Analysis of Runoff Simulation under Changes in Climate Variability: A Case Study of the Upper Awash Sab-basin, Ethiopia | Chapter 1 | Geography, Earth Science and Environment: Research Highlights Vol.4

The impact of precipitation and temperature on runoff over land surfaces is examined through runoff simulation analysis. The Soil and Water Assessment Tool (SWAT) hydrology model is used in this study to predict the sensitivity of runoff to changes in temperature and precipitation. To investigate the sensitivity of runoff to temperature and rainfall, these variables were changed. Rainfall and temperature have a major impact on runoff accessibility by affecting the timing and contribution of water sources. For the entire upper Awash Sab-basin (1980–2010), monthly station-based temperature and rainfall data were used to run the SWAT model. The hydrological model was calibrated during an eight-year period (1993-2000), and the simulation findings were validated using historical stream-flow data at the Hombole gauging station's outlet for four years (2001-2005). The calibrated and validated SWAT hydrological model was used to perform a sensitivity analysis in order to evaluate the effect of changes in temperature and rainfall on the sub-basin's runoff. Utilizing the SWAT model, the effects of several theoretical rainfall and temperature scenarios on the yearly runoff of the Upper Awash sub-basin have been examined. This was accomplished by using temperature increases (up to 5°C) and variations in rainfall (+/-20%) separately and in combination. The findings demonstrated that in the studied area, runoff was responsive to variations in temperature and rainfall.  It has been found that a yearly temperature increase of 1, 2, 3, 4, and 50C results in annual runoff reductions of 0.085, 0.88, 1.75, 2.55, and 3.30%, respectively. There is a negative link between temperature changes and runoff, but a positive correlation with changes in rainfall. The findings show that rainfall has a greater effect on runoff than temperature rise. A 10% increase or decrease in rainfall will cause a 22% or 21% increase or decrease in annual runoff. The findings demonstrated that the availability of water was significantly impacted by changes in the climatic variables.

 

Author (s) Details

 

Mekonnen H. Daba (PhD)
Oromia Agricultural Research Institute, Bako Agricultural Research Center, Bako, Ethiopia.

 

Please see the book here:- https://doi.org/10.9734/bpi/geserh/v4/2245 

Evaluation of Land Use Changes on Stream Discharge by SWAT Model and Remote Sensing in Agro-Forestry Basin in Nghinh Tuong Subwatershed, Northern Vietnam | Chapter 4 | Research Aspects in Agriculture and Veterinary Science Vol. 4

 The purpose of this study is to examine the impact of land-use changes on stream discharge in the Nghinh Tuong watershed (a branch of the Cau river) in Northern Vietnam using the "Soil and Water Assessment Tool (SWAT)" model and GIS. The watershed was 56 percent forested, 30 percent agricultural, and the rest was undeveloped.

Stream discharge observation data from 2001 to 2010 was used for the calibration period, whereas the validation period was from 2011 to 2020.

The results revealed that two coefficients (NSE and PBIAS) were 0.76 and 6.54 percent for calibration and 0.87 and 4.74 percent for validation period, respectively, to evaluate model performance. Changes in land use, as well as the amount of precipitation, have a big impact on stream discharge. Agricultural land (corn, orchard, and tea) increases by 9782.67 ha (2.45 percent) over the baseline scenario, whereas woodland (forest-mixed) drops by 1091.77 ha (2.75 percent ). Furthermore, precipitation increases 3.74 percent in the mean wet season but decreases 0.5 percent in the mean dry season when compared to the baseline period. The SWAT model was able to successfully simulate stream discharge and sediment output for the Nghinh Tuong watershed not only for the Baseline scenario, but also for Scenario 1. SWAT shows its capacity to replicate stream discharge at the subwatershed level in a nutshell. It's a great tool for dealing with water quantity and quality management in the Nghinh Tuong watershed. According to this study, SWAT is an excellent strategy for resource and environmental management.

Author(S) Details

Phan Dinh Binh
Faculty of Resources Management, Thai Nguyen University of Agriculture and Forestry, Viet Nam.

View Book:- https://stm.bookpi.org/RAAVS-V4/article/view/4846