English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/35417
COMPARTIR / IMPACTO:
Estadísticas
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:
Título

Eutrophication and Sedimentation Patterns in Complete Exploitation of Water Resources Scenarios: An Example from Northwestern Semi-arid Mexico

AutorSánchez Carrillo, Salvador ; Alatorre, L. C. ; Sánchez Andrés, Raquel ; Garatuza-Payán, Jaime
Palabras claveNitrogen
Phosphorus
Chlorophyll-a
Sedimentation
Reservoir drawdown
Eutrophication
Semi-arid
Fecha de publicaciónsep-2007
EditorSpringer
CitaciónEnvironmental Monitoring and Assessment 132 (1-3): 377-393 (2007)
ResumenWater requirements to supply human needs lead water stakeholders to store more water during surplus periods to fulfil the demand during – not only – scarcity periods. At the reservoirs, mostly those in semi-arid regions, water level then fluctuates extremely between rises and downward during one single year. Besides of water management implications, changes on physical, chemical and biological dynamics of these drawdown and refilling are little known yet. This paper shows the results, throughout a year, on solids, nutrients (N and P), chlorophyll-a, and sedimentation changes on the dynamics, when the former policy was applied in a reservoir from the semi-arid Northwestern Mexico. Water level sinusoidal trend impinged changes on thermal stratification and mixing, modifying nutrient cycling and primary producer responses. According to nitrogen and phosphorus concentration as well as chlorophyll-a, reservoir was mesotrophic, becoming hypertrophic during drawdown. Nutrient concentrations were high (1.22 ± 0.70 and 0.14 ± 0.12 mg P l−1), increasing phosphorus and lowering N:P significantly throughout the study period, although no intensive agricultural, no urban development, neither industrial activities take place in the watershed. This suggests nutrient recycling complex mechanisms, including nutrient release from the sediment–water interface as the main nutrient pathway when shallowness, at the same time as mineralization, increases. Outflows controlled nitrogen and phosphorus availability on the ecosystem while organic matter depended on river inflows. As on other subtropical aquatic ecosystems, nitrogen limited primary productivity (Spearman correlation R = 0.75) but chlorophyll-a seasonal pattern showed an irregular trend, prompting other no-nutrient related limitants. Shallowness induced a homogeneous temporal pattern on water quality. This observed temporal variability was mainly explained statistically by changes on solids (mineral and organic), chlorophyll-a and flows (62.3%). Annual sedimentation rates of total solids ranged from 11.73 to 16.29 kg m−2 year−1 with organic matter comprising around 30%. N:P ratio on sedimentation rates were as high as could be expected in a resuspension dominated ecosystem, and spatially inverse related with N:P ratio on bottom sediments. Distance from river inlet into the reservoir reveals a marked spatial heterogeneity on solid and nitrogen sedimentation, showing the system dependence on river inflows and supporting resuspension as the main phosphorus pathway. Accretion rates (2.19 ± 0.40 cm year−1) were not related to hydrological variability but decreased with the distance to the river input. Total sediment accumulation (9,895 tons km−2 year−1) denotes siltation as other serious environmental problem in reservoirs but possibly not related with operational procedures.
Descripción17 páginas, 8 figuras, 2 tablas.
Versión del editorhttp://dx.doi.org/10.1007/s10661-006-9541-x
URIhttp://hdl.handle.net/10261/35417
DOI10.1007/s10661-006-9541-x
ISSN0167-6369
Aparece en las colecciones: (IPE) Artículos
Ficheros en este ítem:
No hay ficheros asociados a este ítem.
Mostrar el registro completo
 

Artículos relacionados:


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.