Tributaries Research Articles

Experimental Study on the Accumulation Characteristics and Submergence Degree of Three-Dimensional Granular Rock Landslides in Shallow-Water Areas

This study combined the characteristics of rock mass structure, channel characteristics of main and tributary rivers, and flow conditions in the Three Gorges Reservoir area of the Yangtze River and designed and constructed a three-dimensional granular rock shallow-water landslide surge model test system under dynamic water flow conditions. The main influencing variables, including the volume of the landslide body, the inclination of the sliding surface, the water depth of the channel, and the flow velocity, were determined. A four-factor four-level orthogonal test design and a single-factor test design were combined to determine 28 sets of test conditions. Based on existing field surveys and physical model test simulation results, the motion process of the landslide body was divided into four stages: starting, accelerating, slowly accelerating or decelerating, and rapidly decelerating. The variations in the motion and velocity of the landslide body over time were determined by analyzing the image sequence extracted using a high-speed camera. The morphological characteristics of the landslide accumulation body were analyzed, and the submerged rate of the landslide body was statistically calculated. The relationship between the maximum bottom width of the landslide underwater accumulation body and the volume of the underwater accumulation body was established.

Estimation of river discharge using Monte Carlo simulations and a 1D hydraulic model based on the artificial multi-segmented rating curves at the confluence of two rivers

During extreme floods caused by climate change, reliable flow discharge data are essential for successful reservoir operation to mitigate downstream flood damage. Generally, the flow discharge is computed using the rating curve (RC) established from the relationship between the flow rate and water stage level. Determining the parameters of rating curves is subject to uncertainties related to the difficulties and limitations of flow monitoring in covering a wide range of flow variations. Especially at river confluences, the uncertainties are pronounced when floods occur owing to several factors such as roughness change, backwaters, and levee overflow. The Seomjin River Basin in Korea suffered from flood inundation that occurred at the tributary confluence during an extreme flood in 2020. To identify a reliable flow rate of the main stream and tributary, this study proposes an indirect flow assessment scheme using a 1D hydrodynamic simulation model to find the best simulated water level in an iterative manner based on Monte Carlo (MC) simulations. With a large amount of discharge data generated from random-number combinations, it is possible to obtain the best results automatically by specifying the reliability limitation considering the uncertainty of the predetermined RC parameters associated with the roughness coefficient. Nash Sutcliffe Efficiency (NSE) was incorporated to evaluate the reproduced water level to meet the threshold specified for NSE ≥ 0.75. The simulated flowrates computed from the revised RC and roughness coefficients revealed an error range of 8%–36.6% compared with the design flood. The approach proposed in this study is applicable for determining the valid parameters necessary to create a revised RC at an existing water level gauge station, where the uncertainties of the RC are pronounced, particularly in the vicinity of the channel confluence.

Spatial Distribution of Contaminants in Glacial Streams and River Tributaries in the Ecologically Sensitive Regions of Gilgit Baltistan, Pakistan

Spatial Distribution of Contaminants in Glacial Streams and River Tributaries in the Ecologically Sensitive Regions of Gilgit Baltistan, Pakistan

Morfometría de una cuenca de los Andes Centrales, San Juan, Argentina: evaluación de los factores condicionantes del terreno a la ocurrencia de aluviones

The present work aims to determine flash flood occurrence prone areas, in the Jáchal river basin, San Juan Province, Argentina. The Jáchal river basin covers ~29,000 km2 and has a perimeter of ~2,400 km, while the eponymous river extends for nearly 570 km. It is a 7th order basin according to Strahler’s classification, subdivided into four 6th order sub-basins. Various morphometric basin characteristics are analysed and some basic and derived parameters are calculated. These calculations allow predicting the basin behaviour due to heavy rainfall, which translates into large volumes of water with peak flows capable of generating significant flash floods. The basin has a torrential character, so in case of intense rainfall the terrain conditions would contribute to increasing the flow of the main rivers. An inventory of alluvial deposits was carried out and their relationship with the conditioning variables of the terrain was evaluated. At the confluence zones, the river tributaries show more intense overflows than the main collector. This promotes the generation of flash floods. The areas most likely to be affected by flash flood events correspond to low-humidity, east-facing slightly rough terrains, with slopes of up to 15° as well as low-lying flood plain sectors, and at the confluence of tributaries with the main rivers. Populated centres and provincial and national routes are prone to be affected by alluvial events in the study area.

Morphometric variations among Opsaridium microlepis (Günther, 1864) from Lake Malaŵi migrating to different rivers for breeding

Fish is an important resource in Malawi as a source of food for the majority as it provides affordable source of dietary animal protein as well as income. A number of fish species in the Malawi water bodies have their population dwindling. One of the species under serious threat of extinction is the Opsaridium microlepis - a potamodromous fish species that migrate to the rivers during its spawning period and its management seems a nightmare. A number of studies reveal contrasting results on genetic makeup and morphological aspect of this fish species. With changes in the ecosystems of the rivers connecting Lake Malawi, coupled with absence of strong management measures in the major rivers adjoining the lake, problems have arisen in the conservation of potamodromous fish species. This necessitated the present study to investigate if the morphological features of stocks of O. microlepis are the same or not and if they have changed to adapt to changes in the ecosystems. One hundred and eleven O. microlepis fish samples were collected from Linthipe River (48), Bua River (59) and North Rumphi River (4) monthly from March to August 2020 using trawled and static gillnets. Twenty-four morphometric characteristics were measured to determine if any morphological differences existed among the fish samples from the three rivers. Principal component analysis (PCA) was used to compare morphology of the fish. Results of the study showed no significant morphological differences among stocks from the three rivers, implying that O. microlepis in these rivers belong to same stock morphologically. The study reveals that the species do not differ morphologically even though they migrate to different rivers for breeding. The study further notes that numerous activities taking place along the tributary rivers (as observed during the study) such as modification of fishing gears as well as fishing methods and the deterioration of the spawning grounds due to siltation from soil erosion caused by deforestation and agriculture, are putting the potamodromous fish species such as O. microlepis under serious threat. The study recommends that the populations of O. microlepis from the rivers can be managed equally since they are morphologically similar. Adopting uniform catchment management and sustainable exploitation of O. microlepis (such as regulations on mesh sizes and fishing methods, closing the rivers from fishing activities during spawning period, river bank and catchment management and restoration) with the aim of conserving the stocks from further overexploitation in these rivers is recommended so that the communities and the people at large continue to utilize the resource sustainably and at the same time, sustaining their livelihood. Key words: Potamodromous, Linthipe River, Bua River, North Rumphi River, principal component analysis

High mammalian diversity on the Las Piedras River tributary of Madre de Dios, Peru: An annotated list of species including comments on biogeography and regional conservation.

Several mammal inventories have been reported from the lowland Amazon of Madre de Dios, Peru, but few have been reported for the Las Piedras River. Here we present a list of mammal species from the Las Piedras River. Over a period of seven years (2013–2020), we recorded the presence of mammal species, excluding bats and small rodents, using camera traps and opportunistic sightings. Our study area was near the Huascar-Las Piedras River confluence, 58 km north of the Madre de Dios River and covering an area of 22,430 ha. We recorded 60 species belonging to seven orders, 26 families, and 53 genera, including novel records for the Las Piedras tributary. Notable records reported include Leopardus cf. tigrinus (Schreber, 1775), Galictis vittata (Schreber, 1776), Saguinus imperator subgrisecens (Lönnberg, 1940), Cebuella niveiventris (Lönnberg, 1940), Cyclopes thomasi (Linnaeus, 1758), Coendou ichillus Voss & da Silva, 2001, and Caluromys lanatus (Olfers, 1818).

Contrasted Antibiotics and Pesticides Occurrence in Fish Exposed In Situ to Urban Effluents: A 20-Day Caging Experiment.

Urban freshwater ecosystems receive a wide array of organic pollutants through wastewater-treatment plant (WWTP) discharges and agricultural runoff. Evaluating the fate and effects of antibiotics and pesticides can be a challenging task, especially the effects on freshwater vertebrates because of their abilities to metabolize and excrete these chemicals and because of their high mobility and escape behavior when exposed to stressful environmental conditions. In the present study, 37 wild gudgeons (Gobio gobio) were caged for a period of up to 20 days, upstream and downstream of a WWTP effluent discharge in the Orge River (a tributary of the Seine River, France). Levels of pesticides and antibiotics in fish muscles were monitored weekly and compared with environmental contamination (water and sediments). Our results highlighted a slight bioaccumulation of pesticides in the gudgeon muscles at the downstream site after 20 days of exposure. Concerning antibiotics, ofloxacin was the most detected compound in fish muscles (85% of occurrence) and ranged from undetectable to 8 ng g-1 dry weight. Antibiotic levels in fish muscle were not higher at the downstream site and did not increase with exposure duration, despite high levels in the water (up to 29 times greater than upstream). Potential ecotoxicological effects were also evaluated: Body condition did not differ between the caging location and exposure time. Three oxidative status markers in the fish livers showed significant shifts after 14 days of caging. Our results suggest a high clearance rate of antibiotics and, to a lesser extent, of pesticides in wild gudgeons, which could be explained by changes in xenobiotic metabolism with pollutant exposure. Environ Toxicol Chem 2024;43:701-711. © 2023 SETAC.

A Study on the Biodiversity of Aquatic Invertebrate Fauna of Nizamsagr Irrigation Reservoir, Kamareddy District, Telangana, India

Nizamsagar reservoir constructed across the river Manjeera between Achampeta and Banjapalli villages of newly formed Kamareddy district of Telangana State. The River Manjeera is a tributary river of the Godavari. The height of the dam is 96 meters and length is 3 km having water capacity 30 TMC. The study revealed that a total of 27 invertebrate species belonging to three phyla: Arthropoda, Mollusca, and Annelida. Among these, the Arthropoda phylum species dominated, followed by Mollusca and Annelida. In the Mollusca phylum, the Gastropoda class exhibited rich abundance, with species like Bithynia transsilvanica, Bellamya bengalensis, Perrysisfavidens, and Pila globose being prominent. Within the Annelida phylum, Tubifex tubifex in the Clitellata class showed the highest abundance compared to Limnodrillus hoffmeisteri. In the Arthropoda phylum, specifically in the Insecta class, there were a diverse range of species, including Chironomus Sps., Anophelus mosquito larvae, Culex mosquito larvae, Sympetrum vulgatum, and Orthetrum cancellatum, with the highest diversity observed.

Seasonal particulate organic carbon dynamics of the Kolyma River tributaries, Siberia

Abstract. Arctic warming is causing permafrost thaw and release of organic carbon (OC) to fluvial systems. Permafrost-derived OC can be transported downstream and degraded into greenhouse gases that may enhance climate warming. Susceptibility of OC to decomposition depends largely upon its source and composition, which vary throughout the seasonally distinct hydrograph. Most studies on carbon dynamics to date have focused on larger Arctic rivers, yet little is known about carbon cycling in lower-order rivers and streams. Here, we characterize the composition and sources of OC, focusing on less studied particulate OC (POC), in smaller waterways within the Kolyma River watershed. Additionally, we examine how watershed characteristics control carbon concentrations. In lower-order systems, we find rapid initiation of primary production in response to warm water temperatures during spring freshet, shown by decreasing δ13C-POC, in contrast to larger rivers. This results in CO2 uptake by primary producers and microbial degradation of mainly autochthonous OC. However, if terrestrially derived inorganic carbon is assimilated by primary producers, part of it is returned via CO2 emissions if the autochthonous OC pool is simultaneously degraded. As Arctic warming and hydrologic changes may increase OC transfer from smaller waterways to larger river networks, understanding carbon dynamics in smaller waterways is crucial.

Spatial Distribution, Risk Index, and Correlation of Heavy Metals in the Chuhe River (Yangtze Tributary): Preliminary Research Analysis of Surface Water and Sediment Contamination

This comprehensive study aimed to evaluate the water quality and sediment contamination in the Chuhe River in Nanjing. The spatial assessment of 10 samples collected in September highlighted that, in surface water, Copper (Cu) > Nickel (Ni) > Zinc (Zn) > Chromium (Cr) > Lead (Pb) > Arsenic (As) > Cadmium (Cd) > Mercury (Hg), whereas in sediments, Zn > Cr > Cu > Pb > Ni > As > Cd > Hg. The coefficient of variation (CV) for Ni and Zn in surface water was >15, whereas As, Cu, Pb, and Ni had a CV that was higher than 15 in sediments, indicating variability in contamination sources. The Pollution Load Index values ranged between 2.16 and 3.05, reflecting varying contamination levels across samples. The Geoaccumulation Index data also showed moderate-to-considerable contamination, especially for elements such as Cd and Cu. Correlation analyses in water and sediments unearthed significant relationships, with notable links between Cu and Pb in the water and strong correlations between As and Cu and between Cr and Ni in sediments. In sediments, Total Nitrogen and Phosphorus were significantly correlated with As, Cu, Pb, and Ni. The Potential Ecological Response Index for sediments indicated that they are at medium to high risk (307.47 ± 33.17) and could be potentially detrimental to aquatic life in the tributary. The tributary, influenced by agricultural runoff, residential areas, and other anthropogenic activities, showed that despite Nemerow pollution index values for water samples being below 1, sediment analysis indicated areas of concern. Principal Component Analysis (PCA) was conducted to identify the potential sources of heavy metal contamination. In surface water, shared negative loadings on PC 1 (60.11%) indicated a unified influence, likely from agricultural runoff, while PC 2 (14.26%) revealed additional complexities. Sediments exhibited a unique signature on PC 1 (67.05%), associated with cumulative agricultural impacts, with PC 2 (18.08%) providing insights into nuanced factors, such as sediment composition and dynamic interactions. These findings offer a complete insight into the Chuhe River tributary’s condition, underlining the urgency for ongoing monitoring and potential remediation measures.

Assessment framework of water conservation based on analytical modeling of ecohydrological processes

The water conservation (WC) function is an important indicator for ecosystem health. However, the commonly-used technical term like water retention (WR) and its computation methods could not well reflect the concept of WC because WR focused on the amount of water retained in vegetation canopy and soil, whereas WC includes WR and water supply as well. This study is to propose a new index for assessing the WC function (WCI) by integrating ecological and hydrological factors including WR, water yield, and vegetation production. We further developed a new framework for calculating spatiotemporal dynamics of WCI using ecohydrological modeling of Soil and Water Assessment Tool (SWAT) and remote sensing data. We then used the framework to assess the spatiotemporal dynamics of WC function in the Weihe River Basin (WHRB), the largest tributary of the Yellow River. Compared to the traditional method, our newly-developed approach is more reasonable because it could reflect water retention amount, temporal stability of water yield, and vegetation quality. Further, the case study can tell it is our new index (with forest being the highest, followed by grassland and cropland), instead of WR (with grassland being the highest and forest being the least), that could reflect the definition of WC and meet our cognition. Spatially, the high WCI (0.4 ∼ 0.6) areas are mainly located in the southern and central-eastern parts of the WHRB, characterized by relatively higher forest coverage (e.g., the Qinling Mountains in the southern part of the study area in southern part and representative ‘Grain-For-Green’ in central-eastern part). In brief, this study enhances understanding of the WC function and also provides a method for assessing the dynamics of WC that can be applicable to other regions.

Investigating the antibiotic resistance genes and their potential risks in the megacity water environment: A case study of Shenzhen Bay Basin, China

Antibiotic resistance genes (ARGs) constitute emerging pollutants and pose serious risks to public health. Anthropogenic activities are recognized as the main driver of ARG dissemination in coastal regions. However, the distribution and dissemination of ARGs in Shenzhen Bay Basin, a typical megacity water environment, have been poorly investigated. Here, we comprehensively profiled ARGs in Shenzhen Bay Basin using metagenomic approaches, and estimated their associated health risks. ARG profiles varied greatly among different sampling locations with total abundance ranging from 2.79 × 10−2 (Shenzhen Bay sediment) to 1.04 (hospital sewage) copies per 16S rRNA gene copy, and 45.4% of them were located on plasmid-like sequences. Sewage treatment plants effluent and the corresponding tributary rivers were identified as the main sources of ARG contamination in Shenzhen Bay. Mobilizable plasmids and complete integrons carrying various ARGs probably participated in the dissemination of ARGs in Shenzhen Bay Basin. Additionally, 19 subtypes were assigned as high-risk ARGs (Rank I), and numerous ARGs were identified in potential human-associated pathogens, such as Burkholderiaceae, Rhodocyclaceae, Vibrionaceae, Pseudomonadaceae, and Aeromonadaceae. Overall, Shenzhen Bay represented a higher level of ARG risk than the ocean environment based on quantitative risk assessment. This study deepened our understanding of the ARGs and the associated risks in the megacity water environment.

Design and optimization of salinity gradient energy harvesting system using symmetrical organic redox couples

Salinity gradient energy (SGE) is a rising source of renewable energy that commonly exists at the confluence of rivers and oceans and can be harvested by membrane-based technologies such as reverse electrodialysis (RED) process. However, unavoidable high external resistance and sluggish electrode kinetics in existing RED devices severely hamper power density and recovery efficiency. To solve the issue, aqueous organic species with fast redox kinetics were down-selected and adopted as a storage medium to be internally coupled with the RED module and directly transform SGE into chemical energy. Moreover, a temperature-responsive-fluid-imaging coupled 3D numerical simulation approach was also developed for further promoting the fluid state of the overall module. Owing to the systematic design and optimization, a high SGE harvesting power density of 0.29 W cm−2 and a recovery efficiency of 95.2 % were achieved, offering a promising process for large-scale SGE harvesting and integration into the future electric grid.

Weed survey on cotton (Gossypium hirsutum) fields in the Tarim River region of southern Xinjiang

AbstractThis study was conducted to investigate weed infestations of cotton (Gossypium hirsutum) fields in the region of Tarim River. Forty‐nine species among 17 families were identified in these cotton fields, and 24 of them were annuals. The eight dominant weed species in the cotton fields of Tarim River basin included Chenopodium glaucum, Solanum nigrum, Chenopodium album, Chenopodium hybridum, Bolboschoenus planiculmis, Sonchus arvensis, Phragmites australis, and Mulgedium tataricum. The number of weed species in the Aksu River tributary area, Yeerqiang River tributary area, and the upper and lower reaches of the Tarim River reached 29, 36, 35, and 33, respectively. Twenty species were found widely distributed among each basin. The dominant weeds in the cotton fields in the Aksu River basin and upper reaches of the Tarim River were S. nigrum and C. glaucum, those in the cotton fields in the Yarkand River basin included C. album and C. hybridum, and those in the cotton fields in the lower reaches of the Tarim River were C. glaucum and C. album. Notably the 20 common surveyed species of C. glaucum, S. nigrum, C. album, C. hybridum, B. planiculmis, S. arvensis, P. australis, M. tataricum, and others, could pose a serious challenge to regional crop production if not adequately controlled. As such, each cotton field should adopt a suitable weeding scheme with strengthened weed monitoring according to the local conditions, especially the weed distribution area characteristics.

2D numerical modeling of intense bedload-transport processes at confluences of mountain rivers and steep tributaries

2D numerical modeling of intense bedload-transport processes at confluences of mountain rivers and steep tributaries

Assessment of hydrological, geological, and biological parameters of a river basin impacted by old Hg mining in NW Spain

Mercury (Hg) is a toxic metal that can cause adverse effects for the health of ecosystems. The Caudal River is one of the main rivers in the Asturias region (NW Spain), whose basin is highly anthropized, hosting several Hg mines, closed in the last century. Arsenic (As) is also found in the mineral paragenesis of the Hg deposits, posing a greater environmental risk. In the mining sites, remaining old facilities and tailings continue to release these elements into the environment. In this work, samples of fluvial sediments and water were taken, both in areas affected by anthropic activity and in pristine areas, in order to establish the background levels for the critical elements. The mineralogical study of the sediments, combined with EDS microanalysis, is useful to identify mineralogical traps such as Fe oxides or clays to retain the As. The As content in all sampled sediments is above the threshold effect levels (TEL), the possible effect range within which adverse effects occasionally occur, according to the Canadian Sediment Quality Guidelines for the Protection of Aquatic Life. This fact is related to a naturally high geochemical background in the basin, due to the existing mineral deposits. The PEL threshold (the probable effect range within which adverse effects frequently occur) is exceeded by more than an order of magnitude in the sediments downstream of the Hg mines. In these points, the As content in the water, exceeding 700 μg L−1 As, is also above the quality standard established in Spanish legislation. As a result, the Caudal River tributaries in the lower part of the basin do not reach a good ecological state, according to the Hydrological Planning Office, and in some cases their state is deficient, showing low richness and high dominance of macroinvertebrates. Although the concentrations decrease with distance from the source, these findings justify the low ecological quality of the affected watercourses.

Potential Dam Breach Flood Assessment with the 2D Diffusion and Full Dynamic Wave Equations Using a Hydrologic Engineering Center-River Analysis System

Dam breaches have catastrophic consequences, causing severe property damage, life loss, and environmental impact. The potential dam breach downstream flooding of the Kulekhani reservoir, Nepal, was studied using a 2D Diffusion Wave Equation (DWE) and Full Dynamic Wave Equation (FDWE) through an open-source solver, Hydrologic Engineering Center-River Analysis System (HEC-RAS). The suitable dam breach model was identified based on the dam geometry and sixteen historical dam failure cases. The simulated downstream peak was tested with an empirical relation, considering reservoir volume and duration of failure. Model comparisons through the flood plain mapping of water depth, flow velocity, flood intensity as per guidelines of the American Society of Civil Engineers (ASCE), and arrival time were carried out for flood hazard assessment. FDWE was able to capture the physical flow phenomena in the river bend resulting in higher flow velocity at the outer bend, lower velocity at the inner bend, and formation of eddies due to the application of the turbulence model, considering possible momentum losses, whereas DWE was unable to capture these effects due to a simplified momentum equation. The total area of flood extension was found to be increased by 30% using FDWE than the DWE due to higher water surface elevation. Most of the towns along the Kulekhani River were classified as “Very High” intensity flood regions according to ASCE, due to the V-shape valley. The peak time difference at the Bagmati River confluence was evaluated between the models. This plays an important role in decision-making for the selection of the flood model to make a safe evacuation plan. The application of FDWE was found to be suitable for the rapidly varying unsteady flow in the steep meandering river.

Draft genome of co-cultured Melainabacteria sp. 17Bon1m.

We report the 7.6 Mb draft genome sequence of Melainabacteria sp. strain 17Bon1, which was sequenced from a co-culture with the diatom Rhopalodia gibba collected from the Clark Fork River in Bonita, MT.

Revisiting the genus Pseudocuneopsis (Bivalvia, Unionidae): Morphology, mitochondrial phylogenomics, and the description of a new species

AbstractSpecies diversity can be underestimated due to a lack of regional studies and limitations in research methods. China is widely recognized as one of the primary hotspots for the biodiversity of freshwater mussels as it harbours a wealth of endemic species. Pseudocuneopsis was recently established to belong to the Unioninae subfamily within Unionidae and is endemic to China. Recent research has expanded the diversity and range of distribution of this genus. However, sufficient data is required to precisely determine the phylogenetic relationships within Pseudocuneopsis. This study conducted an integrative taxonomy using morphological, COI barcode, and complete maternal mitogenome data to clarify the taxonomy of Pseudocuneopsis. Both morphological and COI barcode data supported the validity of all Pseudocuneopsis species. Furthermore, a new species, Pseudocuneopsis yemaoi sp. n. was described from a tributary of the Man River in Hubei, China. Mitochondrial phylogenomic analyses showed that P. yemaoi was closely related to P. sichuanensis and resolved phylogenetic relationship as (P. capitata + (P. yangshuoensis + (P. sichuanensis + P. yemaoi))). Our results highlight the significance of utilizing integrative classification methods. Moreover, we propose enhancing the research and preservation measures of minor streams in China, as these streams may house distinctive species.

Assessment of stream order and drainage pattern of flood prone areas of Ebonyi state, Southeastern Nigeria

This study evaluates stream order and drainage pattern of flood in Ebonyi state, Southeastern Nigeria. The drainage network within Ebonyi State was identified using the Shuttle Rader Topographic Mission (SRTM), the stream order and flood drainage pattern with the aid of the Digital Elevation Model (DEM), and the Topographic analysis of Spatial Analyst on Hydrology. The data was acquired using Geometric Positioning and the LANDSAT downloaded from the United States Geological Survey (USGS) Earth Explorer 2019 and Thematic Mapper (TM) 2009. The result shows that the map of the eastern part of Ebonyi State houses the Cross River basin as a main consequent river draining to the Atlantic Ocean. The drainage gets darker down the slope as more volumes of water move into the traversing drainage channels in their corresponding orders. As flood magnitude increases, the velocity decreases because more water from different river orders or tributaries has been added to the adjusting river channels. It proves that consequent rivers like the Enyim River of Izzi, Iyiokwu River of Abakaliki, Alcor River of Ikwo, Iyere River of Afikpo South, and Esu Umuchimaewuze River of Ohaozara Local Government areas slope down through the adjourning tributaries when the basin is saturated. The map legend shows a thick blue outcome indicating that the flood originates from the Enyim River of Izzi, Iyiokwu River of Abakaliki, Alchor River of Ikwo, Iyere River of Afikpo South, and Esu Umuchimaewueze River of Ohaozara. Therefore, urgent adjustments and construction of drainage systems are needed to accommodate more water volumes.