The geomorphic legacy of water and erosion control structures in a semiarid rangeland watershed
| Autor: | Nathan F. Sayre, Jeremy R. Shaw, Mary H. Nichols, Christopher S. Magirl |
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| Rok vydání: | 2017 |
| Předmět: |
Hydrology
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Floodplain Land use Berm Erosion control business.industry 0208 environmental biotechnology Geography Planning and Development Land management Water supply 02 engineering and technology 01 natural sciences 020801 environmental engineering Earth and Planetary Sciences (miscellaneous) Environmental science Land use land-use change and forestry Surface runoff business 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Earth Surface Processes and Landforms. 43:909-918 |
| ISSN: | 1096-9837 0197-9337 |
| Popis: | Control over water supply and distribution is critical for agriculture in drylands where manipulating surface runoff often serves the dual purpose of erosion control. However, little is known of the geomorphic impacts and legacy effects of rangeland water manipulation infrastructure, especially if not maintained. This study investigated the geomorphic impacts of structures such as earthen berms, water control gates, and stock tanks, in a semiarid rangeland in the southwestern USA that is responding to both regional channel incision that was initiated over a century ago, and a more recent land use change that involved cattle removal and abandonment of structures. The functional condition of remnant structures was inventoried, mapped, and assessed using aerial imagery and lidar data. Headcut initiation, scour, and channel incision associated with compromised lateral channel berms, concrete water control structures, floodplain water spreader berms, and stock tanks were identified as threats to floodplains and associated habitat. Almost half of 27 identified lateral channel berms (48%) have been breached and 15% have experienced lateral scour; 18% of 218 shorter water spreader berms have been breached and 17% have experienced lateral scour. A relatively small number of 117 stock tanks (6%) are identified as structurally compromised based on analysis of aerial imagery, although many currently do not provide consistent water supplies. In some cases, the onset of localized disturbance is recent enough that opportunities for mitigation can be identified to alter the potentially damaging erosion trajectories that are ultimately driven by regional geomorphic instability. Understanding the effects of prior land use and remnant structures on channel and floodplain morphologic condition is critical because both current land management and future land use options are constrained by inherited land use legacy effects. |
| Databáze: | OpenAIRE |
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