A spatial assessment of hydrologic alteration within a river network

Abstract

Maintaining natural hydrologic variability is essential in conserving native riverine biota and river ecosystem integrity. Hydrologic variation plays a major role in structuring the biotic diversity within river ecosystems as it controls key habitat conditions within the river channel, the floodplain, and hyporheic (stream‐influenced ground water) zones. Alterations in streamflow regimes may modify many of these habitat attributes and impair ecosystem connectivity. We demonstrate use of the ‘Range of Variability Approach’ for assessing hydrologic alteration at available streamgauge sites throughout a river basin. We then illustrate a technique for spatially mapping the degree of hydrologic alteration for river reaches at and between streamgauge sites. Such maps can be used to assess the loss of natural hydrologic variation at a river basin scale, thereby facilitating river restoration planning. © 1998 John Wiley & Sons, Ltd.

Flow variability and macroinvertebrate community response within riverine systems

“…The results of this linear regression are comparable to those reported by Clausen and Biggs (1997) for rivers in New Zealand, where a single flow variable (FRE3 -frequency of high flow events greater than three times the median discharge) accounted for between 41% and 52% of the variance in periphyton communities (25 sites), and between 14% and 36% of the variance in the macroinvertebrate communities (62 sites). In marked contrast to previous studies, the results of this study indicate that the flow magnitude ('Group 1 -magnitude of monthly water conditions' and 'Group 2 -magnitude and duration of annual extreme water conditions' of the Indicators of Hydrologic Alteration: Richter, et al, 1996Richter, et al, , 1998 were the 'best' predictors of macroinvertebrate community response to flow. The predominance of these variables within hydroecological models may reflect the variable temperate maritime climate of England and Wales and the absence of intermittent and snowmelt dominated riverine systems within the dataset reported in other investigations (Poff, 1996;Clausen and Biggs, 1997;Poff, et al, 1997;Clausen and Biggs, 2000;Olden and Poff, 2003).…”

“…The 'ecologically-relevant' hydrological variables were identified from previous research reported within 15 hydrological and ecological journal papers (see Appendix I, Hughes and James, 1989;Poff and Ward, 1989;Richards, 1989;Biggs, 1990;Jowett and Duncan, 1990;Poff, 1996;Richter, et al, 1996;Clausen and Biggs, 1997;Puckridge, et al, 1998;Richter, et al, 1998;Clausen and Biggs, 2000;Clausen, et al, 2000;Wood, et al, 2000;Wood, et al, 2001). Flow variables were assigned to one of five hydrological regime facets, as originally proposed in the Indicators of Hydrologic Alteration methodology (Richter, et al, 1996) and its derivatives (Poff, et al, 1997;Olden and Poff, 2003).…”

“…The LIFE score yielded the strongest correlation coefficients for six of the ten flow regime composite classes while ASPT yielded the strongest relationships for four composite classes (RC 1C and RC 2B , RC 2C and RC 5A ) (Table 3). Hydrological variables describing the magnitude component of the flow regime ('Group 1 -magnitude of monthly water conditions' and 'Group 2 -magnitude and duration of annual extreme water conditions' of the Indicators of Hydrologic Alteration: Richter, et al, 1996Richter, et al, , 1998 consistently produced the most significant (p < 0.01) correlations with the LIFE score when compared with any of the flow regime facets (i.e. frequency, duration, timing and rate of change) (Table 3).…”

“…Models were developed for all sites (global model), and for regime shape, magnitude and composite classes (Table 4) (Richter, et al, 1996;Poff, et al, 1997;Richter, et al, 1998;Olden and Poff, 2003) and benthic macroinvertebrate communities at multiple sites. Additionally, this paper is the first analysis of hydroecological relationships at the scale of England and Wales.…”

A new framework to evaluate ecosystem health: a case study in the Wei River basin, China

“…Among the hydrology parameters, annual multiday minimum flows and monthly mean flows in the dry season altered moderately or highly, indicating that the low-flow regime was easily influenced by the flow diversion (Shiau . Baojiaxia diversion project had significant impacts on hydrology regime, but these effects generally attenuate with distance downstream toward Tongguan except for X-L reach, which was in accordance with the results from Richter et al (1998). Urbanization had a number of important effects on hydrology (Bobbi et al 2013).…”