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Subsidence of Agricultural Lands in the Sacramento‐San Joaquin Delta, California: Role of Aqueous and Gaseous Carbon Fluxes
Author(s) -
Deverel Steven J.,
Rojstaczer Stuart
Publication year - 1996
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/96wr01338
Subject(s) - san joaquin , hydrology (agriculture) , soil water , subsidence , environmental science , delta , drainage , total organic carbon , dissolved organic carbon , carbon fibers , geology , soil science , oceanography , environmental chemistry , geomorphology , ecology , chemistry , geotechnical engineering , engineering , composite material , biology , materials science , structural basin , aerospace engineering , composite number
To examine the causes of land subsidence on marshes drained for agriculture, carbon fluxes and changes in land‐surface elevation were determined on three islands in the Sacramento‐San Joaquin Delta, California. Over the time period of March 1990 to May 1992, gaseous CO 2 fluxes were determined approximately monthly using closed chambers, and dissolved carbon fluxes were determined from the dissolved carbon loads of drainage ditches adjacent to each field site. Surface elevation changes were measured continuously by measuring the distance between the land surface and an elevated structure anchored beneath the organic soil layer. Gaseous CO 2 fluxes accounted for most of the permanent subsidence measured over the monitoring period. Gaseous CO 2 fluxes are strongly affected by soil temperature. Net subsidence rates for the three islands, which have different depths of organic soils and water‐management practices, range from 0.46 to 1.06 cm/yr. Estimates of dissolved organic carbon fluxes for all three islands were small relative to gaseous CO 2 losses and represent <1% of the measured subsidence.