity of cropland C flux simulations to two widely used soil databases (i.e. State Soil Geographic-STATSGO of a scale of 1:250,000 and Soil Survey Geographic-SSURGO of a scale of 1:24,000) in Iowa, USA. To efficiently execute numerous EPIC runs resulting from the use of high resolution spatial data (56m), we developed a parallelized version of EPIC. Both STATSGO and SSURGO led to similar simulations of crop yields and Net Ecosystem Production (NEP) estimates at the State level. However, substantial differences were observed at the county and sub-county (grid) levels. In general, the fine resolution SSURGO data outperformed the coarse resolution STATSGO data for county-scale crop-yield simulation, and within STATSGO, the area-weighted approach provided more accurate results. Further analysis showed that spatial distribution and magnitude of simulated NEP were more sensitive to the resolution difference between SSURGO and STATSGO at the county or grid scale. For over 60% of the cropland areas in Iowa, the deviations between STATSGO- and SSURGO-derived NEP were larger than 1MgCha(-1)yr(-1), or about half of the average cropland NEP, highlighting the significant uncertainty in spatial distribution and magnitude of simulated C fluxes resulting from differences in soil data resolution.<br /> (Copyright © 2014 Elsevier B.V. All rights reserved.)

Details

Language :
English
ISSN :
1879-1026
Volume :
479-480
Database :
MEDLINE
Journal :
The Science of the total environment
Publication Type :
Academic Journal
Accession number :
24561293
Full Text :
https://doi.org/10.1016/j.scitotenv.2014.01.099