Decadal climate variability and the spatial organization of deep hydrological drought
Empirical Orthogonal Function (EOF), wavelet, and wavelet coherence analysis of baseflow time-series from 126 streamgauges (record-length > 50 years; small and mid-size watersheds) in the US South Atlantic (USSA) region reveal three principal modes of space-time variability: (1) a region-wide dom...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2017-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/aa81de |
| _version_ | 1797748244586954752 |
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| author | Ana P Barros Jared L Hodes Malarvizhi Arulraj |
| author_facet | Ana P Barros Jared L Hodes Malarvizhi Arulraj |
| author_sort | Ana P Barros |
| collection | DOAJ |
| description | Empirical Orthogonal Function (EOF), wavelet, and wavelet coherence analysis of baseflow time-series from 126 streamgauges (record-length > 50 years; small and mid-size watersheds) in the US South Atlantic (USSA) region reveal three principal modes of space-time variability: (1) a region-wide dominant mode tied to annual precipitation that exhibits non-stationary decadal variability after the mid 1990s concurrent with the warming of the AMO (Atlantic Multidecadal Oscillation); (2) two spatial modes, east and west of the Blue Ridge, exhibiting nonstationary seasonal to sub-decadal variability before and after 1990 attributed to complex nonlinear interactions between ENSO and AMO impacting precipitation and recharge; and (3) deep (decadal) and shallow (< 6 years) space-time modes of groundwater variability separating basins with high and low annual mean baseflow fraction (MBF) by physiographic region. The results explain the propagation of multiscale climate variability into the regional groundwater system through recharge modulated by topography, geomorphology, and geology to determine the spatial organization of baseflow variability at decadal (and longer) time-scales, that is, deep hydrologic drought. Further, these findings suggest potential for long-range predictability of hydrological drought in small and mid-size watersheds, where baseflow is a robust indicator of nonstationary yield capacity of the underlying groundwater basins. Predictive associations between climate mode indices and deep baseflow (e.g. persistent decreases of the decadal-scale components of baseflow during the cold phase of the AMO in the USSA) can be instrumental toward improving forecast lead-times and long-range mitigation of severe drought. |
| first_indexed | 2024-03-12T16:02:08Z |
| format | Article |
| id | doaj.art-f00e6cd8812d4445a2ad2ae9fd34b0ff |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T16:02:08Z |
| publishDate | 2017-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-f00e6cd8812d4445a2ad2ae9fd34b0ff2023-08-09T14:36:12ZengIOP PublishingEnvironmental Research Letters1748-93262017-01-01121010400510.1088/1748-9326/aa81deDecadal climate variability and the spatial organization of deep hydrological droughtAna P Barros0Jared L Hodes1Malarvizhi Arulraj2Duke University , 2453 CIEMAS, Box 90287, Durham, NC 27708, United States of America; Author to whom any correspondence should be addressed.Duke University , 2453 CIEMAS, Box 90287, Durham, NC 27708, United States of AmericaDuke University , 2453 CIEMAS, Box 90287, Durham, NC 27708, United States of AmericaEmpirical Orthogonal Function (EOF), wavelet, and wavelet coherence analysis of baseflow time-series from 126 streamgauges (record-length > 50 years; small and mid-size watersheds) in the US South Atlantic (USSA) region reveal three principal modes of space-time variability: (1) a region-wide dominant mode tied to annual precipitation that exhibits non-stationary decadal variability after the mid 1990s concurrent with the warming of the AMO (Atlantic Multidecadal Oscillation); (2) two spatial modes, east and west of the Blue Ridge, exhibiting nonstationary seasonal to sub-decadal variability before and after 1990 attributed to complex nonlinear interactions between ENSO and AMO impacting precipitation and recharge; and (3) deep (decadal) and shallow (< 6 years) space-time modes of groundwater variability separating basins with high and low annual mean baseflow fraction (MBF) by physiographic region. The results explain the propagation of multiscale climate variability into the regional groundwater system through recharge modulated by topography, geomorphology, and geology to determine the spatial organization of baseflow variability at decadal (and longer) time-scales, that is, deep hydrologic drought. Further, these findings suggest potential for long-range predictability of hydrological drought in small and mid-size watersheds, where baseflow is a robust indicator of nonstationary yield capacity of the underlying groundwater basins. Predictive associations between climate mode indices and deep baseflow (e.g. persistent decreases of the decadal-scale components of baseflow during the cold phase of the AMO in the USSA) can be instrumental toward improving forecast lead-times and long-range mitigation of severe drought.https://doi.org/10.1088/1748-9326/aa81delarge-scale groundwaterbaseflow and recession analysisclimate and precipitation variability |
| spellingShingle | Ana P Barros Jared L Hodes Malarvizhi Arulraj Decadal climate variability and the spatial organization of deep hydrological drought Environmental Research Letters large-scale groundwater baseflow and recession analysis climate and precipitation variability |
| title | Decadal climate variability and the spatial organization of deep hydrological drought |
| title_full | Decadal climate variability and the spatial organization of deep hydrological drought |
| title_fullStr | Decadal climate variability and the spatial organization of deep hydrological drought |
| title_full_unstemmed | Decadal climate variability and the spatial organization of deep hydrological drought |
| title_short | Decadal climate variability and the spatial organization of deep hydrological drought |
| title_sort | decadal climate variability and the spatial organization of deep hydrological drought |
| topic | large-scale groundwater baseflow and recession analysis climate and precipitation variability |
| url | https://doi.org/10.1088/1748-9326/aa81de |
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