Impact of floodplain and Stage 0 stream restoration on flood attenuation and floodplain exchange during small frequent storms

River flooding impacts human life and infrastructure, yet provides habitat and ecosystem services. Traditional flood control (e.g., levees, dams) reduces habitat and ecosystem services, and exacerbates flooding elsewhere. Floodplain restoration (i.e., bankfull floodplain reconnection and Stage 0) can also provide flood management, but has not been sufficiently evaluated for small frequent storms. We used 1D unsteady Hydrologic Engineering Center's River Analysis System to simulate small storms in a 5 km-long, second-order generic stream from the Chesapeake Bay watershed, and varied % channel restored (starting at the upstream end), restoration location, restoration bank height (distinguishes bankfull from Stage 0 restoration), and floodplain width/Manning's n. Stream restoration decreased (attenuated) peak flow up to 37% and increased floodplain exchange by up to 46%. Floodplain width and % channel restored had the largest impact on flood attenuation. The incremental effects of new restoration projects on flood attenuation were greatest when little prior restoration had occurred. By contrast, incremental effects on floodplain exchange were greatest in the presence of substantial prior restoration, setting up a tradeoff. A similar tradeoff was revealed between attenuation and exchange for project location, but not bank height or floodplain width. In particular, attenuation and exchange were always greater for Stage 0 than for bankfull floodplain restoration. Stage 0 thus may counteract human impacts such as urbanization.     

Restrictive dermopathy and fetal behaviour

We report three siblings from consecutive pregnancies affected with restrictive dermopathy (RD). During the second pregnancy, fetal behavioural development and growth were studied extensively using ultrasound at 1–4 week intervals. Dramatic and sudden changes occurred in fetal body movements and growth but not until the end of the second trimester of pregnancy. Prominent at that time were prolonged periods of fetal quiescence and very low heart rate variability, together with abnormally executed body movements of short duration. Retarded femoral development and jerky abrupt fetal body movements (abnormal movement quality) were already present in the early second trimester of pregnancy. Facial anomalies emerged despite the presence of fetal mouth movements. The clinical features of RD were only partly explained by present knowledge of skin development and the fetal akinesia deformation sequence hypothesis. Quantitative assessment of fetal movements proved to be a poor early marker for antenatal diagnosis of this disorder. Copyright © 2001 John Wiley & Sons, Ltd.     

Changes in fetal heart rate pattern after intrauterine paracentesis in one twin with meconium peritonitis

We report a case of in utero paracentesis of ascites in a fetus with meconium peritonitis due to volvulus at 34 weeks which resulted in the correction of an abnormal fetal heart rate pattern and enabled vaginal delivery by preventing abdominal dystocia. The intrauterine intervention also helped to establish the diagnosis and potentially reduced the respiratory compromise after birth. Copyright © 2001 John Wiley & Sons, Ltd.     

Fluctuations of Population Size and Structure in the Northern Mole Vole: Preliminary Analysis

Long-term stationary studies on the ecology of the northern mole vole (Ellobius talpinus Pall.), performed by the mark–recapture method from 1985 to 1997, have provided original data on population dynamics and structure. The analysis shows that, to reveal cyclic fluctuations of population size in this species, the period of three years should be taken as a unit of time for estimating the duration of one phase. The 12-year population cycle in E. talpinus has four distinct phases: an increase, a peak, a decline, and a minimum. At each phase, the population is characterized by certain features of family structure, age composition, birth and death rates, and the composition of migrants.     

母岩的风化剥蚀速率与土壤允许流失量的关系 --以长江三峡坝区风化花岗岩土壤为例

土壤允许流失量的确定是一个非常复杂而又必须解决的问题，它关系到水土保持措施的布设和土壤的可持续利用。然而，发育在不同母质上的土壤，其土壤的最大允许流失量差异很大，确定这一值的依据也各不相同。在岩成土壤地区，母岩风化剥蚀速率的大小直接影响土壤的发育。是确定土壤允许流失量、分析人类加速水土流失的重要依据之一。选长江三峡黄陵背斜段风化花岗岩土壤为研究对象，根据剥蚀沉积相关原理，通过恢复古地理环境及时代，计算出新生代以来本区花岗岩的平均风化剥蚀速率为16．97mm／ka．最大剥蚀速率为49．56。又根据区内太平溪流域的泥沙资料，算出了当地现代的剥蚀速率，多年平均为297．7mm／ka，最小值为31．5mm／ka，而水利部颁布的当地土壤允许流失量为200t／km^2,a，折合为76．9mm／ka，二者相差近1．5—4．5倍。基于此。提出了确定土壤允许流失量必须参考母岩风化剥蚀速率的新观点。     

北京市发展CNG汽车的条件与前景分析

北京市汽车排放污染物贡献率已达到：HC73.5％，CO63．4％，NOx46％。用CNG代替汽油作汽车燃料，可使CO减少97％、HC减少72％、NOx减少39％、CO2减少24％、SO2减少90％。建立CNG加气站和CNG汽车改装这两个CNG应用关键问题在技术上、经济上都是可行的。北京市CNG燃料来源有保障。北京市车辆都比较适合使用CNG气体燃料。北京有很强的CNG汽车产业科技力量。对北京市当前发展CNG汽车产业提出了一些建议。     

Modeling Parent and Metabolite Fate and Transport in Subsurface Drained Fields With Directly Connected Macropores1

Abstract: Few studies exist that evaluate or apply pesticide transport models based on measured parent and metabolite concentrations in fields with subsurface drainage. Furthermore, recent research suggests pesticide transport through exceedingly efficient direct connections, which occur when macropores are hydrologically connected to subsurface drains, but this connectivity has been simulated at only one field site in Allen County, Indiana. This research evaluates the Root Zone Water Quality Model (RZWQM) in simulating the transport of a parent compound and its metabolite at two subsurface drained field sites. Previous research used one of the field sites to test the original modification of the RZWQM to simulate directly connected macropores for bromide and the parent compound, but not for the metabolite. This research will evaluate RZWQM for parent/metabolite transformation and transport at this first field site, along with evaluating the model at an additional field site to evaluate whether the parameters for direct connectivity are transferable and whether model performance is consistent for the two field sites with unique soil, hydrologic, and environmental conditions. Isoxaflutole, the active ingredient in BALANCE^® herbicide, was applied to both fields. Isoxaflutole rapidly degrades into a metabolite (RPA 202248). This research used calibrated RZWQM models for each field based on observed subsurface drain flow and/or edge of field conservative tracer concentrations in subsurface flow. The calibrated models for both field sites required a portion (approximately 2% but this fraction may require calibration) of the available water and chemical in macropore flow to be routed directly into the subsurface drains to simulate peak concentrations in edge of field subsurface drain flow shortly after chemical applications. Confirming the results from the first field site, the existing modification for directly connected macropores continually failed to predict pesticide concentrations on the recession limbs of drainage hydrographs, suggesting that the current strategy only partially accounts for direct connectivity. Thirty‐year distributions of annual mass (drainage) loss of parent and metabolite in terms of percent of isoxaflutole applied suggested annual simulated percent losses of parent and metabolite (3.04 and 1.31%) no greater in drainage than losses in runoff on nondrained fields as reported in the literature.