Impact of Forest Cover and Aridity on the Interplay between Effective Rooting Depth and Annual Runoff in South-West Western Australia
Variants of the Budkyo hydrological model describe the effects of land use change on annual water yield. A recent modification using a simple process-based ecohydrological model provides insight into the partitioning of rainfall between runoff and evapotranspiration. In particular, the ‘effective ve...
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| Format: | Article |
| Language: | English |
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MDPI AG
2014-08-01
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| Series: | Water |
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| Online Access: | http://www.mdpi.com/2073-4441/6/9/2539 |
| _version_ | 1811316701993631744 |
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| author | Keith Smettem Nik Callow |
| author_facet | Keith Smettem Nik Callow |
| author_sort | Keith Smettem |
| collection | DOAJ |
| description | Variants of the Budkyo hydrological model describe the effects of land use change on annual water yield. A recent modification using a simple process-based ecohydrological model provides insight into the partitioning of rainfall between runoff and evapotranspiration. In particular, the ‘effective vegetation rooting depth’ becomes the single free parameter in the model and can be related to land use and climate. We applied this approach to investigate the relations between mean annual runoff from 2000 to 2011, catchment average effective rooting depth and the proportion of forest cover across eleven catchments in South-west Western Australia. The proportion of forested and cleared land was partitioned using MODIS minimum annual average LAI values from 1 km2 pixels over 2000–2011, with forest clearing ranging from 1% to 98% across the 11 catchments. Estimated mean annual runoff using catchment averaged effective rooting depths for forest and cleared (grassland) land obtained using an independent physiologically-based model gave better estimates than a widely used ‘default’ Budkyo-based model. If effective rooting depth declines with aridity, as described by the model then runoff decline may be considerably less (about 50%) than predicted if the effective root depth remains unchanged (70%–92% decline). This highlights the importance of understanding ecohydrological feedbacks between vegetation and climate in projecting scenarios of water yield response to climate change. |
| first_indexed | 2024-04-13T11:54:04Z |
| format | Article |
| id | doaj.art-b2b16b2627de48c0aba38b686271b910 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-04-13T11:54:04Z |
| publishDate | 2014-08-01 |
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| series | Water |
| spelling | doaj.art-b2b16b2627de48c0aba38b686271b9102022-12-22T02:47:58ZengMDPI AGWater2073-44412014-08-01692539255110.3390/w6092539w6092539Impact of Forest Cover and Aridity on the Interplay between Effective Rooting Depth and Annual Runoff in South-West Western AustraliaKeith Smettem0Nik Callow1School of Civil, Environmental and Mining Engineering, The University of Western Australia, Nedlands, WA 6009, AustraliaSchool of Earth and Environment, The University of Western Australia, Nedlands, WA 6009, AustraliaVariants of the Budkyo hydrological model describe the effects of land use change on annual water yield. A recent modification using a simple process-based ecohydrological model provides insight into the partitioning of rainfall between runoff and evapotranspiration. In particular, the ‘effective vegetation rooting depth’ becomes the single free parameter in the model and can be related to land use and climate. We applied this approach to investigate the relations between mean annual runoff from 2000 to 2011, catchment average effective rooting depth and the proportion of forest cover across eleven catchments in South-west Western Australia. The proportion of forested and cleared land was partitioned using MODIS minimum annual average LAI values from 1 km2 pixels over 2000–2011, with forest clearing ranging from 1% to 98% across the 11 catchments. Estimated mean annual runoff using catchment averaged effective rooting depths for forest and cleared (grassland) land obtained using an independent physiologically-based model gave better estimates than a widely used ‘default’ Budkyo-based model. If effective rooting depth declines with aridity, as described by the model then runoff decline may be considerably less (about 50%) than predicted if the effective root depth remains unchanged (70%–92% decline). This highlights the importance of understanding ecohydrological feedbacks between vegetation and climate in projecting scenarios of water yield response to climate change.http://www.mdpi.com/2073-4441/6/9/2539ecohydrologyland useclimate changeeffective root depthBudkyo curve |
| spellingShingle | Keith Smettem Nik Callow Impact of Forest Cover and Aridity on the Interplay between Effective Rooting Depth and Annual Runoff in South-West Western Australia Water ecohydrology land use climate change effective root depth Budkyo curve |
| title | Impact of Forest Cover and Aridity on the Interplay between Effective Rooting Depth and Annual Runoff in South-West Western Australia |
| title_full | Impact of Forest Cover and Aridity on the Interplay between Effective Rooting Depth and Annual Runoff in South-West Western Australia |
| title_fullStr | Impact of Forest Cover and Aridity on the Interplay between Effective Rooting Depth and Annual Runoff in South-West Western Australia |
| title_full_unstemmed | Impact of Forest Cover and Aridity on the Interplay between Effective Rooting Depth and Annual Runoff in South-West Western Australia |
| title_short | Impact of Forest Cover and Aridity on the Interplay between Effective Rooting Depth and Annual Runoff in South-West Western Australia |
| title_sort | impact of forest cover and aridity on the interplay between effective rooting depth and annual runoff in south west western australia |
| topic | ecohydrology land use climate change effective root depth Budkyo curve |
| url | http://www.mdpi.com/2073-4441/6/9/2539 |
| work_keys_str_mv | AT keithsmettem impactofforestcoverandaridityontheinterplaybetweeneffectiverootingdepthandannualrunoffinsouthwestwesternaustralia AT nikcallow impactofforestcoverandaridityontheinterplaybetweeneffectiverootingdepthandannualrunoffinsouthwestwesternaustralia |