Natural Drainage Research Articles

Hydrological Analysis and Statistical Modelling of Swat River Basin for Flood Risk Assessment

The climatic variations and anthropogenic activities in the river catchments worldwide are causing severe weather events and flooding. The narrowing down of natural floodplains/ channels, land-use changes, deforestation and mushroom urbanisation with unplanned infrastructure development are aggravating causes of severe storms and floods, especially in developing countries. Hydrological studies, flood modelling and statistical flood frequency analysis are considered imperative to assess the hazards/ risks of flooding and their mitigation measures. Estimating predicted storms/ floods for different return periods can give a reasonable idea about the frequency of storm events. This study analysed the Swat river basin to determine the predicted return periods with expected storm/ flood in its catchment and Swat river. The weather and rainfall in the Swat river basin remain unpredictable. Historically, it has seen peak precipitation of 150mm – 274mm and a super flood of 10050 m3/sec in 2010, more than its 200 years return period. Flood frequency and statistical analysis using Log Pearson 3 (LP3), Generalized Extreme Value (GEV) and Gumbel Maximum (Gumb-Max) on Easy Fit software and Log Pearson 3 equations have predicted weather instability in the Swat basin with the prediction of super flood like 2010 happening in 40 years return period. Construction of Swat expressway on elevated embankment will disturb the natural drainage pattern and likely result in inundation in flood plains due to inadequate capacity of cross drainage structures to withstand the spontaneous flash flooding. However, these have been designed on 100 years return period. However, probability density and hazard functions show a lesser probability of any mega hazard; therefore, cross drainage structures and crisscrossing channels in the river catchments may be planned on a minimum 100 years return period as an economic/ reasonable safe limit. Still, additional structural/ non-structural measures should augment these for efficient flood-fighting like plantation and maintenance of drainage structures, construction of small dams/ reservoirs for swift water management in case of a flash flood and placement of rescue/ relief resources at accessible points as per flood zoning.

Dumping on Waters: The Lacunae in Waste Management in the Niger Delta, Nigeria

The need to provide additional information towards adopting a well-developed and standard waste management scheme in Yenagoa Metropolis prompted this study. It was based on waste source, transferring process and stakeholders, location and elevation, ecological sensitivity, risk factors and general people’s wellbeing. The operation of waste stakeholders and their activities were recorded on daily basis through Mass-Volume Analysis method using weighbridge scale for twelve (12) months (January–December 2021); Student-T test (t) and Two-Ways ANOVA were used to analyzed results. Results confirmed that, Etelebou is a government approved open-air-dumpsite for both liquid and solid waste; the Brikari Nig. Ltd. Company is transferring 50% solid waste while the Patico and Saturday (21.8% each) merged top commuters transferring liquid waste to the central Dumpsite. In general, the open-air-dumpsite is receiving an average 546.830 tonnes of waste annually consisting of 91% solid and 9% liquid with less than 10% material recovery for reuse and recycling. At 5% (ά=0.05%) interval, the difference between weekly waste stream and wastes stakeholders (commuters) is insignificant (0.324<2.57); so also waste stream per monthly summary (0.32<2.14). We therefore discouraged the current dumping operation at Etelebou due to its elevation (5 meters below sea level), proximity to natural drainage with a porous geological structure that posses’ ecological health risk on flora and fauna. Therefore, the study advises alternative disposal site and recommends controlled incineration, compositing and waste recycling for best practice in low regions like the Niger Delta of Nigeria.

Engineering Investigation of the Geological Problems for Old Mosul City by Remote Sensing and GIS

Mosul is the provincial capital of the Nineveh Governorate located on the River Tigris, near the ancient city of Nineveh. The study focused on the urban planning of the old Mosul City, which was built hundreds of years ago, or even thousands of years, and its cultural, security, economic, and environmental importance. The city was designed according to the topography of the undulating area, and the slopes and tops of the hills were used for building houses, and the valleys that represent water drainage systems were used to make zukaks. This is evidenced by the passage of the waters of the runways and their movement from the highest areas and their flow to the main streets that represent the highest levels of drainage systems or the main valleys that eventually flow into the Tigris River. This unique design was of great importance in the cleanliness of the city, especially in the rainy seasons. The city was washed from the highest point to the bottom, and there were no floods inside the city except in relatively newly built areas, such as the Tawafa area, which was named as a result of its immersion in water during the winter and spring seasons. The obtained results of the study show a significant match between the natural drainage systems and the urban planning of the old city. This congruence appeared as a result of some geotechnical problems in the buildings and main streets, as there was a large inclination for most of the relatively high commercial buildings in and towards these streets. In these streets over time, there has been numerous successive collapse and settlement. The cause may be attributed to the weakness of the filling materials, as well as the flow of groundwater through them because this water follows the ancient course of the main valleys.

Variability of Water Exchange in the Hyporheic Zone of a Lowland River in Poland Based on Gradientometric Studies

Abstract The Moszczenica is a lowland river, which is a third-order river with a length of 55 km; it flows into the Bzura River in central Poland. The objective of this study was to evaluate two important factors in the exchange between surface water and groundwater in the hyporheic zone: a considerable change in water flow conditions and various origins of riverbed sections, natural and artificial. To identify the spatial variation of the hydraulic gradient in the hyporheic zone of the river, a gradientmeter was applied. The measurements show that at low water stages, upwelling was dominant, with an evidently inactive zone, whereas downwelling was inconsiderable. However, the morphology of the riverbed changed during the flood flow, and downwelling clearly dominated. Upwelling zones retained their activity despite a major change in hydrological conditions. Present studies on the artificially dug Moszczenica Canal have documented outflow of water from an artificial medieval canal to a naturally formed drainage base. This means that despite the passage of hundreds of years, the natural drainage base of the Moszczenica River is still active. Studies have demonstrated the applicability of the gradientmeter for evaluating the interaction between surface and groundwaters in the hyporheic zone.

Genome‐wide analysis resolves the radiation of New Zealand's freshwater Galaxias vulgaris complex and reveals a candidate species obscured by mitochondrial capture

AbstractAimFreshwater fish radiations are often characterized by multiple closely related species in close proximity, which can lead to introgression and associated discordance of mitochondrial and nuclear characterizations of species diversity. As a case in point, single locus nuclear versus mitochondrial analyses of New Zealand's stream‐resident Galaxias vulgaris complex have yielded conflicting phylogenies. Our goal is to use genome‐wide divergence patterns among these fishes to evaluate the potential role of mitochondrial capture in obscuring species diversity, and to understand how ancient and anthropogenic drainage modification explain this diversity.LocationFreshwater ecosystems of New Zealand.MethodsWe generate and analyse a genome‐wide dataset comprising 52,352 SNPs across 187 Galaxias specimens to resolve the phylogeny of this recent fish radiation. We conduct phylogenetic, PCA, STRUCTURE, and ABBA‐BABA analyses to evaluate the evolutionary relationships of lineages in the context of natural and anthropogenic river drainage alterations.ResultsIn addition to the 11 previously recognized stream‐resident lineages, genome‐wide data reveal a twelfth candidate species (G. ‘Pomahaka’), apparently obscured by introgressive mitochondrial capture. We identify additional examples of mito‐nuclear discordance and putative mitochondrial capture, likely mediated by geological and anthropogenic modification of drainage boundaries.Main conclusionsOur study highlights the need for genome‐wide approaches for delimiting freshwater biodiversity. Genetic data also reveal the influence of drainage history on freshwater biodiversity, including the rapid divergence of recently fragmented fish populations, and the conservation genetic risks of anthropogenic translocations events.

The Use of 0° and 70° Endoscopes in Maxillary Antrostomy.

Performing an effective maxillary antrostomy is critical to improving chronic maxillary sinusitis symptomatology. Incomplete dissection of the uncinate process and failure to incorporate the natural drainage pathway may lead to recirculation and need for revision surgery. The purpose of this study is to determine if 70° endoscopes provide added value in determining incomplete dissection or residual disease. Prospective study of 35 sinuses from 18 patients undergoing FESS for Chronic Rhinosinusitis (CRS) between 11/1/2020 and 4/30/2021. Two fellowship trained Rhinologists initially performed maxillary antrostomies exclusively using a 0° endoscope, then transitioned to a 70° endoscope. Surgeons completed a survey to assess completion of the antrostomy prior to use of 70° endoscope, sino-nasal anatomy, and difficulty of the operation. Intraoperative photographs before and after using a 70° endoscope were evaluated by a third party. Pre-operative CT scans were used to evaluate the sphenoid keel-caudal septum-nasolacrimal duct (SK-CS-NL) angle. Of 35 sinuses from 18 patients all 35 sinuses had CRS with 48.5% having nasal polyposis and 42.9% having active infection. There was residual inflammatory tissue in the anterior maxillary sinus, including polypoid tissue and uncinate process prior to using the 70° endoscope in 82.9% of sinuses. The natural drainage pathway was not incorporated into the dissection in 28.6% of sinuses before converting to 70° endoscope. Incomplete dissection with 0° endoscope was not associated with nasal polyposis (P = .086) or uncinate position (0.741). Narrow SK-CS-NL angles were associated with incomplete dissection of the anterior maxillary sinus with 0° endoscope (16.0° ± 3.0° vs 20.6° ± 3.2°; P = .013). Use of 70° endoscope in maxillary antrostomy may be beneficial in identifying and resecting disease within the anterior maxillary sinus that may otherwise be difficult to find using a 0° endoscope. This is especially true in patients with narrow nasolacrimal duct positioning.

Analysis of Morphometric Parameters of the Drainage Network and Road Network of the Ribeirão Paraíso Watershed, Jataí - GO

Studies related to morphometric analysis are extremely important for hydrogemorphological knowledge in watersheds. However, most rural roads are not considered in these analyses. Therefore, the objective of this article was to verify if the relations between the drainage network, the relief parameters, and the road network indicate changes in the drainage dynamics of a watershed occupied by agricultural use. The sugarcane crop is an influencing factor in the increase in rural roads in the watershed and arrived in the region from 2009 onwards. Therefore, the time frame of 2005, 2010, 2015, and 2020 was chosen for the investigation. Bibliographic research and quantitative measurements were used as a methodology to extract information from the drainage network and road network through morphometric parameters. For this, ArcGIS® 10.6.1 and Excel 2019 software were used. As a result, it was identified that the watershed has a fourth-order river hierarchy; its area is 903.6 km², the drainage density is 0.45 km/km², and when rural roads were included in the analysis in 2005, 2010, 2015, and 2020, corresponding to 2.1, 2.2, 2.4, and 3.1 km/km², respectively. Thus, the average density of roads in the period was 84% higher when considering only natural drainage, increasing mainly after the insertion of sugarcane in the scenario. Therefore, it is concluded that the analysis of morphometric parameters is essential to generate new knowledge about the studied watershed. Rural roads should be included in the analysis since they influence the hydrogeomorphological aspects of the watersheds. In this case, the increase in drainage density is directly related to the increase in roads and sugarcane. With the inclusion of these in the morphometric analysis, the watershed increases its drainage capacity, significantly altering the hydrological response in hydrographic watersheds.

Assessing the urban road waterlogging risk to propose relative mitigation measures

Road waterlogging has become a significant issue in developed cities due to the rapid urbanization in China. It is necessary to accurately identify the risk of waterlogging in urban roads and propose appropriate mitigation measures. This study considered urban waterlogging as a landscape ecological process. The road waterlogging risk was simulated and estimated using the Minimum Cumulative Resistance model under natural drainage conditions. The results indicate that: 1) The Minimum Cumulative Resistance model effectively assesses the waterlogging risk for each road segment. The roads in and around the central city have relatively higher waterlogging risks. The overall length of high-risk roads is 918.7 km, accounting for 31.3 % of the total. 2) There are 448 potential runoff paths and 448 inflow sites. The city's center and its north and south sides are the primary locations of the high-risk runoff paths and the inflow sites. 3) Road waterlogging is significantly more affected by the land-use types of High density residential and Industrial under rainfall intensities of a-year, 2-year, 3-year, and 5-year return periods. And the effects of various land-use types on waterlogging vary with the rainfall intensity. Using landscape ecology theory to analyze the risk of road waterlogging is a novel method to address urban waterlogging issues. This approach provides a more accurate approach to identifying the urban waterlogging risks and can be applied to developed cities suffering from waterlogging to help decision-makers devise the most effective mitigation measures.

Concha bullosa mucocele disguising as a nasal tumor in an epistaxis patient: A case report

Concha bullosa is the most common anatomical variant of middle turbinate in both children and adults. When the natural drainage of concha bullosa is obstructed, it leads to the formation of mucocele. It is confusing with nasal tumor when the entire nasal cavity gets occupied. Concha bullosa mucocele and profuse epistaxis is rarely found in the same patient. Both pathologies require appropriate management for the early recovery of the patient and prevent severe complications like concha bullosa mucopyocele from concha bullosa mucocele and hypovolemic shock from profuse epistaxis. We present a 74-year-old female who presented with profuse epistaxis from the left nasal cavity due to concha bullosa mucocele filling the right nasal cavity and pushing nasal septum towards left side which was confused with nasal tumor.

Investigation and Estimation of Groundwater Level Fluctuation Potential: A Case Study in the Pei-Kang River Basin and Chou-Shui River Basin of the Taiwan Mountainous Region

The analysis of the spatiotemporal characteristics of groundwater level variation is a prerequisite for evaluating groundwater potential or underpinning aquifer sustainability development in hydrogeological engineering practices. This study explores the dominant influencing factors that control groundwater dynamics and develops an estimation of groundwater level fluctuation (GWLF) potential in the complex aquifer systems of mountainous areas. Eight natural environmental factors, including slope, drainage density, land use, lithology, hydraulic conductivity, porosity, groundwater depth, and regolith thickness, have been selected as influencing factors, and the feature scores for different factors associated with GWLF potential were given with the expert scoring method. The weighting coefficients of individual influencing factors for wet/dry seasons were determined using the pseudo-inverse method based on the groundwater level data of 18 well stations observed from 1 November 2011 to 31 October 2019 in Taiwan mountainous areas. The results show that the weighting coefficients of these factors in controlling GWLF potential are variable and affected by seasonal and annual rainfall conditions. Based on the determined weighting coefficients, the spatial distribution of GWLF potential can be effectively produced. Finally, the simulated GWLF potential results were verified by comparing the observed data. The verification result demonstrates that the developed model can predict the spatial GWLF distribution based on the groundwater level data from a few wells.

An analysis of multidimensional poverty in Nigeria using statistical and geospatial modelling: A case study of Jigawa state

Despite recent advances in reducing poverty across the world, millions of people remain on the verge of or already living in severe multidimensional poverty especially in third world nations. The poor in Nigeria suffer from a feeling of voicelessness, helplessness, mistreatment, a complete lack of capacity to influence important choices that impact their life, and a lack of social networking inside state and societal organisations. The goal of this research is to conduct a geospatial analysis of Nigeria’s multidimensional poverty and to identify the geospatial distribution pattern of poverty in Jigawa State as a case study. As a result, comprehend the causes of Jigawa’s complicated poverty condition and to create the state’s first ever poverty map. Also, to look at the country’s poverty trends, with a particular emphasis on Jigawa. The National Bureau of Statistics provided the headcount poverty statistics for Nigerian states, which were downloaded and analysed using simple geospatial approach. The findings revealed a dynamic pattern in Nigerian state poverty from 1996 to 2019. The distribution of poverty in Jigawa state, as a case study, revealed that physical and natural environment resources play a critical role in the state’s high poverty rate. Natural drainage, fertile soil, flat topography, and vegetation pattern all aid other people’s poverty levels in different parts of the state. Future study will examine the linking between environmental, social, religious, and political factors and multidimensional poverty using a geospatial method to map the state’s poverty, which has consistently ranked at the bottom of the Nigeria States Poverty Index.

Geomorphological classification of the landscape in urban areas: hints from some study cases in Italy

Urban geomorphology is a recent topic and its theory and practice require continuous updates. However, few studies have focused on issues specifically connected with the cartographic representation of geomorphological processes and landforms in urban environments, with the aim of reconstructing and clarifying the original physical landscape. Recent studies conducted in Italian cities have tried to propose new strategies for detecting and mapping human induced modifications to the topography, and anthropogenic landform classification has been recently deepened in the revised Italian national guidelines for geomorphological mapping, proposed by AIGeo and ISPRA. In this work, natural landforms modified by man and new artificial landforms are explored and compared in three Italian cities: Genoa, Rome and Perugia. In these urban areas, human activities have remodeled the topographic surface and become the most important landscape moulder. Many reliefs have been erased, whereas thick layers of anthropogenic deposits covered most of the natural landforms, with the result, for example, of hiding or greatly modifying the natural drainage network. Geomorphological studies in urban environments allow the reconstruction of the physical landscape before human modifications and the implementation of innovative methodological tools, and an effective legend to represent the urban landforms and their evolution over time.

Hydraulic performance of mole drains and validation of steady-state drainage spacing equations for Mollisols

Central Santa Fe (Argentina) is a low-gradient region with impaired natural drainage. Extreme rainfall events are increasingly common and cause significant economic losses to agriculture. There is a growing interest in the use of mole drainage as a cost-effective strategy to mitigate such impacts. However, there is no information available that assists with mole drainage design, installation and maintenance, or the field assessment of a system’s hydraulic performance. This work was conducted with the dual objective of evaluating the hydraulic performance of an existing mole drains system and validating Hooghoudt’s steady-state drainage spacing equation for Mollisols. Three treatments representing different hydrologic conditions were tested; namely: (T1) rainfall of 360-min duration and intensity of 23 mm h-1, (T2) surface water ponding achieved through rainfall intensity of 50 mm h-1 and water depths between 50 and 100 mm, and (T3) similar surface water ponding conditions to treatment T2, but achieved through a rainfall intensity of 65 mm h-1 and either one (T3A) or two (T3B) sequential rainfall events. Following application of water, drainage commenced at 270 and 21 min for T1 and T2, and at 40 and 30 min for T3A and T3B, respectively. Mean drained depths were 1 and 3 mm for T1 and T2, respectively. For T3A, the mean drained depth was about one-third that measured for T3B (2.5 vs. 8.5 mm). Under a dry antecedent soil moisture condition, and rainfall intensity of 23 mm h-1, downward water movement was better described by piston flow. As surface water depth and soil water content increased, water flowed preferentially through the fissures and leg slots created by the mole plough implement at installation. Soil fissuring increased field hydraulic conductivity by factors between approximately three and ten. A 4 m mole drains spacing system was considered to be appropriate for managing excess water in the studied soil type. If the contribution of soil fissures to the field hydraulic conductivity can be accounted for, the Hooghoudt’s equation applied to two-layered soils may be used with confidence to help optimise the design of mole drainage systems for Mollisols. Application of this numerical approach, however, will require that the resultant spacing between mole drains be increased by about 30–40 %. Such an allowance will reduce installation costs and will not compromise the hydraulic efficiency of the drainage system.

Contaminant Discharge From Outfalls and Subsequent Aquatic Ecological Risks in the River Systems in Dhaka City: Extent of Waste Load Contribution in Pollution.

Dhaka, the capital city, which is the nerve center of Bangladesh, is crisscrossed by six different rivers. A network of peripheral rivers connects the city and functions as a natural drainage system for a massive amount of wastewater and sewage by the increased number of inhabitants impacting the overall environmental soundness and human health. This study intended to identify and characterize the outfalls along the peripheral rivers of Dhaka city with the assessment of different pollution indices such as comprehensive pollution index (CPI), organic pollution index (OPI), and ecological risk indices (ERI). The study evaluated the status of the pollution in the aquatic system in terms of ambient water quality parameters along the peripheral rivers due to discharge from outfalls with a particular focus on waste load contribution. Among the identified outfalls, the majority are industrial discharge (60%), and some are originated from municipal (30%), or domestic sewers (10%). Water quality parameters such as suspended solids (SS), 5-day biochemical oxygen demand (BOD5), and Ammoniacal Nitrogen (NH3-N) for most of the peripheral rivers deviated by as much as 40–50% from industrial discharge standards by the environment conservation rules, Bangladesh, 1997. Based on the CPI, the rivers Buriganga, Dhaleshwari, and Turag could be termed as severely polluted (CPI > 2.0), while the OPI indicated heavy organic pollutant (OPI > 4) contamination in the Dhaleshwari and Buriganga rivers. The associated pollution indices demonstrate a trend for each subsequent peripheral river with significant pollution toward the downstream areas. The demonstrated waste loading map from the outfalls identified sources of significant environmental contaminants in different rivers leading to subsequent ecological risks. The study outcomes emphasize the necessity of systematic investigation and monitoring while controlling the point and non-point urban pollution sources discharging into the peripheral rivers of Dhaka city.

Groundwater modelling of a shallow aquifer for the assessment of water logging: A case study of the Cebala‐Borj Touil irrigation perimeter, northern Tunisia

AbstractThe Cebala‐Borj Touil (Cebala) Plain in Tunisia is a large perimeter with an area of 3,200 ha. In 1990, a drainage and irrigation system was installed. The groundwater system is complex due to the proximity to the sea, the low slope, and the low performance of natural drainage. It is characterized by shallow groundwater and soil water logging. The flooded area is controlled by natural and artificial factors. The natural parameters are the flat slope and the soil texture. The man‐made problems are caused by inappropriate irrigation and drainage deficiency. The numerical groundwater flow simulation model FEFLOW (Finite Element Subsurface Flow System) was used to simulate the groundwater depth variability. The calculated water table depth ranged from less than 0.5 m from the ground surface to more than 8 m. Based on the calibrated model, several management scenarios were investigated to study the possibilities to mitigate the problem of water logging in the perimeter. The model results showed that improving the drainage efficiency and reducing the irrigation amounts could solve the water logging problem, but not entirely. For the low flooded parts, a pumping option could be considered. The final management scheme might include the combination of all the tested management scenarios.

Assessment of Flood Risk and Mapping of Flood Risk Zones in Yenagoa, Bayelsa State, Nigeria

In recent years, most Nigerian cities have experienced several major flood episodes with serious catastrophes. Hence, this study was carried out to assess and map flood risk zones in Yenagoa. The Geographic Information System (GIS) and remote sensing technologies were used in generating and analyzing data to identify the different flood risk zones in Yenagoa. Environmental indices such as flood heights, land elevation and land cover images were analyzed using geo-statistical tools such as map overlay operations to produce a flood risk map. The flood risk map produced and the ground truthing carried out confirmed that the highest flood risk are located within residential areas where about 32% of the built-up area was vulnerable to moderate or high risk of flooding. The study revealed that both natural and anthropogenic factors are responsible for the severe flooding experienced in Yenagoa, especially due to heavy precipitation, elevation of the area, poor waste disposal, and inadequate urban development control amongst other factors. The city was classified into three flood risk zones-high, moderate and low, with about 48% of the area being either at moderate or high risk of flooding. It is therefore recommended that the Ministry of Physical and Urban Development should carryout proper urban development control, which will prevent building on flood plains, wetlands and natural drainage channels.

A Case Study of the 12 July 2021 Bhagsunath (McLeod Ganj) Flash Flood in Dharamshala, Himachal Pradesh: A Warning Against Constricting Natural Drainage

Abstract Extreme rainfall events leading to the occurrence of flash floods and cloudbursts are common in the Himalaya. Bhagsu nala in McLeod Ganj area of Dharamshala township, Himachal Pradesh has witnessed the worst flash flood in the morning of 12th July 2021 causing damage to property and infrastructure in the region. Though the catchment area of the Bhagsu nala is very small of the order of ~ 2.8 km2, the geomorphological and hydrological characteristics of the catchment are susceptible to peak flow for a shorter duration. Further, the anthropogenic intervention of slopes in the form of constricting natural drainage has reduced the carrying capacity of the nala, exaggerating the consequences of the flash flood.

Precision Endonasal Endoscopic Surgery of the Frontal Recess Cells and Frontal Sinus Guided by the Natural Sinus Drainage Pathway.

BackgroundThe endoscopic endonasal approach to removing lesions in the nasal cavity and sinuses has become the modern first choice. However, if endoscopic surgery is performed without proper knowledge of sinus anatomy, there is a risk of residual lesions, recurrence, and even serious complications. Therefore, this article illustrates the importance of precise sinus opening guided by the natural sinus drainage pathway, using the anatomy of the frontal sinus (FS) and the frontal recess (FR) cells as an example.MethodA total of 82 sides cadaveric heads were dissected and analyzed, and the natural drainage pathways of the FR cells and FS were observed at 0°and 70°nasal endoscopic views, and the findings were summarized. The data of 79 patients who accepted endonasal endoscopic surgery (EES) guided by natural sinus drainage pathways to remove mucoceles in our department from January 2015 to January 2021 were retrospectively analyzed.ResultsTwo natural drainage pathways of the FR cells were discovered, identified, and named the medial pathway of the FR (MPFR) and the lateral pathway of the FR (LPFR). The 79 patients who accepted EES to remove mucoceles through the natural drainage pathways of FR cells and the FS showed significant improvement in clinical symptoms, and none of them had recurrence after surgery without serious complications.ConclusionThe EES of the FR cells and FS through the natural drainage pathways to remove the mucoceles facilitates exposure of the cells without residual lesions and without serious complications.

When the natural pendulum swings between drought and flood, a bifunctional natural drainage system safeguards a mountain village’s water security incessantly for centuries

When the natural pendulum swings between drought and flood, a bifunctional natural drainage system safeguards a mountain village’s water security incessantly for centuries

A roadmap for sustaining biodiversity and ecosystem services through joint conservation and restoration of northern drainage basins

Abstract1. Freshwater ecosystems and their biota are more seriously threatened than their marine and terrestrial counterparts. A solution to halt increasing negative impacts of anthropogenic development would be to reconsider the basics of nature conservation (i.e. protection of pristine and near‐pristine areas) and restoration (i.e. returning an impacted site to as natural condition as possible) through inclusion of the knowledge on abiotic and biotic dynamics of rivers draining pristine catchments. In boreal and Arctic regions, such comparisons are still possible because in addition to harbouring strongly modified drainage basins, some of the most natural drainage basins are also situated in these high‐latitude areas.2. A suitable approach for simultaneous planning of joint river conservation and restoration would be to (i) examine how well different kinds of rivers are covered by existing protected area networks and (ii) to restore parts of degraded rivers to facilitate colonization by aquatic and riparian organisms that have found havens in existing protected areas. This joint approach is a two‐way road, as conservation and restoration benefit from each other by allowing river networks to facilitate movements of organisms and matter, thereby mimicking natural riverine meta‐systems in anthropogenically modified drainage basins, with restored sites acting as stepping‐stones between protected areas.3. We argue that existing policy instruments should consider the fact that river ecosystems are spatially and temporally dynamic meta‐systems. These characteristics should be given due attention in conservation and restoration rather than relying on a static approach where a snap‐shot classification of river reaches is thought to be enough without considering underlying ecological dynamics. Taking ecological dynamics into account would contribute to sustainable management and maintenance of biodiversity and ecosystem services.