Streamflow Forecasting Using Singular Value Decomposition and Support Vector Machine for the Upper Rio Grande River Basin

The current study improves streamflow forecast lead‐time by coupling climate information in a data‐driven modeling framework. The spatial–temporal correlation between streamflow and oceanic–atmospheric variability represented by sea surface temperature (SST), 500‐mbar geopotential height (Z₅₀₀), 500‐mbar specific humidity (SH₅₀₀), and 500‐mbar east–west wind (U₅₀₀) of the Pacific and the Atlantic Ocean is obtained through singular value decomposition (SVD). SVD significant regions are weighted using a nonparametric method and utilized as input in a support vector machine (SVM) framework. The Upper Rio Grande River Basin (URGRB) is selected to test the applicability of the proposed model for the period of 1965–2014. The April–August streamflow volume is forecasted using previous year climate variability, creating a lagged relationship of 1–13 months. SVD results showed the streamflow variability was better explained by SST and U₅₀₀ as compared to Z₅₀₀ and SH₅₀₀. The SVM model showed satisfactory forecasting ability with best results achieved using a one‐month lead to forecast the following four‐month period. Overall, the SVM results showed excellent predictive ability with average correlation coefficient of 0.89 and Nash–Sutcliffe efficiency of 0.79. This study contributes toward identifying new SVD significant regions and improving streamflow forecast lead‐time of the URGRB.     

2007—2016年嘉峪关市城市绿地生态评价及障碍因子分析

对城市绿地进行科学评价有助于人们正确认识和改造城市绿地建设,为城市绿地规划和管理提供参考。以2007—2016年嘉峪关市城市绿地为研究对象,从数量、结构、功能三个方面构建评价指标体系,通过障碍度模型,识别影响城市绿地生态水平的障碍因子。结果表明：（1）10 a来嘉峪关市城市绿地生态水平整体呈波动上升趋势,级别由较低等级提高到高等级,但目前城市绿地生态水平属于低层次、不稳定的高等级阶段,城市绿地建设工作压力还很大。（2）从准则层看,嘉峪关市城市绿地生态水平的主要威胁变化较为明显,数量指标和结构指标是主要障碍因子;从指标层看,各年份主要障碍因子不尽相同,最大障碍因子历经了从人均公园绿地面积、树种丰富度到净化空气能力的演变。     

Warfare in Biodiversity Hotspots

Abstract:  Conservation efforts are only as sustainable as the social and political context within which they take place. The weakening or collapse of sociopolitical frameworks during wartime can lead to habitat destruction and the erosion of conservation policies, but in some cases, may also confer ecological benefits through altered settlement patterns and reduced resource exploitation. Over 90% of the major armed conflicts between 1950 and 2000 occurred within countries containing biodiversity hotspots, and more than 80% took place directly within hotspot areas. Less than one-third of the 34 recognized hotspots escaped significant conflict during this period, and most suffered repeated episodes of violence. This pattern was remarkably consistent over these 5 decades. Evidence from the war-torn Eastern Afromontane hotspot suggests that biodiversity conservation is improved when international nongovernmental organizations support local protected area staff and remain engaged throughout the conflict. With biodiversity hotspots concentrated in politically volatile regions, the conservation community must maintain continuous involvement during periods of war, and biodiversity conservation should be incorporated into military, reconstruction, and humanitarian programs in the world's conflict zones.     

Long-term relationships between mercury wet deposition and meteorology

Daily-event precipitation samples collected in Underhill, VT from 1995 to 2006 were analyzed for total mercury and results suggest that there were no statistically significant changes in annual mercury wet deposition over time, despite significant emissions reductions in the Northeast United States. Meteorological analysis indicates that mercury deposition has not decreased as transport of emissions from major source regions in the Midwest and East Coast have consistently contributed to the largest observed mercury wet deposition amounts over the period. In contrast, annual volume-weighted mean (VWM) mercury concentration declined slightly over the 12-years, and a significant decrease was observed from CY 2001 to 2006. An increase in the total annual precipitation amount corresponded with the decline in annual VWM mercury concentration. Analysis suggests that the increase in precipitation observed was strongly related to changes in the amount and type of precipitation that fell seasonally, and this departure was attributed to a response in meteorological conditions to climate variability and the El Niño-Southern Oscillation (ENSO) cycle. Increased amounts of rainfall and mixed precipitation (mixture of rainfall and snowfall), particularly in the spring and fall seasons, enhanced annual precipitation amounts and resulted in declining VWM mercury concentrations during these periods. Thus, declines in concentration at the more remote Underhill site appear to be more directly linked to local scale meteorological and climatological variability than to a reduction in emissions of mercury to the atmosphere.     

Metal Products and Machinery: Proposed Rule for Pretreatment and Effluent Guidelines

EPA's proposal outlines technology‐based effluent limits and pretreatment standards for waste‐water discharges from facilities that manufacture, rebuild, repair, or maintain finished metal products, parts, or machines. © 2001 John Wiley & Sons, Inc.     

Echolocation signals of the bat Eptesicus serotinus recorded using a vertical microphone array: effect of flight altitude on searching signals

The acoustic behaviour of Eptesicus serotinus was investigated in the field using a 13.5-m vertical, linear microphone array that allowed for simultaneous recordings at three different heights and for the calculation of flight altitude and distance from the array. Recordings were made at two locations that differed in bat species diversity. E. serotinus hunted on average at an altitude of 10.7 m (±2.7) at one location and 6.8 m (±3.6) at the other location. Search signals were 5–17 ms long depending on flight altitude, and consisted of two to three frequency-modulated harmonics. For bats flying below 8–10 m altitude, signal duration decreased with decreasing flight altitude, whereas signal interval, terminal frequency, peak frequency and frequency range of the first harmonic increased. Above 8–10 m flight altitude, the signal parameters were fairly constant. The –10 dB bandwidth and duty cycle did not change with flight altitude. Source levels were calculated to between 121 and 125 dB peSPL re 20 μPa at 10 cm. For bats flying higher than 9 m, the microphone placed 1.5 m above the ground recorded significantly reduced signal durations and frequency ranges of the first harmonic compared to the same signals recorded with the microphones at heights of 7 or 15 m. We caution the use of ground recordings to fully describe the echolocation signals of high-flying bats. We demonstrate that flight altitude significantly influences the structure of sonar signals from E. serotinus. Received: 17 May 1999 / Received in revised form: 20 September 1999 / Accepted: 25 September 1999