Impacts of Climate Change on Extreme Precipitation Events Over Flamingo Tropicana Watershed1

Abstract: Climate change, particularly the projected changes to precipitation patterns, is likely to affect runoff both regionally and temporally. Extreme rainfall events are expected to become more intense in the future in arid urban areas and this will likely lead to higher streamflow. Through hydrological modeling, this article simulates an urban basin response to the most intense storm under anthropogenic climate change conditions. This study performs an event‐based simulation for shorter duration storms in the Flamingo Tropicana (FT) watershed in Las Vegas, Nevada. An extreme storm, defined as a 100‐year return period storm, is selected from historical records and perturbed to future climatic conditions with respect to multimodel multiscenario (A1B, A2, B1) bias corrected and spatially disaggregated data from the World Climate Research Programme's (WCRP's) database. The cumulative annual precipitation for each 30‐year period shows a continuous decrease from 2011 to 2099; however, the summer convective storms, which are considered as extreme storms for the study area, are expected to be more intense in future. Extreme storm events show larger changes in streamflow under different climate scenarios and time periods. The simulated peak streamflow and total runoff volume shows an increase from 40% to more than 150% (during 2041‐2099) for different climate scenarios. This type of analysis can help evaluate the vulnerability of existing flood control system and flood control policies.     

Removal of aqueous nickel (II) using laterite as a low-cost adsorbent.

The present paper describes the laboratory study of laterite as a low-cost adsorbent for removal of aqueous nickel (II). At pH 7 and a temperature of 30 degrees C, a sorbent dose of 15 mg/L resulted in approximately 90% removal of nickel (II) from its initial concentration of 10 mg/L. A maximum removal of 98% of the adsorbate was observed with an adsorbent particle size of 210 micro with the above conditions. Batch kinetics results were described by fitting in a Langmuir isotherm. Helffrich's half-time equation (Helffrich, 1962) has been applied to evaluate the adsorption process. It appears that film diffusion would be the rate-limiting step. The effect of pH on the sorption process was carried out to a value of 8.0. The removal rate of nickel was found to be the function of pH of the reaction mixture. The rate of nickel uptake by laterite with the decrease in pH value has been explained on the basis of aqueous-complex formation and the subsequent acid-base dissociation at the solid-solution interface.     

Assessment of spatiotemporal variability and trend analysis of reference crop evapotranspiration for the southern region of Peninsular India

Environmental Science and Pollution Research - Accurate estimation of reference evapotranspiration (ET0) is an essential requirement for water resource management and scheduling agricultural...     

湖泊水动力模型外部输入条件不确定性和敏感性分析

以我国典型的大型浅水湖泊太湖为研究区域,采用国内外常用的环境流体动力学模型(EFDC),结合拉丁超立方取样(LHS)方法,研究湖泊水动力模型中4个重要的外部输入条件,即3个边界输入条件(出入湖流量、风速、风向)和1个初始输入条件(初始水位),对模型水动力模拟结果(水位、水龄以及流场)的影响与贡献.结果表明,初始水位的设定对模拟全湖水位和水龄产生决定性影响,不确定性的贡献率分别达到85.73%和66.125%,对垂向平均流速影响的贡献率只有3%;风速对表面流速模拟结果影响较大,贡献率达到58.70%,而对水位和水龄的贡献率分别为5.25%和3.00%.在垂向上,各层流速受外部输入条件不确定性的影响规律相似,贡献率排序为风速(55%~60%)>风向(10%~15%)>初始水位≈出入湖流量(1%~5%).因此在模拟大型浅水湖泊水动力过程时,可以根据不同的输出目标能够有针对性地提高外部输入条件的准确度,为提高模型精确度提供有效信息.     

Study on turbulence characteristics and sensitivity of quadrant analysis to threshold level in Lake Taihu

Environmental Science and Pollution Research - The identification of coherent structures is very important in investigating the sediment transport mechanism and controlling the eutrophication in...     

The Mass and Energy Exchange of a Tibetan Glacier: Distributed Modeling and Climate Sensitivity

Most glaciers in the Tibetan Plateau (TP) are not closely monitored for mass balance (MB) due to their inaccessibility, which makes it difficult to better understand the dynamics of glacial advancement or retreat. Surface energy budget, MB, and the resulting melt runoff were calculated for Zhadang glacier (5,710 m above sea level) of the central TP. Energy balance was calculated on 30‐m square grids for the summers of 2007 and 2008. On average, net radiation dominated the total energy source (66%) while the residual was supplied by sensible heat flux. More than 67% of the energy sink was available for melting on the glacier. Thus, less than 33% of the total energy was consumed by latent heat flux. A large and a slightly negative summer MB were calculated for the 2007 and 2008 summers, respectively. The high sensitivity of the glacier to air temperature may indicate that the lower than average seasonal temperature was more important than the increased precipitation for the slightly negative MB in the summer of 2008. Comparisons of glacial melt runoff indicated that rainfall and snowmelt were the dominant contribution to total runoff in the glacierized basin and the ice melting is also very important. Glacial melt calculation provides a basis for quantifying glacial melt‐runoff contribution to the river streamflow in the TP.     

Characterization of extracellular polymeric substance (EPS) fractions produced by Microcystis aeruginosa under the stress of linoleic acid sustained-release microspheres

Environmental Science and Pollution Research - This paper focuses on the characterization of extracellular polymeric substances (EPS), which are composed of soluble EPS (SL-EPS), loosely bound EPS...