HYDROLOGIC EFFECTS FROM CHANGES IN GROUND WATER PUMPAGE1

ABSTRACT: Simulation of a large stream-aquifer system in Nebraska has been accomplished for the period from 1975 to 2020 to determine effects of controls on ground water pumpage. Three scenarios tested consisted of average annual withdrawals of 15.2 ac-in/ac (FUTURE 1), 14.8 ac-in/ac (FUTURE 2), and 9.8 ac-in/ac (FUTURE 3). The highest quantity represents the historical tendency; while the 14.8 in. figure represents a slight reduction and also represents an equalization of irrigation application efficiencies throughout the area. The lowest figure represents a substantial increase in application efficiency. Comparisons between simulated ground water elevations indicate maximum savings of FUTURE 2 over FUTURE 1 of less than 8 ft. FUTURE 3 ft. FUTURE 3 levels are projected to be a maximum of approximately 13 ft. higher than FUTURE 1's. The relatively small savings from reductions in pumpage result primarily from recirculation effects. Differences between ground water contributions to stream flow are small for all scenarios. These contributions decrease with time and increasing pumpage amounts. Base flow rates at the end of the simulation are approximately 25 percent of those at the beginning.     

Rapid and simple spectrophotometric determination of persulfate in water by microwave assisted decolorization of Methylene Blue

A rapid and simple method for determination of persulfate in aqueous solution was developed. The method is based on the rapid reaction of persulfate with Methylene Blue(MB) via domestic microwave activation, which can promote the activation of persulfate and decolorize MB quickly. The depletion of MB at 644 nm(the maximum absorption wavelength of MB) is in proportion to the increasing concentration of persulfate in aqueous solution. Linear calibration curve was obtained in the range 0–1.5 mmol/L, with a limit of detection of 0.0028 mmol/L. The reaction time is rapid(within 60 sec), which is much shorter than that used for conventional methods. Compared with existing analytical methods, it need not any additives, especially colorful Fe2+, and need not any pretreatment for samples, such as p H adjustment.     

Holocene fire history from the Greater Blue Mountains World Heritage Area, New South Wales, Australia: the climate, humans and fire nexus

This study presents a reconstruction of the fire activity of the last ~14,200 cal. years BP (before AD 1950) from Gooches Crater Right, located on the Newnes Plateau, approximately 150 km to the west of Sydney (~33°27′S, 150°16′E) within the Blue Mountains National Park. Charcoal analysis and palynology were undertaken with the aim of untangling any inter-relationship between climate, humans and fire. A chronology of the site was provided by radiocarbon dating. The dominant control on fire in this environment during the Holocene appears to be climate. Periods of climate change, identified in previous studies, are associated with higher levels of fire activity. Fire was less ubiquitous between ~9,000 and 6,000 years BP, a period normally described as having a higher effective moisture in south-eastern Australia. The mid-Holocene fluctuations in charcoal may reflect anthropogenic fire, climate forcing or alternatively human responses to any climate change. Coeval changes in palaeoclimatic sequences elsewhere and palynology at the site support a climatic explanation or that Aboriginal people used fire within a climatic framework.     

Gravity model formulation for an extensive National Parkway Site

The purpose of this study was to collect specific information on the characteristics and intensity of local Blue Ridge Parkway use and to use that information to develop a recreation use model of local Parkway visitation. Data were obtained from a self-administered mail-back questionnaire sent to a random sample of people living in the 29 counties adjacent to the Parkway.We developed two recreation use projection/demand models that employ three variables (distance, alternative recreation sites, and population density) to predict visitation to different Parkway areas from various local origins. The derived model estimates indicated that about one-fourth of all Parkway visits in 1978 were one-day visits made by area residents.     

What limits predator detection in blue tits (<Emphasis Type="Italic">Parus caeruleus</Emphasis>): posture,task or orientation?

To detect threats and reduce predation risk prey animals need to be alert. Early predator detection and rapid anti-predatory action increase the likelihood of survival. We investigated how foraging affects predator detection and time to take-off in blue tits (Parus caeruleus) by subjecting them to a simulated raptor attack. To investigate the impact of body posture we compared birds feeding head-down with birds feeding head-up, but could not find any effect of posture on either time to detection or time to take-off. To investigate the impact of orientation we compared birds having their side towards the attacking predator with birds having their back towards it. Predator detection, but not time to take-off, was delayed when the back was oriented towards the predator. We also investigated the impact of foraging task by comparing birds that were either not foraging, foraging on chopped mealworms, or foraging on whole ones. Foraging on chopped mealworms did not delay detection compared to nonforaging showing that foraging does not always restrict vigilance. However, detection was delayed more than 150% when the birds were foraging on whole, live mealworms, which apparently demanded much attention and handling skill. Time to take-off was affected by foraging task in the same way as detection was. We show that when studying foraging and vigilance one must include the difficulty of the foraging task and prey orientation.Communicated by P.A. Bednekoff     

应用生态动力学模型评价上海淀山湖富营养化控制方案

近年来,由于淀山湖入湖河流和环湖污水排放,淀山湖水质严重富营养化,夏季高温季节蓝藻水华时有发生。基于最近开展的比较系统的大规模水文、水质、生物同步监测和底质氮磷营养盐释放通量实验,进行入湖氮磷营养盐通量计算分析。通过建立淀山湖水动力一生态动力学耦合模型,利用同步实测和历史资料进行水动力模型和生态动力学模型的率定验证,模拟典型风场作用下的淀山湖三维流场特征;利用生态动力学模型系统研究淀山湖氮磷营养盐和藻类的时空变化和演替规律,初步掌握淀山湖的富营养化过程;综合评价了污染负荷削减、水力调度（水体停留时间）等措施对控制淀山湖富营养化的作用,明确磷是淀山湖藻类生长的关键营养盐限制因子。模型预测结果表明,磷负荷削减50％以上才能使淀山湖夏季蓝藻生物量开始下降;削减90％以上的营养盐负荷才能有效抑制蓝藻水华;水体停留时间的长短是藻类是否过度繁殖的重要条件,加大引水流量,减少淀山湖水体停留时间是有效控制蓝藻水华的重要途径;目前阶段,与控制营养盐负荷（50％）相比,增大引水流量可以更有效地降低蓝藻暴发时的生物量。     

Modeling of adsorption kinetics and equilibria of acid dyes onto activated carbon in single- and binary-component systems

Adsorptive removal of Acid Blue 127 and Acid Yellow 17 from their single and binary solutions has been studied using powdered activated carbon (PAC). The dyes used extensively for dying of nylon fiber in textile industry are known as Nylomine Blue P-B (NB) and Nylomine Yellow P-4G (NY), respectively. Time-dependent results obtained from single-component system have been better predicted by two resistance diffusion model rather than homogeneous surface diffusion. The magnitudes of film- and intraparticle diffusion coefficients calculated from McKay equation are ～10^?9 and ～10^?15 m² s^?1, whereas surface diffusion coefficients have been estimated as ～10^?13 m² s^?1 using Vermeulen approximation. Experimental equilibrium isotherms have been evaluated by changing initial dye concentrations in the range of 0.02–1.00 of mmol L^?1. Freundlich isotherm parameters for individual solutions of the dyes have been used to predict their equilibrium behaviors in binary solutions by applying extended Freundlich model. Langmuir isotherm model and its extended form have also been fitted to the data for single- and binary-dye solutions, respectively. Thermodynamic functions derived from the temperature dependence of adsorption equilibrium constants in 298–318 K range show that adsorption processes are endothermic but spontaneous.     

Generation of Monthly Precipitation Under Climate Change for the Upper Blue Nile River Basin,Ethiopia1

Abstract: This work develops a methodology to project the future precipitation in large river basins under limited data and climate change while preserving the historical temporal and spatial characteristics. The computationally simple and reliable conditional generation method (CGM) is presented and applied to generate reliable monthly precipitation data in the upper Blue Nile River Basin of Ethiopia where rain‐fed agriculture is prevalent. The results showed that the temporal analysis with the CGM performs better to reproduce the historical long‐term characteristics than other methods, and the spatial analysis with the CGM reproduced the historical spatial structure accurately. A 100‐year time series analysis using the outcomes of the six general circulation models showed that precipitation changes by the 2050s (2040 through 2069) can be ?7 to 28% with a mean increase of about 11%. The seasonal results showed increasing wet conditions in all seasons with changes of mean precipitation of 5, 47, and 6% for wet, dry, and mild seasons, respectively.     

玄武湖蓝藻水华成因探讨

为了解南京玄武湖蓝藻水华的成因,对玄武湖长期监测资料进行了分析和现场调查。结果表明,玄武湖鲢鳙急剧减少中断了正常的食物链,使浮游植物的牧食压力降低,在东南湖回水的诱因作用下,发生了以微囊藻为优势种群的蓝藻水华。指出,玄武湖蓝藻水华的发生进程表明,东南湖回水可能是蓝藻水华发生的诱因,生态失衡是蓝藻水华发生的主要原因,蓝藻水华的暴发与富营养化程度无显著相关性,其暴发加重了玄武湖富营养化程度。     

不同波长紫外光催化降解活性艳蓝KN-R动力学研究

以蒽醌类染料活性艳蓝KN-R(以下简称KN-R)为对象,以TiO2为光催化剂,实验了不同波段紫外光条件下KN-R的降解过程。结果表明:365 nm和254 nm两种波段对于KN-R的光催化降解过程均符合假一级动力学方程,但是通过对比各初始浓度下活性艳红KN-R的反应速率常数(Kapp)可以发现,在相同紫外灯功率下,短波辐射下的Kapp平均为长波辐射下Kapp的3倍,说明短波紫外更有利于活性艳蓝KN-R的降解。