Identification of critical areas and evaluation of best management practices using SWAT for sustainable watershed management

Bhumika Uniyal; Madan K Jha; Arvind Kumar Verma; Prajna Kasargodu Anebagilu

doi:10.1016/j.scitotenv.2020.140737

Identification of critical areas and evaluation of best management practices using SWAT for sustainable watershed management

Sci Total Environ. 2020 Nov 20:744:140737. doi: 10.1016/j.scitotenv.2020.140737. Epub 2020 Jul 10.

Authors

Bhumika Uniyal¹, Madan K Jha², Arvind Kumar Verma³, Prajna Kasargodu Anebagilu⁴

Affiliations

¹ Professorship of Ecological Services, Faculty of Biology, Chemistry and Earth Sciences, BayCEER, University of Bayreuth, Universitaetsstrasse 30, 95440 Bayreuth, Germany.. Electronic address: Bhumika.Uniyal@uni-bayreuth.de.
² Agricultural and Food Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur 721 302, West Bengal, India.
³ Department of Agricultural Engineering, SASRD, Nagaland University, Medziphema 797 106, Nagaland, India.
⁴ Professorship of Ecological Services, Faculty of Biology, Chemistry and Earth Sciences, BayCEER, University of Bayreuth, Universitaetsstrasse 30, 95440 Bayreuth, Germany.

PMID: 32711306
DOI: 10.1016/j.scitotenv.2020.140737

Abstract

Identification of critical erosion-prone areas and selection of best management practices (BMPs) for watersheds are necessary to control their degradation by reducing sediment yields. The current research assesses and proposes a combination of potential BMPs for the Baitarani catchment in India using the Soil and Water Assessment Tool (SWAT). After the successful calibration and validation of the SWAT model developed for this catchment, the model was applied to evaluate the efficacy of eight agricultural and structural management practices and their combinations (three scenarios) for controlling sediment yields at watershed and sub-watershed levels as well as to assess the impacts of combined BMPs on water balance components. A combination of BMPs was found more effective in reducing sediment yields than individual BMPs. Comparative evaluation revealed that structural BMPs (0.66-70%) are better than agricultural BMPs (2-7%) in minimizing sediment yields at watershed level. The costly measures like grade and streambank stabilization structures can reduce the sediment yield up to 70% at the watershed level. The modeling results of the impacts of different combinations of BMPs (three scenarios) indicated that if all the eight BMPs are implemented, the reduction of sediment yields is increased by 76% and 80% at sub-watershed and watershed levels, respectively compared to the Base Scenario. Based on funds availability, a suitable combination of BMPs can be adopted by the concerned decision-makers to effectively reduce sediment yields in the study area. Further, the simulation results of BMPs impacts on water balance components revealed that the annual average surface runoff reduces by 4-14% in the three scenarios, while aquifer recharge (6.8-8.7%), baseflow (8-10.5%), and percolation (1.2-3.9%) increase due to implementation of BMPs. Overall, the findings of this study are very useful for ensuring sustainable management of land and other resources at a catchment scale.

Keywords: Agricultural BMPs; Best management practices (BMPs); SWAT; Sediment yield; Structural BMPs; Watershed management.