Assessing the Sustainability in Water Use under Different Agricultural Management Planning in Yeongsan-River Basin, South Korea

Assessing the Sustainability in Water Use under
Different Agricultural Management Planning
in Yeongsan-River Basin, South Korea

 

Yujong Jeong¹, Hyun-woo Jo¹, YanYan¹, Minwoo Noh¹, Woo-Kyun Lee^1*

 

¹ Department of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea

*E-mail: leewk@korea.ac.kr

(Address: Korea University, Anamro 145, Seongbukgu, Seoul 02841, Republic of Korea)

 

Abstract:

From the past, South Korea has been experiencing high level of water stress as reported by WRI, in 2013, and chronically imbalanced spatiotemporal water allocation. Yeongsan-river basin, where the biggest national breadbasket is located, is facing unequal water allocation among different water uses and inefficient water management under episodic water shortage conditions. Therefore, the main objective of this study was to analyse current water management and allocation scheme, and to evaluate 3 different agricultural management plans in terms of efficiency and equity. The Soil and Water Assessment Tool(SWAT) was applied to simulate the hydrological process and crop yield in the basin. The model was calibrated and validated using observed outflows to set adequate system parameters for the entire watershed. Crop water productivity and spatial-temporal-sectoral water distribution are utilized as the indices to evaluate different agricultural strategies. The results suggested that there was potential to improve both crop productivity and water allocation at the same time with the suggested plannings. Crop water productivity increased in all three strategies in order of on-farm management measures (precise agriculture), crop diversification (replacing rice to beans) and agroforestry (mixing trees and crops). The crop water productivity of on-farm measurement ranges from 5t/L to 13t/L and rises about 20% on average. In addition, it is found that applying the combination of different agricultural management measures could achieve better water allocation in terms of space and time, and between agriculture and ecosystem. The outcomes of this study can serve scientific-evidence policy and decision-making systems for sustainable agricultural society and ecosystem.

Keywords: Hydrological Modelling, SWAT, Crop water productivity, Water allocation, Agricultural Management Planning, Yeongsan-River Basin

Acknowledgements: This work was supported under the framework of international cooperation program managed by the National Research Foundation of Korea (No. 2021K2A9A1A02101519).