scholarly journals Re-conceptualizing the Soil and Water Assessment Tool to Predict Subsurface Water Flow Through Macroporous Soils

2021 ◽  
Vol 3 ◽  
Author(s):  
David Poon ◽  
Joann K. Whalen ◽  
Aubert R. Michaud
Keyword(s):  
Assessment Tool ◽  
Subsurface Flow ◽  
Growing Season ◽  
Subsurface Drainage ◽  
Macropore Flow ◽  
Water Flows ◽  
Flow Algorithm ◽  
Water Assessment ◽  
Soil And Water ◽  
Flow Pathway

More water and nutrients from artificially-drained agricultural land reach surface waters by leaching through macropores than by percolating through the soil matrix. However, the Soil and Water Assessment Tool (SWAT) describes water flows poorly in land with subsurface drainage because it does not partition water between macropore and matrix transport processes. We produced a new percolation algorithm to distinguish the macropore flow pathway, which was integrated in the SWAT-MAC model and used to predict water flows in a 30 km2 agricultural subwatershed in southern Quebec, Canada. Partitioning of subsurface flow between macropore and matrix components was reasonable, compared to a chemical-based hydrograph separation of streamflow in this subwatershed. The macropore flow algorithm also improved water allocation between the annual surface runoff and subsurface flow in the SWAT-MAC model. We predict more macropore flow into tile drains under fine-textured soils than coarse-textured soils, which is consistent with experimental observations. However, macropore flow was underestimated in the non-growing season and over-predicted during the growing season, which can be adjusted in the macropore flow algorithm by accounting for dynamic macropore connectivity or effective macroporosity. There are too few observations of regional-specific effects of soil moisture and management practices on macropore flow to correct the algorithm at this time. We conclude that the percolation algorithm of SWAT-MAC represents the macropore flow pathway and improves the description of water movement through agricultural soils with subsurface drainage systems, which are important for transferring water and nutrients to downstream aquatic systems in cold, humid temperate regions.

scholarly journals High-Resolution Simulations of Decadal Climate Variability Impacts on Water Yield in the Missouri River Basin with the Soil and Water Assessment Tool (SWAT)

2016 ◽  
Vol 17 (9) ◽  
pp. 2455-2476 ◽  
Author(s):  
Vikram M. Mehta ◽  
Katherin Mendoza ◽  
Prasad Daggupati ◽  
Raghavan Srinivasan ◽  
Norman J. Rosenberg ◽  
...  
Keyword(s):  
Climate Variability ◽  
River Basin ◽  
Assessment Tool ◽  
Missouri River ◽  
Positive Phase ◽  
Decadal Climate Variability ◽  
Water Flows ◽  
Decadal Climate ◽  
Water Assessment ◽  
Soil And Water

ABSTRACT The Missouri River basin (MRB) is the largest river basin in the United States and is one of the most important agricultural regions in the world. Three decadal climate variability (DCV) phenomena—the Pacific decadal oscillation (PDO), the tropical Atlantic sea surface temperature (SST) gradient variability (TAG), and the west Pacific warm pool SST variability (WPWP)—substantially influence hydrometeorology in the MRB. The authors report on a simulation study with the Soil and Water Assessment Tool (SWAT) to estimate impacts on water availability in response to realistic values of PDO, TAG, and WPWP indices in approximately 13 500 hydrologic unit areas covering the MRB. SWAT, driven by hydrometeorological anomalies associated with positive and negative phases of PDO and TAG, indicated major impacts on water yields and streamflows, as much as ±40% of the average in many locations. Impacts of the WPWP index were smaller. Consistent with observations during 1949–2010, SWAT showed water flow increases of as much as 80% of the average, causing very wet periods when the positive phase of the PDO and the negative phase of the TAG at extreme amplitudes were superposed. Water flows decreased by a similar amount, resulting in severe to extreme droughts when the negative phase of the PDO and the positive phase of the TAG at extreme amplitudes were superposed. Thus, the combined and cumulative effects of these DCV phenomena on water flows, droughts, and wet periods in the MRB can be dramatic, with important consequences for all water-consuming sectors as well as for feedbacks to the climate system.

AN EVALUATION OF BLUE WATER PREDICTION IN SOUTHERN PART OF IRAN USING THE SOIL AND WATER ASSESSMENT TOOL (SWAT)

2016 ◽  
Vol 15 (1) ◽  
pp. 175-188 ◽  
Author(s):  
Mohsen Salarpour ◽  
Milad Jajarmizadeh ◽  
Sobri Harun ◽  
Rozi Abdullah
Keyword(s):  
Assessment Tool ◽  
Blue Water ◽  
Water Assessment ◽  
Soil And Water

Modeling Miscanthus in the Soil and Water Assessment Tool (SWAT) to Simulate Its Water Quality Effects As a Bioenergy Crop

2010 ◽  
Vol 44 (18) ◽  
pp. 7138-7144 ◽  
Author(s):  
Tze Ling Ng ◽  
J. Wayland Eheart ◽  
Ximing Cai ◽  
Fernando Miguez
Keyword(s):  
Water Quality ◽  
Assessment Tool ◽  
Bioenergy Crop ◽  
Water Assessment ◽  
Soil And Water

Can-GLWS: Canadian Great Lakes Weather Service for the Soil and Water Assessment Tool (SWAT) modelling

2020 ◽  
Author(s):  
Narayan K. Shrestha ◽  
Taimoor Akhtar ◽  
Uttam Ghimire ◽  
Ramesh P. Rudra ◽  
Pradeep K. Goel ◽  
...  
Keyword(s):  
Great Lakes ◽  
Assessment Tool ◽  
Water Assessment ◽  
Soil And Water ◽  
Weather Service

scholarly journals Pemodelan Erosi dan Sedimentasi di DAS Bajulmati : Aplikasi Soil dan Water Assesment Tool (SWAT)

2020 ◽  
Vol 18 (2) ◽  
pp. 220-230
Author(s):  
Mohamad Wawan Sujarwo ◽  
Indarto Indarto ◽  
Marga Mandala
Keyword(s):  
Assessment Tool ◽  
Response Unit ◽  
Water Assessment ◽  
Soil And Water

DAS bajulmati merupakan DAS kecil (± 173.4 km2) yang berada di wilayah timur pulau Jawa. DAS bajulmati memiliki iklim yang spesifik yaitu relatif kering dengan musim kemarau yang panjang (8-9 bulan selama setahun). Meskipun kondisi iklim yang kurang mendukung, sebagian besar masyarakat bekerja sebagai petani landang. Adanya perluasan lahan pertanian non irigasi/ladang mengakibatkan tutupan vegetasi semakin berkurang. Oleh karena itu, evaluasi DAS bajulmati diperlukan untuk mengetahui dampak perluasan lahan pertanian terhadap laju aliran dan sedimentasi dengan kondisi iklim yang cukup spesifik (kering). Salah satu model evaluasi pengelolaan DAS terhadap perubahan lahan adalah model SWAT (Soil and Water Assessment Tool). SWAT dapat menggambarkan proses hidrologi (erosi dan sedimentasi) unit lahan. data DEM resolusi (10x10 m) sebagai masukan utama untuk proses delinasi DAS. Data tanah, tutupan lahan, dan kontur digunakan untuk menentukan unit lahan/hydrolocal response unit (HRU) DAS. Data curah hujan dan iklim (suhu, kelembaban rata-rata, intensitas matahari, kecepatan angin) diperoleh dari stasiun yang tersebar di wilayah DAS. Semua data diintegrasikan ke dalam SWAT untuk menghitung proses hidrologi, erosi dan sedimentasi. Debit yang diamati digunakan untuk mengkalibrasi keluaran debit hasil SWAT di outlet DAS. Hasil kalibrasi debit menunjukkan nilai Nash-Sutcliffe Efficiency sebesar 0,53 dan validasi sebesar 0,5 serta koefisien determinasi sebesar 0,58 dan 0,78 (memuaskan) dan model dapat digunakan untuk ilustrasi proses hidrologi dalam DAS bajulmati. Analisis tingkat erosi SWAT menunjukkan bahwa 34,46; 39,19; dan 17,83 menunjukkan tingkat erosi sangat ringan sampai kategori sedang. Oleh karena itu, DAS Bajulmati masih dalam kategori aman karena rata-rata erosi berat dan sangat berat dibawah 10%. Nilai sedimentasi tertinggi pada HRU 512 dan SubDAS 23. Wilayah tersebut merupakan wilayah perkebunan dengan tingkat kemiringan diatas 40%.

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