A Method for Assessing Hydrologic Alteration within Ecosystems

Abstract

Hydrologic regimes play a major role in determining the biotic composition, structure, and function of aquatic, wetland, and riparian ecosystems. But human land and water uses are substantially altering hydrologic regimes around the world. Improved quantitative evaluations of human‐induced hydrologic changes are needed to advance research on the biotic implications of hydrologic alteration and to support ecosystem management and restoration plans. We propose a method for assessing the degree of hydrologic alteration attributable to human influence within an ecosystem. This method, referred to as the “Indicators of Hydrologic Alteration,” is based upon an analysis of hydrologic data available either from existing measurement points within an ecosystem (such as at stream gauges or wells) or model‐generated data. We use 32 parameters, organized into five groups, to statistically characterize hydrologic variation within each year. These 32 parameters provide information on ecologically significant features of surface and ground water regimes influencing aquatic, wetland, and riparian ecosystems. We then assess the hydrologic perturbations associated with activities such as dam operations, flow diversion, groundwater pumping, or intensive land‐use conversion by comparing measures of central tendency and dispersion for each parameter between user‐defined “pre‐impact” and “post‐impact” time frames, generating 64 Indicators of Hydrologic Alteration. This method is intended for use with other ecosystem metrics in inventories of ecosystem integrity, in planning ecosystem management activities, and in setting and measuring progress toward conservation or restoration goals.

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

“…Indicators of Hydrologic Alteration (IHA) (Richter et al 1996;Wu et al 2012a) Before hydrologic impacts, determined using change point analysis of long term flow record (Wu et al 2012a) Physical form condition Substrate; habitat complexity; velocity/depth regimes; bank stability; channel alteration…”

“…It is identified by Indicators of Hydrologic Alteration (IHA), which is widely used to evaluate the alteration degree of hydrologic regime for regulated rivers since it is developed by Richter et al (1996). It quantifies the alteration degree of hydrology regime on the basis of the 33 IHA parameters, organized into five groups, including the magnitude, timing, frequency, duration, and rate of changes.…”

“…This was kindly related to their different temporal and spatial scale to environmental changes. Water quality and hydrology regime were the most sensitive factor to environmental changes, which was the essential aspect of water resource, and are widely applied in the world (Richter et al 1996;Magilligan and Nislow 2005;Lai et al 2013). Fish assemblages were an effective indicator on environmental changes, including hydrology regime, water quality, and habitat.…”

Stream restoration and environmental river mechanics

“…Statistical procedures (Richter et al, 1996) were used to compare the water discharge records prior to and following dam closure at the Otowi, Otowi/Cochiti combined and Albuquerque gages. The mean daily discharge records were grouped according to water year and divided between pre-dam (prior to 1974) and post-dam periods for the un-regulated flow (Otowi gage), the inflow to the study reach downstream of Cochiti dam (Cochiti gage), and the outflow from the study reach (Bernalillo/Albuquerque gages).…”

An evaluation of the Stormwater Footprint Calculator and the Hydrological Footprint Residence for communicating about sustainability in stormwater management

“…These areas, in turn, generate large volumes of stormwater runoff that directly affect receiving bodies of water by causing flooding, erosion, and degradation of in-stream ecosystem habitats (Leopold, 1968;Richter et al 1996;Roesner et al 2001;USEPA, 2004aUSEPA, , 2004b. Centralized infrastructure, such as detention ponds, may be constructed to manage increased runoff through storing and slowly releasing large volumes of water.…”