Hydrology and aquatic habitat characteristics of a riverine swamp: I. Influence of flow on water temperature and chemistry

Citation
Mj. Sabo et al., Hydrology and aquatic habitat characteristics of a riverine swamp: I. Influence of flow on water temperature and chemistry, REGUL RIVER, 15(6), 1999, pp. 505-523
Citations number
29
Categorie Soggetti
Environment/Ecology
Journal title
REGULATED RIVERS-RESEARCH & MANAGEMENT
ISSN journal
08869375 → ACNP
Volume
15
Issue
6
Year of publication
1999
Pages
505 - 523
Database
ISI
SICI code
0886-9375(199911/12)15:6<505:HAAHCO>2.0.ZU;2-B
Abstract
We monitored water temperature, air temperature, hydrologic characteristics , and chemical variables for 25 months in a 254-km(2) portion of the Atchaf alaya Basin, Louisiana, USA, a distributary swamp of the Mississippi River. We related observed trends in thermal and chemical variables to characteri stics of the flood pulse, available channel types, and paths of water flow within the study area. Dissolved oxygen (range 0.05-13.05 mg L-1), percent oxygen saturation (range 0.6-142.4%), and pH (range 6.31-8.52) increased as river stages decreased, and water temperatures (range 4.75-32.25 degrees C ), specific conductance (range 207.8-931.5 mu mhos), and the top-bottom dif ference in dissolved oxygen (- 7.5-12.05 mg L-1) increased as air temperatu res rose. The maximum variance observed for all chemical and thermal habita t characteristics occurred during periods when air temperatures exceeded, a nd river stages were less than, their respective medians observed during th e study. At any point in time, thermal and chemical variables varied most a mong stations in water courses with no visible water turbulence low-energy channels), and these channels consistently had lower dissolved oxygen, perc ent oxygen saturation, and pH than turbulent water courses (high-energy cha nnels) or lakes contained. Water was directed from the river into one regio n of the study area from two opposing directions, thereby impeding water fl ow through the region. Low-energy channels in this region consistently exhi bited lower dissolved oxygen concentrations, percent oxygen saturation, and pH than was observed in low-energy channels of regions where water flow wa s unimpeded. The quantity and quality of aquatic habitat characteristics in riverine swamps can be manipulated by controlling the timing and magnitude of the flood pulse, relative availability of different water courses, and internal paths of water flow through the swamp. Copyright (C) 1999 John Wil ey & Sons, Ltd.