scholarly journals Study on the Relationship between Snowmelt Runoff for Different Latitudes and Vegetation Growth Based on an Improved SWAT Model in Xinjiang, China

2021 ◽  
Vol 13 (3) ◽  
pp. 1189
Author(s):  
Yongchao Duan ◽  
Min Luo ◽  
Xiufeng Guo ◽  
Peng Cai ◽  
Fu Li
Keyword(s):  
High Altitude ◽  
Assessment Tool ◽  
Swat Model ◽  
Precipitation Pattern ◽  
Mountainous Area ◽  
Snowmelt Runoff ◽  
Mountainous Areas ◽  
Snow Melting ◽  
Modified Model ◽  
Vegetation Growth

Rivers located in high altitude mountainous areas provide a large number of water resources and are also high-risk areas for seasonal snow melt floods. The accurate calculation and simulation of snow melting processes can provide reliable data for flood disaster prediction. In order to make the Soil and Water Assessment Tool (SWAT) model more suitable for high altitude mountainous areas, the effect of the daily accumulated temperature on the precipitation pattern and snow melting is fully considered. Applying the modified model to three mountain systems with different latitudes in Xinjiang can not only improve our understanding of the characteristics of snowmelt flooding but can also be used to test the applicability of the modified model. Through comparison, it was found that the simulation accuracy of the modified model of the flood peak value was improved by 56.19%. The correlation coefficient between the Normalized Difference Vegetation Index (NDVI) and snowmelt increased from 0.27 to 0.68. This study provides a new method for accurately understanding the process of snowmelt runoff in the mountainous area and provides new insights into the effects of snowmelt runoff on vegetation growth at different latitudes.

scholarly journals Increasing Rainfall and Runoff in Alpine Mountainous Areas Can't Completely Eliminate Drought Driven by Temperature Rise 

2020 ◽  
Author(s):  
Yu Deng ◽  
Zhifeng Guo ◽  
Fuquan Ni ◽  
Lianqing Xue ◽  
Yiping Wu ◽  
...  
Keyword(s):  
Climate Change ◽  
Temperature Rise ◽  
Assessment Tool ◽  
Swat Model ◽  
Heihe River ◽  
Mountainous Area ◽  
Mountainous Areas ◽  
Runoff Change ◽  
Scientific Significance ◽  
The Impact

Abstract Drought research under climate change is of great scientific significance. For Land Use and Land Cover Change (LUCC), temperature and rainfall in climate change, which factor has a greater impact on runoff change in alpine mountainous areas? Can the increase of rainfall in the alpine mountainous area completely eliminate the drought driven by temperature rise? This study takes the upper reaches of Heihe River basin (URHRB) as an example, the URHRB's Soil and Water Assessment Tool (SWAT) model is constructed. Based on 58 scenarios and The Budyko Framework, here we show that a)climate change has a greater contribution to runoff than LUCC, effect of increased rainfall greater than temperature rising on runoff in alpine mountainous area; b)the drought of 57.14% of UHRRB’s sub-basins have eased, 42.86% of the sub-basins is more serious, the increase in rainfall can't completely eliminate the drought driven by temperature rise. This study coupling SWAT simulation with Budyko Framework and other methods solves the problem of lack of data in alpine mountainous areas, and more accurately quantifies the impact of climate change, LUCC on runoff changes, realizing theoretical and method innovation. The results of this study provide a scientific paradigm for solving scientific problems in similar regions in China and other countries, and have important promotion value.

scholarly journals Sub-Daily Simulation of Mountain Flood Processes Based on the Modified Soil Water Assessment Tool (SWAT) Model

2019 ◽  
Vol 16 (17) ◽  
pp. 3118 ◽  
Author(s):  
Yongchao Duan ◽  
Fanhao Meng ◽  
Tie Liu ◽  
Yue Huang ◽  
Min Luo ◽  
...  
Keyword(s):  
High Altitude ◽  
Soil Water ◽  
Assessment Tool ◽  
Swat Model ◽  
High Temporal Resolution ◽  
Distributed Hydrological Model ◽  
Mountainous Areas ◽  
Accumulated Temperature ◽  
Soil Water Assessment Tool ◽  
Water Assessment

Floods not only provide a large amount of water resources, but they also cause serious disasters. Although there have been numerous hydrological studies on flood processes, most of these investigations were based on rainfall-type floods in plain areas. Few studies have examined high temporal resolution snowmelt floods in high-altitude mountainous areas. The Soil Water Assessment Tool (SWAT) model is a typical semi-distributed, hydrological model widely used in runoff and water quality simulations. The degree-day factor method used in SWAT utilizes only the average daily temperature as the criterion of snow melting and ignores the influence of accumulated temperature. Therefore, the influence of accumulated temperature on snowmelt was added by increasing the discriminating conditions of rain and snow, making that more suitable for the simulation of snowmelt processes in high-altitude mountainous areas. On the basis of the daily scale, the simulation of the flood process was modeled on an hourly scale. This research compared the results before and after the modification and revealed that the peak error decreased by 77% and the time error was reduced from ±11 h to ±1 h. This study provides an important reference for flood simulation and forecasting in mountainous areas.

scholarly journals Inclusion of Modified Snow Melting and Flood Processes in the SWAT Model

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1715 ◽  
Author(s):  
Yongchao Duan ◽  
Tie Liu ◽  
Fanhao Meng ◽  
Min Luo ◽  
Amaury Frankl ◽  
...  
Keyword(s):  
Assessment Tool ◽  
Swat Model ◽  
Melting Process ◽  
Peak Performance ◽  
Maximum Temperature ◽  
Snow Melting ◽  
Flood Simulation ◽  
Flood Peak ◽  
Forecasting Method ◽  
Time Accuracy

Flooding, one of the most serious natural disasters, poses a significant threat to people’s lives and property. At present, the forecasting method uses simple snowmelt accumulation and has certain regional restrictions that limit the accuracy and timeliness of flood simulation and prediction. In this paper, the influence of accumulated temperature (AT) and maximum temperature (MT) on snow melting was considered in order to (1) reclassify the precipitation categories of the watershed using a separation algorithm of rain and snow that incorporates AT and MT, and (2) develop a new snow-melting process utilizing the algorithm in the Soil and Water Assessment Tool Model (SWAT) by considering the effects of AT and MT. The SWAT model was used to simulate snowmelt and flooding in the Tizinafu River Basin (TRB). We found that the modified SWAT model increased the value of the average flood peak flow by 43%, the snowmelt amounts increased by 45%, and the contribution of snowmelt to runoff increased from 44.7% to 54.07%. In comparison, we concluded the snowmelt contribution to runoff, flood peak performance, flood process simulation, model accuracy, and time accuracy. The new method provides a more accurate simulation technique for snowmelt floods and flood simulation.

scholarly journals Calibration of a modelling approach for sediment yield in a wattle plantation, KwaZulu-Natal, South Africa

Water SA ◽  
2020 ◽  
Vol 46 (2 April) ◽  
Author(s):  
BC Scott-Shaw ◽  
TR Hill ◽  
JS Gillham
Keyword(s):  
South Africa ◽  
Assessment Tool ◽  
Swat Model ◽  
Catchment Scale ◽  
Vegetation Growth ◽  
Erosion Risk ◽  
Kwazulu Natal ◽  
Input Parameters ◽  
Risk Areas ◽  
Managed Ecosystems

Hydrological modelling is an appropriate approach to investigate the effect of interactions of climate, land-use and soil on the water-use of natural or managed ecosystems, in particular where spatial heterogeneity exists. The Soil and Water Assessment Tool (SWAT) model has evolved into one of the most widely used catchment-scale hydrological models, which has been extensively used to better understand hydrological processes. In this paper, the SWAT model was adopted to simulate a wattle plantation in KwaZulu-Natal, South Africa. User-defined vegetation growth, soil and management input parameters were constructed for the study area based on site measurements. These parameters were subsequently modified using the Sequential Uncertainty Fitting (SUFI-2) analysis routine to calibrate the model. The calibrated model captured seasonal trends in the observed sediment and streamflow data. The compilation of spatially explicit sediment output provides a useful approach to manage catchments by identifying high erosion-risk areas. The SWAT model, using site-specific input parameters, provides a platform for subsequent hydrological and sediment modelling in South Africa.

scholarly journals Improved SWAT vegetation growth module for tropical ecosystem

2017 ◽  
Author(s):  
Tadesse Alemayehu ◽  
Ann van Griensven ◽  
Willy Bauwens
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Soil Moisture ◽  
Management Practices ◽  
Assessment Tool ◽  
Swat Model ◽  
Evergreen Forest ◽  
Tropical Ecosystem ◽  
Area Index ◽  
Vegetation Growth

Abstract. The Soil and Water Assessment Tool (SWAT) is a globally applied river basin eco-hydrological simulator in a wide spectrum of studies, ranging from land use change and climate change impacts studies to research for the development of best water management practices. However, SWAT has limitations in simulating the seasonal growth cycles for trees and perennial vegetation in tropics, where the major plant growth controlling factor is the rainfall (via soil moisture) rather than temperature. Our goal is to improve the vegetation growth module of the SWAT model for simulating the vegetation parameters such as the leaf area index (LAI) for tropics. Therefore, we present a modified SWAT version for the tropics (SWAT-T) that uses of a simple but robust soil moisture index (SMI) – a quotient of the rainfall (P) and reference evapotranspiration (PET) – to initiate a new growing season after a defined dry season. Our results for the Mara Basin (Kenya/Tanzania) show that the SWAT-T simulated LAI corresponds well with the Moderate Resolution Imaging Spectroradiometer (MODIS) LAI for evergreen forest, savanna grassland and shrubs, indicating that the SMI is a reliable proxy to dynamically initiate a new growing cycle. The water balance components (evapotranspiration and flow) simulated by the SWAT-T exhibit a good agreement with remote sensing-based evapotranspiration (RS-ET) and observed flow. The SWAT-T simulator with the proposed improved vegetation growth module for tropical ecosystem could be a robust tool for several applications including land use and climate change impact studies.

Improved Swat Model and Application in Simulation of Snowmelt Runoff

2012 ◽  
Vol 550-553 ◽  
pp. 2561-2564
Author(s):  
Zhen Min Zhou ◽  
Yan Jie Bi ◽  
Xue Chao Wang
Keyword(s):  
Double Layer ◽  
Swat Model ◽  
Model Parameters ◽  
Snowmelt Runoff ◽  
Snow Melting ◽  
Improved Model ◽  
Runoff Model ◽  
Relevant Factors ◽  
Better Than ◽  
Parameters Calculation

The improved model for double layer snowpack melting was put forward to overcome the disadvantages of the DG (Degree-Day) model which had simple principle and neglected the relevant factors which could be important to the simulation of snowmelt runoff. The surface snowpack model, improved top layer snowpack model and model parameters calculation were studied. The structure and calculation method were put forward to improve double layer snowpack runoff model. Finally, taking the Lancangjiang River as an example, the snowmelt runoff was calculated by the improved SWAT model. Through comparison, it revealed that between two models that the simulation results of the improved double layer snow melting model was obviously better than that of the DG model in evapo-transpiration loss, the distinguish among cover layer, snowfall, rainfall and snowpack water equivalent calculation, and melting snowpack refrozen as well as adaption condition.

scholarly journals Modifications to Snow-Melting and Flooding Processes in the Hydrological Model—A Case Study in Issyk-Kul, Kyrgyzstan

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1580
Author(s):  
Solange Uwamahoro ◽  
Tie Liu ◽  
Vincent Nzabarinda ◽  
Jules Habumugisha ◽  
Theogene Habumugisha ◽  
...  
Keyword(s):  
River Flow ◽  
Assessment Tool ◽  
Swat Model ◽  
Melting Process ◽  
Flood Frequency ◽  
Snow Melting ◽  
Forecasting Method ◽  
Flood Peaks ◽  
Maximum Temperatures

Streamflow impacts water supply and flood protection. Snowmelt floods occur frequently, especially in mountainous areas, and they pose serious threats to natural and socioeconomic systems. The current forecasting method relies on basic snowmelt accumulation and has geographic limitations that restrict the accuracy and timeliness of flood simulation and prediction. In this study, we clarified the precipitation types in two selected catchments by verifying accumulated and maximum temperatures’ influences on snow melting using a separation algorithm of rain and snow that incorporates with the temperatures. The new snow-melting process utilizing the algorithm in the soil and water assessment tool model (SWAT) was also developed by considering the temperatures. The SWAT model was used to simulate flooding and snowmelt in the catchments. We found that the contributions of snowmelt to the river flow were approximately 6% and 7% higher, according to our model compared to the original model, for catchments A and B, respectively. After the model improvement, the flood peaks increased by 49.42% and 43.87% in A and B, respectively. The contributions of snowmelt to stream flow increased by 24.26% and 31% for A and B, respectively. Generally, the modifications improved the model accuracy, the accuracy of snowmelt’s contributions to runoff, the accuracy of predicting flood peaks, the time precision, and the flood frequency simulations.

scholarly journals The Effect of Vegetation on the Propagation Loss of V2I Network in High Altitude and Mountainous Area

2021 ◽  
pp. 437-443
Author(s):  
Dongjie Xie ◽  
◽  
Rong Guo ◽  
Huafu Li ◽  
Yanmei Jing ◽  
...  
Keyword(s):  
High Altitude ◽  
High Reliability ◽  
Propagation Loss ◽  
Equivalent Model ◽  
The Internet ◽  
Mountainous Area ◽  
Mountainous Areas ◽  
Complex Environment ◽  
Internet Of Vehicles ◽  
Transmitting Antenna

With the gradual formation of the commercialization of the fifth-generation communication technology, the Internet of Vehicles technology has developed rapidly, and the vehicle to infrastructure (V2I) network technology is an important part of the Internet of Vehicles. In high-altitude and mountainous areas, the communication quality of the V2I network is not only affected by terrain, but forest vegetation will also cause greater propagation loss. Aiming at the influence of vegetation in high-altitude and mountainous complex environment on the propagation loss of V2I network, this paper establishes an equivalent model of vegetation in high-altitude and mountainous areas, and analyzes the relationship between propagation loss, propagation distance and frequency of transmitting antenna. At the same time, through digital elevation model (DEM) data and triangulated irregular network (TIN), MATLAB was used to simulate the communication coverage of V2I network in the complex area covered by vegetation, and the influence of vegetation on the propagation loss of V2I network in high altitude and mountainous areas was obtained. In the future, constructing the Internet of Vehicles in a complex environment, the results of research in this article will provide a scientific basis for network quality with high reliability and low latency.

scholarly journals Hydrologic evaluation and effects of climate change on the Nong Han Lake Basin, northeastern Thailand

2019 ◽  
Vol 11 (4) ◽  
pp. 992-1000
Author(s):  
Jirawat Supakosol ◽  
Kowit Boonrawd
Keyword(s):  
Climate Change ◽  
Assessment Tool ◽  
Swat Model ◽  
Climate Projections ◽  
Lake Basin ◽  
Model Soil ◽  
Regional Climates ◽  
Water Assessment ◽  
Effective Water ◽  
Northeastern Thailand

Abstract The purpose of this study is to investigate the future runoff into the Nong Han Lake under the effects of climate change. The hydrological model Soil and Water Assessment Tool (SWAT) has been selected for this study. The calibration and validation were performed by comparing the simulated and observed runoff from gauging station KH90 for the period 2001–2003 and 2004–2005, respectively. Future climate projections were generated by Providing Regional Climates for Impacts Studies (PRECIS) under the A2 and B2 scenarios. The SWAT model yielded good results in comparison to the baseline; moreover, the results of the PRECIS model showed that both precipitations and temperatures increased. Consequently, the amount of runoff calculated by SWAT under the A2 and B2 scenarios was higher than that for the baseline. In addition, the amount of runoff calculated considering the A2 scenario was higher than that considering the B2 scenario, due to higher average annual precipitations in the former case. The methodology and results of this study constitute key information for stakeholders, especially for the development of effective water management systems in the lake, such as designing a rule curve to cope with any future incidents.

scholarly journals SWAT Model Adaptability to a Small Mountainous Forested Watershed in Central Romania

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 860
Author(s):  
Nicu Constantin Tudose ◽  
Mirabela Marin ◽  
Sorin Cheval ◽  
Cezar Ungurean ◽  
Serban Octavian Davidescu ◽  
...  
Keyword(s):  
Metropolitan Area ◽  
Hydrological Model ◽  
Assessment Tool ◽  
Swat Model ◽  
Decision Makers ◽  
Forested Watershed ◽  
Sensitive Parameters ◽  
Lower Uncertainty ◽  
Validation Stage ◽  
Water Assessment

This study aims to build and test the adaptability and reliability of the Soil and Water Assessment Tool hydrological model in a small mountain forested watershed. This ungauged watershed covers 184 km2 and supplies 90% of blue water for the Brașov metropolitan area, the second largest metropolitan area of Romania. After building a custom database at the forest management compartment level, the SWAT model was run. Further, using the SWAT-CUP software under the SUFI2 algorithm, we identified the most sensitive parameters required in the calibration and validation stage. Moreover, the sensitivity analysis revealed that the surface runoff is mainly influenced by soil, groundwater and vegetation condition parameters. The calibration was carried out for 2001‒2010, while the 1996‒1999 period was used for model validation. Both procedures have indicated satisfactory performance and a lower uncertainty of model results in replicating river discharge compared with observed discharge. This research demonstrates that the SWAT model can be applied in small ungauged watersheds after an appropriate parameterisation of its databases. Furthermore, this tool is appropriate to support decision-makers in conceiving sustainable watershed management. It also guides prioritising the most suitable measures to increase the river basin resilience and ensure the water demand under climate change.

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