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Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

Liu X, Wang S, Xue H, Singh VP - PLoS ONE (2015)

Bottom Line: On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model.Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged.The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation.

View Article: PubMed Central - PubMed

Affiliation: Department of Water Resources and Civil Engineering, China Agricultural University, Beijing, China.

ABSTRACT
Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

No MeSH data available.


Related in: MedlinePlus

DEM of Qingyuan Irrigation District.
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pone.0139839.g004: DEM of Qingyuan Irrigation District.

Mentions: Qingyuan Irrigation District is located in the middle reach of Shiyang River basin, the arid region of northwest China. The total area of the irrigation district is approximately 390 km2 (Fig 2). The climate of the area is temperate continental climate. The annual precipitation is 150–160 mm, and precipitation occupies 80–85% from April to September. Annual evaporation is 2020 mm and average temperature is 7.7°C. The land resources in Qingyuan Irrigation District can be divided into cultivated land, forestland, grassland, rural residential area, unused land and others (Fig 3). Cultivated land constitutes 59.99% of the total land resources and the proportions of other land types are presented as Table 1. The terrain inclines downward from southwest to northeast in the irrigation district. The longitudinal slope is 1/800–1/200 and the altitude is 1500–1600 m. The digital elevation model (DEM) of Qingyuan Irrigation District is shown in Fig 4. There are four soil types in the irrigation district: grey desert soil, irrigated desert soil, aeolian sandy soil and sierozem (Fig 5). Spring wheat and summer maize are the main grain crops, and potato, soybean, beet and chili are the main economic crops in Qingyuan Irrigation District.


Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

Liu X, Wang S, Xue H, Singh VP - PLoS ONE (2015)

DEM of Qingyuan Irrigation District.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4595335&req=5

pone.0139839.g004: DEM of Qingyuan Irrigation District.
Mentions: Qingyuan Irrigation District is located in the middle reach of Shiyang River basin, the arid region of northwest China. The total area of the irrigation district is approximately 390 km2 (Fig 2). The climate of the area is temperate continental climate. The annual precipitation is 150–160 mm, and precipitation occupies 80–85% from April to September. Annual evaporation is 2020 mm and average temperature is 7.7°C. The land resources in Qingyuan Irrigation District can be divided into cultivated land, forestland, grassland, rural residential area, unused land and others (Fig 3). Cultivated land constitutes 59.99% of the total land resources and the proportions of other land types are presented as Table 1. The terrain inclines downward from southwest to northeast in the irrigation district. The longitudinal slope is 1/800–1/200 and the altitude is 1500–1600 m. The digital elevation model (DEM) of Qingyuan Irrigation District is shown in Fig 4. There are four soil types in the irrigation district: grey desert soil, irrigated desert soil, aeolian sandy soil and sierozem (Fig 5). Spring wheat and summer maize are the main grain crops, and potato, soybean, beet and chili are the main economic crops in Qingyuan Irrigation District.

Bottom Line: On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model.Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged.The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation.

View Article: PubMed Central - PubMed

Affiliation: Department of Water Resources and Civil Engineering, China Agricultural University, Beijing, China.

ABSTRACT
Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

No MeSH data available.


Related in: MedlinePlus