Hydrological alteration along the Missouri River Basin: A time series approach

Abstract

Human alteration of large rivers is commonplace, often resulting in significant changes in flow characteristics. We used a time series approach to examine daily mean flow data from locations throughout the mainstem Missouri River. Data from a pre-alteration period were compared with a post-alteration period , with separate analyses conducted using either data from the entire year or restricted to the spring fish spawning period (1 April-30 June). Daily mean flows were significantly higher during the postalteration period at all locations. Flow variability was markedly reduced during the post-alteration period as a probable result of flow regulation and climatological shifts. Daily mean flow during the spring fish spawning period was significantly lower during the post-alteration period at the most highly altered locations in the middle portion of the river, but unchanged at the least altered locations in the upper and lower port ions of the river. Our data also corroborate other analyses, using alternate statistical approaches, that suggest similar changes to the Missouri River system. Our results suggest human alterations on the Missouri River, particularly in the middle portion most strongly affected by impoundments and channelization, have resulted in changes to the natural flow regime. Abstract. Human alteration of large rivers is commonplace, often resulting in significant changes in flow characteristics. We used a time series approach to examine daily mean flow data from locations throughout the mainstem Missouri River. Data from a pre-alteration period (1925 -1948) were compared with a post-alteration period (1967 -1996), with separate analyses conducted using either data from the entire year or restricted to the spring fish spawning period (1 April -30 June). Daily mean flows were significantly higher during the post-alteration period at all locations. Flow variability was markedly reduced during the post-alteration period as a probable result of flow regulation and climatological Aquat. Sci. 65 (2003) 63 -72 1015-1621/03/010063-10 © EAWAG, Dübendorf, 2003 Aquatic Sciences shifts. Daily mean flow during the spring fish spawning period was significantly lower during the post-alteration period at the most highly altered locations in the middle portion of the river, but unchanged at the least altered locations in the upper and lower portions of the river. Our data also corroborate other analyses, using alternate statistical approaches, that suggest similar changes to the Missouri River system. Our results suggest human alterations on the Missouri River, particularly in the middle portion most strongly affected by impoundments and channelization, have resulted in changes to the natural flow regime.

Impact of the Farakka Dam on Thresholds of the Hydrologic Flow Regime in the Lower Ganges River Basin (Bangladesh)

“…However, the threshold determination of flow variability is a complex procedure, and several studies have been conducted in this area [8,23,[28][29][30][31][32][33][34][35][36]. To determine the ecological flow threshold, Richter et al [28,29] proposed the "Range of Variability Approach (RVA)" based on hydrologic characteristics of magnitude, frequency, duration, timing and the rate of the change of flow.…”

“…To determine the ecological flow threshold, Richter et al [28,29] proposed the "Range of Variability Approach (RVA)" based on hydrologic characteristics of magnitude, frequency, duration, timing and the rate of the change of flow. Pegg et al [31], Magilligan and Nislow [32] and Jiang et al [33] applied the RVA technique to quantify the effects of dam construction on hydrological alteration. Applying a similar approach, recently, Gain et al [8] investigated the climate change impact on the thresholds of the hydrologic flow regime.…”

“…In assessing the thresholds and evaluating the impact of the Farakka Dam, this study does not present any new approach. Instead, we apply the existing method of the RVA approach developed by Richter et al [28,29] and applied by Pegg et al [31], Magilligan and Nislow [32], Gain et al [8] and Jiang et al [33]. The reason behind the selection of RVA approach is that the method is simple, but very much effective for policymakers.…”

A Review of the Effects of Hydrologic Alteration on Fisheries and Biodiversity and the Management and Conservation of Natural Resources in Regulated River Systems

“…Some changes, such as stabilization of mean monthly discharges and variation in the number of high pulses, were absent or mild at leastaltered locations and more pronounced at middle and channelized locations (Galat and Lipkin 2000). Pegg et al (2003) used an alternative, time-series approach for assessing the impacts of hydrologic alteration on the Missouri River, and their findings generally corroborated those of Galat and Lipkin (2000).…”

Assessment of pallid sturgeon relative condition in the upper channelized Missouri River

“…The total water surface of the channelized reach has been reduced by approximately 50% (Funk & Robinson 1974) and annual sediment discharge has decreased by 100À150 million metric tons, more than is currently transported annually by the entire MissouriÀMississippi River systems to the Gulf of Mexico (Meade & Moody 2010). The mainstem dams and current water management practices have altered the natural hydrograph and sediment transport system that historically created the dynamic habitat elements for the native fauna and flora (Funk & Robinson 1974;Latka et al 1993;Pegg et al 2003). Furthermore, these modifications have eliminated the natural flow regime and created a high-energy channel that has promoted stream bed degradation and disconnected the Missouri River from much of its floodplain (Winston & Criss 2003).…”