Environmental Efficiency of Farming Production
TERRECO Cluster A-02
From 06/2012 to 01/2016Principal Investigator: John Tenhunen, Trung Thanh Nguyen, Bernd Huwe, Yong Sik Ok
Staff: Ganga Ram Maharjan
Abstract: The study focuses on a small catchment of 60 km2 in Haean, in S-Korea. Intensive agriculture carried out with a variety of management practices, and changes in land use due to urbanization and deforestation affect the nature and magnitude of groundwater-surface water interactions and seasonal water availability. With typical farm management, especially the Haean and Jawoon Catchments export large amounts of nutrients and sediments to the Soyang Reservoir downstream due to excess fertilization and strong monsoon rains.
The purpose of the study is to evaluate environmental efficiency of the catchment viewed as agricultural yield versus impacts on water quality, and to examine this at both catchment and individual field level, considering spatially distributed properties. The model SWAT (Soil and Water Assessment Tool) will be used to quantify spatially distributed contributions to landscape performance. The study builds on a background survey of farm management which provides georeferenced information field by field on investments for fertilizer, mulch and other managerial costs as well as agricultural yields and farm incomes.
The intensive research carried out in Haean Catchment by the TERRECO project (2009 - 2012) has generated requisite data set for SWAT model simulations. We calibrated and validated the model hydrologically by using flow data at several locations. The model performance indicated by coefficient of determination (R2) and Nash and Sutcliffe Efficiency (ENS) values were greater than 0.75 during calibration and validation periods. Next the model will be calibrated and validated for sediment and nutrient exports. We hope to recommend improved farm management methods that allow higher environmental efficiencies by reducing non-point pollution to the stream network.
Key Words: ecosystem services, non-point pollution, SWAT, environmental efficiency