Stream Length Research Articles

Gravitational dark matter: Free streaming and phase space distribution

Gravitational dark matter (DM) is the simplest possible scenario that has recently gained interest in the early Universe cosmology. In this scenario, DM is assumed to be produced from the scattering of inflatons through the gravitational interaction during reheating. Gravitational production from the radiation bath will be ignored as our analysis shows it to be suppressed for a wide range of reheating temperatures $({T}_{\mathrm{re}})$. Ignoring any other internal parameters except the DM mass $({m}_{Y})$ and spin, a particular inflation model such as $\ensuremath{\alpha}$ attractor, with a specific scalar spectral index $({n}_{s})$ has been shown to uniquely fix the DM mass of the present Universe. For fermion type DM, we found the mass ${m}_{f}$ should be within $({10}^{4}--{10}^{13})\text{ }\text{ }\mathrm{GeV}$, and for boson/vector type DM, the mass ${m}_{s}/{m}_{X}$ turned out to be within $(1.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}14}/9.6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}14}--{10}^{13})\text{ }\text{ }\mathrm{GeV}$. Interestingly, if the inflaton equation of state ${\ensuremath{\omega}}_{\ensuremath{\phi}}\ensuremath{\rightarrow}1/3$, the DM mass also approaches towards unique value, ${m}_{f}\ensuremath{\sim}{10}^{10}\text{ }\text{ }\mathrm{GeV}$ and ${m}_{s}({m}_{X})\ensuremath{\sim}{10}^{3}(8\ifmmode\times\else\texttimes\fi{}{10}^{3})\text{ }\text{ }\mathrm{GeV}$. We further analyzed the phase space distribution ${f}_{Y}$ and free streaming length ${\ensuremath{\lambda}}_{\mathrm{fs}}$ of these gravitationally produced DM. ${f}_{Y}$, which is believed to encode important information about DM, contains a characteristic primary peak at the initial time where the gravitational production is maximum for both fermionic and bosonic DM. Apart from this fermionic phase space, the distribution function contains an additional peak near the inflaton and fermion mass equality (${m}_{Y}\ensuremath{\sim}{m}_{\ensuremath{\phi}}$) arising for ${\ensuremath{\omega}}_{\ensuremath{\phi}}>5/9$. Furthermore, the height of this additional peak turned out to be increasing with decreasing ${T}_{\mathrm{re}}$ and at some point, dominates over the primary one. Since reheating is a causal process and DM is produced during this phase, gravitational instability forming small-scale DM structures during this period will encode those phase space information and be observed at present. The crucial condition of forming such a small-scale DM structure during reheating suggests that the ${\ensuremath{\lambda}}_{\mathrm{fs}}$ must be less than the length scale associated with the mode reentering the Hubble radius at the end of reheating ${\ensuremath{\lambda}}_{\mathrm{re}}$, which has been analyzed in detail. We further estimate in detail the range of scales within which the above condition will be satisfied for different masses of scalar, fermionic, and vector DM. Finally, we end by stating the fact that all our results are observed to be insensitive on the parameter $\ensuremath{\alpha}$ of the inflaton potential within the allowed range set by the latest Planck and BICEP/Keck results.

Digital Hydrography Underestimates Stream Length and Leads to Underestimates of Trout Population Size

AbstractStream length is measured for many fisheries management applications. Characteristics of populations and habitats measured at field sites are commonly generalized to unsampled areas using estimates of stream length or stream network length. There are many ways to measure stream length, but map‐based stream length measurements are commonly used in fisheries applications even though they are known to be biased. We evaluated how length of headwater streams in Arizona may be underestimated by the National Hydrography Dataset and how that bias influences streamwide abundance estimates for adult Apache Trout Oncorhynchus apache. As expected, stream lengths measured using National Hydrography Dataset flowlines underestimated true length revealed by National Agricultural Imagery Program imagery on average 11.1% (SD = 4.1%), and this bias was higher in meadow versus forested habitats. The observed bias led to streamwide estimates of adult Apache Trout abundance that were only 88% on average (SD = 5%) of those made with more realistic imagery‐based stream measurements. As we have shown, high‐resolution imagery, now widely available, can be used to assess and quantify stream length bias, and we conclude that it is important to assess whether this bias has the potential to negatively impact important fishery management decisions.

Hydrologic Turnover Matters — Gross Gains and Losses of Six First‐Order Streams Across Contrasting Landscapes and Flow Regimes

AbstractGross gains and losses of stream water and the consequent hydrologic turnover may modify the composition of stream water and drive in‐stream ecological functioning. We evaluated over 500 breakthrough curves of conservative tracer additions to analyze the channel water balance resulting in gross gains and losses, net exchange, and hydrologic turnover. During the hydrological year 2019, seven tracer experiments had been carried out in six first‐order streams along 400 m study reaches. All streams are located in the Holtemme catchment (Central Germany) with three each dominated by forested and agricultural land use. Four of the six streams were characterized by net‐losing conditions. The overall median of gross exchange was five times higher than net exchange. On average, subsurface gains replaced 50% of the original stream water over less than one kilometer of stream length. We even observed cases where over 95% of the stream water turned over within 100 m. Gross exchange was relatively higher in forested than in agricultural streams. Patterns of exchange in the forested streams persisted spatially and were temporally independent of streamflow, whereas in the agricultural ones, variable spatial patterns and streamflow dependence occurred. Overall, moderate flow coincided with highest relative gross exchange. Our results support previous findings that in‐stream solute concentrations could heavily depend on location and magnitude of gains and losses. Gross exchange embodies a permanent but variable control of downstream solute concentrations interacting with the signal of biogeochemical activity. We highlight the importance to include reach‐scale hydrological processes in studies on nutrient spiraling.

Morphometric Interpretation for Sub-Basin Management Planning and Practices in Hassan District, Karnataka India Using GIS and Remote Sensing

Classification and categorization of water basins is essential in sustainable growth, planning and management. Implementing the modern strategic techniques over a wider area needs huge resources and proper planning. Hence, morphometric analysis can be used as necessary tool for prioritizing sub- watersheds in the present study. The study area encompasses 265 sq. km, which is divided into nine sub-basins, specifically Bannur (W-1), Conimarur (W-2), Hampapura (W-3), Harohalli (W-4), Kaneyar (W-6), Konanuru (W-7), Saraguru (W-8), and Torenuru (W-9) ranging from 8 to 64 km2. The Survey of Indian toposheets and Digital Terrain Model are utilized to explain the drainage characteristics. The study reveals dendritic stream arrangement of fourth to fifth order. The density of drainage ranged between 1.03 to 1.32 km/km2, suggesting that the drainage texture was coarse to moderate, but low infiltration and high runoff. The change in stream length ratio over time implies that geomorphological progress is approaching its end. The bifurcation ratios range from 0.5 to 2.58, indicating that the region has good lithological control over the stream system and whole sub-watersheds are classified as "normal”. The form factor and circulatory ratio suggest elongated to circular sub-watersheds. Thus, the results of this analysis would be useful for the basin management planning and groundwater development. Keywords: Morphometry, Aerial Aspects, Linear aspects, Relief aspects, Hassan District

Experimental and Numerical Simulations of Sediment in Fusre River Basin, Nepal

This study presents about the analysis of sediment generation of the ungauged basin Fusre basin by modeling and also with the help of rainfall simulator. Many rivers in Nepal are either ungauged or poorly gauged due to extreme complex terrains, monsoon climate and lack of technical and financial supports. The Soil and Water Assessment Tool (SWAT) was applied for watershed delineation of the Fusre basin and the basin delineated into seven sub-basin that generate the river network, which also provides the information like stream link, stream order, stream length, slope etc. The calibration was performed using data from 2003 to 2010 and validation for the period from 2011 to 2015 at a daily time step. The model performance was evaluated based on computed statistical parameters. For the calibration period of the discharge and sediment flow, the performance of the model was very good, with a coefficient of determination R2= 0.9528, Nash-Sutcliffe Efficiency NSE = 0.942, RMSE = 0.24, and Percent Bias= 14.78, Similarly, the continuous model performance for the validation period was good, with R2 = 0.8655, NSE = 0.925, RMSE = 0.275 and Percent Bias = 18.03. Also a series of laboratory experiments was also carried out by changing the land use, soil parameter, and rainfall intensity by varying depth of soil sample and slope for comparative study with model but just for performance of apparatus. The performance of rainfall simulator was good. From the experimental method the calculation value of coefficient of determination R2 is equal to 0.67, NSE value is equal to 0.865 and PBIAS was equal to 30. The performance of both experimental and simulated data was satisfactory.

Physical habitat in conterminous US streams and Rivers, part 2: A quantitative assessment of habitat condition

Rigorous assessments of the ecological condition of water resources and the effect of human activities on those waters require quantitative physical, chemical, and biological data. The U.S. Environmental Protection Agency’s river and stream surveys quantify river and stream bed particle size and stability, instream habitat complexity and cover, riparian vegetation cover and structure, and anthropogenic disturbance activities. Physical habitat is strongly controlled by natural geoclimatic factors that co-vary with human activities. We expressed the anthropogenic alteration of physical habitat as O/E ratios of observed habitat metric values divided by values expected under least-disturbed reference conditions, where site-specific expected values vary given their geoclimatic and geomorphic context. We set criteria for good, fair, and poor condition based on the distribution of O/E values in regional least-disturbed reference sites. Poor conditions existed in 22–24% of the 1.2 million km of streams and rivers in the conterminous U.S. for riparian human disturbance, streambed sediment and riparian vegetation cover, versus 14% for instream habitat complexity. Based on the same four indicators, the percentage of stream length in poor condition within 9 separate U.S. ecoregions ranged from 4% to 42%. Associations of our physical habitat indices with anthropogenic pressures demonstrate the scope of anthropogenic habitat alteration; habitat condition was negatively related to the level of anthropogenic disturbance nationally and in nearly all ecoregions. Relative risk estimates showed that streams and rivers with poor sediment, riparian cover complexity, or instream habitat cover conditions were 1.4 to 2.6 times as likely to also have fish or macroinvertebrate assemblages in poor condition. Our physical habitat condition indicators help explain deviations in biological conditions from those observed among least-disturbed sites and inform management actions for rehabilitating impaired waters and mitigating further ecological degradation.

Evaluation of Morphometric and Hypsometric Analysis of the Bagh River Basin using Remote Sensing and Geographic Information System Techniques

Water availability and scarcity are impacted by geomorphological changes that occur within a catchment. As a result, determining the influence of geomorphological processes on the catchment's hydrology requires a quantitative study of the catchment geometry. Approaches based on remote sensing (RS) and geographic information systems (GIS) have grown in popularity in recent years because they assist strategists and decision-makers in making accurate and effective choices and plans. For this research, the Bagh River basin was chosen. The study shows that GIS and RS data can be used to analyse and approximate the period and erosional operations' speed in a Bagh river basin for better design and maintenance. The method utilises a 30-metre shuttle radar topography mission digital elevation model (SRTM-DEM) for morphometric parameters and hypsometric analysis extraction that is both operative and time-saving. The thirteen morphometric parameters were applied to the Bagh catchment's linear, shape, and relief aspects. An elongated basin shape is suggested by the Re, Rc, and Ff. Statistical analysis shows that there is a good relationship between stream order and stream length, as well as stream order and stream number. The hypsometric curves' structure as well as estimated hypsometric integral results reflects the Bagh river basin's erosional stages. As a result, the study concludes that morphometric and hypsometric analysis findings may be useful to stakeholders participating in catchment development and management projects.

Identifying corridors of river recovery in coastal NSW Australia, for use in river management decision support and prioritisation systems.

By connecting corridors of river recovery, resilience can be built into river systems to mitigate against future floods and droughts driven by anthropogenic disturbance or climate extremes. However, identifying where these corridors can be built is still lacking in river management practice. The Open Access NSW River Styles database contains comprehensive information on geomorphic river condition and recovery potential. The database can be used to systematically analyse where corridors of river recovery could be created via conservation or rehabilitation. Analysis was undertaken in ArcGIS using the recovery potential layer along 84,342 km of freshwater stream length, across 20 catchments of coastal NSW. We identified 4,905 km of reach connections, defined as an upstream to downstream section of river that is connected end-to-end, and 17,429 km of loci connections defined as more isolated sections of river from which recovery can be seeded and extended into adjacent reaches. There was significant spatial variability in the types and lengths of connections made across the catchments. Some catchments have significant potential to build corridors of recovery along large sections of river, whereas other catchments are more fragmented. These results provide practitioners with a user-friendly distillation of where river conservation and rehabilitation activities could be focussed when working with river recovery in practice. Combined with local on-ground knowledge, this information forms an important input to evidence-based prioritisation and decision making in river management.

Analysis of drought conditions and their impacts in a headwater stream in the Central European lower mountain ranges

Headwaters represent a significant fraction of the global stream length and are important for streamflow quality and quantity. Since climate change is predicted to affect runoff generation processes fundamentally, it is essential to understand potential consequences for the water availability in headwater catchments. The Lehstenbach catchment, located in the Fichtel Mountains (Germany), represents many headwater catchments in the lower mountain ranges in Central Europe. This study’s primary objective is to predict and analyze potential shifts in the catchment’s water balance, estimate periods of hydrological drought conditions, and their characteristics. For this purpose, we used an integrated process-based hydrological model to represent surface/groundwater interactions and runoff generation mechanisms for the Lehstenbach catchment until 2100, using a Regional Climate Model Ensemble. The simulations indicate decreased water availability in summer and autumn, mainly due to increased evapotranspiration rates. The Minimum Environmental Flow (MEF), a quantitative measure of aquatic species’ exposition to abnormally low streamflow conditions, implies an increase of low flow conditions towards 2100. A first estimate indicates a possible increase of hydrological drought duration and intensity in the future. These findings suggest severe impacts on ecosystem health and services, such as decreasing water availability, leading to consequences like forest and wetland degradation and declining biodiversity. These findings can be used to implement suitable mitigation strategies to reduce climate change effects on the headwater ecosystems, such as water shortage for irrigation and drinking water supply and loss of flora and fauna.

Morphometric Analysis on Vanniyar Basin in Dharmapuri, Southern India, Using Geo-Spatial Techniques

The Vanniyar basin is located in Dharmapuri district, South India, and is severely affected by climate change. Due to changing climatic conditions and resulting poor precipitation characteristics, this district has received less rainfall over the last three decades (Dharmapuri District Statistical Hand book 2020). The objective of this investigative study is to utilize morphometric techniques and analyze their properties using GIS and image processing techniques. The linear, aerial, and relief morphometric aspects of the Vanniyar basin are analyzed. From the preliminary investigation, the study area occupies the Archean group of rocks. The drainage pattern of the Vanniyar basin is sub-dendritic to dendritic and classified into fifth-order drainage basins. The mean drainage density of the Vanniyar basin is 1.95 km/km2, which indicates that the basin has very permeable soil with intermediate drainage and low to moderate relief. The circularity ratio value reveals that the basin is circular with high to moderate relief and a structurally controlled drainage system. The elongation ratio value reveals that the basin is characterized by high susceptibility to erosion and sediment load. The stream length ratio between the streams of different orders of the Vanniyar basin shows a change in each sub-basin, indicating late youth stage of geomorphic development. From these research studies, farmers in the Vanniyar basin, river Cauvery may now comprehend their drainage basin’s geohydrological characteristics.

Using Automated Seepage Meters to Quantify the Spatial Variability and Net Flux of Groundwater to a Stream

AbstractWe utilized 251 measurements from a recently developed automated seepage meter (ASM) in streambeds in the Nebraska Sand Hills, USA to investigate the small‐scale spatial variability of groundwater seepage flux (q) and the ability of the ASM to estimate mean q at larger scales. Small‐scale spatial variability of q was analyzed in five dense arrays, each covering an area of 13.5–28.0 m2 (169 total point measurements). Streambed vertical hydraulic conductivity (K) was also measured. Results provided: (a) high‐resolution contour plots of q and K, (b) anisotropic semi‐variograms demonstrating greater correlation scales of q and K along the stream length than across the stream width, and (c) the number of rows of points (perpendicular to streamflow) needed to represent the groundwater flux of areas up to 28.0 m2. The findings suggest that representative streambed measurements are best conducted perpendicular to streamflow to accommodate larger seepage flux heterogeneity in this direction and minimize sampling redundancy. To investigate the ASM's ability to produce accurate mean q at larger scales, seepage meters were deployed in four stream reaches (170–890 m), arranged in three to six transects (three to eight points each) per reach across the channel. In each reach, the mean seepage flux from ASMs was compared to the seepage flux from bromide tracer dilution. Agreement between the two methods indicates the viability of a modest number of seepage meter measurements to determine the overall groundwater flux to the stream and can guide sampling for solutes and environmental tracers.

Remote sensing and GIS based morphometric characterization of Bichiya river watershed of Rewa district, MP

Remote Sensing & GIS technique was used for extracting geomorphological characteristics of watersheds. Its application provides an efficient and accurate means for evaluation of these characteristics. Drainage system delineation is important to better understand hydrologic system, water resource management and its planning. Morphometric analysis of any drainage basin in a systematic method has a great importance in understanding hydrological behavior of the basin. Morphometric parameters describe the topology, the structure, the platform and the relief of basin area. Its characteristics are commonly used for planning & management of regional hydrological models. Physical characteristics of watershed provides some pre-information mainly runoff, stages of its development and soil loss productivity characteristics. Morphometric parameters viz; Stream order, Stream length, Bifurcation ratio, Drainage density, Drainage frequency, Drainage texture, Form factor, Circularity ratio, Elongation ratio and Compactness ratio etc. were measured for prioritization and compound parameter values were calculated and finally prioritization of seven sub watersheds was marked. Morphometric parameters are relevant and useful to identify various characteristics of drainage Watershed. Patterns, shape, stage of stream, as well as help to correlate with lithological characteristics. GIS and Remote sensing techniques have proved to be accurate and efficient tool in drainage delineation and their updation. Stream order show the Watershed is 5th order watershed with dendritic drainage pattern and with homogeneous nature and some area with parallel drainage pattern. The average Bifurcation Value of study area 2.98, usually these values are common in the areas where geologic structures do not exercise a dominant influence on the drainage pattern. The Drainage density of Watershed is 1.75indicating moderate drainage densities. The Moderate drainage density indicates the Watershed is permeable. It also shows the Texture of Watershed is Moderate.

Assessment of active tectonics in the Siwalik basin around the Subansiri river, NE India

In this paper we evaluate the morphotectonics of the area around the Subansiri river in north-eastern India. Research focuses on understanding the impacts on areas experiencing active tectonic deformation. It also explains the variety of kinematics observed in the area from the Miocene to the present. The tectonics can explain some structures related to the extensional tectonics predominant in the region and the development of the minor and major morph structures driven by faults with different kinematics. We developed a morphotectonic evolutionary model for the area based on the morphotectonic analysis and geological mapping. Morphotectonic indices used to evaluate the tectonic activeness in this study are Mountain Front sinuosity Index, Valley Floor Width to Valley Height Ratio, Asymmetry Factor, Transverse Topographic Symmetry Factor, Mountain Front Steepness Index, Basin Shape Index and Stream Length Gradient Index. There are numerous lineaments present in the study area which are trending in NW-SE and NE-SW direction.

Quantitative estimation of drainage characteristics of the Pohru Catchment, Kashmir valley, India: a remote sensing and GIS based approach

The applicability of remotely sensed data and geographic information systems (GIS) for catchment area characterization are found of enormous utility in soil and water management. Morphometric parameters were evaluated using Digital Elevation Model to characterize the hydrological behaviour. The catchment is seventh order with sub-dendritic to sub-parallel pattern and high drainage density upstream. Youthful geomorphic stage, fine drainage texture and high runoff probability eventually influence the low lying areas. High relief and steep surface gradient makes faster surface water circulation with less water-table recharge resulting into more surface flow towards low lying areas to be severely affected by this extra amount of unusual water. Heavy rainfall and maximization of first-order streams in uplands triggers the likelihood of sudden flash-floods in the downstream areas. The stream order of the catchment is primarily regulated by the lithological and physiographical setting of the locale. The area of study under observation is designated as the seventh order catchment with the calculated drainage density value being as 3.077 km/km2. The changing stream length proportion from lower to higher order explains that the area is yet to reach the phase of geomorphic maturity. The elongation ratio (Re) of Pohru catchment is 0.75, which indicates steep ground slope and high relief. The drainage texture of the Pohru catchment is 34.171 indicating very fine drainage texture, resulting by the impact of various geomorphological processes of the area. To minimize the catchment degradation and future risk, proper treatment should be given to the low lying areas where drainage density is naturally low and death of streams is more common due to human intervention.

Morphometric analysis for prioritizing sub-watersheds of Murredu River basin, Telangana State, India, using a geographical information system

The Murredu watershed in Telangana State was chosen for the morphometric and land use/land cover (LULC) analysis in this current study. Geographical information system (GIS) and remote sensing (RS) techniques can estimate the morphometric features and LULC analysis of a catchment. A total of fourteen sub-watersheds (SWs) were created from the watershed (SW 1 to SW 14), and sub-watersheds were prioritized based on morphometric and LULC features. Evaluation of various morphometric characteristics such as linear aspects, relief aspects, and aerial aspects has been carried out for every sub-watershed to prefer ranking. Four parameters were utilized for the LULC analysis to rank and prioritize sub-watersheds. The sub-watersheds were categorized into three groups as low, medium, and high, for soil and water conservation priority based on morphometric and LULC analysis. Using morphometric analysis, higher priorities have been assigned to SW 12 and SW 1, while using LULC analysis, higher priorities have been assigned to SW 9 and SW 11. SW 10 and SW 13 are the most common sub-watersheds that fall within the same priority while using morphometric and LULC analysis. The coefficient of regression results reveals that stream length and stream order, and also stream number and stream order, have a strong association. The deployment of soil and water conservation measures may be conducted in the high-priority sub-watersheds.

Surface drainage features identification using LiDAR DEM smoothing in agriculture area: a study case of Kebumen Regency, Indonesia

ABSTRACT Digital Elevation Model (DEM) is the most vital data to generate drainage networks and to provide critical terrain factors and hydrologic derivatives, such as slope, aspect, and streamflow. The accuracy of generated drainage features is extensively dependent on the quality and resolution of DEM, such as LiDAR-derived DEM. Contrary, it has a high level of roughness and complexity. Thus, smoothing methods are sometimes employed to conquer the roughness. This paper presents feature-preserving DEM smoothing (FPDEM-S) and edge-preserving DEM smoothing (EPDEM-S) approaches to smooth surface complexity in kind of preserving small drainage features using the 0.5 m – resolution LiDAR DEM of the Kedungbener River area in Kebumen Regency, Indonesia. Entangling linear morphometric factors, those smoothing approaches delivered a slight difference of stream number, with the FPDEM-S stream length ratio performing 7% better tendencies. The FPDEM-S method perormed better than EPDEM-S in this study area to provide an optimal smoothed LiDAR DEM at certain parameter values. Summarising that two smoothing methods approaches performed similar characteristics of watershed as an oval structure close to the circular shape. Also, it can be revealed that the watershed did not reach maturity phase.

Anthropogenic Intensity-Determined Assembly and Network Stability of Bacterioplankton Communities in the Le'an River.

Bacterioplankton are essential components of riverine ecosystems. However, the mechanisms (deterministic or stochastic processes) and co-occurrence networks by which these communities respond to anthropogenic disturbances are not well understood. Here, we integrated niche-neutrality dynamic balancing and co-occurrence network analysis to investigate the dispersal dynamics of bacterioplankton communities along human activity intensity gradients. Results showed that the lower reaches (where intensity of human activity is high) had an increased composition of bacterioplankton communities which induced strong increases in bacterioplankton diversity. Human activity intensity changes influenced bacterioplankton community assembly via regulation of the deterministic-stochastic balance, with deterministic processes more important as human activity increases. Bacterioplankton molecular ecological network stability and robustness were higher on average in the upper reaches (where there is lower intensity of human activity), but a human activity intensity increase of about 10%/10% can reduce co-occurrence network stability of bacterioplankton communities by an average of 0.62%/0.42% in the dry and wet season, respectively. In addition, water chemistry (especially NO3–-N and Cl–) contributed more to explaining community assembly (especially the composition) than geographic distance and land use in the dry season, while the bacterioplankton community (especially the bacterioplankton network) was more influenced by distance (especially the length of rivers and dendritic streams) and land use (especially forest regions) in the wet season. Our research provides a new perspective of community assembly in rivers and important insights into future research on environmental monitoring and classified management of aquatic ecosystems under the influence of human activity.

Dark matter and low scale leptogenesis in a flavor symmetric neutrino two Higgs doublet model (nu 2HDM)

We have studied dark matter (DM) phenomenology, neutrinoless double beta decay (NDBD) and realized low scale leptogenesis in an extension of Standard Model (SM) with three neutral fermions, a scalar doublet and a dark sector incorporating a singlet scalar and a Dirac singlet fermion. A generic model based on A_4times Z_4 flavor symmetry including five flavons is used to explain both normal and inverted hierarchy mass patterns of neutrino and also to accommodate the dark matter mass. In this extension of the nu 2HDM, the effective neutrino mass observed in 0nu beta beta is well within the experimental limit provided by KamLAND-ZEN. In order to validate DM within this model, we have checked relic abundance and free streaming length of the dark sector component, i.e. a Dirac singlet fermion constraining its mass in keV range. More importantly we have also realised low scale leptogenesis simultaneously within this framework and also the Dirac CP phase gets constrained with the results. Bound from LFV is also incorporated in order to constrain the Yukawa couplings. More importantly, we have analyzed the dependence of various phenomenology with decay parameter for different choice of arbitrary complex angles.

Stream or discharge? Analysing hydrosocial relations in the Waimapihi Stream to innovate urban water politics

AbstractIn Te Whanganui‐a‐Tara Wellington, Aotearoa New Zealand, 95% of the length of urban streams are piped and buried, leaving them hidden. Technocratic management regimes separate streams into discrete parts, and thus overlook important relationships that can improve or maintain the state of streams. This paper takes a hydrosocial perspective on urban streams, exploring connections between water flow, infrastructure, and social structures and institutions to consider the buried Waimapihi Stream. Drawing on interviews, it examines implications of the Waimapihi's legislative status and management for its headwaters at the Waimapihi Reserve and the stormwater piped section, and considers the potential for daylighting the piped section.

Identification of Artificial Levees in the Contiguous United States

AbstractArtificial levees are anthropogenic structures designed to hydrologically disconnect rivers from floodplains. The extent of artificial levees in the contiguous United States (CONUS) is unknown. To better estimate the distribution of artificial levees, we tested several different geomorphic, land cover, and spatial variables developed from the National Elevation Dataset, the National Land Cover database, and the National Hydrology Dataset HR Plus. We used known levee locations from the National Levee Database as training data. We tested machine learning and general logistic models’ ability to detect artificial levees in a 100‐year hydrogeomorphic floodplain of seven geographically diverse 8‐digit HUC basins. Random forest models outperformed other models in predicting the location of levees using variables representing geomorphic attributes, land cover, and distance from streams ranging in size between stream order one through six. To demonstrate the ability of our approach to detect unknown levees, we conducted a leave‐one‐out cross‐validation in the lower Mississippi Basin using approximately 1,100 artificial levees. This approach detected known levees constituting 94% of the total levee length in the basin. Scaling up to the CONUS, we applied a high performing (overall accuracy of 97%) random forest model using land cover and stream order variables. We detected 182,213 km of potential levees, mostly along streams of order 2–6 in the Mississippi and Missouri River Basins, indicating that the national levee database contains 20.4% of levee length. Potential levees and those documented in the national levee database modify 2% of the total length of streams in the contiguous United States.