Land cover controls on summer discharge and runoff solution chemistry of semi-arid urban catchments

Abstract

cover controls on summer discharge and runoff solution chemistry of semi-arid urban catchments" (2013 Recharge of urban runoff to groundwater as a stormwater management practice has gained importance in semi-arid regions where water resources are scarce and urban centers are growing. Despite this trend, the importance of land cover in controlling semi-arid catchment runoff quantity and quality remains unclear. Here we address the question: How do land cover characteristics control the amount and quality of storm runoff in semi-arid urban catchments? We monitored summertime runoff quantity and quality from five catchments dominated by distinct urban land uses: low, medium, and high density residential, mixed use, and commercial. Increasing urban land cover increased runoff duration and the likelihood that a rainfall event would result in runoff, but did not increase the time to peak discharge of episodic runoff. The effect of urban land cover on hydrologic responses was tightly coupled to the magnitude of rainfall. At distinct rainfall thresholds, roads, percent impervious cover and the stormwater drainage network controlled runoff frequency, runoff depth and runoff ratios. Contrary to initial expectations, runoff quality did not vary in repose to impervious cover or land use. We identified four major mechanisms controlling runoff quality: (1) variable solute sourcing due to land use heterogeneity and above ground catchment connectivity; (2) the spatial extent of pervious and biogeochemically active areas; (3) the efficiency of overland flow and runoff mobilization; and (4) solute flushing and dilution. Our study highlights the importance of the stormwater drainage systems characteristics in controlling urban runoff quantity and quality; and suggests that enhanced wetting and in-stream processes may control solute sourcing and retention. Finally, we suggest that the characteristics of the stormwater drainage system should be integrated into stormwater management approaches.

Dynamics of surface water quality driven by distinct urbanization patterns and storms in a Portuguese peri-urban catchment

“…3), possibly because road runoff is diverted into pervious soils, located at a greater distance from the stream network than at PB. These contrasts highlight the importance of variations in stormwater drainage system characteristics in controlling urban runoff quantity and quality rather than simply percentage urbanization, as found also to be the case in Tucson, Arizona (Gallo et al 2013).…”

“…Accumulated solutes are then available for mobilization during rainfall and subsequent runoff (Vidon et al 2009;Gallo et al 2013). The flushing process recorded in late summer led to higher NH 4 -N and Nk-N during the rising limb of the hydrographs in E, PB and Q (Fig.…”

Combined impact of catchment size, land cover, and precipitation on streamflow and total dissolved nitrogen: A global comparative analysis

“…[], Chen and Driscoll [], Coats and Goldman [], Durdu and Cvetkovic [], Emmerson [], Fulweiler and Nixon [, ], Gallo et al . [, ], Goolsby et al . [], Granlund et al .…”

“…Transport of N in streamflow is the second largest flux of N out of catchments (second to gaseous losses), can account for up to 20% of the change in catchment N storage [ Baker et al ., ; Mulholland et al ., ; Suddick et al ., ; van Breemen et al ., ], and can alter downstream biogeochemical cycling and ecosystem function [ Kaye et al ., ; Lohse et al ., ]. Land use, land cover, and climate can control N fluxes by altering catchment‐scale hydrologic responses [ Dougherty et al ., ; Gallo et al ., , ; Kaye et al ., ]; N cycling processes such as N mineralization, uptake, and denitrification [ Inwood et al ., ; Mulholland et al ., ]; by shifting the magnitude and direction of N exchange pathways such as N gas flux and atmospheric deposition [ Galloway et al ., ; Kaushal et al ., ; Lohse et al ., ], and by altering point and nonpoint anthropogenic N sourcing [ Stanley and Maxted , ; Tu , ].…”

International Low Impact Development Conference 2015

“…However, modeling studies have suggested that the adaptability of LID designs to other regions is problematic, requiring modified solutions to be field tested in every location to confirm how they will perform (Gallo et al, 2012). Therefore, there is still a great need to evaluate these practices in the field and to collect quantitative data on LID practices performance, especially in the Southern part of the United States.…”