scholarly journals CALIBRATION AND VALIDATION OF SWMM MODEL IN A SUB CATCHMENT IN ELDORET TOWN, KENYA

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Rotich Abraham Metto ◽  
Kiptum Clement Kiprotich ◽  
Kipkorir Emmanuel Chessum
Keyword(s):  
Environmental Protection Agency ◽  
Rain Gauge ◽  
Transportation Systems ◽  
Base Flow ◽  
Maximum Rainfall ◽  
Calibration And Validation ◽  
Digital Elevation ◽  
Final Design ◽  
Elevation Model ◽  
Swmm Model

Flooding in Eldoret town has been occurring during heavy downpours resulting in loss of property, live and interruption of transportation systems. This study aimed at determining the catchment characteristics in Eldoret town for the calibration and validation of SWMM5 model. This model was developed by US Environmental Protection Agency. The model has been evolving from Version 1 in 1971 to Version 5 of 2005 called SWMM5. It can simulate runoff quantity in any given catchment. Rainfall was measured using rain gauge while discharge was measured using current meter. Digital Elevation Model of the study area was also obtained. The results showed that the catchment drained an area of approximately 696.5 hectares with a total of 23 sub catchments. The average slope was found to be 2.57% and the mean average imperviousness was 25.72%. The drain base flow was found to be 0.002 m3/s. However, during prolonged rainfall, the discharge increased up to 32.4 m3/s. The maximum rainfall observed during the study period was 32.4 mm which resulted in the maximum average discharge of 0.131m3/s and resulted in overflow in the drain.  Calibrated model had N-Imperv of 0.45, Dstore-Imperv of 2.5 and Dstore-Perv of 8. ISE values of 1.9 and 1.4 were observed for calibration and validation, respectively.  NSE values of 0.97 and 0.99 were observed for calibration and validation, respectively. This meant that model excellently simulated rainfall-discharge relationship in the study area and can be used for final design by the Eldoret town engineers. Future study is required to calibrate the model based on more measurements of rainfall and their discharges in the catchment.

scholarly journals Vehicle Movement Analyses Considering Altitude Based on Modified Digital Elevation Model and Spherical Bilinear Interpolation Model: Evidence from GPS-Equipped Taxi Data in Sanya, Zhengzhou, and Liaoyang

2020 ◽  
Vol 2020 ◽  
pp. 1-21 ◽  
Author(s):  
Jiawei Gui ◽  
Qunqi Wu
Keyword(s):  
Intelligent Transportation Systems ◽  
Transportation Systems ◽  
Special Importance ◽  
Labor Costs ◽  
Bilinear Interpolation ◽  
Safety Level ◽  
Bright Future ◽  
Digital Elevation ◽  
Elevation Model ◽  
Vehicle Movement

Aggravating energy shortages and increasing labor costs have become global problems and have garnered special importance in recent years in the transportation sector, especially in taxi markets. Automatic vehicles have a bright future, however, there is an equal amount of skepticism and concern about safety for all the optimism. To unlock the potential of automatic vehicles in intelligent transportation systems, a lot more data and testing are required to promote safety level as far as possible and achieve the organizational aim of reducing accidents to zero tolerance. And it is vital to provide accurate models for vehicle movement analyses. In this study, Modified Digital Elevation (MDE) model and Spherical Bilinear Interpolation (SBI) model were proposed for vehicle movement analyses considering altitude. And the experimental data of 9,990 GPS-enabled taxis in Sanya, Zhengzhou, and Liaoyang were adopted to support comparisons. Measurement results showed that MDE model had over 99% less disparity with direct solution than original model and SBI model could further improve the effects. It indicated that the application of MDE model and SBI model could improve both accuracy and efficiency of vehicle movement analyses and it had a bright future in the field of automatic vehicles. Future directions could be improving models and expanding data.

scholarly journals Study on the Improved Method of Urban Subcatchments Division Based on Aspect and Slope- Taking SWMM Model as Example

Hydrology ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 26
Author(s):  
Zening Wu ◽  
Bingyan Ma ◽  
Huiliang Wang ◽  
Caihong Hu
Keyword(s):  
Catchment Area ◽  
Current Method ◽  
Model Parameters ◽  
Rainfall Runoff ◽  
Storm Water Management Model ◽  
Digital Elevation ◽  
Catchment Areas ◽  
Average Slope ◽  
Elevation Model ◽  
Swmm Model

The storm water management model (SWMM) is widely used in urban rainfall runoff simulations, but there are no clear rules for the division of its sub catchment areas. At present, the popular sub catchment area division method takes the average slope as the slope parameter of the sub catchment area, which brings errors to the model in mechanism. Based on the current method, this paper proposes a new method to further subdivide the sub catchment area of the SWMM model, according to the Digital Elevation Model (DEM) data of underlying surface, slope and aspect information. By comparing with the previous methods, it was found that the division method based on slope and aspect can make the setting of model parameters and hydraulic exchange conditions clearer, and improve the accuracy of the model on a certain level.

scholarly journals Analysis of land cover change and its impact on peak discharge in Jelap Sub-Watershed, Sintang District

2018 ◽  
Vol 16 (1) ◽  
pp. 61
Author(s):  
Diah Auliyani
Keyword(s):  
Remote Sensing ◽  
Land Cover ◽  
Land Cover Change ◽  
Digital Elevation Model ◽  
Shuttle Radar Topography Mission ◽  
Peak Discharge ◽  
Dry Land ◽  
Maximum Rainfall ◽  
Digital Elevation ◽  
Elevation Model

ABSTRAKInformasi mengenai debit puncak sangat penting dalam perencanaan pembangunan infrastruktur. Debit puncak dapat diprediksi menggunakan data dari alat pengukur tinggi muka air yang di pasang di outlet Daerah Aliran Sungai (DAS). Namun demikian, tidak semua DAS memiliki alat tersebut, terutama yang berada pada daerah dengan tingkat aksesibilitas rendah. Teknologi penginderaan jauh dapat menggantikan cara tersebut dalam menyediakan data dan informasi sumberdaya alam maupun pemantauan lingkungan. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh perubahan penutupan lahan terhadap debit puncak di Sub DAS Jelap. Sub DAS Jelap merupakan bagian dari DAS Kapuas yang berada di Kabupaten Sintang, Propinsi Kalimantan Barat. Data curah hujan diperoleh dari stasiun pengamatan curah hujan Bandara Susilo. Debit puncak dihitung menggunakan metode Rational dengan memanfaatkan data satelit penginderaan jauh berupa Digital Elevation Model/ Shuttle Radar Topography Mission (DEM/ SRTM). Selama 1990-2016, hutan lahan kering sekunder dan hutan rawa sekunder mengalami penurunan seluas 1298 ha dan 338 ha, sedangkan semak belukar, semak belukar rawa, pertanian lahan kering campur semak, perkebunan dan area pertambangan mengalami peningkatan sebesar 78 ha, 102 ha, 814 ha, 640 ha, dan 2 ha. Perubahan penutupan lahan tersebut telah meningkatkan koefisien runoff dengan rata-rata peningkatan sebesar 0,14%. Dengan luas daerah terbangun kurang dari 1%, debit puncak yang dihasilkan berdasarkan analisis spasial memiliki pola yang hampir sama dengan fluktuasi curah hujan maksimum. Hal ini menunjukkan bahwa dibandingkan faktor lainnya, curah hujan maksimum merupakan faktor yang sangat menentukan nilai debit puncak di Sub DAS Jelap.Kata kunci: Penutupan lahan, curah hujan, debit puncak, Jelap, SintangEnglish title: Analysis of land cover change and its impact on peak discharge in Jelap Sub-Watershed, Sintang DistrictABSTRACTInformation on peak discharge is crucial in infrastructure development planning. Peak discharge could be predicted using data from water level gauges which installed at the watershed outlet. However, not all of the watersheds have such tools, especially those in areas with low accessibility levels. Remote sensing technology could replace such tools in providing data and information of natural resources as well as environmental monitoring. The objective of this research was to analyze the land cover change and its impact on peak discharge at Jelap Sub-Watershed. Jelap Sub-Watershed is part of Kapuas Watershed located in Sintang District, West Kalimantan Province. The rainfall data were collected from Susilo Airport Rainfall Station. Peak discharge was calculated using a rational method by utilizing remote sensing satellite data in the form of Digital Elevation Model/ Shuttle Radar Topography Mission (DEM/ SRTM). Throughout 1990-2016, the area of secondary dry land forest and secondary swamp forest declined by 1298 ha and 338 ha, while shrubs, swamp shrubs, mixed dry land agriculture, plantations, and mining areas increased by 78 ha, 102 ha, 814 ha, 640 ha, and 2 ha. The change in land cover has increased the runoff coefficient with 0,14% average increment. With built area less than 1%, the peak discharge generated spatially had a similar pattern with the fluctuation of maximum rainfall. Compared to other factors, the maximum rainfall was the most decisive factor to determine peak discharge in Jelap Sub-Watershed.Keywords: Landcover, Rainfall, Peak discharge, Jelap, SintangCitation: Auliyani, D. (2018). Analisis perubahan penutupan lahan dan pengaruhnya terhadap debit puncak di Sub Daerah Aliran Sungai Jelap, Kabupaten Sintang. Jurnal Ilmu Lingkungan, 16(1),61-67, doi:10.14710/jil.16.1.61-67

scholarly journals Catchment-Scale Flood Modelling in Data-Sparse Regions Using Open-Access Geospatial Technology

2020 ◽  
Vol 9 (9) ◽  
pp. 512
Author(s):  
Iguniwari Thomas Ekeu-wei ◽  
George Alan Blackburn
Keyword(s):  
Integrated Approach ◽  
Catchment Scale ◽  
Aerial Photos ◽  
Flood Modelling ◽  
Calibration And Validation ◽  
Niger Delta Region ◽  
Digital Elevation ◽  
Data Variability ◽  
Radar Imagery ◽  
Elevation Model

Consistent data are seldom available for whole-catchment flood modelling in many developing regions, hence this study aimed to explore an integrated approach for flood modelling and mapping by combining available segmented hydrographic, topographic, floodplain roughness, calibration, and validation datasets using a two-dimensional Caesar-Lisflood hydrodynamic model to quantify and recreate the extent and impact of the historic 2012 flood in Nigeria. Available segments of remotely-sensed and in situ datasets (including hydrological, altimetry, digital elevation model, bathymetry, aerial photo, optical imagery, and radar imagery data) available to different degrees in the Niger-South hydrological area were systematically integrated to draw maximum benefits from all available data. Retrospective modelling, calibration, and validation were undertaken for the whole Niger- South hydrological catchment area of Nigeria, and then these data were segmented into sub-domains for re-validation to understand how data variability and uncertainties impact the accuracy of model outcomes. Furthermore, aerial photos were applied for the first time in the study area for flood model validation and for understanding how different physio-environmental properties influenced the synthetic aperture radar flood delineation capacity in the Niger Delta region of Nigeria. This study demonstrates how the complementary strengths of open, readily available geospatial datasets and tools can be leveraged to model and map flooding within acceptable levels of uncertainty for flood risk management.

scholarly journals Inventory of landslides triggered by hurricane Matthew in Guantánamo, Cuba

2021 ◽  
Author(s):  
Yusmira Savón Vaciano ◽  
Ricardo Delgado Tellez ◽  
Enrique A. Castellanos Abella ◽  
Rafael Guardado Lacaba ◽  
Arisleidys Peña de la Cruz
Keyword(s):  
Wide Distribution ◽  
Rain Gauge ◽  
Landslide Risk ◽  
Eastern Region ◽  
Landslide Occurrence ◽  
Digital Elevation ◽  
Geological Map ◽  
Sentinel 2A ◽  
Elevation Model ◽  
Landslide Hazard Map

Abstract An inventory of landslides triggered by Hurricane Matthew (4–5 October 2016) through the eastern region of Cuba was carried out using Sentinel 2A satellite images. The inventory was compared with the slope map generated from the digital elevation model at 25 m per pixel and with the geological map at 1: 100 000 scale. The precipitation data from the 1-hour rain gauge records of four stations of the Cuban Institute of Meteorology (INSMET) and 24-hour rain gauge records of six stations of National Institute of Hydraulic Resources (INRH) were processed and analysed during this event. In total, 237 landslides were classified into rockslides, debrisflows and topples. A wide distribution of landslides was found within the selected slope classes, depending of the landslide type. Most of the landslides were generated in green schist of volcanic and vulcanoclastic rocks and rocks of the ophiolitic complex made up of ancient remains of oceanic crust. Findings increase understanding of landslide occurrence in this area in order to update landslide hazard map and to reduce landslide risk.

scholarly journals Simulation of runoff in Baitarani basin using composite and distributed curve number approaches in HEC-HMS model

MAUSAM ◽  
2021 ◽  
Vol 71 (4) ◽  
pp. 675-686
Author(s):  
SAHOO NIHARIKA ◽  
PANIGRAHI B. ◽  
DAS DWARIKA MOHAN ◽  
DAS D. P.
Keyword(s):  
Curve Number ◽  
Base Flow ◽  
Coefficient Of Determination ◽  
Validation Period ◽  
Runoff Simulation ◽  
Statistical Parameters ◽  
Calibration Period ◽  
Digital Elevation ◽  
Spatial Analyst ◽  
Elevation Model

The present study was conducted in Baitarani basin up to Anandapur gauging station of Odisha covering an area of 8603.7 km2. Pre-processing of basin from digital elevation model (DEM) was done using HEC-Geo-HMS extension and spatial analyst tool in ArcGIS. These pre-processed files were then imported to HEC-HMS for simulating runoff. In this study, runoff simulation was done using two methods, viz., composite and distributed curve number (CN) approaches. SCS curve number method was used for computation of runoff volume, SCS UH method for direct runoff, constant- monthly varying base flow method for base flow and Muskingum method for flow routing.  The model was calibrated and validated using both composite and distributed CN approaches. Data from 1st January, 2007 to 31st December, 2013 were used for calibration and 1st January, 2014 to 31st December, 2016 were used for validation. During the calibration period of composite CN approach, the statistical parameters like Nash-Sutcliffe efficiency (NSE), Coefficient of determination (R2), Percent bias (PBIAS) and RMSE-observations standard deviation ratio (RSR) were found to be 0.51, 0.63, 12.82 and 0.7, respectively and during the validation period they were found to be 0.53, 0.54,    -19.73 and 0.7, respectively. In case of distributed CN approach, the statistical parameters like NSE, R2, PBIAS and RSR were found to be 0.62, 0.63, -8.64 and 0.6, respectively during the calibration period and 0.67, 0.66, -2.25 and 0.6,  respectively during the validation period. The study indicated that distributed CN approach is more accurate than composite CN approach in simulation of runoff using HEC-HMS model.

scholarly journals Flood modelling using satellite-based precipitation estimates and digital elevation model in eastern Iraq

2018 ◽  
Vol 6 (1) ◽  
pp. 72 ◽  
Author(s):  
Zaidoon Abdulrazzaq ◽  
Nadia Aziz ◽  
Abdulkareem Mohammed
Keyword(s):  
Digital Elevation Model ◽  
Rainfall Intensity ◽  
Tropical Rainfall Measuring Mission ◽  
Rain Gauge ◽  
Landsat 8 ◽  
Flood Prediction ◽  
Tropical Rainfall ◽  
Digital Elevation ◽  
Elevation Model ◽  
The Relationship

Increasingly available and a virtually uninterrupted supply of satellite-estimated rainfall data is gradually becoming a cost-effective source of input for flood prediction under a variety of circumstances. The study conducted in Wasit province/Eastern Iraq when a flood occurs due to heavy rainfall in May 2013. In this study the capability of Tropical Rainfall Measuring Mission (TRMM) rainfall daily data have been used to estimate the relationship between measured precipitation and the Digital Elevation Model (DEM), also to study the relationship between rainfall intensity and flood waters areas. Rainfall estimation by remote sensing using satellite-derived data from the Tropical Rainfall Measuring Mission (TRMM) is a possible means of supplementing rain gauge data, having the better spatial cover of rainfall fields. The approach used throughout this paper has integrated recently compiled data derived from satellite imagery (rainfall, and digital elevation model) into a GIS geodatabase to study the relationship between rainfall intensity and floodwater's areas then the results' comparison with the Normalized Difference Water Index (NDWI) after the flood. ArcGIS software has been used to process, analyze the archived Tropical Rainfall Measuring Mission (TRMM) precipitation data, and calculate NDWI from Landsat 8 images. In conclusions, the study explains the flood-area clearly captured by the TRMM measurements; and the region’s water increased. Also, good correlation between measured precipitation and the Digital Elevation Model (DEM) has been detected.

STUDY OF THE LANDSLIDE MORPHOLOGY BASED ON GNSS DATA AND AIRBORNE SOUNDING (ON THE EXAMPLE OF A SECTION OF THE PROTVA RIVER VALLEY)

2018 ◽  
Vol 12 (5-6) ◽  
pp. 50-57 ◽  
Author(s):  
I. S. Voskresensky ◽  
A. A. Suchilin ◽  
L. A. Ushakova ◽  
V. M. Shaforostov ◽  
A. L. Entin ◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Geodetic Network ◽  
Aerial Survey ◽  
River Valley ◽  
Ease Of Use ◽  
Digital Elevation ◽  
Loose Deposits ◽  
Positioning Method ◽  
Landslide Body ◽  
Elevation Model

To use unmanned aerial vehicles (UAVs) for obtaining digital elevation models (DEM) and digital terrain models (DTM) is currently actively practiced in scientific and practical purposes. This technology has many advantages: efficiency, ease of use, and the possibility of application on relatively small area. This allows us to perform qualitative and quantitative studies of the progress of dangerous relief-forming processes and to assess their consequences quickly. In this paper, we describe the process of obtaining a digital elevation model (DEM) of the relief of the slope located on the bank of the Protva River (Satino training site of the Faculty of Geography, Lomonosov Moscow State University). To obtain the digital elevation model, we created a temporary geodetic network. The coordinates of the points were measured by the satellite positioning method using a highprecision mobile complex. The aerial survey was carried out using an unmanned aerial vehicle from a low altitude (about 40–45 m). The processing of survey materials was performed via automatic photogrammetry (Structure-from-Motion method), and the digital elevation model of the landslide surface on the Protva River valley section was created. Remote sensing was supplemented by studying archival materials of aerial photography, as well as field survey conducted immediately after the landslide. The total amount of research results made it possible to establish the causes and character of the landslide process on the study site. According to the geomorphological conditions of formation, the landslide refers to a variety of landslideslides, which are formed when water is saturated with loose deposits. The landslide body was formed with the "collapse" of the blocks of turf and deluvial loams and their "destruction" as they shifted and accumulated at the foot of the slope.

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