Regional flood frequency analysis using kernel- based fuzzy clustering approach

Regionalization approaches are widely used in water resources engineering to identify hydrologically homogeneous groups of watersheds that are referred to as regions. Pooled information from sites (depicting watersheds) in a region forms the basis to estimate quantiles associated with hydrological extreme events at ungauged/sparsely gauged sites in the region. Conventional regionalization approaches can be effective when watersheds (data points) corresponding to different regions can be separated using straight lines or linear planes in the space of watershed related attributes. In this paper, a kernel-based Fuzzy c-means (KFCM) clustering approach is presented for use in situations where such linear separation of regions cannot be accomplished. The approach uses kernel-based functions to map the data points from the attribute space to a higher-dimensional space where they can be separated into regions by linear planes. A procedure to determine optimal number of regions with the KFCM approach is suggested. Further, formulations to estimate flood quantiles at ungauged sites with the approach are developed. Effectiveness of the approach is demonstrated through Monte-Carlo simulation experiments and a case study on watersheds in United States. Comparison of results with those based on conventional Fuzzy c-means clustering, Region-of-influence approach and a prior study indicate that KFCM approach outperforms the other approaches in forming regions that are closer to being statistically homogeneous and in estimating flood quantiles at ungauged sites. Key Points <list id=''wrcr20861-list-0001'' list-type=''plain''> <list-item id=''wrcr20861-li-0001''>Kernel-based regionalization approach is presented for flood frequency analysis <list-item id=''wrcr20861-li-0002''>Kernel procedure to estimate flood quantiles at ungauged sites is developed <list-item id=''wrcr20861-li-0003''>A set of fuzzy regions is delineated in Ohio, USA

Evaluating Methods to Predict Streamflow at Ungauged Sites using Regional Flow Duration Curves: A Case Study

Precise information on streamflows is of major importance for planning and monitoring of water resources schemes related to hydro power, water supply, irrigation, flood control, and for maintaining ecosystem. Engineers encounter challenges when streamflow data are either unavailable or inadequate at target locations. To address these challenges, there have been efforts to develop methodologies that facilitate prediction of streamflow at ungauged sites. Conventionally, time intensive and data exhaustive rainfall-runoff models are used to arrive at streamflow at ungauged sites. Most recent studies show improved methods based on regionalization using Flow Duration Curves (FDCs). A FDC is a graphical representation of streamflow variability, which is a plot between streamflow values and their corresponding exceedance probabilities that are determined using a plotting position formula. It provides information on the percentage of time any specified magnitude of streamflow is equaled or exceeded. The present study assesses the effectiveness of two methods to predict streamflow at ungauged sites by application to catchments in Mahanadi river basin, India. The methods considered are (i) Regional flow duration curve method, and (ii) Area Ratio method. The first method involves (a) the development of regression relationships between percentile flows and attributes of catchments in the study area, (b) use of the relationships to construct regional FDC for the ungauged site, and (c) use of a spatial interpolation technique to decode information in FDC to construct streamflow time series for the ungauged site. Area ratio method is conventionally used to transfer streamflow related information from gauged sites to ungauged sites. Attributes that have been considered for the analysis include variables representing hydrology, climatology, topography, land-use/land- cover and soil properties corresponding to catchments in the study area. Effectiveness of the presented methods is assessed using jack knife cross-validation. Conclusions based on the study are presented and discussed. (C) 2015 The Authors. Published by Elsevier B.V.

Analytical approach to quantile estimation in regional frequency analysis based on fuzzy framework

Regional frequency analysis is widely used for estimating quantiles of hydrological extreme events at sparsely gauged/ungauged target sites in river basins. It involves identification of a region (group of watersheds) resembling watershed of the target site, and use of information pooled from the region to estimate quantile for the target site. In the analysis, watershed of the target site is assumed to completely resemble watersheds in the identified region in terms of mechanism underlying generation of extreme event. In reality, it is rare to find watersheds that completely resemble each other. Fuzzy clustering approach can account for partial resemblance of watersheds and yield region(s) for the target site. Formation of regions and quantile estimation requires discerning information from fuzzy-membership matrix obtained based on the approach. Practitioners often defuzzify the matrix to form disjoint clusters (regions) and use them as the basis for quantile estimation. The defuzzification approach (DFA) results in loss of information discerned on partial resemblance of watersheds. The lost information cannot be utilized in quantile estimation, owing to which the estimates could have significant error. To avert the loss of information, a threshold strategy (TS) was considered in some prior studies. In this study, it is analytically shown that the strategy results in under-prediction of quantiles. To address this, a mathematical approach is proposed in this study and its effectiveness in estimating flood quantiles relative to DFA and TS is demonstrated through Monte-Carlo simulation experiments and case study on Mid-Atlantic water resources region, USA. (C) 2015 Elsevier B.V. All rights reserved.

Maximum magnitude estimation considering the regional rupture character

The main objective of the paper is to develop a new method to estimate the maximum magnitude (M (max)) considering the regional rupture character. The proposed method has been explained in detail and examined for both intraplate and active regions. Seismotectonic data has been collected for both the regions, and seismic study area (SSA) map was generated for radii of 150, 300, and 500 km. The regional rupture character was established by considering percentage fault rupture (PFR), which is the ratio of subsurface rupture length (RLD) to total fault length (TFL). PFR is used to arrive RLD and is further used for the estimation of maximum magnitude for each seismic source. Maximum magnitude for both the regions was estimated and compared with the existing methods for determining M (max) values. The proposed method gives similar M (max) value irrespective of SSA radius and seismicity. Further seismicity parameters such as magnitude of completeness (M (c) ), ``a'' and ``aEuro parts per thousand b `` parameters and maximum observed magnitude (M (max) (obs) ) were determined for each SSA and used to estimate M (max) by considering all the existing methods. It is observed from the study that existing deterministic and probabilistic M (max) estimation methods are sensitive to SSA radius, M (c) , a and b parameters and M (max) (obs) values. However, M (max) determined from the proposed method is a function of rupture character instead of the seismicity parameters. It was also observed that intraplate region has less PFR when compared to active seismic region.

Regional hydrological impacts of climate change: implications for water management in India

Climate change is most likely to introduce an additional stress to already stressed water systems in developing countries. Climate change is inherently linked with the hydrological cycle and is expected to cause significant alterations in regional water resources systems necessitating measures for adaptation and mitigation. Increasing temperatures, for example, are likely to change precipitation patterns resulting in alterations of regional water availability, evapotranspirative water demand of crops and vegetation, extremes of floods and droughts, and water quality. A comprehensive assessment of regional hydrological impacts of climate change is thus necessary. Global climate model simulations provide future projections of the climate system taking into consideration changes in external forcings, such as atmospheric carbon-dioxide and aerosols, especially those resulting from anthropogenic emissions. However, such simulations are typically run at a coarse scale, and are not equipped to reproduce regional hydrological processes. This paper summarizes recent research on the assessment of climate change impacts on regional hydrology, addressing the scale and physical processes mismatch issues. Particular attention is given to changes in water availability, irrigation demands and water quality. This paper also includes description of the methodologies developed to address uncertainties in the projections resulting from incomplete knowledge about future evolution of the human-induced emissions and from using multiple climate models. Approaches for investigating possible causes of historically observed changes in regional hydrological variables are also discussed. Illustrations of all the above-mentioned methods are provided for Indian regions with a view to specifically aiding water management in India.

A recursive multi-scaling approach to regional flood frequency analysis

Scaling approaches are widely used by hydrologists for Regional Frequency Analysis (RFA) of floods at ungauged/sparsely gauged site(s) in river basins. This paper proposes a Recursive Multi-scaling (RMS) approach to RFA that overcomes limitations of conventional simple- and multi-scaling approaches. The approach involves identification of a separate set of attributes corresponding to each of the sites (being considered in the study area/region) in a recursive manner according to their importance, and utilizing those attributes to construct effective regional regression relationships to estimate statistical raw moments (SMs) of peak flows. The SMs are then utilized to arrive at parameters of flood frequency distribution and quantile estimate(s) corresponding to target return period(s). Effectiveness of the RMS approach in arriving at flood quantile estimates for ungauged sites is demonstrated through leave-one-out cross-validation experiment on watersheds in Indiana State, USA. Results indicate that the approach outperforms index-flood based Region-of-Influence approach, simple- and multi-scaling approaches and a multiple linear regression method. (C) 2015 Elsevier B.V. All rights reserved.

Evaluation of the Index-Flood Approach Related Regional Frequency Analysis Procedures

Index-flood related regional frequency analysis (RFA) procedures are in use by hydrologists to estimate design quantiles of hydrological extreme events at data sparse/ungauged locations in river basins. There is a dearth of attempts to establish which among those procedures is better for RFA in the L-moment framework. This paper evaluates the performance of the conventional index flood (CIF), the logarithmic index flood (LIF), and two variants of the population index flood (PIF) procedures in estimating flood quantiles for ungauged locations by Monte Carlo simulation experiments and a case study on watersheds in Indiana in the U.S. To evaluate the PIF procedure, L-moment formulations are developed for implementing the procedure in situations where the regional frequency distribution (RFD) is the generalized logistic (GLO), generalized Pareto (GPA), generalized normal (GNO) or Pearson type III (PE3), as those formulations are unavailable. Results indicate that one of the variants of the PIF procedure, which utilizes the regional information on the first two L-moments is more effective than the CIF and LIF procedures. The improvement in quantile estimation using the variant of PIF procedure as compared with the CIF procedure is significant when the RFD is a generalized extreme value, GLO, GNO, or PE3, and marginal when it is GPA. (C) 2015 American Society of Civil Engineers.

Repeat-Associated Fission Yeast-Like Regional Centromeres in the Ascomycetous Budding Yeast Candida tropicalis

The centromere, on which kinetochore proteins assemble, ensures precise chromosome segregation. Centromeres are largely specified by the histone H3 variant CENP-A (also known as Cse4 in yeasts). Structurally, centromere DNA sequences are highly diverse in nature. However, the evolutionary consequence of these structural diversities on de novo CENP-A chromatin formation remains elusive. Here, we report the identification of centromeres, as the binding sites of four evolutionarily conserved kinetochore proteins, in the human pathogenic budding yeast Candida tropicalis. Each of the seven centromeres comprises a 2 to 5 kb non-repetitive mid core flanked by 2 to 5 kb inverted repeats. The repeat-associated centromeres of C. tropicalis all share a high degree of sequence conservation with each other and are strikingly diverged from the unique and mostly non-repetitive centromeres of related Candida species-Candida albicans, Candida dubliniensis, and Candida lusitaniae. Using a plasmid-based assay, we further demonstrate that pericentric inverted repeats and the underlying DNA sequence provide a structural determinant in CENP-A recruitment in C. tropicalis, as opposed to epigenetically regulated CENP-A loading at centromeres in C. albicans. Thus, the centromere structure and its influence on de novo CENP-A recruitment has been significantly rewired in closely related Candida species. Strikingly, the centromere structural properties along with role of pericentric repeats in de novo CENP-A loading in C. tropicalis are more reminiscent to those of the distantly related fission yeast Schizosaccharomyces pombe. Taken together, we demonstrate, for the first time, fission yeast-like repeat-associated centromeres in an ascomycetous budding yeast.

Efecto de exposición a deshidrataci��n del coyolillo (Cyperus rotundus L.) sobre su densidad y el crecimiento y rendimiento del cultivo de Ajonjol�� (Sesamun indicum L.) c.v. Cuyumaqui

En 1991 se estableci�� un ensayo en ��poca seca (20-30 Abril) en el Centro Experimental del Algod��n, Posoltega, Chinandega, con los objetivos de determinar si el efecto de diferentes tiempos de exposición a deshidrataci��n del coyolillo (Cyperus rotundus L.) al arar el suelo en seco con arado de discos para reducir su densidad, se mantiene hasta la ��poca de postrera y asimismo si tiene efecto sobre el crecimiento y rendimiento del cultivo de ajonjol�� (Sesamun indicum L.). Para tales efectos se us�� un dise��o de Bloques Completos al Azar (B.C.A.) con seis tratamientos y seis repeticiones, evalu��ndose el factor tiempo de exposición a deshidrataci��n del coyolillo. Los tratamientos consistieron en realizar la pr��ctica de arar el suelo en seco en las diferentes parcelas a intervalos de dos d��as, empezando el 20 de abril con el tratamiento diez d��as y terminando el 30 de abril con el tratamiento cero d��as de exposición, aplic��ndose ese mismo d��a el riego en todo el ��rea. Los tub��rculos quedaron expuestos a la deshidrataci��n durante 1O, 8, 6, 4, 2 y O d��as. Despu��s de establecer lo tratamientos, se sembr�� el 2 de mayo el cultivo de soya (Glycine max (L.) Merr.) (��poca de primera) y el cultivo de ajonjol�� del presente ensayo el 5 de septiembre (��poca de postrera). Las variables evaluadas consistieron para coyolillo: densidad y para ajonjol��: altura de plantas, n��mero de hojas, di��metro del tallo y rendimiento. El an��lisis de varianza mostr�� significancia estad��stica (P < 0.05) en densidad a los 14, 28 y 42��� dds, altura de plantas 42 y 89 dds, n��mero de hojas 28 dds y di��metro del tallo 42 dds. El contraste olinomial planificado present�� significancia estad��stica para la tendencia lineal (P <0.05) para densidad a los 14, 28.y 42.dds, altura de plantas 14, 42y 89 dds, n��mero de hojas 28 y 42 dds, di��metro del tallo 28 y 42 dds y rendimiento. Los mayores valores de medias para densidad de coyolillo se presentan en el tratamiento cero d��as y los menores valores en el tratamiento ocho d��as de exposición a deshidrataci��n del coyolillo para las tres fechas de muestreo. Todas las variables evaluadas en el cultivo de ajonjol�� presentan los mayores valores en el tratamiento ocho d��as y los menores valores en el tratamiento cero d��as de exposición, excepto altura 14 dds, donde el mayor valor se presenta en el tratamiento cero d��as y el 'menor valor en el tratamiento seis d��as de exposición a deshidrataci��n del coyolillo. Los an��lisis de regresi��n realizados entre la variable independiente tiempo de exposición y las variables dependientes del coyolillo y el cultivo del ajonjol��, mostraron una respuesta de tendencia lineal negativa en densidad de coyolillo y tendencia lineal positiva en todas las variables del cultivo de ajonjol��, excepto altura 14 dds que present�� una tendencia lineal negativa.

Ensayo regional de h��bridos experimentales de sorgos (Sorghum bicolor L. Moench.), durante el a��o 2001

La siembra de sorgo en monocultivo, en Centroam��rica, ocupa un 39% de su superficie cultivada, lo cual significa unas 11 O 000 ha. Casi en su totalidad, este sistema de cultivo se realiza utilizando semilla h��brida. La semilla utilizada para la siembra, es importada por no poderse producir en la regi��n debido a que los progenitores no tienen adaptaci��n tropical. Esta situaci��n hace que la semilla no este accesible a todos los productores. El presente vivero permitir�� seleccionar h��bridos que se puedan reproducir en la regi��n y que las empresas locales puedan ponerlos accesibles. El vivero incluy�� 29 h��bridos experimentales m��s un testigo local. El dise��o utilizado fue l��tice simple 6 x 5 con 4 repeticiones, ��rea experimental y parcela ��til fue de 7 m2��� Las variables a medir fueron: rendimiento de grano, altura de planta, d��as a floraci��n, largo y exerci��n de panoja, d��as a madurez fisiol��gica, tolerancia a plagas, enfermedades y acame. Los ensayos se enviaron a cuatro localidades .. Solamente se recibieron datos de San Andr��s (El Salvador) y CNIA (Nicaragua). Se realiz�� un an��lisis de varianza por localidad y un combinado de las dos localidades. En San Andr��s, el h��brido ATX 623 x 96 A 635, de grano blanco, produciendo 861 O kg ha�� 1 , fue el mejor. En el an��lisis combinado de ambas localidades, los h��bridos: ATC 629 x 86EO 361 (7758 kg ha��') y ATX 623 x 96CA635 (7445 kg ha��1), ambos de grano blanco, fueron los mejores, rindiendo un 21% m��s que el testigo local. La media general fue de 5783 kg ha��, y el coeficiente de variaci��n de 18.5%.

Nicaragua: potencial faro regional para el dise��o y evaluaci��n de agroecosistemas agroecol��gicos

En este art��culo se expresa la imperiosa necesidad de convertir los sistemas de producci��n convencionales en fincas agroecol��gicas como alternativa para que la nueva empresa agraria garantice la implementaci��n de buenas pr��cticas productivas y de manufactura que contribuyan a ofrecer productos de calidad e inocuos y servicios con un enfoque de calidad total. Desde esta perspectiva, la Univer sidad Nacional Agraria oferta un programa de formaci��n de talentos humanos a diferentes niveles en agroecolog��a, que consta de cinco grandes proyectos. Tambi��n, se expresa el andamiaje jur��dico nacional actual para implementar la pol��tica de la producci��n agroecol��gica y org��nica, as�� como los pasos para el dise��o y evaluaci��n de sistemas agroecol��gicos del presente siglo, cuyos t��picos son: grupos y caracter��sticas de agro ecosistemas, tipos de agro ecosistemas complejos o diversificados, biodiversidad a considerar para el dise��o de sistemas diversificados sostenibles en el tr��pico, ejes aconsiderar para el dise��o de sistemas diversificados sostenibles en el tr��pico que incluya un manejo integral de los recursos naturales, procesos para el dise��o de sistemas diversificados sostenibles en el tr��pico, pasos y herramientas para el dise��o de sistemas diversificados sostenibles en el tr��pico oferentes de bienes y servicios a la sociedad, ejemplos de sistemas diversificados sostenibles en el tr��pico oferentes de bienes y servicios, desaf��os para el dise��o de sistemas diversificados sostenibles en el tr��pico y la evaluaci��n de sistemas diversificados sostenibles. El prop��sito es fomentar una agricultura resiliente al cambio clim��tico, productiva y eficiente (energ��tica, econ��mica y biodiversa), pero tambi��n que garantice la seguridad alimentaria y nutricional.

Efeitos ambientais da medida provis��ria 1.956

Consultoria Legislativa - ��rea XI - Meio Ambiente e Direito Ambiental, Organiza����o Territorial, Desenvolvimento Urbano e Regional.

PICES Press, Vol. 15, No. 1, January 2007

PICES science ��� 2006 (pdf, 0.1 Mb) 2006 Wooster Award (pdf, 0.1 Mb) Thank you note from the Past-Chairman of PICES (pdf, 0.1 Mb) A comparison of regional mechanisms for fish production: Ecosystem perspectives (pdf, 0.3 Mb) 2006 CREAMS/PICES international workshop and summer school (pdf, 0.2 Mb) PICES Calendar (pdf, 0.2 Mb) 2006 Harmful Algal Bloom Section annual workshop (pdf, 0.1 Mb) 2006 PICES Workshop on ���Modeling iron biogeochemistry and ocean ecosystems��� (pdf, 0.1 Mb) Strolling through the NEMURO ecosystem model (pdf, 0.1 Mb) Climate and marine birds and mammals in the North Pacific (pdf, 0.2 Mb) Photo highlights of the PICES Fifteenth Annual Meeting (pdf, 3.5 Mb) Recent trends in waters of the subarctic NE Pacific: Cooler and fresher in summer of 2006 (pdf, 0.2 Mb) The state of the western North Pacific in the first half of 2006 (pdf, 0.3 Mb) Latest and upcoming PICES publications (pdf, 0.3 Mb) A seven-year effort of the PICES CCCC MODEL Task Team culminates in a dedicated issue of Ecological Modelling (pdf, 0.1 Mb) Japan joins PICES Marine Metadata Federation (pdf, 0.3 Mb) Argo: A 2006 status report (pdf, 0.3 Mb) New Chairmen in PICES (pdf, 0.2 Mb) PICES Interns (pdf, 0.2 Mb)

Aquaculture Asia, Vol. 8, No. 1, pp.1-58, January-March 2003

*Table of Contents* Sustainable Aquaculture Fertilization, soil and water quality management in small-scale ponds part II:Soil and water quality management S. Adhikari Fisheries and aquaculture activities in Nepal Tek Gurung Peter Edwards writes on rural aquaculture: A knowledge-base for rural aquaculture Farmers as Scientists: Commercialization of giant freshwater prawn culture in India M.C. Nandeesha Aquaculture in reservoir fed canal based irrigation systems of India ��� a boon for fish production K.M. Rajesh, Mridula R. Mendon, K. N. Prabhudeva and P. Arun Padiyar Research and Farming Techniques Production and grow-out of the Black-lip pearl oyster Pinctada margaritifera Idris Lane Breeding of carps using a low-cost, small-scale hatchery in Assam, India: A farmer proven technology S.K. Das Genes and Fish: Hybridisation ��� more trouble than its worth? Graham Mair Breeding and culture of the sea cucumber Holothuria scabra in Vietnam R. Pitt and N. D. Q. Duy The potential use of palm kernel meal in aquaculture feeds Wing-Keong Ng Using a Simple GIS model to assess development patterns of small-scale rural aquaculture in the wider environment Simon R. Bush Aquaculture fundamentals: Getting the most out of your feed Simon Wilkinson Marine finfish section Status of marine finfish aquaculture in Myanmar U Khin Kolay Regional training course on grouper hatchery production Aquatic Animal Health Advice on aquatic animal health care: Problems in Penaeus monodon culture in low salinity areas Pornlerd Chanratchakool

STREAM Journal, Vol. 1, No. 1, pp. 1-12. January-March 2002

CONTENTS: Learning from each other about conflict, by Ronet Santos. E-learning to support knowledge sharing in aquatic resources, by Robert T. Raab and Jonathan Woods. Livelihood strategies, gender and participation in aquaculture: findings from participatory research in northwestern Sri Lanka, by Lindsay J. Pollock and David C. Little. Farming of giant tiger shrimp in northern central Vietnam, by Jesper Clausen. Interacting with stakeholders and policy-makers, by To Phuc Tuong. The role of nutrition communications in meeting the nutritional challenges of the Asia-Pacific region, by Georgina Cairns. (PDF has 16 pages.)