Chemistry and evolution of desert ephemeral stream runoff

Al-Qudah, Omar; Walton, John C.; Woocay, Arturo

doi:10.1016/j.jaridenv.2015.06.010

Cited by 6 publications

(3 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This scenario has been well described in catchments dominated by intermittent rivers, where high peaks of nitrogen and phosphorus are usually recorded after seasonal floods ("first flush events") (e.g., [128,129]). Despite flood events being sporadic, similar results have been described in DRs (e.g., [130]).…”

Section: Biogeochemical Processing In Dry Riverssupporting

confidence: 85%

Defining Dry Rivers as the Most Extreme Type of Non-Perennial Fluvial Ecosystems

et al. 2020

View full text Add to dashboard Cite

We define Dry Rivers as those whose usual habitat in space and time are dry channels where surface water may interrupt dry conditions for hours or a few days, primarily after heavy rainfall events that are variable in time and that usually lead to flash floods, disconnected from groundwater and thereby unable to harbor aquatic life. Conceptually, Dry Rivers would represent the extreme of the hydrological continuum of increased flow interruption that typically characterizes the non-perennial rivers, thus being preceded by intermittent and ephemeral rivers that usually support longer wet phases, respectively. This paper aims to show that Dry Rivers are ecosystems in their own right given their distinct structural and functional characteristics compared to other non-perennial rivers due to prevalence of terrestrial conditions. We firstly reviewed the variety of definitions used to refer to these non-perennial rivers featured by a predominant dry phase with the aim of contextualizing Dry Rivers. Secondly, we analyzed existing knowledge on distribution, geophysical and hydrological features, biota and biogeochemical attributes that characterize Dry Rivers. We explored the capacity of Dry Rivers to provide ecosystem services and described main aspects of anthropogenic threats, management challenges and the conservation of these ecosystems. We applied an integrative approach that incorporates to the limnological perspective the terrestrial view, useful to gain a better understanding of Dry Rivers. Finally, we drew main conclusions where major knowledge gaps and research needs are also outlined. With this paper, we ultimately expect to put value in Dry Rivers as non-perennial rivers with their own ecological identity with significant roles in the landscape, biodiversity and nutrient cycles, and society; thus worthy to be considered, especially in the face of exacerbated hydrological drying in many rivers across the world.

show abstract

Section: Biogeochemical Processing In Dry Riverssupporting

confidence: 85%

Defining Dry Rivers as the Most Extreme Type of Non-Perennial Fluvial Ecosystems

et al. 2020

View full text Add to dashboard Cite

show abstract

“…This may be explained by the fact that (a) our measurements were carried out on rock surfaces while all other measurements were conducted on soil, and (b) the small plot size and therefore the short distance and traveling time, implying short duration of rain-substrate contact, and therefore lower salinity. These unique conditions of our experiment may also explain the lower EC ratio of runoff to rain (2-3 fold higher) in comparison to floodwater values in the Negev (up to 6-fold higher; Nativ et al 1983), or other deserts, such as the Amargoza Desert, Nevada (10-fold higher; Al-qudah et al, 2015).…”

Section: Discussionmentioning

confidence: 78%

“…The quality of runoff water was extensively studied in arid and semiarid regions (Al-Qudah et al, 2015;Fisher and Grimm, 1985). This was also the case for the Negev Desert (Nativ et al, 1983(Nativ et al, , 1997.…”

Section: Introductionmentioning

confidence: 99%

Lithobiont-dependent ionic composition in runoff water

Kidron

Starinsky

2020

Journal of Hydrology and Hydromechanics

View full text Add to dashboard Cite

Rock dwelling organisms (lithobionts) such as cyanobacteria (prokaryotes) and chlorolichens (eukaryotes) abound in the Negev Desert, where they cover almost all calcareous bedrocks and rock particles (cobbles, boulders). In a small limestone watershed in the Negev Highlands, cyanobacteria inhabit the south-facing (SF) bedrocks, epilithic lichens (accompanied by endolithic lichens) inhabit the north-facing (NF) bedrocks, while endolithic lichens cover most of the cobbles and boulders in both aspects. In order to study their contribution to runoff water, a pair of runoff plots was established on habitats with cyanobacteria, endolithic lichens, and epilithic lichens. Rain and runoff were collected during the hydrological year 2006/07, and the chemical composition (Ca, Mg, Na, K, Cl, SO4, HCO3, Si) of the rain and runoff water was analyzed. Several patterns were observed: (a) as indicated by Si, more dust accumulated on the bedrocks; (b) all substrates exhibited high amounts of Ca, and HCO3; (c) while SF-bedrocks showed enrichment in K, both bedrocks (and especially the NF bedrocks), as well as the NF boulders showed an enrichment in Mg. While the enrichment in Ca and HCO3 can be explained by the contribution of the limestone parent material, the enrichment in K and Mg can be explained by the contribution of the living lithobionts, with K being mainly contributed by the cyanobacteria and Mg mainly by the epilithic lichens. Ion enrichment may therefore be aspect-dependent, reflecting the lithobiont distribution within the drainage basin, partially explaining the enrichment in K and Mg previously recorded in runoff water from the Negev.

show abstract