PMID- 35132506 OWN - NLM STAT- MEDLINE DCOM- 20220209 LR - 20220209 IS - 1573-2959 (Electronic) IS - 0167-6369 (Linking) VI - 194 IP - 3 DP - 2022 Feb 7 TI - Spatial modeling of soil organic carbon using remotely sensed indices and environmental field inventory variables. PG - 152 LID - 10.1007/s10661-022-09842-8 [doi] AB - The relationship between soil organic carbon (SOC) and environmental parameters was investigated in the Galazchai Watershed, Iran. Therefore, correlating the SOC amounts with remote sensing (RS) indices, topographic variables, and soil texture was analyzed. Some 125 soil samples gather from the upper 30 cm, and the weight of each sample was about 0.5 kg. The RS indices, consisting of difference vegetation index (DVI), enhanced vegetation index (EVI), optimized soil adjusted vegetation index (OSAVI), normalized difference vegetation index (NDVI), and soil adjusted vegetation index (SAVI), were used. Topographic variables included slope, elevation, aspect, and topographical wetness index (TWI), as well as clay and silt contents. The ordinary least square (OLS) and the geographically weighted regression (GWR) were employed to develop the SOC relationship considering different combinations of the variables. Results showed that none of the combinations of variables accurately estimated SOC (R(2) < 0.32 and p value > 0.001). However, EVI with GWR (R(2) = 0.291) and OSAVI, clay, slope, and aspect with GWR (R(2)= 0.32) better estimated SOC. Therefore, results showed that the study remotely sensed indices and environmental field inventory variables could not favorably predict the SOC content. These results can be attributed to the low SOC values varying from 0.917 to 3.355%, with a mean of 2.194 +/- 0.522 in the study watershed. However, studies using more uniformly distributed and denser sampling in the study area and other methods to investigate the relationship between variables are recommended. CI - (c) 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG. FAU - Katebikord, Azadeh AU - Katebikord A AD - Department of Watershed Management Engineering, Faculty of Natural Resources, Tarbiat Modares University, 46417-76489, Noor, Iran. FAU - Sadeghi, Seyed Hamidreza AU - Sadeghi SH AUID- ORCID: 0000-0002-5419-8062 AD - Department of Watershed Management Engineering, Faculty of Natural Resources, Tarbiat Modares University, 46417-76489, Noor, Iran. sadeghi@modares.ac.ir. FAU - Singh, Vijay P AU - Singh VP AD - Department of Watershed Management Engineering, Faculty of Natural Resources, Tarbiat Modares University, 46417-76489, Noor, Iran. AD - Department of Biological and Agricultural Engineering and Zachry Department of Civil Engineering, Texas A & M University, College Station, TX, 77843-2117, USA. LA - eng GR - IG-39713/Tarbiat Modares University/ PT - Journal Article DEP - 20220207 PL - Netherlands TA - Environ Monit Assess JT - Environmental monitoring and assessment JID - 8508350 RN - 0 (Soil) RN - 7440-44-0 (Carbon) SB - IM MH - *Carbon/analysis MH - Environmental Monitoring MH - Least-Squares Analysis MH - *Soil MH - Spatial Regression OTO - NOTNLM OT - Carbon spatial distribution OT - Digital soil mapping OT - Geospatial modeling OT - Landsat images OT - Remote sensing predictors OT - Soil organic carbon prediction EDAT- 2022/02/09 06:00 MHDA- 2022/02/10 06:00 CRDT- 2022/02/08 05:52 PHST- 2021/05/04 00:00 [received] PHST- 2022/01/29 00:00 [accepted] PHST- 2022/02/08 05:52 [entrez] PHST- 2022/02/09 06:00 [pubmed] PHST- 2022/02/10 06:00 [medline] AID - 10.1007/s10661-022-09842-8 [pii] AID - 10.1007/s10661-022-09842-8 [doi] PST - epublish SO - Environ Monit Assess. 2022 Feb 7;194(3):152. doi: 10.1007/s10661-022-09842-8.