Geomorphological Parameters Research Articles

Sustainability of Small-Scale Capture Fisheries Based on Coastal Vulnerability in Pangpang Bay, Banyuwangi Regency, Indonesia

Graphical Abstract Highlight Research Climate change impacts on coastal vulnerability. Low coastal vulnerability in Pangpang Bay, Banyuwangi Regency. Sustainability of small-scale capture fisheries based on vulnerability. Sustainable small-scale fisheries management. Abstract Teluk Pangpang is one of the water areas that has considerable capture fisheries potential in Banyuwangi Regency, Indonesia. On the other hand, climate change impacts the vulnerability of coastal areas and coastal communities, especially small-scale fishers. This study aims to analyse the coastal vulnerability of Pangpang Bay and formulate a sustainable development of small-scale capture fisheries in Pangpang Bay. The research method used a descriptive method with a quantitative approach. Data collection techniques used geographic information systems and focus group discussions (FGDs). The data analysis used was Coastal Vulnerability Index (CVI) analysis with spatial approach and Participatory Prospective Analysis (PPA). From the CVI analysis, through the assessment of geomorphological parameters, erosion/accretion, coastal slope, distance of plants from the beach, wave height, and average tide range, the level of coastal vulnerability of Teluk Pangpang is included in the low category. Meanwhile, the PPA analysis resulted in seven variables that most influence the sustainability of small-scale capture fisheries, namely climate change, coastal vulnerability, coral reef area and density, number of small-scale fishers, catches, human resources of small-scale fishers, and management of small-scale fisheries resources. Furthermore, for the formulation of the sustainability scenario of small-scale capture fisheries in Pangpang Bay, is to minimise the impact of climate change and conduct disaster mitigation, improve the human resources of small-scale fishers, and equalise perceptions as outlined in the commitment between all interested parties and small-scale fishing communities.

Mapping the intrinsic potential of water infiltration in urban subsurface: feedback from France

In a context of increasing urbanization, with strong soil sealing, and with an increase in extreme weather events, the management of rainwater in urban areas is becoming a major issue. In order to improve water resource management and to prevent urban floods, more and more cities are considering or already implementing water infiltration systems. Infiltration of water is not possible anywhere due to natural and/or anthropic reasons. In this frame, the intrinsic infiltration capacity of the subsurface is one key natural parameter. Global maps are needed to build territorial strategies. In France, a lot of studies are available but a national methodological framework for mapping this index does not exist. In this paper, we analyse various studies carried out in France for such mapping and compare the methods with examples in other countries. Most of the French studies combine a Multi-Criteria Analysis (MCA) and a Geographic Information System (GIS) spatial analysis. The criteria include geological, hydrogeological and geomorphological parameters. The PHOEBUS method developed on Rennes Metropolis seems the most relevant and replicable one to provide a common framework at French scale. It takes into account 7 criteria, including rock/soil permeability, topographic slope and thickness of the unsaturated zone. The obtained maps may be used as such, modified by integrating sealed surfaces or crossed with other criteria linked to the urban environment (e.g. sealed surfaces, soil pollution, heat islands). They provide a decision support tool for urban planning. In particular, they are useful to improve rainwater management, but also in the elaboration of desealing or renaturation strategies. It seems essential to act in concertation with local stakeholders to identify their needs and the specificities of the territory.

Prediction of flash flood peak discharge in hilly areas with ungauged basins based on machine learning

ABSTRACT Peak discharge is an essential element of hydrological forecasting. Due to rapid outbreaks of flash floods in hilly areas and the lack of measured data, the fast and accurate estimation of peak discharge is crucial for flash flood hazard management. Three machine learning algorithms were applied to estimate peak discharge; this estimation was compared with the results of hydrological–hydraulic models, and the results were verified with measured watershed data. In this paper, 10 hydrological and geomorphological parameters were selected to predict the flood peak discharge in 103 watersheds in Taiyi Mountain North District. The results show that the particle swarm optimization backpropagation (PSO-BP) neural network model outperforms the BP neural network and random forest regression in prediction performance. PSO-BP has a lower mean absolute error (2.51%), root mean square error (3.74%), and mean absolute percentage error (2.74%) than the other models, which indicates that PSO-BP has high prediction accuracy. Importance analysis revealed that rainfall, early impact rainfall, catchment area, and rain intensity are the key input parameters of PSO-BP. The proposed method was confirmed to be a fast and relatively accurate algorithm for estimating the peak discharge of flash floods in ungauged basins.

Unveiling seasonal nitrate contamination dynamics in cropland sub-watersheds: A geo-morphological analysis of the bilate agricultural watershed

Cropland sub-watershed surface and groundwater contamination are pressing issues for water management. This study examines the impact of sediment transport indices (STI) on nitrate concentration in downstream water bodies. The research highlights rainfall's significant role in predicting seasonal nitrate levels. Employing GIS-SWPT tools and hydro-geomorphologic analysis, cropland sub-watersheds, particularly sub-watersheds one and three, are prioritized for their high contribution to downstream surface and groundwater nitrate contamination, with prioritization values of 105.58 and 180.63, respectively. Statistical analysis, conducted using Python's scikit-learn library, validated the findings of the study, with the model's F-statistic of 79.63 and a corresponding p-value of 0.0147 underscoring its overall significance. However, while STI alone showed a prioritization parametric correlation coefficient of 0.5077, suggesting other external factors also contribute to nitrate loading, a strong relationship between STI and nitrate concentration was revealed (R² of 0.993). This integrated approach enhances understanding of how geomorphologic parameters of cropland sub-watersheds influence water quality downstream. By clarifying the complex interactions between sediment transport and nitrate concentration, evidence-based strategies can be developed to mitigate surface and groundwater nitrate pollution. This research provides valuable insights into cropland sub-watershed pollution dynamics and informs targeted management interventions.

Investigation of the Basin Characteristics through Morphometric Analysis of Hadejia River Sub-Basin: Implications for Groundwater Recharge

Understanding the geohydrological properties of a drainage basin in relation to the topographical feature and its flow patterns depends heavily on morphometric analysis. Estimating a watershed's frequency of infiltration and runoff as well as its other hydrological characteristics is also helpful. The study was conducted using Geographical Information System (GIS) techniques with the aim of establishing relationship between surface morphometry, underlying geology and groundwater recharge. For detailed measurement and analysis, Digital Elevation Model (DEM) and high resolution imageries were employed for basin delineation, slope characterization, channel network extraction and stream ordering in order to derive the linear, areal, and relief aspects of morphometric parameters. The findings showed that a total number of 116 streams joined the 4th order stream in which 83 streams were 1st order, 25 streams were 2nd order, 7 streams were 3rd order and the major trunk was 4th order stream, occupied an area of 1486.86km2. The stream network's drainage system exhibits dendritic design. The results further indicate that the values for stream frequency, infiltration number, drainage density, drainage texture, length of overland flow, elongation ratio and basin relief are 0.08, 0.032, 0.41km/km2, 0.023, 1.22km, 0.54 and 28.59m respectively. The observed values of both linear, areal and relief parameters were generally low. Low values for the areal and relief criteria indicates that the sub-basin is at its youthful stage of development and possesses very good permeable subsurface formation and prospect with the possibility of high potential groundwater resources. The result help us understand the connections between hydrological variables and geomorphological parameters as guidance and/or decision-making instruments for the authorities to develop decisions for the environmentally friendly growth of the basin, water supply planning, water budgeting, and disaster mitigation within the Hadejia river sub-basin.

Machine learning modeling of lake chlorophyll content in a data scarce region (Northern Patagonia, Chile): insights for environmental monitoring

Among South America, Chile is highly susceptible to climate change impacts on water resources and ecosystems. Chilean lakes and rivers have been impacted by anthropogenic activities leading to chemical pollution and eutrophication. Concerns for conservation and management of water resources has led to the current development of secondary norms for environmental quality of Northern Patagonian lakes. In this context, we analyze historical limnological databases (1979-2022) for these lakes utilizing Random Forest (RF) models. After filtering, we retained data for 11 lakes including key variables of: dissolved oxygen, electric conductivity, transparency, temperature, pH, total nitrogen, total phosphorus and chlorophyll-a. This dataset yielded robust results, accurately predicting chlorophyll-a content. Furthermore, we added lake geomorphological parameters, enhancing the performance of the model. Our study demonstrates the need to improve long-term monitoring programs, optimizing environmental data recording and decreasing costs. We conclude that the studied lakes generally maintain their oligotrophic characteristics, however further analysis suggests that these lakes are more sensitive to nitrogen loading than phosphorus. Our results highlight the need to implement adaptative management plans at the watershed level to regulate anthropogenic nitrogen contamination (from agriculture, pisciculture and urbanization). The features selected by RF, coupled with the assessment of historical trophic state variation, allow the establishment of permissible concentration thresholds for major nutrients and other sentinel parameters, informing the development of regulations such as the secondary norms for environmental quality. Lastly, the enhanced performance of RF modeling when including geographical parameters unveils the need to standardize and integrate geographical data in monitoring practices.

A Quantitative Provenance Analysis (QPA) Approach to Quantify Controls on Sediment Generation and Sediment Flux in the Upper Reaches of the Magdalena River (Colombia): 1. Natural and Anthropic Controls on the Sand Fraction

AbstractThis study investigates the upper Magdalena river basin (Colombia), which is characterized by tectonic activity, tropical climate, heterogeneous lithological assemblages, and anthropic influence. It aims to comprehend factors controlling sediment generation, flux, and composition by incorporating petrographic data from 27 recent fluvial samples along with geochemistry, geomorphological parameters, historical precipitation, land cover, landsliding and suspended sediment load data. The analysis shows mismatches between sand composition and drainage lithology distribution. A new set of endmember mixing models is presented, quantifying the impacts of erodibility, sand generation potential (related to lithology), and sediment connectivity between hillslopes and river outlets (related to geomorphology). Results show enhanced sediment generation from sedimentary rocks (up to 40%) due to high erodibility, and decreased sediment flux from low‐ to medium‐grade metamorphic rocks (up to 60%) due to controlling morphometric parameters. Overrepresentation of plutonic and high‐grade metamorphic rocks and underrepresentation of volcanic rocks (up to 100%) are controlled by mineralogical and textural parameters. Enhanced landsliding activity in areas with volcanic activity occasionally overshadows basin‐wide compositional trends driven by morphological and lithological characteristics, as it controls rare overrepresentation of volcanic and low‐grade metamorphic detritus in the sand fraction. Sediment retention by hydroelectric dams significantly decreases suspended sediment flux by 30%, while deforestation plays a minor role in sediment flux. This study underscores the importance of coupling sediment generation, geomorphology and the distribution of stochastic events related to seismic activity in any sediment production‐focused study and for developing numerical models in Quantitative Provenance Analysis (QPA).

Rock Glacier Inventory of the Southwestern Pamirs Supported by InSAR Kinematics

Although rock glaciers (RGs) are prevalent in the southwestern Pamirs, systematic studies on them are scarce. This article introduces the first inventory of RGs in the southwestern Pamirs, situated at the western edge of the High Mountain Asia region. The inventory, established through a combination of Google Earth optical imagery and Interferometric Synthetic Aperture Radar (InSAR) techniques, encompasses details on the locations, geomorphological parameters, and kinematic attributes of RGs. A total of 275 RGs were cataloged in an area of 55.52 km2 from 3620 to 5210 m in altitude. Our inventory shows that most RGs in this region are talus-connected (213 landforms), with the highest frequency facing northeast (23%). The distribution of RGs thins from west to east and is more abundant in higher altitudes. The Shakhdara range to the south hosts a denser and more active population of RGs than the Shughnon range to the north, highlighting the influence of topography and precipitation. Overall, RGs in the southwestern Pamirs exhibit high activity levels, with active RGs predominating (58%). A comparison between active and transitional RGs showed no significant differences in elevation, temperature, and slope. Glacier-connected and glacier forefield-connected RGs demonstrated higher line-of-sight (LOS) velocities than talus-connected and debris-mantled slope-connected RGs, underscoring the significant impact of precipitation and meltwater on their activity.

Geomorphological changes and landscape ecosystem services dynamics of the Bhasan Char Island in the Northern Bay of Bengal, Bangladesh

Geomorphological changes have had numerous environmental impacts on landscape features, natural resources, landform stability, and ecosystem services on Bhasan Char Island in the Northern Bay of Bengal, Bangladesh. Therefore, the present study examines the morphological change of the island and its impacts on landscape features, landform stability, and coastal mangrove forest resources since its evolution. Optical satellite images from Landsat (TM and OLI) spanning from 2003 to 2023 have been used to assess geomorphological parameters using the bio-physical indices NDWI and MNDWI. A hybrid classification method involving unsupervised classification, supervised machine learning, and post-classification refinement was employed to precisely delineate landscape features and evaluate ecosystem services. Indeed, to evaluate forest cover health dynamics, the leaf area index (LAI) was estimated using the Google Earth Engine (GEE) cloud platform. The study results reveal that the geomorphology of the island was changed by fluvial and marine processes and responses, whereas only 3% of the landscape ages older than 19 years. Results also disclosed that built-up area construction for Rohingya nations drastically lost ∼ 7% of mangrove plantations over the last 8 years, from 2015 to 2023. The current research delivers crucial management strategies regarding further structural development by evading unplanned construction, hastening reforestation, and evolving the green belt along the existing embankment. The study findings will help policymakers, environmental managers, coastal and marine resource planners, ecologists, and geomorphologists take an eco-friendly sustainable development plan and conserve the coastal island and its landscape resources from the risk of fluvial and marine processes.

Variable downcanyon morphology controlling the recent activity of shelf-incised submarine canyons (Alboran Sea, western Mediterranean)

This research aims to distinguish genetic sedimentary processes building canyon geomorphological patterns and the factors driving different sedimentary activities in two nearby Mediterranean shelf-incised submarine canyons (Carchuna and Motril) that exhibit different degrees of incision on the narrow margin of the northern Alboran Sea.The straight Carchuna Canyon incises the shelf up to 200 m off the coastline and exhibit steep canyon walls featuring narrow terraces, muddy sands with high contents of organic matter along the thalweg, and transported shelf benthic foraminifera in distal settings. The Motril Canyon head is wider and incises the shelf edge, ca. 2 km off the coastline. It exhibits a sinuous morphology and less steep walls, wider terraces, and higher sedimentation rates with muddy sediments along the thalweg. In both canyons, cross-section relief, width, incision, and area decrease downslope, although these parameters increase locally.The downslope variations of geomorphological parameters are attributed to enhanced erosional/depositional processes promoted by tectonically controlled abrupt changes of the axial channel orientation. The degree of shelf incision, the location of the canyon heads in relation with the local sediment sources, and the seasonally variable hydrodynamic regimes determine the different degrees of recent canyon activity. The Motril Canyon is interpreted as a mature system that reflects episodic activity, collecting fine-grained sediments from the nearby Guadalfeo River. The Carchuna Canyon exhibits a youthful developmental stage whose activity is more continuous and involves sediment trapping of littoral cells and continuous downslope sand transport.

Development of a hazard risk map for assessing pedestrian risk in urban flash floods: A case study in Cúcuta, Colombia

AbstractThe rapid growth of impervious areas in urban basins worldwide has increased the number of impermeable surfaces in cities, leading to severe flooding and significant economic losses for civilians. This trend highlights the urgent need for methodologies that assess flood hazards and specifically address the direct impact on pedestrians, which is often overlooked in traditional flood hazard analyses. This study aims to evaluate a methodology for assessing the risk to pedestrians from hydrodynamic forces during urban floods, with a specific focus on Cúcuta, Colombia. The methodology couples research outcomes from other studies on the impact of floodwaters on individuals of different ages and sizes with 1D/2D hydrological modeling. Advanced computational algorithms for image recognition were used to measure water levels at 5‐s intervals on November 6, 2020, using drones for digital elevation model data collection. In Cúcuta, where flood risk is high and drainage infrastructure is limited, the PCSWMM (Computer‐based Urban Stormwater Management Model) was calibrated and validated to simulate extreme flood events. The model incorporated urban infrastructure details and geomorphological parameters of Cúcuta's urban basin. Four return periods (5, 10, 50, 100), with extreme rainfall of 3 h, were used to estimate the variability of the risk map. The output of the model was analyzed, and an integrated and time‐varying comparison of the results was done. Results show that the regions of high‐water depth and high velocity could vary significantly along the duration of the different extreme events. Also, from 5 to 100 years return period, the percentage of area at risk increased from 9.6% to 16.6%. The pedestrian sensitivity appears much higher than the increase in velocities or water depth individually. This study identified medium to high‐risk locations, which are dynamic in time. We can conclude dynamics are spatiotemporal, and the added information layer of pedestrians brings vulnerability information that is also dynamic. Areas of immediate concern in Cúcuta can enhance pedestrian safety during flash flood events. The spatiotemporal variation of patterns requires further studies to map trajectories and sequences that machine learning models could capture.

An assessment of the geomorphodiversity and land use/cover change (LUCC) effects associated with landslides in Meghalaya, India

AbstractThe Shillong Plateau in the Eastern Himalayas is exposed to high seismicity, neo‐tectonic activity and orographic precipitation that aggravated landslides in the region by affecting hillslope processes. Landscape development is influenced by landslide phenomenon and depends upon geomorphic processes and geomorphodiversity (GmD). It is linked intimately with geomorphology, hydrology and soil type. This study uses a remote sensing and GIS‐based approach to assess the spatial linkage between GmD and landslide distribution in Meghalaya (India). GmD index (GmDI) is developed using geological, morphometric and geomorphological parameters and analysed with landslide distribution. The landslide distribution considering land use/cover change (LUCC) is also examined. The result shows that the region with high‐relief, valley and depression zone, mainly along the Dauki fault, have a high to a very high GmDI. About 61% of landslide localities are in zones of high GmDI, concentrated in the central and eastern parts of Meghalaya. Density analysis of the very high class (class 5) of GmD confirms the same. Most of these landslides occur in dense and light‐vegetated landmasses. However, the LUCC analysis reveals a significant increase in the built area on steeper slopes (average expansion ratio of 2.30 for slopes >15°) between 2017 and 2022, indicating a rising threat of landslides in urban areas of Meghalaya. The study presents the importance of GmD in active tectonic regions with particular reference to landslide potential and recent LUCC. It can aid decision‐makers in planning sustainable developments and risk mitigation strategies for landslide hazards and geoconservation.

Characterization of Active Riverbed Spatiotemporal Dynamics through the Definition of a Framework for Remote Sensing Procedures

The increasing availability and quality of remote sensing data are changing the methods used in fluvial geomorphology applications, allowing the observation of hydro-morpho-biodynamics processes and their spatial and temporal variations at broader and more refined scales. With the advent of cloud-based computing, it is nowadays possible to reduce data processing time and increase code sharing, facilitating the development of reproducible analyses at regional and global scales. The consolidation of Earth Observation mission data into a single repository such as Google Earth Engine (GEE) offers the opportunity to standardize various methods found in literature, in particular those related to the identification of key geomorphological parameters. This work investigates different computational techniques and timeframes (e.g., seasonal, annual) for the automatic detection of the active river channel and its multi-temporal aggregation, proposing a rational integration of remote sensing tools into river monitoring and management. In particular, we propose a quantitative analysis of different approaches to obtain a synthetic representative image of river corridors, where each pixel is computed as a percentile of the bands (or a combination of bands) of all available images in a given time span. Synthetic images have the advantage of limiting the variability of individual images, thus providing more robust results in terms of the classification of the main components of the riverine ecosystem (sediments, water, and riparian vegetation). We apply the analysis to a set of rivers with analogous bioclimatic conditions and different levels of anthropic pressure, using a combination of Landsat and Sentinel-2 data. The results show that synthetic images derived from multispectral indexes (such as NDVI and MDWI) are more accurate than synthetic images derived from single bands. In addition, different temporal reduction statistics affect the detection of the active channel, and we suggest using the 90th percentile instead of the median to improve the detection of vegetated areas. Individual representative images are then aggregated into multitemporal maps to define a systematic and easily replicable approach for extracting active river corridors and their inherent spatial and temporal dynamics. Finally, the proposed procedure has the potential to be easily implemented and automated as a tool to provide relevant data to river managers.

Evaluation of multiple digital elevation models for hypsometric analysis in the watersheds affected by the opening of the Red Sea

Climate change is increasingly affecting the Red Sea-related terrains in Egypt and Saudi Arabia with a notable increase in heavy precipitation events. This highly vulnerable region to flashfloods and other climate change-driven hazards encompasses rough terrains with more than 11,000 basins/subbasins, which necessitates the accurate estimation of their hydrological and geomorphological parameters among which the hypsometric analysis. In this regard, The study examines the accuracy of the hypsometric analysis extracted using open source SRTM-1, ASTER-GDEM, Copernicus-GLO30, ALOS-DEM against high-resolution Topo-1 m and Topo-2.8 m DEMs for Talat Hamdh basin in Egypt and Wadi El-Salwely basin in Saudi Arabia, respectively. Copernicus-GLO30 shows the highest accuracy among all DEMs with the root-mean-squared–error (RMSE), mean elevation error, standard deviation, maximum and minimum absolute errors of 3.03, 2.0, 2.3, 11.7 and 0.1 m, respectively for Talat Hamdh basin. The findings also show that, regardless of the geology and geomorphic evolution of the basin, the hypsometric analysis is sensitive to the DEM type rather than the spatial resolution as Copernicus DEM yields similar basin numbers (a single basin) and area (1.366 and 141.9 km2) compared to the reference DEMs (1.408 and 154.4 km2) for Talat Hamdh and Wadi El-Salwely basins, respectively. Contrariwise, other open source DEMs yield multiple basins and thus significantly smaller basin area. Given the DEM-type dependence of the hypsometric analysis, the study recommends that large-scale hydrological and geomorphological analyses should consider using a high-resolution reference DEM on a local-scale basin to examine the accuracy of open source DEMs prior to conducting the analysis.

Hydro-geomorphological conditions for the classification of terrain susceptibility to shallow translational landslides: a geo-hydro ecological approach

This work is part of the review of methodological procedures for the analysis and classification of terrain susceptibility to shallow translational landslides, following the geohydro ecological approach. The pilot area is located in Nova Friburgo (RJ), specifically in the D’Antas Creek basin (53 km2). At this stage of the work, geomorphological parameters and indices were evaluated, including slope angle, curvature, drainage efficiency index (DEI) and topography position index (TPI), seen as relevant in regulating the hydrological and mechanical behavior of soils. The results obtained were intersected with an inventory of landslide scars (n = 382) referring to the extreme rainfall event in January 2011, which occurred in the highland region, called Região Serrana, of the state of Rio de Janeiro. This intersection allowed an evaluation between these parameters and the slopes rupture. The concentration of landslide area per class subsidized the establishment of weights for each of the adopted classes, based on the AHP method. A readjustment of the slope angle classes was proposed, as well as the inclusion of the standard curvature in the construction of the Hydro-Geomorphological Conditions Map. The results were promising, with a concentration of 88.74% (0.85 km2) of the landslide areas in the class of high erosive potential.

Regional tectonic uplift indicated by geomorphological parameters in the Bahe River Basin, central China

Abstract Multiple uplifts of the Qinghai-Tibet Plateau since the late Cenozoic have generated large effects on the geomorphology and environment over Asia. However, how the basin responded to the uplifted Tibetan Plateau remains unknown. Here, we examined the digital geomorphology of the Bahe River basin, the greatest first-order tributary in the southern Weihe River basin. The geomorphogenesis of the watershed, the far-field effects, and the long-range consequences of the elevation from the Tibetan Plateau were thoroughly discussed. We found that there were five layers of terraces, which were mainly controlled by tectonic activity. The geomorphological characteristics suggested that Bahe basin was influenced by a severe tectonic activity prime, with intense river erosion. The Lishan-North Qinling Mountains uplift, facilitated by the horizontal expansion of the northern Qinghai-Tibet Plateau, was also responsible for the development of the Bahe River basin.

Estimation of Runoff in Data Scare Watershed of Middle Gujarat, India Using HEC-HMS Model

The accurate estimation of the hydrologic response in water resources planning and development is crucial. In this study, the rainfall-runoff relationship and hydrologic response of the Devgadh Baria watershed in the Panam river catchment were investigated. Due to limited availability and accuracy of runoff data, Clark UH, and SCS UH models were explored for runoff estimation. Remote sensing and GIS techniques were integrated to assess the ungauged watershed in the Middle Gujarat region.
 Rainfall and discharge data, Sentinel-2 data, 12.5m ALOS PALSAR DEM, base maps, and soil maps were collected from various sources. The study area's five different events were randomly selected, and a Thiessen map was prepared to calculate weighted rainfall. Geomorphological parameters and Horton's ratios were estimated using remote sensing and GIS software ILWIS.
 The composite curve number (CN) for the watershed was found to be 77.69. Excess-rainfall hyetographs were separated using the SCS-loss method, and the time to peak estimated by the models matched well with observed data, except for a one-day delay in the HEC-HMS based Clark UH model.
 Four performance indices, namely NSE, PBIAS, RMSE, and d, were used to compare model performance. The SCS UH model demonstrated the highest NSE value (-0.28) for event-1, while the HEC-HMS based SCS UH model showed the lowest NSE value (-0.28) for event-1. The SCS model outperformed the other models based on performance indicators NSE, RMSE, and d. Overall, the SCS UH approach provided the best estimation of peak discharge and time to peak discharge. The direct surface runoff hydrographs estimated using.

Post-Shock Gravitational Erosion and Sediment Yield: A Case Study of Landscape Transformation along the Wenchuan–Yingxiu Section of the Minjiang River, Sichuan, China

In Wenchuan, China, which was severely affected by an M8.1 earthquake in 2008, the geomorphic process has been driven by gravitational erosion brought on by post-shock rockfalls and landslides. However, a process-based delineation of the post-shock landscape modification using quantitative methods employing mathematical modeling and control experiments has not yet been successfully undertaken. This is due to the areas’ substantial sediment yield and growing transportation capacity. This study looked into 31 minor watersheds along the Minjiang River’s Wenchuan–Yingxiu stretch. Additionally, a digital gully model based on multi-source remote sensing, Geographic Information System (GIS), Differential Intereferometric Synthetic Aperture Radar (D-InSAR), and amplitude tracking technology was created for the quantitative estimation of post-shock gravity erosion and sediment yield by comparison of three-dimensional topographical alternation (before and after the shock). Following regression analysis, a useful model for sediment yield estimation was suggested. The following conclusions were reached: (1) There was a considerable favorable effect between an angle of 50 and 70 degrees, and various geomorphological parameters had scale effects. Gravitational sediment yield modulus displayed a positive power function relationship with relative relief and surface fragmentation, but there was no clear correlation between the modulus and slope, relative relief, or surface fragmentation at the watershed scale; (2) Both the budget for post-shock geo-materials and the production of sediment from gravity erosion showed an annual trend of decline; (3) A 10–20-year active period would be recognized by gravity erosion.

Understanding the landscape evolution of El Mogote barrier spit, Baja California Sur, Mexico, using OSL dating, satellite images and a multivariate analysis

Barrier spits are natural archives that provide information about coastal evolution and prevailing environmental conditions of the mainland. In this study, we analyze one of the largest barrier spits in Baja California Sur, Mexico, known as El Mogote bar, using a multi-method approach to unravel the coastal landscape evolution. We used (1) OSL dating to provide a robust geochronology and depositional rates of the emerged beach-dune ridges, (2) satellite imagery interpretation using the Digital Shoreline Analysis System (DSAS) software to assess shoreline changes on Landsat images from 1986 to 2014, and (3) the Principal Component Analysis (PCA) with climatic and geomorphologic parameters to elucidate the environmental conditions of the beach-dune ridges for the period comprised in the DSAS analysis. OSL results indicate that the emerged bars started to form ∼2 ka and were developed in three main building phases: (1) the Medieval Warm Period (MWP) and part of the Little Ice Age (LIA) with accretional rates of 1.13 m yr −1, (2) the ending of the LIA with 7.03 m yr −1 and (3) the post-LIA with 3.98 m yr −1. In this paper, we hypothesize two probable causes that led to the destruction of the former beach-dune ridges: (1) tsunami waves triggered by seismic events and (2) local sea level rise associated with local tectonic subsidence. Satellite images and DSAS analysis show that, in the barrier spit, accretion and erosion have been in dynamic equilibrium for at least three decades. PCA results indicate that dry and cold weather conditions, El Niño modes, and tropical cyclone occurrence with high accretional rates on the barrier spit are the main controls on the beach-dune ridges. We conclude that the multi-method approach used in this research is suitable to tease out the landscape evolution of a barrier spit from a climatic and geomorphological perspective, as we were able to identify that the accretional episodes of El Mogote bar are mainly related to rainfall during the coldest and driest environmental conditions that enhance sediment supply from continental areas to the coast.

Direct runoff hydrograph model’s collation for a Pakistan’s region

Rainfall-Runoff modeling is among the classical applications of hydrology. This paper examines the results of 3 hydrologic approaches, particularly Clark Model, Nash Model, and Geomorphic Instantaneous Unit Hydrograph Model. Assumptions are forwarded for the long run use of the Rawalpindi Division, Pakistan’s Small Dam Organization. The catchment of Shahpur Dam was an area under consideration for the study. The Digital elevation model (DEM) was implicated to measure the Nash and Clark model’s geomorphic parameters. Using ArcGIS, catchment satellite imagery was processed to estimate geomorphological parameters. The models have been applied to multiple storm cases. Geographic Instantaneous Unit Hydrograph (GIUH) model gave direct surface runoff hydrograph, whereas, on measured precipitation excess rainfall hyetograph was obtained. Four types of statistical parameters, namely efficiency of the model (EFF), percentage defect in time to attain peak (PETP), percent defect in attained peak Q (PEP), percentage defect in runoff rate (PEV) are used to check model’s efficiency. The comparison is done between the findings of Clark and Nash GIUH models and the original Clark and Nash models. It was observed that GIUH models are equally good even when optimization is done for Clark and Nash model’s parameters. Since the results obtained from these models are more credible, so, these models can be used in ungauged catchments to estimate the hydrographs.