Northern Delta Research Articles

Hydrodynamic and water quality modeling of Lake Manzala (Egypt) under data scarcity

Egyptian coastal lakes represent about 25 % of the Mediterranean total wetlands. Four of the coastal lakes are located north of the Nile Delta and are known as the Northern Delta Lakes. They are severely environmentally degraded and are considered vulnerable to the impacts of climate change, in particular the expected sea level rise. Lake Manzala lies on the eastern north coast of Egypt and is considered as the largest Egyptian coastal lake. Economically, Lake Manzala is considered as one of the most valuable fish sources in Egypt. The water quality status of the lake has been degraded due to the progressive increase in industrial, municipal, and agricultural wastewater discharge. In this work, a hydrodynamic and water quality model for Lake Manzala was developed, under the limitation of hydrological data, which prevented model validation, using MIKE21 modeling system. The proposed model was calibrated with observed data for 1 year (August 2010–July 2011). Typical records at five stations for water levels were used, while the water quality data were collected from 11 field stations. The model results show good agreement with the observed water depth, water temperature, and salinity records. The values of average absolute error, for all stations, were about 0.06 m and 0.56 °C for water depth and water temperature, respectively. In the following, the calibrated model is going to be used to investigate the impacts of future climatic changes on hydrodynamic and water quality characteristics of the lake. Moreover, this developed model will be used as a management tool to examine different enhancement water quality scenarios for the lake.

Study on the Cretaceous turbidite and reservoir features in the Qingshankou Formation in northern Songliao Basin, NE China

Based on analysis of well and drilling data, cores, sediment grains and 3D seismic data, four types of turbidites–slope fan, channelized, laminated and sublacustrine fan turbidite–are identified in Members 1 and 2 of the Qingshankou Formation in northern Songliao Basin. The slope fan turbidite is located in Members 1 and 2 of the Qingshankou Formation. It is dominated by silt and fine sand and is distributed in an SN-trending ribbon zone along the slope break at delta front in the western part of the basin. The channelized turbidite is located at the bottom of Member 1 of the Qingshankou Formation. It is dominated by silt and fine sand and is distributed in an SN-trending strip-shaped zone along the Qijia-Gulong sag, with funnel-shaped sublacustrine fans at the end. The laminated turbidite body is located in Member 2 of the Qingshankou Formation. It is dominated by siltstone and argillaceous siltstone and is distributed continuously in a tongue-shaped zone along the northern delta front towards the lacustrine region, with belt-like distributaries at the central part and sublacustrine fans at the end. Low-permeability and low-yield lithologic reservoirs are formed near the delta front within the slope fan turbidite and channelized turbidite. There are “sweet spots” in local regions, where reservoir reform techniques are required to attain high industrial yields. Laminated turbidite and sublacustrine fans can form unconventional and continuous reservoirs that generally have no natural productivity; industrial production is impossible until horizontal drilling and multistage volume fracturing are employed. Therefore, the research results are important to the exploration of unconventional oil and gas reservoirs in northern Songliao Basin.

Design Storm for Mixed Urban and Agricultural Drainage Systems in the Northern Delta in Vietnam

AbstractA design storm definition procedure for the sizing of channels within mixed urban and lowland rice drainage systems is developed, with reference to the Northern Delta in Vietnam. By analyzi...

Implications of climate change on the groundwater flow regime and geochemistry of the Nile Delta, Egypt

Environmental isotope analyses in conjunction with the hydro-geochemical investigations and tentative reviewing of the paleoclimatic sea level changes are carried out to fingerprint the implications of climatic changes on the groundwater flow regime and geochemistry at the Nile Delta. Following up the footprints of groundwater flow history, it is observed that the Pleistocene, main groundwater aquifer of the Nile Delta was drained and refilled with Nile water several times due to the eustatic sea level propagations between dry and wet periods. Therefore, the present-day groundwater flow regime could be affected by the latest Holocene phase of climate changes during which no significant dramatic sea level changes were recorded. After the time slice of the Mediterranean humid phase, 8000-5500 BP, the sea level started to rise steeply from –15 m to the present-day level. Under this rising rate, the seawater invaded most of the northern delta lope and several 10ths of kilometres inland via the mouths of the ancient Nile branches. During these arid conditions, deterioration of the Pleistocene unconfined aquifer could take place. This finding matches a famine and economic instabilities during the arid periods and flourishing and economic stabilities during the humid pluvial periods along the history of the ancient Egyptian civilization. In accordance to the latest active sea level rise stage in conjunction with the delta subsidence, a contagious groundwater level rise with a recent order of 3 cm/year is taking place leading to form several lake-like lagoons, water logging and soil salinization along the coastal plain and the eastern low lands. The Nile Delta is expected to suffer extreme soil salinization and gradual merging under the groundwater logging and seawater transgression especially, along the eastern coastal zone which suffers a high subsidence rate of about 5 mm/year. In contrast to previous studies, our findings show that, the present groundwater composition and salinity in the Nile Delta aquifers cannot be attributed to a recent seawater intrusion. The physico-chemical processes that explain this composition are combination of salt dissolution (mainly from Holocene fluvio-marine aquifer), flushing by recent Nile water, ion exchange and evaporation.

PHONG TRÀO ĐẤU TRANH CỦA NÔNG DÂN ĐỒNG BẰNG BẮC KÌ NHỮNG NĂM 1930 - 1931

PHONG TRÀO ĐẤU TRANH CỦA NÔNG DÂN ĐỒNG BẰNG BẮC KÌ NHỮNG NĂM 1930 - 1931

A quantitative assessment of the neoichnology and biology of a delta front and prodelta, and implications for delta ichnology

The Fraser River delta front exhibits asymmetry with respect to its neoichnological, biological, and sedimentological characteristics on opposing sides of the main distributary channel, as well as the submarine canyon seaward of the channel. This phenomenon is attributed to asymmetric tidal flow, wherein there is a net northward tidal flow along the delta front. The southern delta front lying updrift of the Main Channel, is primarily composed of sandy beds and bedsets that exhibit low bioturbation intensities (BI 0–3) and limited biodiversity (H` 0.9–1.4). Tracemakers in the updrift delta front predominantly consist of polychaetes and bivalves that produce suites dominated by simple vertical and horizontal traces attributable to the Skolithos Ichnofacies. The suites consist of traces comparable to Thalassinoides, Planolites, Skolithos, rare Conichnus, and Cylindrichnus. The northern delta front lying downdrift of the Main Channel, and the prodelta consist of muddy beds and bedsets that display high bioturbation intensities (BI 3–6) and diverse infaunal populations (H` 1.4–2.3). Polychaetes, bivalves, and echinoderms comprise the main tracemakers, and these infauna produce complex and robust ichnological suites typical of the Cruziana Ichnofacies. The downdrift delta front and prodelta trace assemblage includes traces comparable to Skolithos, Planolites, Thalassinoides, Artichnus, Palaeophycus, Conichnus, Asterosoma, Rosselia, Cylindrichnus, Gyrolithes, Teichichnus, Phycosiphon, Arenicolites, Polykladichnus, and Scolicia. The spatial distribution (area and volume) of biogenically induced sediment disruption indicates that the updrift delta front is significantly less bioturbated than its downdrift counterpart. Additionally, the prodelta does not exhibit evidence of asymmetry with respect to its neoichnological character; all spatial variability is recorded in delta front positions.

El colapso ambiental en el rio Patia, Colombia: variaciones morfologicas y alteraciones en los ecosistemas de

The Patia River delta has experienced major morphological variations in the last four decades due to anthropogenic pressures. The diversion of the Patia River to the Sanquianga River as a result of the construction of the Canal Naranjo in 1973, and the former development of the Patianga River, has generated complex environmental issues that are evidenced by the reactivation of the northern delta lobe and the abandonment of the previous river mouth in the southern lobe. This paper analyzes the main alterations taking place in the Patia delta as a result of the river diversion and the consequent variations in the water and sediment discharge. This alterations are reflected in: (1) drastic changes in coastline, with erosion rates up to 70 m y -1 ; (2) freshening conditions in the Sanguianga distributary channel, a hydrologic change that has shifted the upper estuarine region (salinity <1) 15 km downstream; and (3) alterations in the Sanquianga National Park land cover with increase in freshwater vegetation up to 42%, and decrease in mangrove cover up to 31% for a 15 years period. The current conditions of the Patia River delta are a clear example of the importance of human activities as change agents in the evolution of deltaic systems, and also reveal the need of deepen in the studies of this delta and establish appropriate management and conservation strategies.

Spatial variation of acid-volatile sulfide and simultaneously extracted metals in Egyptian Mediterranean Sea lagoon sediments

In risk assessment of aquatic sediments, the immobilizing effect of acid-volatile sulfide (AVS) on trace metals is a principal control on availability and associated toxicity of metals to aquatic biota, which reduces metal bioavailability and toxicity by binding and immobilizing metals as insoluble sulfides. Spatial variation pattern of AVS, simultaneously extracted metals (SEM), and sediment characteristics were studied for the first time in surface sediment samples (0-20 cm) from 43 locations in Egyptian northern delta lagoons (Manzalah, Burullus, and Maryut) as predictors of the bioavailability of some divalent metals (Cu, Zn, Cd, Pb, and Ni) in sediments as well as indicators of metal toxicity in anaerobic sediments. The results indicated that the ∑SEM (Cu + Zn + Cd + Pb + Ni) values in sediments of lagoon Burullus had higher concentrations than those of Maryut and Manzalah. In contrast, AVS concentrations were considerably higher in lagoons Manzalah and Maryut and seemed to be consistent with the increase in organic matter than lagoon Burullus. Generally, the average concentrations of the SEM in all lagoons were in the order of Zn > Cu > Ni > Pb > Cd. The ratios of ∑SEM/AVS were less than 1 at all the sampling stations except at one station in lagoon Maryut as well as four stations located in lagoon Burullus (∑SEM/AVS > 1), which suggests that the metals have toxicity potential in these sediments. Therefore, SEM concentrations probably are better indicators of the metal bioavailability in sediments than the conventional total metal concentrations.

Evaluation of WARM Model for Simulating Some Rice Varieties in Northern Delta

Evaluation of WARM Model for Simulating Some Rice Varieties in Northern Delta

Infaunal holothurian distributions and their traces in the Fraser River delta front and prodelta, British Columbia, Canada

Holothurians (sea cucumbers) constitute one of the largest and most abundant infaunal groups inhabiting the Fraser River delta front (0 to 150m water depth) and prodelta (greater than 150m water depth). The spatial distribution and density of animals reveal their preferred substrate grain sizes, and their tolerance or sensitivity to various stress factors, including salinity fluctuations, available food resources, sedimentation rate, and pollution. In the delta front, below 25m water depth (below storm-wave base), holothurians are asymmetrically distributed with respect to the main distributary channel. Population densities primarily reflect asymmetry in grain-size distributions across the delta front. Holothurians are absent or occur in low density in the sand-dominated southern delta front (SDF) whereas the mud-dominated northern delta front (NDF) is more heavily colonized. Sedimentation rate and nutrient content are equally important in holothurian distribution. Population densities of certain holothurians show significant increase where there are moderate sedimentation rates (2–4cmyr−1), and river-derived nutrient supply.Several subsurface traces and their surface expressions are attributed to holothurians. Subsurface traces include diminutive- and robust-Artichnus, Thalassinoides, and U-shaped bio-deformation structures. On the sediment surface, bio-topographic structures such as mounds and funnel-shaped depressions are produced by the activity of sea cucumbers. Of the holothurian-generated traces, only Artichnus can conclusively be attributed to sea cucumbers. Based on the distributions of the trace makers of Artichnus, we hypothesize that in the rock record this trace fossil can be used as evidence of stable euhaline salinity conditions, and sediment deposition and colonization below storm-wave base. Artichnus occurs mainly in mud-dominated (>55% mud) substrates.

Mercury Export to the Arctic Ocean from the Mackenzie River, Canada

Circumpolar rivers, including the Mackenzie River in Canada, are sources of the contaminant mercury (Hg) to the Arctic Ocean, but few Hg export studies exist for these rivers. During the 2007-2010 freshet and open water seasons, we collected river water upstream and downstream of the Mackenzie River delta to quantify total mercury (THg) and methylmercury (MeHg) concentrations and export. Upstream of the delta, flow-weighted mean concentrations of bulk THg and MeHg were 14.6 ± 6.2 ng L(-1) and 0.081 ± 0.045 ng L(-1), respectively. Only 11-13% and 44-51% of bulk THg and MeHg export was in the dissolved form. Using concentration-discharge relationships, we calculated bulk THg and MeHg export into the delta of 2300-4200 kg yr(-1) and 15-23 kg yr(-1) over the course of the study. Discharge is not presently known in channels exiting the delta, so we assessed differences in river Hg concentrations upstream and downstream of the delta to estimate its influence on Hg export to the ocean. Bulk THg and MeHg concentrations decreased 19% and 11% through the delta, likely because of particle settling and other processes in the floodplain. These results suggest that northern deltas may be important accumulators of river Hg in their floodplains before export to the Arctic Ocean.

On Establishment and Development of Mother Goddess in the Northern Delta in Vietnam - Seen from a Philosophical Angle

Normal 0 false false false MicrosoftInternetExplorer4 The worship of Mother Goddesses is a kind of folk belief. It combines the worships of Goddesses, of Mother Goddesses, of Three or Four Palaces. It manifests the sacred faith in Mother Goddesses ’ ability that creates and sponsors human beings, universe and society . /* Style Definitions */ table.MsoNormalTable {mso-style-name:Table Normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:Times New Roman; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

Mucor racemosus as a biosorbent of metal ions from polluted water in Northern Delta of Egypt

Mucor racemosus as a biosorbent of metal ions from polluted water in Northern Delta of Egypt

Assessing the effect of sea-level change and human activities on a major delta on the Pacific coast of northern South America: The Patía River

This paper presents the main physical and human-induced stresses that have shaped the recent evolution of the Patía River delta, the largest and best-developed delta on the western margin of South America. During the Holocene, the Patía Delta moved southward and the northern part became an estuarine system characterized by large extensions of mangrove ecosystems. However, a major human-induced water diversion, starting in 1972, diverted the Patía flow to the Sanguianga River, and shifted the active delta plain back to its former Holocene location. This discharge diversion has led to sediment starvation of the southern delta lobe and changed the northern estuarine system into an active delta plain. In addition, coastal areas of the Patía delta subsided as a result of a devastating tsunami in 1979. Morphological changes along the delta coast are evidenced by: (1) coastal retreat along the whole delta front during the period 1986–2001; (2) coastal retreat along the abandoned delta lobe for the period 2001–2008; 56% of the southern delta shoreline is retreating and only 4% of the coast shows signs of accretion; (3) progradation of the northern delta region during the period 2001–2008; the discharge diversion of the Patía River to the Sanquianga has apparently balanced the observed trends in coastal erosion and sea-level rise (5.1mmyr−1 for the period 1984–2006, after the 1979 tsunami); (4) formation of transgressive barrier islands with exposed peat soils in the surf zone; and (5) abandonment of former active distributaries in the southern delta plain with associated inlet closure. In the northern delta lobe, major geomorphic changes include: (1) distributary channel accretion by morphological processes such as sedimentation (also in crevasses), overbank flow, increasing width of levees, inter-distributary channel fill, and colonization of pioneer mangrove; (2) freshening conditions in the Sanguianga distributary channel, a hydrologic change that has shifted the upper estuarine region (salinity<1psu) downstream; and (3) changes in vegetation succession; approximately 30% of mangrove forests in the current delta apex have been replaced by freshwater vegetation. Overall, the recent evolution of the Patía has been controlled by the interplay of (1) high basin-wide sediment load; (2) low discharge variability (Qmax/Qmin); (3) spatial switch of delta distributaries related to tectonic movements and subsidence; (4) a relative sea-level rise of 5.1mmyr−1 after the occurrence of the 1979 tsunami; (5) episodes of sea-level rise associated with the ENSO cycle; and (6) human-induced discharge diversion. The information presented here is valuable evidence for understanding the role of extreme events versus ‘normal’ conditions in creating and shaping deltas.

Impact of Environmental Contaminants on the Testes of Oreochromis niloticus with Special Reference to Ultrastructure of Spermatozoa in Lake Manzala (Egypt)

Background: Pollution of the aquatic environment by inorganic and organic chemicals is a major factor posing serious threat to the survival of aquatic organisms including fish. Lake Manzala (LM) is one of the Egypt’s northern Delta Lakes situated on the Mediterranean Coast of the Delta. It is affected by drainage water polluted by different heavy metals that their concentrations exceed the maximum world permissible levels. Aim: This study aims to study the testicular histopathological alterations of Oreochromis niloticus using light microscope and the mature sperm using TEM during spawning season in LM. Materials and methods: Samples of water and 48 specimen of Nile tilapia, Oreochromis niloticus about 14-20 cm in length were collected from two areas; Demitta branch of river (RN) at Mansoura city as a control site and LM as a polluted area during the spawning season from March- June. The gonado-somatic index (GSI) was then calculated for each fish samples. Pieces of testes were then taken and prepared for light and electron microscopic studies. Cd and Pb were estimated in water samples during the spawning season from March to June. Results: Examined Sections revealed that the testes of specimens of LM had degenerative germinal epithelium of the seminiferous tubules, vacuolization in proliferating germ cells; decline in spermatogenic cell and sperm density than those collected from RN. Ultrastructure study of mature sperm of LM revealed nuclear degeneration, vacuolization and shortage of bilateral fins of the flagellum comparing to mature sperm of RN. Conclusion: This study giving an alarm that environmental hazard like increasing the levels of different heavy metals as Cd and Pb could alter the sperms structure and their ability to produce new offspring, and further studies may be needed to confirm these findings.

EFFECTS OF TEMPERATURE ON SOME VEGETABLE CROP YIELDS UNDER DIFFERENT CLIMATIC ZONES IN EGYPT

The climatic betas play an important role in the detennioation of the yield of any crop, ether directly or indirectly, where they affect wowth, production qualty and quantity. Tina study alms to vet* the most importer/ dirnabc parameters, (temperature) and the economic effects on the yield of tomato, potato and cucumber cops grown to the summer season at various Egyptian climatic tones during the period or (1990-2005). The study restated that In key the effect of the temperature was very oiticat parameter on the tomato *la at the Northern Delta, where they caused a preducbelly decease by 0.67 tonifeddan. On the ether hand, ternperabes that In February and March caused an Increase in tomato yield by 0.33 and 0.36 tonesifeddan respectively, at the southern Delta and Middle Egypt. Moreover, temperature during March at Upper Egypt bad a negative effect on the crop pecductivIly by 1.19 tonifeddan. Also at south Sinal the effect ol the temperature In luly Is considered as anon parameter on the tomato yield, Minh decreased by 1.53 ton. For potato crop the study reveakd that in February when temperature bloused the pnattuctivny of potato crop increased by 0.48 ton/leddan, at Upper Egypt, Moreover, temperatures in gamine and Mardi were neeebve parameters that Increased the total produotion of potato crop by 0.61 and 0.74 tones, respective, at North Sinai. But the Increase of temperature during March at northern Deb caused a yield decease by 0.73 ton per redden. For the Cucumber crop, the study showed the increase Cl temperature to March at the Northern Delta, in February at the Southern Delta and Middle Egypt, In March at the North Simi and in Febtuary at Matrouh, the odd or cucumber Increased by 0.27, 0.22, 0.34, and 0.47 tonsifecklan, respectively. However at Southern Delta and Midc•e Egypt, the Incase 'temperature in May, mused a pecduclivIty decease by 0.50 ton per fecktan.

Impact of milk consumption on performance and health of primary school children in rural Vietnam.

This is a follow-up study to an investigation on the prevalence of malnutrition and micronutrient deficiencies among Vietnamese primary schoolchildren. A total of 454 children aged 7 to 8 years attending three primary schools in the Northern delta province of Vietnam were either provided with regular milk, milk fortified with vitamins, minerals and inulin or served as a reference control group. Children were monitored for anthropometrics, (micro)-nutritional status, faecal microbiota composition, school performance, and health indices. Both weight-for-age (WAZ) and height-for-age (HAZ) significantly improved during 6 months of milk intervention; and underweight and stunting dropped by 10% in these groups. During intervention the incidence of anemia decreased and serum ferritin levels increased significantly in all groups. Serum zinc levels increased and consequently the incidence of zinc deficiency improved significantly in all three groups. Serum retinol levels and urine iodine levels remained stable upon intervention with fortified milk whereas in the control group the incidence of iodine deficiency increased. Bifidobacteria composed less than 1% of the total faecal bacteria. After three months of milk intervention total bacteria, bifidobacteria and Bacteroides sp. increased significantly in both milk and inulin fortified milk groups. Children in the milk consuming groups had significantly better short-term memory scores. Parent reported that health related quality of life status significantly improved upon milk intervention. In conclusion, (fortified) milk consumption benefited the children in rural Vietnam including lowering the occurrence of underweight and stunting, improving micronutrients status and better learning indicators as well as improving the quality of life.

SUCCESSIVE SOLAR FLARES AND CORONAL MASS EJECTIONS ON 2005 SEPTEMBER 13 FROM NOAA AR 10808

We present a multiwavelength study of the 2005 September 13 eruption from NOAA 10808 that produced total four flares and two fast coronal mass ejections (CMEs) within 1.5 hours. Our primary attention is paid to the fact that these eruptions occurred in close succession in time, and that all of them were located along an S-shaped magnetic polarity inversion line (PIL) of the active region. In our analysis, (1) the disturbance created by the first flare propagated southward along the PIL to cause a major filament eruption that led to the first CME and the associated second flare underneath. (2) The first CME partially removed the overlying magnetic fields over the northern Delta spot to allow the third flare and the second CME. (3) The ribbon separation during the fourth flare would indicate reclosing of the overlying field lines opened by the second CME. It is thus concluded that this series of flares and CMEs are interrelated to each other via magnetic reconnections between the expanding magnetic structure and the nearby magnetic fields. These results complement previous works made on this event with the suggested causal relationship among the successive eruptions.

Land subsidence in the Nile Delta: inferences from radar interferometry

The Nile Delta formed by progression of a complex system of deltaic fans throughout the Pleistocene, with the Modern delta being formed from sediments supplied by at least ten distinct distributaries throughout the Holocene. With an average elevation of approximately 1 m above sea level within 30 km of the coast and a predicted rise in sea level of 1.8—5.9 mm/yr the subsidence of the northern delta has become a topic of major concern to the Egyptian population and government. The Nile Delta is home to more than 50 million people and the major agricultural production area for Egypt. We evaluated the modern rates of subsidence of sections of the northeastern Nile Delta (a total length of 110 km, up to 50 km from the coastline) using persistent scatterer radar interferometry techniques applied to 14 ERS-1 and ERS-2 scenes. The area covered includes the present active depocenter of the Damietta promontory, and the nearby Mendesian depocenter that was active up to recent times (to 2500 years ago). The highest subsidence rates (~8 mm/yr; twice average Holocene rates) do not correlate with the distribution of the thickest Holocene sediments, but rather with the distribution of the youngest depositional centers (major deposition occurred between ~3500 yr BP and present) at the terminus of the Damietta branch. The adjacent, slightly older (8000—2500 yr BP) Mendesian branch depositional center is subsiding at slower rates of 2—6 mm/yr. Results are interpreted to indicate that: (1) modern subsidence in the Delta is heavily influenced by compaction of the most recent sediments, and (2) highly threatened areas are at the terminus of the Damietta and possibly the Rosetta branches, where active deposition is occurring.

Estimating the extent of near‐surface permafrost using remote sensing, Mackenzie Delta, Northwest Territories

AbstractThe extent of near‐surface permafrost, or perennially frozen ground within 3 m of the surface, was estimated for the Mackenzie River delta by determining its association with riparian vegetation communities in the field, and by subsequently mapping these vegetation communities using SPOT‐5 data and the supervised maximum‐likelihood classification technique. Near‐surface permafrost was absent beneath willow–horsetail (Salix‐Equisetum) vegetation communities on point bars and alluvial islands throughout the delta and beneath horsetail (Equisetum) communities in the southern and central delta. Near‐surface permafrost was found beneath all other vegetation communities and land surface types. Multispectral SPOT‐5 data were classified with overall accuracies greater than 80 per cent. Using the remotely sensed vegetation community data, near‐surface permafrost was estimated to occur beneath 93 per cent, 95 per cent and 96 per cent of the land surface within the investigation areas of the southern, central and northern delta, respectively. In contrast to the most recent Permafrost Map of Canada, these results indicate that the Mackenzie Delta is part of the continuous permafrost zone. Copyright © 2009 Her Majesty the Queen in right of Canada. Published by John Wiley &amp; Sons, Ltd.