{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,28]],"date-time":"2026-03-28T08:12:00Z","timestamp":1774685520368,"version":"3.50.1"},"reference-count":54,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2016,2,20]],"date-time":"2016-02-20T00:00:00Z","timestamp":1455926400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The Songnen Plain of the Northeast China is one of the three largest soda saline-alkali regions worldwide. To better understand soil alkalinization and salinization in this important agricultural region, it is vital to explore the distribution and variation of soil alkalinity and salinity in space and time. This study examined soil properties and identified the variables to extract soil alkalinity and salinity via physico-chemical, statistical, spectral, and image analysis. The physico-chemical and statistical results suggested that alkaline soils, coming from the main solute Na2CO3 and NaHCO3 in parent rocks, characterized the study area. The pH and electric conductivity (EC ) were correlated with both narrow band and broad band reflectance. For soil pH, the sensitive bands were in short wavelength (VIS) and the band with the highest correlation was 475 nm (r = 0.84). For soil EC, the sensitive bands were also in VIS and the band with the highest correlation was 354 nm (r = 0.84). With the stepwise regression, it was found that the pH was sensitive to reflectance of OLI band 2 and band 6, while the EC was only sensitive to band 1. The R2Adj (0.73 and 0.72) and root mean square error (RMSE) (0.98 and 1.07 dS\/m) indicated that, the two stepwise regression models could estimate soil alkalinity and salinity with a considerable accuracy. Spatial distributions of soil alkalinity and salinity were mapped from the OLI image with the RMSE of 1.01 and 0.64 dS\/m, respectively. Soil alkalinity was related to salinity but most soils in the study area were non-saline soils. The area of alkaline soils was 44.46% of the basin. Highly alkaline soils were close to the Zhalong wetland and downstream of rivers, which could become a severe concern for crop productivity in this area.<\/jats:p>","DOI":"10.3390\/rs8020163","type":"journal-article","created":{"date-parts":[[2016,2,22]],"date-time":"2016-02-22T10:24:17Z","timestamp":1456136657000},"page":"163","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":61,"title":["Remote Sensing of Soil Alkalinity and Salinity in the Wuyu\u2019er-Shuangyang River Basin, Northeast China"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5400-9519","authenticated-orcid":false,"given":"Lin","family":"Bai","sequence":"first","affiliation":[{"name":"Key Laboratory of Remote Sensing Monitoring of Geographic Environment, College of Heilongjiang Province, Harbin Normal University, Harbin, Heilongjiang 150025, China"},{"name":"Department of Human Geography and Urban-Rural Planning, Qiqihar University, Qiqihar, Heilongjiang 161006, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cuizhen","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Remote Sensing Monitoring of Geographic Environment, College of Heilongjiang Province, Harbin Normal University, Harbin, Heilongjiang 150025, China"},{"name":"Department of Geography, University of South Carolina, Columbia, SC 29208, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shuying","family":"Zang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Remote Sensing Monitoring of Geographic Environment, College of Heilongjiang Province, Harbin Normal University, Harbin, Heilongjiang 150025, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuhong","family":"Zhang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Remote Sensing Monitoring of Geographic Environment, College of Heilongjiang Province, Harbin Normal University, Harbin, Heilongjiang 150025, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qiannan","family":"Hao","sequence":"additional","affiliation":[{"name":"Key Laboratory of Remote Sensing Monitoring of Geographic Environment, College of Heilongjiang Province, Harbin Normal University, Harbin, Heilongjiang 150025, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuexiang","family":"Wu","sequence":"additional","affiliation":[{"name":"Qiqihar Meteorological Bureau, Qiqihar, Heilongjiang 161006, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2016,2,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1007\/s10333-009-0166-x","article-title":"The causes of soil alkalinization in the Songnen Plain of Northeast China","volume":"7","author":"Wang","year":"2009","journal-title":"Paddy Water Environ."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/S0304-3800(01)00371-4","article-title":"Assessing temporal and spatial changes of salinity using fuzzy logic, remote sensing and GIS: Foundations of expert system","volume":"144","author":"Metternicht","year":"2001","journal-title":"Ecol. Model."},{"key":"ref_3","first-page":"170","article-title":"Dynamic population models of the ecological dominance during the deterioration of Leymuschinensis grassland","volume":"19","author":"Wang","year":"1995","journal-title":"ActaPhytoecol Sin."},{"key":"ref_4","first-page":"51","article-title":"The alkili-saline land and agricultural sustainable development of the Western Songnen Plain in China","volume":"20","author":"Li","year":"2000","journal-title":"SciGeogr Sin."},{"key":"ref_5","first-page":"282","article-title":"Study on the relation between the formation of saline-alkali soil and the neotectonic movement","volume":"24","author":"Lin","year":"2005","journal-title":"Global Geol."},{"key":"ref_6","first-page":"79","article-title":"Research of mechanism of saline desertification in Western Songnen Plain","volume":"17","author":"Wu","year":"2003","journal-title":"Soil Water Conserv."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1006\/jare.2002.1087","article-title":"Effects of climatic change on biomass and biomass allocation in Leymuschinensis (Poaceae) along the North-east China Transect (NECT)","volume":"54","author":"Wang","year":"2003","journal-title":"J. Arid Environ."},{"key":"ref_8","first-page":"79","article-title":"The groundwater effect in the process of soil salinization of the Songnen Plain, Jilin province","volume":"21","author":"Wang","year":"2002","journal-title":"Jilin Geol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1007\/s002540100348","article-title":"Mechanism of freeze-thaw action in the process of soil salinization in northeast China","volume":"41","author":"Zhang","year":"2001","journal-title":"Environ. Geol."},{"key":"ref_10","first-page":"63","article-title":"Analyses on current situation, causes of formation, and way of management of desertification in western Northeast Plain of China","volume":"25","author":"Qiu","year":"2005","journal-title":"Quat. Sci."},{"key":"ref_11","first-page":"83","article-title":"Influences of agriculture practices on soil degradation","volume":"34","author":"Fauck","year":"1977","journal-title":"FAO Soil Bulletion. UN."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"300","DOI":"10.2136\/sssaj2000.641300x","article-title":"Performance of soil condition indicators aross taxonomic groups and land uses","volume":"64","author":"Schipper","year":"2000","journal-title":"Soil Sci. Soc. Am. J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1016\/0034-4257(93)90068-9","article-title":"Spectral band selection for the characterization of salinity status of soils","volume":"43","author":"Csillag","year":"1993","journal-title":"Remote Sens. Environ."},{"key":"ref_14","unstructured":"Buckman, H.O., Brady, N.C., and Weil, R.R. (2002). The Nature and Properties of Soils, Prentice Hall."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1097\/00010694-195408000-00012","article-title":"Diagnosis and improvement of saline and alkali soils","volume":"78","author":"Richards","year":"1954","journal-title":"Soil Sci."},{"key":"ref_16","unstructured":"Song, H.Y. (2013). Detection in Near-Infrared Spectroscopy of Soils, Chemistry Industry Press."},{"key":"ref_17","first-page":"455","article-title":"Application of soil electrical conductivity to precision ag-riculture: Theory, principles, and guidelines","volume":"95","author":"Corwin","year":"2003","journal-title":"Agron. J."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Rhoades, J.D. (1982). Soluble Salts, ASA and SSSA.","DOI":"10.2134\/agronmonogr9.2.2ed.c10"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1907","DOI":"10.1080\/01431169608948746","article-title":"Monitoring of salt-affected soils of the Indo-Gangetic alluvial plains using principal component analysis","volume":"17","author":"Dwivedi","year":"1996","journal-title":"Int. J. Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1080\/03650340.2011.646996","article-title":"Soil salinity characteristics using moderate resolution imaging spectroradiometer (MODIS) images and statistical analysis","volume":"59","author":"Zare","year":"2013","journal-title":"Arch. Agron. Soil Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"35","DOI":"10.2134\/jeq2009.0140","article-title":"Regional-scale assessment of soil salinity in the Red River Valley using multi-year MODIS EVI and NDVI","volume":"39","author":"Lobell","year":"2010","journal-title":"J. Environ. Qual."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1080\/01431169108929662","article-title":"Mapping the magnitude of sodicity in part of the Indo-Gangetic Plains of Uttar Pradesh, Northern India using Landsat-TM data","volume":"12","author":"Rao","year":"1991","journal-title":"Int. J. Remote Sens."},{"key":"ref_23","first-page":"178","article-title":"Remote sensing and mapping of saline sodic land based on spectral characteristics for Da\u2019an city","volume":"23","author":"Wu","year":"2007","journal-title":"Syst. Sci. Compr. Stud. Agric."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2571","DOI":"10.1080\/014311697217486","article-title":"Spatial discrimination of salt- and sodium-affected soil surfaces","volume":"18","author":"Metternicht","year":"1997","journal-title":"Int. J. Remote Sens."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"371","DOI":"10.1016\/S0304-3800(03)00147-9","article-title":"Categorical fuzziness: A comparison between crisp and fuzzy class boundary modelling for mapping salt-affected soils using Landsat TM data and a classification based on anion ratios","volume":"168","author":"Metternicht","year":"2003","journal-title":"Ecol. Model."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"605","DOI":"10.1080\/014311698215883","article-title":"Image transforms as a tool for the study of soil salinity and alkalinity dynamics","volume":"19","author":"Dwivedi","year":"1998","journal-title":"Int. J. Remote Sens."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3001","DOI":"10.1080\/01431169608949124","article-title":"Potentiality of Landsat, SPOT and IRS satellite imagery, for recognition of salt affected soils in Indian Arid Zone","volume":"17","author":"Kalra","year":"1996","journal-title":"Int. J. Remote Sens."},{"key":"ref_28","first-page":"708","article-title":"Accuracy assessment of soil salinity map in Yazd-Ardakan Plain, central Iran, based on Landsat ETM+ imagery","volume":"3","author":"Mehrjardi","year":"2008","journal-title":"Am.-Eurasian J. Agric. Environ. Sci."},{"key":"ref_29","unstructured":"Lillesand, T.M., and Kiefer, R.W. (2000). Remote Sensing and Image Interpretation, John Wiley & Sons."},{"key":"ref_30","first-page":"544","article-title":"Optimal model of soil pH and influencing factors by using hyperspectral data","volume":"46","author":"Wang","year":"2014","journal-title":"Soils"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1111\/ejss.12160","article-title":"Mapping contaminated soils: Using remotely-sensed hyperspectral data to predict pH","volume":"65","author":"Ong","year":"2014","journal-title":"Eur. J. Soil Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1016\/S1002-0160(10)60027-6","article-title":"A spectral index for estimating soil salinity in the Yellow River Delta Region of China using EO-1 Hyperion data","volume":"20","author":"Weng","year":"2010","journal-title":"Pedosphere"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"138","DOI":"10.3724\/SP.J.1010.2008.00138","article-title":"Soil saline-alkalization evaluation basing on spectral reflectance characteristics","volume":"27","author":"Liu","year":"2008","journal-title":"J. Infrared Millim. Waves."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2795","DOI":"10.1080\/00103620802432717","article-title":"Characterization of slightly and moderately saline and sodic soils in irrigated agriculture land using simulated data of advanced land imaging (EO-1) sensor","volume":"39","author":"Bannari","year":"2008","journal-title":"Commun. Soil Sci. Plant. Anal."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"488","DOI":"10.3390\/rs70100488","article-title":"Soil salinity retrieval from advanced multi-spectral sensor with partial least square regression","volume":"7","author":"Fan","year":"2015","journal-title":"Remote Sens."},{"key":"ref_36","unstructured":"Stoner, E.R., and Baumgardner, M.F. (1980). Physiochemical, Site and Bidirectional Reflectance Factor Characteristics of Uniformly Moist Soils, LARS, Purdue University."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0034-4257(02)00188-8","article-title":"Remote sensing of soil salinity: Potentials and constraints","volume":"85","author":"Metternicht","year":"2003","journal-title":"Remote Sens. Environ."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"McLean, E.O. (1982). Soil pH and Lime Requirement. Methods of Soil Analysis. Part. 2, Chemical and Microbiological Properties, ASA and SSSA.","DOI":"10.2134\/agronmonogr9.2.2ed.c12"},{"key":"ref_39","unstructured":"Du, S., and Gao, X.Z. (2006). Technical Specifications of Soil Analysis, Chinese Agricultural Press. [2nd ed.]."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2208","DOI":"10.3390\/rs70202208","article-title":"Landsat-8 Operational Land Imager (OLI) radiometric performance on-orbit","volume":"7","author":"Morfitt","year":"2015","journal-title":"Remote Sens."},{"key":"ref_41","unstructured":"The United States Geological Survey (USGS), Available online: http:\/\/glovis.usgs.gov\/."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Adler-Golden, S.M., Matthew, M.W., Bernstein, L.S., Levine, R.Y., Berk, A., Richtsmeier, S.C., Acharya, P.K., Anderson, G.P., Felde, G., and Gardner, J. (1999). Atmospheric correction for shortwave spectral imagery based on MODTRAN4. Proc. SPIE.","DOI":"10.1117\/12.366315"},{"key":"ref_43","unstructured":"Kruse, A.F. (2004, January 31). Comparison of ATREM, ACORN, and FLAASH atmospheric corrections using low-altitude AVIRIS data of Boulder, Co.. Proceedings of the Summaries of 13th JPL Airborne Geoscience Workshop, Pasadena, CA, USA."},{"key":"ref_44","first-page":"231","article-title":"Applicability of vegetation indices to estimate fractional vegetation coverage","volume":"46","author":"Yu","year":"2015","journal-title":"Trans. Chin. Soc. Agric. Mach."},{"key":"ref_45","unstructured":"Xu, J.H. (2012). Mathematical Methods in Contemporary Geography, Higher Education Press."},{"key":"ref_46","unstructured":"Kutner, M.H., Nachtsheim, C.J., and Neter, J. (2005). Applied Linear Statistical Models, Irwin."},{"key":"ref_47","unstructured":"Belsley, D.A., Kuh, E., and Welsch, R.E. (2005). Regression Diagnostics: Identifying Influential Data and Sources of Collinearity, John Wiley & Sons."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1071\/S96034","article-title":"Carbonate chemistry, pH, and physical properties of an alkaline sodic soil as affected by various amendments","volume":"35","author":"Chorom","year":"1997","journal-title":"Aust. J. Soil Res."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1243","DOI":"10.1071\/SR9941243","article-title":"Clay dispersion as infuenced by pH and net particle charge of sodic soils","volume":"32","author":"Chorom","year":"1994","journal-title":"Soil Res."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1016\/j.eja.2004.12.003","article-title":"Using geoestatistical and remote sensing approaches for mapping soil properties","volume":"23","year":"2005","journal-title":"Eur. J. Agron."},{"key":"ref_51","unstructured":"Stoner, F.R. (1979). Physicochemical, Site, and Bidirectional Reflectance Factor Characteristics of Uniformly Moist Soils. [Ph.D. Thesis, Purdue University]."},{"key":"ref_52","unstructured":"Bear, F.E. (1965). Chemistry of the Soil, Reinhold Publication Corporation. [2nd ed.]."},{"key":"ref_53","unstructured":"Panda, B.C. (2005). Remote Sensing: Principle and Application, Viva Books Pvt Ltd."},{"key":"ref_54","unstructured":"Farifteh, J., and Farshad, A. (2002, January 14\u201321). Remote sensing and modeling of topsoil properties: A clue for assessing land degradation. Proceedings of the 17th World Congress of Soil Science CD-ROM Conference, Bangkok, Thailand."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/8\/2\/163\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:19:27Z","timestamp":1760210367000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/8\/2\/163"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,2,20]]},"references-count":54,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2016,2]]}},"alternative-id":["rs8020163"],"URL":"https:\/\/doi.org\/10.3390\/rs8020163","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,2,20]]}}}