scholarly journals Assessment of Future Climate Change Impact on Agricultural Water Supply Capacity in Geum River Basin Using SWAT and MODSIM-DSS

2020 ◽  
Vol 20 (6) ◽  
pp. 55-66
Author(s):  
Sehoon Kim ◽  
Chunggil Jung ◽  
Jiwan Lee ◽  
Jinuk Kim ◽  
Seongjoon Kim

This study is to evaluate future agricultural water supply capacity in Geum river basin (9,865 km<sup>2</sup>) using SWAT and MODSIM-DSS. The MODSIM-DSS was established by dividing the basin into 14 subbasins, and the irrigation facilities of agricultural reservoirs, pumping stations, diversions, culverts and groundwater wells were grouped within each subbasin, and networked between subbasins including municipal and industrial water supplies. The SWAT was calibrated and validated using 11 years (2005-2015) daily streamflow data of two dams (DCD and YDD) and 4 years (August 2012 to December 2015) data of three weirs (SJW, GJW, and BJW) considering water withdrawals and return flows from agricultural, municipal, and industrial water uses. The Nash−Sutcliffe efficiency (NSE) of two dam and three weirs inflows were 0.55∼0.70 and 0.57∼0.77 respectively. Through MODSIM-DSS run for 34 years from 1982 to 2015, the agricultural water shortage had occurred during the drought years of 1982, 1988, 1994, 2001 and 2015. The agricultural water shortage could be calculated as 197.8 × 10<sup>6</sup> m<sup>3</sup>, 181.9 × 10<sup>6</sup> m<sup>3</sup>, 211.5 × 10<sup>6</sup> m<sup>3</sup>, 189.2 × 10<sup>6</sup> m<sup>3</sup> and 182.0 × 10<sup>6</sup> m<sup>3</sup> respectively. The big shortages of agricultural water were shown in water resources unit map number of 3004 (Yeongdongcheon) and 3012 (Geumgang Gongju) areas exceeding 25.1 × 10<sup>6</sup> m<sup>3</sup> and 47.4 × 10<sup>6</sup> m<sup>3</sup>. From the estimation of future agricultural water requirement using RCP 8.5 INM-CM4 scenario, the 3004 and 3012 areas showed significant water shortages of 26.1 × 10<sup>6</sup> m<sup>3</sup> (104.1%) and 50.9 × 10<sup>6</sup> m<sup>3</sup> (107.4%) in 2080s (2070∼2099) compared to the present shortages. The water shortages decreased to 23.6 × 10<sup>6</sup> m<sup>3</sup> (94.0%) and 43.3 × 10<sup>6</sup> m<sup>3</sup> (91.4%) below of the present shortages by developing irrigation facilities.

2020 ◽  
Vol 20 (8) ◽  
pp. 3216-3232
Author(s):  
Nguyen Thi Thuy Linh ◽  
Frederick N.-F. Chou

Abstract To meet increasing water consumption with limited water resources, management approaches that transfer water between purposes must be improved for sustainable development. This entails an urgent requirement for appropriate water resources management within water–energy interaction if severe water shortage occurs occasionally. This study evaluates hydropower generation policies of a cascade reservoir system in the Be River Basin in terms of security of water supply and energy production. The Generalized Water Allocation Simulation Model (GWASIM) was applied to simulate the water use of a complex system of hydropower generation and water supply. Two water allocation scenarios and six alternatives defined by varying monthly generating hours were modeled and compared. The results demonstrate that a compromise between hydropower generation and water supply can be negotiated to reduce the severity of water shortages. Different monthly hours of hydropower generation among alternatives show an effect on improving power production and reliable water supply. This study provides overall insight into the performance of a multi-purpose cascade reservoir system. It will provide a foundation for improving future study of reservoir operations in meeting the increasing demands of water and energy in Vietnam.


Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 938
Author(s):  
Frederick N.-F. Chou ◽  
Nguyen Thi Thuy Linh ◽  
Chia-Wen Wu

Resource shortages are having an increasingly severe impact as global trends like rapid population growth, urbanization, economic development, and climate change unfold. Moreover, rising living standards across many regions are also affecting water and energy resources. This entails an urgent requirement to improve water resources management. An important improvement is to transfer water between the different uses of the reservoir system. A compromise between the needs of hydropower generation and the water supply can be negotiated for the reservoir system to reduce the severity of water shortages. The Be River basin in Vietnam was selected as a case study to investigate. The combination of the generalized water allocation simulation model (GWASIM) and the bounded optimization by quadratic approximation (BOBYQA) algorithm was applied to optimize hydropower generation in various water shortage scenarios. The results present optimized hydropower generation policies for cascade reservoirs that would significantly improve the present operating policy in terms of both the water supply and hydropower generation. Moreover, multiple scenarios will provide flexibility to the reservoir operator by giving the relationship between water and energy. Given water supply conditions, the operator will be able to choose among several optimal solutions to ensure greater water resource efficiency in the Be River basin.


2012 ◽  
Vol 212-213 ◽  
pp. 498-501
Author(s):  
Rui Guo ◽  
Sheng Le Cao

Scientific and reasonable water price is the foundation of beneficial operation of water supply project, and water pricing is on the basis of per cubic meter water supply cost. According to characteristics of water supply project in the plain irrigation area of the Yellow River, a research on calculation methods of agricultural water supply cost is made. Calculation formulas of project lines are put forward and an example was given.


Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 662 ◽  
Author(s):  
Jung-Hun Song ◽  
Younggu Her ◽  
Sang Min Jun ◽  
Soonho Hwang ◽  
Jihoon Park ◽  
...  

Agricultural water supply (AWS) estimation is one of the first and fundamental steps of developing agricultural management plans, and its accuracy must have substantial impacts on the following decision-making processes. In modeling the AWS for paddy fields, it is still common to determine parameter values, such as infiltration rates and irrigation efficiency, solely based on literature and rough assumptions due to data limitations; however, the impact of parameter uncertainty on the estimation has not been fully discussed. In this context, a relative sensitivity index and the generalized likelihood uncertainty estimation (GLUE) method were applied to quantify the parameter sensitivity and uncertainty in an AWS simulation. A general continuity equation was employed to mathematically represent the paddy water balance, and its six parameters were investigated. The results show that the AWS estimates are sensitive to the irrigation efficiency, drainage outlet height, minimum ponding depth, and infiltration, with the irrigation efficiency appearing to be the most important parameter; thus, they should be carefully selected. Multiple combinations of parameter values were observed to provide similarly good predictions, and such equifinality produced the substantial amount of uncertainty in AWS estimates regardless of the modeling approaches, indicating that the uncertainty should be counted when developing water management plans. We also found that agricultural system simulations using only literature-based parameter values provided poor accuracy, which can lead to flawed decisions in the water resources planning processes, and then the inefficient use of public investment and resources. The results indicate that modelers’ careful parameter selection is required to improve the accuracy of modeling results and estimates from using not only information from the past studies but also modeling practices enhanced with local knowledge and experience.


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