عنوان

Quantifying Activated Floodplains on a Lowland Regulated River: Its Application to Floodplain Restoration in the Sacramento Valley

شماره

LA1sn8r310

زبان متن نوشتاري يا گفتاري و مانند آن

انگلیسی

عنوان اصلي

Quantifying Activated Floodplains on a Lowland Regulated River: Its Application to Floodplain Restoration in the Sacramento Valley

نام عام مواد

[Article]

نام نخستين پديدآور

Williams, Philip B.; Andrews, Elizabeth; Opperman, Jeff J.; Bozkurt, Setenay; Moyle, Peter B.; et al.

متن يادداشت

We describe a process and methodology for quantifying the extent of a type of historically prevalent, but now relatively rare, ecologically-valuable floodplains in the Sacramento lowland river system: frequently-activated floodplains. We define a specific metric the "Floodplain Activation Flow" (FAF), which is the smallest flood pulse event that initiates substantial beneficial ecological processes when associated with floodplain inundation. The "Activated Floodplain" connected to the river is then determined by comparison of FAF stage with floodplain topography. This provides a simple definition of floodplain that can be used as a planning, goal setting, monitoring, and design tool by resource managers since the FAF event is the smallest flood and corresponding floodplain area with ecological functionality-and is necessarily also inundated in larger flood events, providing additional ecological functions. For the Sacramento River we selected a FAF definition to be the river stage that occurs in two out of three years for at least seven days in the mid-March to mid-May period and ''Activated Floodplains'' to be those lands inundated at that stage. We analyzed Activated Floodplain area for four representative reaches along the lower Sacramento River and the Yolo Bypass using stream gauge data. Three of the most significant conclusions are described: (1) The area of active functional floodplain is likely to be less than commonly assumed based on extent of riparian vegetation; (2) Levee setbacks may not increase the extent of this type of ecologically-productive floodplain without either hydrologic or topographic changes; (3) Within the Yolo Bypass, controlled releases through the Fremont Weir could maximize the benefits associated with Activated Floodplain without major reservoir re-operation or grading. This approach identifies a significant opportunity to integrate floodplain restoration with flood management by establishing a FAF stage metric as an engineering design criterion alongside the commonly-used 100-year flood stage for flood hazard reduction.

تاريخ نشر

2009

عنوان

San Francisco Estuary and Watershed Science

شماره جلد

7/1

عنصر شناسه اي

Williams, Philip B.; Andrews, Elizabeth; Opperman, Jeff J.; Bozkurt, Setenay; Moyle, Peter B.; et al.

نام الکترونيکي

نوع ماده

[Article]

کد کاربرگه

275578

سطح دسترسي

a

تكميل شده

Y