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1.
Environ Sci Pollut Res Int ; 27(35): 44279-44291, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32761350

RESUMEN

This paper assesses the potential impact of reduced Nile water due to the construction of Grand Ethiopian Renaissance Dam (GERD) on flow and contaminant transport pattern in Ismailia Canal and its surrounding area. The groundwater/surface water system has been characterized, conceptualized, and modeled numerically and analytically, with assessing the response against this expected reduced discharge. The isotopic signature of seventeen samples helped in the identification of different recharge sources in the study area and demarcates the boundary conditions that might encounter the conceptualization of the study area. Based on the inflow/outflow components from MODFLOW under present-day conditions and reducing surface water discharge in the studied area, it was revealed that at the end of the year 2024, the contribution from the canal to the modeled groundwater system will be decreased by 6%, 8%, and 11%, by decreasing 20%, 30%, and 40% of the original canal flow according to three proposed scenarios. This reduced flow would increase the contaminate load of 137Cs in the groundwater system by 2.5-fold than that expected in case of the non-reduced flow in Ismailia Canal at the end of the simulation (year 2038). Furthermore, the impact of surface water conditions (flow, velocity, dispersion) on 137Cs dispersion and temporal/spatial distribution has been analyzed, revealing the side effect of GERD on Ismailia Canal, as a response to the decrement in the Nile flow.


Asunto(s)
Agua Subterránea , Radioisótopos de Cesio , Movimientos del Agua
2.
J Clin Med Res ; 10(3): 189-195, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29416576

RESUMEN

BACKGROUND: We investigated SIRT-1 genetic variant and its association with vitamin D level in Egyptian patients with rheumatoid arthritis (RA). METHODS: Seventy Egyptian subjects were enrolled in our study and divided into two groups: RA group (n = 50 patients) and healthy control group (n = 20 subjects). Five milliliter blood sample was withdrawn from each subject followed by laboratory investigation and DNA extraction for SIRT-1 gene polymorphism assessment (rs7895833 A>G, rs7069102 C>G and rs2273773 C>T) and vitamin D level expression. RESULTS: There was statistically significant difference between rheumatoid cases and controls with regard to vitamin D level with 88% of cases showing insufficient vitamin D versus all controls showing sufficient level. SIRT-1 different SNPs rs2273773, rs7895833and rs7069102 genotype frequencies were statistically significant in RA compared to control group (P = 0.001). There was no statistically significant difference between different genotypes of rs2273773, rs7895833 and rs7069102 with regard to vitamin D level. CONCLUSION: We concluded that there is a strong association between SIRT-1 polymorphism genotyping and RA. Vitamin D level was insufficient in Egyptian patients with RA.

3.
Ann Thorac Surg ; 97(5): 1562-7, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24636705

RESUMEN

BACKGROUND: Since the advent of endovascular techniques for repair of descending thoracic aortic aneurysms (DTAAs), there has been a relative paucity of current data for open repairs. The purpose of this study was to assess the operative and long-term outcomes in a contemporary series of open repairs of DTAAs. METHODS: We conducted a retrospective review of 68 patients (63±14.5 years) who underwent DTAA repairs between January 1999 and December 2010. Forty-two patients (62%) were male, 16 (24%) had chronic obstructive pulmonary disease, 7 (10%) required dialysis preoperatively, 11 (16%) had contained rupture, 25 (37%) had previous cardioaortic operations, and 10 (15%) had previous aortic arch replacement (stage 1 elephant trunk). The entire descending thoracic aorta was replaced in 34 patients (50%). Cardiopulmonary bypass was used in 64 patients (94%) and deep hypothermic arrest in 22 (32%). RESULTS: In-hospital mortality was 3% (2 patients). There was no immediate paraplegia. Delayed paraplegia developed in 1 patient (1.5%). Postoperative stroke occurred in 3 patients (4.4%), and 20 (29%) required prolonged ventilatory support (intubation≥48 hours). New-onset renal insufficiency (creatinine≥2.5 mg/dL) developed postoperatively in 6 patients (9%), and 1 (1.5%) required temporary dialysis. The median follow-up time was 5.8±3.8 years. Sixteen of the 66 operative survivors (24.2%) died during follow-up. Probability of survival was 82%±0.05% at 5 years and 67%±0.07% at 10 years. Reintervention was necessary in 4 patients (6%). Freedom from reintervention was 98%±0.02% at 5 years and 89%±0.06% at 10 years. The univariable predictor of long-term death was postoperative reintubation (p<0.05). CONCLUSIONS: In the era of endovascular repair of DTAAs, operative death and morbidity outcomes for open repairs are observed to be low. In addition to good long-term survival rates, open repairs are durable, as evidenced by low reintervention rates.


Asunto(s)
Aneurisma Roto/mortalidad , Aneurisma Roto/cirugía , Aneurisma de la Aorta Torácica/mortalidad , Aneurisma de la Aorta Torácica/cirugía , Implantación de Prótesis Vascular/métodos , Mortalidad Hospitalaria , Anciano , Análisis de Varianza , Aneurisma Roto/diagnóstico por imagen , Angiografía/métodos , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Implantación de Prótesis Vascular/mortalidad , Puente Cardiopulmonar/métodos , Paro Circulatorio Inducido por Hipotermia Profunda/métodos , Estudios de Cohortes , Procedimientos Endovasculares/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Seguridad del Paciente , Complicaciones Posoperatorias/mortalidad , Complicaciones Posoperatorias/fisiopatología , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Medición de Riesgo , Índice de Severidad de la Enfermedad , Análisis de Supervivencia , Toracotomía/efectos adversos , Toracotomía/métodos , Resultado del Tratamiento
4.
J Vasc Surg ; 59(5): 1217-23, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24423480

RESUMEN

OBJECTIVE: Open surgical repair (OSR) for chronic type B aortic dissection (CTBAD) has an associated morbidity and mortality. The role of thoracic endovascular aortic repair (TEVAR) in CTBAD has not been determined. We analyzed our contemporary experience of CTBAD undergoing OSR to identify high-risk patients who may be considered for TEVAR. METHODS: From 1999 to 2010, 221 patients had repair of descending thoracic and thoracoabdominal aortic aneurysms, including 86 patients with CTBADs. We analyzed this cohort for mortality, complications, length of stay, and reinterventions. RESULTS: OSR was performed in 25 (29%) and 61 (71%) patients for descending thoracic and thoracoabdominal CTBAD, respectively. Median age was 57.0 years (interquartile range [IQR], 52.0-64.2 years), and median diameter was 6.0 cm (IQR, 5.0-6.9 cm). Fifty-nine patients (69%) were male. Eight (9%) were treated for rupture. Follow-up duration was 4.6 years (IQR, 2.8-6.9 years). Hospital mortality occurred in five patients (5.8%). Cardiopulmonary bypass was used in 83 patients (97%) and deep hypothermic arrest in 36 (42%). Two patients (2.3%) each developed paraplegia, stroke, and renal failure requiring permanent hemodialysis in the postoperative period. Length of stay was 13.5 days (IQR, 10.0-21.0 days). Univariate predictors of hospital death included redo operations and prolonged pump time (P < .05). Six patients (7%) had aortic-related reoperations at 4.3 years (IQR, 2.7-5.2 years): one for an ascending aortic aneurysm and five for descending aortic aneurysms. Overall survival at 1, 5, and 7 years was 92%, 83%, and 70%, respectively, and freedom from reoperation was 99%, 90%, and 86%, respectively. CONCLUSIONS: OSR of CTBAD is a durable option with low mortality. Patients requiring redo operations or anticipated prolonged pump time need further evaluation to determine whether conventional OSR or TEVAR, if feasible, is the optimal treatment option.


Asunto(s)
Aneurisma de la Aorta Abdominal/cirugía , Aneurisma de la Aorta Torácica/cirugía , Disección Aórtica/cirugía , Implantación de Prótesis Vascular , Disección Aórtica/diagnóstico , Disección Aórtica/mortalidad , Aneurisma de la Aorta Abdominal/diagnóstico , Aneurisma de la Aorta Abdominal/mortalidad , Aneurisma de la Aorta Torácica/diagnóstico , Aneurisma de la Aorta Torácica/mortalidad , Implantación de Prótesis Vascular/efectos adversos , Implantación de Prótesis Vascular/mortalidad , Enfermedad Crónica , Femenino , Mortalidad Hospitalaria , Humanos , Estimación de Kaplan-Meier , Tiempo de Internación , Masculino , Persona de Mediana Edad , Selección de Paciente , Complicaciones Posoperatorias/mortalidad , Complicaciones Posoperatorias/cirugía , Sistema de Registros , Reoperación , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
5.
Tex Heart Inst J ; 41(6): 645-8, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25593533

RESUMEN

Heparin-induced thrombocytopenia is a well-recognized complication of anticoagulation with heparin. We present the case of a patient with recent heparin-induced thrombocytopenia who subsequently needed surgery on an emergency basis for acute type A aortic dissection. This article reports the successful use of bivalirudin, a direct thrombin inhibitor, as an alternative to heparin throughout cardiopulmonary bypass and deep hypothermic circulatory arrest. We contend that bivalirudin is a safe alternative to heparin when performing surgery for aortic dissection and should be considered as an option for use in patients who present with heparin-induced thrombocytopenia.


Asunto(s)
Anticoagulantes/administración & dosificación , Aneurisma de la Aorta/cirugía , Disección Aórtica/cirugía , Implantación de Prótesis Vascular , Paro Circulatorio Inducido por Hipotermia Profunda , Heparina , Hirudinas/administración & dosificación , Fragmentos de Péptidos/administración & dosificación , Trombocitopenia/inducido químicamente , Trombocitopenia/prevención & control , Anciano de 80 o más Años , Disección Aórtica/diagnóstico , Anticoagulantes/inmunología , Aneurisma de la Aorta/diagnóstico , Puente Cardiopulmonar , Contraindicaciones , Esquema de Medicación , Urgencias Médicas , Heparina/inmunología , Humanos , Masculino , Proteínas Recombinantes/administración & dosificación , Factores de Riesgo , Trombocitopenia/inmunología , Resultado del Tratamiento
6.
Innovations (Phila) ; 8(4): 302-6, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24145976

RESUMEN

OBJECTIVE: This study was undertaken to evaluate the use of somatosensory-evokedpotential (SSEP) monitoring on intercostal artery reimplantation (IAR) and spinal cord ischemia rates during thoracoabdominal ortic aneurysm repair. METHODS: Fifty-two patients had thoracoabdominal aortic aneurysm repair with IAR under SSEP guidance and 79 patients had repair with routine IAR without SSEP guidance from 1999 to 2010. RESULTS: No differences were observed between the two groups in age (63.1 ± 11.6 vs 64.8 ± 9.8 years), sex (57.7% vs 50.6% men), chronic dissections (40.4% vs 44.3%), renal insufficiency (11.5% vs 10.1%), and Crawford type 1 and 2 aneurysms (53.9% vs 53.9%). There was one case (1.9%) of immediate paraplegia and one case (1.9%) of delayed paraplegia in the SSEP group versus 2 cases (2.5%) of immediate paraplegia in the non-SSEP group (P = 0.92). In the SSEP group, 38 patients (73.1%) had SSEP changes, but only 15 (28.8%) required reimplantation. There were fewer IARs in the SSEP group compared with the non-SSEP group (28.8% vs. 59.5%, P = 0.004). No difference was observed in 30-day mortality between the SSEP and the non-SSEP group (3.9% vs. 7.6%, P = 0.48). CONCLUSIONS: The use of SSEP monitoring led to a significant decrease in the need for IAR without increasing the paraplegia rate.


Asunto(s)
Aneurisma de la Aorta Torácica/cirugía , Potenciales Evocados Somatosensoriales , Monitoreo Intraoperatorio/métodos , Reimplantación/métodos , Isquemia de la Médula Espinal/prevención & control , Arterias Torácicas/trasplante , Anciano , Angiografía/métodos , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Músculos Intercostales/irrigación sanguínea , Masculino , Persona de Mediana Edad , Paraparesia/prevención & control , Paraplejía/prevención & control , Flujo Sanguíneo Regional , Estudios Retrospectivos , Medición de Riesgo , Índice de Severidad de la Enfermedad , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento , Procedimientos Quirúrgicos Vasculares/efectos adversos , Procedimientos Quirúrgicos Vasculares/métodos
7.
BJU Int ; 111(4 Pt B): E235-41, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23130741

RESUMEN

OBJECTIVE: To evaluate perioperative and 6-month renal functional outcomes of patients undergoing off-clamp vs complete hilar control laparoscopic partial nephrectomy (LPN). PATIENTS AND METHODS: A retrospective review of 489 patients undergoing LPN was completed. Preoperative imaging assessed tumour characteristics. Patient demographics, perioperative parameters, and postoperative outcomes were documented. Multivariable regression analysis was used to assess factors contributing to changes in postoperative renal function between off-clamp and clamped LPN. RESULTS: In all, 289 LPNs were performed on-clamp and 150 were performed off-clamp. Tumours in the on-clamp group were larger than those in the off-clamp group (mean [range] 3.3 [0.5-13.5] vs 2.7 [0.4-9] cm, P = 0.003). Univariable analysis comparing off-clamp to on-clamp cohorts showed that estimated glomerular filtration rate (eGFR) was better preserved in the off-clamp cohort at 6 months (-5.8% vs -11.4%, P = 0.046). Multivariable analysis of the groups showed that estimate blood loss (P = 0.015) and warm ischaemia time (WIT, P < 0.001) were the only significant predictors of decreased eGFR in the postoperative period. Difference in eGFR at 6 months was not significant when WIT was limited to 30 min. The complication rate was greater in the clamped cohort (10% vs 20%, P = 0.012). There was no difference in transfusion rate or positive margin status. CONCLUSIONS: LPN without hilar clamping is feasible, safe and associated with less renal injury as assessed by postoperative GFR in select patients. With experience, it can be applied to complex renal lesions.


Asunto(s)
Neoplasias Renales/cirugía , Laparoscopía/métodos , Nefrectomía/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular/fisiología , Humanos , Neoplasias Renales/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Robótica/métodos , Resultado del Tratamiento , Isquemia Tibia , Adulto Joven
8.
J Urol ; 188(5): 1783-7, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22998903

RESUMEN

PURPOSE: Patients with chronic pelvic pain disorders often present with neuropathic features. We examined a cohort of patients with a primary complaint of chronic pelvic pain for the presence of neuropathic pain symptoms. MATERIALS AND METHODS: Patients with chronic pelvic pain disorders from 2 tertiary referral centers were prospectively evaluated. The validated S-LANSS (Self-Administered Leeds Assessment of Neuropathic Symptoms and Signs) survey was used to examine pain symptoms of neuropathic origin. Patients completed SF-12v2™ to assess mental/physical health domains. The 2-tailed t test and chi-square analysis were used to compare physical and mental component summaries in patients with vs without neuropathic symptoms. RESULTS: A total of 142 patients mean age of 45 years were included in analysis. Of the patients 72.5% with chronic pelvic pain carried more than 1 primary diagnosis. The S-LANSS survey identified symptoms suggestive of neuropathic pain in 44 patients (31%). A greater proportion of patients with a neuropathic component had altered sensation in the affected area (86.4% vs 24.5%). Patients with neuropathic pain scored 4.28 and 5.45 points lower on the physical and mental component summaries (p = 0.053 and 0.008, respectively). CONCLUSIONS: A large proportion of patients with chronic pelvic pain present with neuropathic features and report decreased quality of life compared with the general population. Those with neuropathic symptoms have significantly lower quality of life than those without such symptoms. Clinicians can identify patients to use targeted therapies and use a multidisciplinary approach to care.


Asunto(s)
Dolor Crónico/complicaciones , Neuralgia/complicaciones , Dolor Pélvico/complicaciones , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neuralgia/epidemiología , Estudios Prospectivos , Adulto Joven
9.
BJU Int ; 109(9): 1356-9, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21883848

RESUMEN

UNLABELLED: Study Type--Diagnostic (symptom prevalence). Level of Evidence 2b. What's known on the subject? And what does the study add? Symptom variability is profound in the population of patients diagnosed with interstitial cystitis and painful bladder syndrome because these diagnoses represent a very heterogeneous patient population. Recently, younger patients are being diagnosed with these pain syndromes, without any specific investigation into the symptoms they experience. We identified that patients diagnosed with interstitial cystitis and painful bladder syndrome have variable clinical symptom profiles depending on the age at the time of their diagnosis. Dyspareunia, external genitalia pain, urgency, frequency and dysuria were more common in younger patients whereas nocturia, urinary incontinence and the presence of Hunner's ulcers were more common in older patients. Better defining symptom profiles for patients at the time of evaluation may potentially aid in more accurate and expedited diagnosis of these conditions, particularly in the youngest patient population which is being recognized more commonly in recent times. OBJECTIVE: • To investigate the clinical profile differences among patients with interstitial cystitis/painful bladder syndrome (IC/PBS) based upon age at the time of diagnosis from childhood into the geriatric age group. METHODS: • An analysis of 268 patients with IC/PBS seen between 1990 and 2008 was performed. • Three age cohorts were analysed: <30 years, ≥30 years but <60 years, and ≥60 years of age at time of diagnosis. • Patient demographics, disease characteristics and IC/PBS-associated symptoms were compared across the three groups. RESULTS: • Of the 268 patients, 60 were <30 years of age at the time of IC diagnosis (median 22, range 11-29), 105 were ≥30 but <60 years (median 48, range 30-59) and 103 patients were ≥60 years of age (median 69, range 60-88). • Of the patients in the youngest, middle and oldest age cohorts: 12.0, 42.0 and 39.8% had Hunner's ulcers, respectively (P<0.001). • Dyspareunia and external genitalia pain were more common in the youngest age cohort, P<0.001 and P=0.001, respectively. • Urinary urgency (P=0.033), frequency (P=0.006) and dysuria (P<0.001) were also more common in patients diagnosed before 30 years of age. • The reported rate of nocturia and urinary incontinence increased with age, P=0.002 and P<0.001, respectively. CONCLUSIONS: • Patients with IC/PBS analysed across a wide spectrum of ages at time of diagnosis portrayed a unique symptom profile pattern. • Patients diagnosed at the youngest ages experienced significantly more urinary urgency, frequency, dysuria, dyspareunia and pain in their external genitalia. • Older patients had higher rates of nocturia, urinary incontinence and Hunner's ulcer disease.


Asunto(s)
Cistitis Intersticial/fisiopatología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Niño , Cistitis Intersticial/complicaciones , Femenino , Humanos , Síntomas del Sistema Urinario Inferior/complicaciones , Masculino , Persona de Mediana Edad , Dolor Pélvico/complicaciones , Estudios Retrospectivos , Factores de Riesgo , Úlcera/complicaciones , Enfermedades de la Vejiga Urinaria/complicaciones , Trastornos Urinarios/complicaciones , Adulto Joven
10.
J Endourol ; 25(12): 1925-8, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21988126

RESUMEN

BACKGROUND AND PURPOSE: The R.E.N.A.L nephrometry score (NS) was developed to characterize renal tumor anatomy to facilitate standardized reporting and ultimately clinical decision making. Up to three points are assigned for each of the following criteria: Tumor size (R), exophytic vs endophytic nature (E), nearness to the collecting system (N), anterior vs posterior (A), and polar location (L), with more complex lesions receiving higher scores. There are no independent studies to date that validate the reproducibility of this scoring system. Our aim was to validate the R.E.N.A.L. NS system by assessing interobserver variability, and therefore reproducibility and fidelity of this proposed assessment tool. PATIENTS AND METHODS: We reviewed our prospectively collected laparoscopic partial nephrectomy (LPN) database and identified 306 patients with available preoperative CT or MRI. Of these, 149 were independently read by two urology residents who assigned NS. The Pearson test was used to assess interobserver variability of total NS as well as each of the five components of the scoring system. RESULTS: Interobserver correlation of total NS calculated by the Pearson test was found to be 0.92 (P<0.001). Concordance rates for each of the individual nephrometry components R.E.N.A.L (hilar) were 96%, 92%, 86%, 96%, 89%, and 99% respectively. A t test showed no significant difference between final NS assigned by two different observers. CONCLUSION: The R.E.N.A.L. NS system is a comprehensive and reproducible tool that may aid surgeons in communicating tumor characteristics effectively. Interobserver correlation is high, rendering it a high fidelity assessment tool.


Asunto(s)
Neoplasias Renales/clasificación , Neoplasias Renales/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
11.
J Urol ; 185(4): 1289-93, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21334028

RESUMEN

PURPOSE: Surgical site infections have been categorized by the Centers for Medicare and Medicaid Services as "never events". The incidence of surgical site infection following laparoscopic urological surgery and its risk factors are poorly defined. We evaluated surgical site infection following urological laparoscopic surgery and identified possible factors that may influence occurrence. MATERIALS AND METHODS: Patients who underwent transperitoneal laparoscopic procedures during a 4-year period by a single laparoscopic surgeon were retrospectively reviewed. Surgical site infections were identified postoperatively and defined using the Centers for Disease Control criteria. Clinical parameters, comorbidities, smoking history, preoperative urinalysis and culture results as well as operative data were analyzed. Nonparametric testing using the Mann-Whitney U test, multivariable logistic regression and Spearman's rank correlation coefficient were used for data analysis. RESULTS: In 556 patients undergoing urological laparoscopic procedures 14 surgical site infections (2.5%) were identified at mean postoperative day 21.5. Of the 14 surgical site infections 10 (71.4%) were located at a specimen extraction site. Operative time, procedure type and increasing body mass index were significantly associated with the occurrence of surgical site infections (p = 0.007, p = 0.019, p = 0.038, respectively), whereas history of diabetes mellitus (p = 0.071) and intraoperative transfusion (p = 0.053) were found to trend toward significance. Age, gender, positive urine culture, steroid use, procedure type and smoking history were not significantly associated with surgical site infection. Body mass index and operative time remained significant predictors of surgical site infection on multivariate logistic regression analysis. CONCLUSIONS: Surgical site infection is an infrequent complication following laparoscopic surgery with the majority occurring at the specimen extraction site. Infection is associated with prolonged operative time and increasing body mass index.


Asunto(s)
Laparoscopía/efectos adversos , Infección de la Herida Quirúrgica/epidemiología , Infección de la Herida Quirúrgica/etiología , Procedimientos Quirúrgicos Urológicos/efectos adversos , Procedimientos Quirúrgicos Urológicos/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
13.
Isotopes Environ Health Stud ; 44(1): 83-98, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18320430

RESUMEN

Deuterium and oxygen-18 enrichment in river water during its transit across dryland region is found to occur systematically along evaporation lines with slopes of close to 4 in (2)H-(18)O space, largely consistent with trends predicted by the Craig-Gordon model for an open-water dominated evaporating system. This, in combination with reach balance assessments and derived runoff ratios, strongly suggests that the enrichment signal and its variability in the Barwon-Darling river, Southeastern Australia is acquired during the process of evaporation from the river channel itself, as enhanced by the presence of abundant weirs, dams and other storages, rather than reflecting inherited enrichment signals from soil water evaporation in the watershed. Using a steady-state isotope mass balance analysis based on monthly (18)O and (2)H, we use the isotopic evolution of river water to re-construct a perspective of net exchange between the river and its contributing area along eight reaches of the river during a drought period from July 2002 to December 2003, including the duration of a minor flow event. The resulting scenario, which uses a combination of climatological averages and available real-time meteorological data, should be viewed as a preliminary test of the application rather than as a definitive inventory of reach water balance. As expected for a flood-driven dryland system, considerable temporal variability in exchange is predicted. While requiring additional real-time isotopic data for operational use, the method demonstrates potential as a non-invasive tool for detecting and quantifying water diversions, one that can be easily incorporated within existing water quality monitoring activities.


Asunto(s)
Deuterio/análisis , Monitoreo del Ambiente/métodos , Isótopos de Oxígeno/análisis , Ríos/química , Abastecimiento de Agua/análisis , Australia , Clima , Deuterio/química , Desastres , Salud Ambiental , Geografía , Isótopos de Oxígeno/química , Volatilización , Movimientos del Agua
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