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Simulation of Runoff Changes Caused by Cropland to Forest Conversion in the Upper Yangtze River Region, SW China.

Yu P, Wang Y, Coles N, Xiong W, Xu L - PLoS ONE (2015)

Bottom Line: The simulated total runoff generated from the two rainfall events displayed limited variation for the conversion of dry croplands to forest, while it strongly decreased after paddy fields were converted to forest.The effect of paddy terraces on runoff generation was dependent on the rainfall characteristics and antecedent moisture (or saturation) conditions in the fields.The reduction in simulated runoff generated from intense rainfall events suggested that afforestation and terracing might be effective in managing runoff and had the potential to mitigate flooding in southwestern China.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Wan-Shou-Shan, Beijing, 100091, P. R. China.

ABSTRACT
The "Grain for Green Project" is a country-wide ecological program to converse marginal cropland to forest, which has been implemented in China since 2002. To quantify influence of this significant vegetation change, Guansihe Hydrological (GSH) Model, a validated physically-based distributed hydrological model, was applied to simulate runoff responses to land use change in the Guansihe watershed that is located in the upper reaches of the Yangtze River basin in Southwestern China with an area of only 21.1 km2. Runoff responses to two single rainfall events, 90 mm and 206 mm respectively, were simulated for 16 scenarios of cropland to forest conversion. The model simulations indicated that the total runoff generated after conversion to forest was strongly dependent on whether the land was initially used for dry croplands without standing water in fields or constructed (or walled) paddy fields. The simulated total runoff generated from the two rainfall events displayed limited variation for the conversion of dry croplands to forest, while it strongly decreased after paddy fields were converted to forest. The effect of paddy terraces on runoff generation was dependent on the rainfall characteristics and antecedent moisture (or saturation) conditions in the fields. The reduction in simulated runoff generated from intense rainfall events suggested that afforestation and terracing might be effective in managing runoff and had the potential to mitigate flooding in southwestern China.

No MeSH data available.


Related in: MedlinePlus

The comparison of hydrographs measured and simulated by the GSH model under four simulated rainfall events.The total precipitation of rainfall event in a, b, c, and d were 206 mm, 90 mm, 20.3 mm and 16.9 mm, respectively; RI is rain intensity.
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pone.0132395.g005: The comparison of hydrographs measured and simulated by the GSH model under four simulated rainfall events.The total precipitation of rainfall event in a, b, c, and d were 206 mm, 90 mm, 20.3 mm and 16.9 mm, respectively; RI is rain intensity.

Mentions: The hydrograph simulated by the GSH model was compared to the observed data as shown in Fig (5A–5D). Under low intensity rainfall (i.e., 16.9 mm and 20.3 mm rainfall events), no peak in discharged is observed for either the measured or GSH-simulated hydrographs (Fig 5D). Small discharge peaks observed in Fig 1C were not simulated by the GSH model owing to the very low discharges (<0.02 m3s-1). These could be viewed as the base flow of the original hydrograph. Note that the relative errors of the simulated total runoff are less than 10% (Table 4). Under more intense rainfall (90 mm, with an average recurrence interval (ARI) of 1 year), the relative errors in simulated peak discharge and total runoff are 8.5% and 0.9%, respectively. Under extreme rainfall (206 mm, with an ARI of 30 years), the simulated hydrograph displays a relative error of 3.8% in peak discharge and 13.6% in total runoff (Table 4). The non-dimensional efficiency criterion of Nash and Sutcliffe (E) was 0.88 for rainfall of 90 mm and 0.92 for rainfall of 206 mm. These results demonstrate that the calibration and validation of the GSH model was representative of watershed response.


Simulation of Runoff Changes Caused by Cropland to Forest Conversion in the Upper Yangtze River Region, SW China.

Yu P, Wang Y, Coles N, Xiong W, Xu L - PLoS ONE (2015)

The comparison of hydrographs measured and simulated by the GSH model under four simulated rainfall events.The total precipitation of rainfall event in a, b, c, and d were 206 mm, 90 mm, 20.3 mm and 16.9 mm, respectively; RI is rain intensity.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507881&req=5

pone.0132395.g005: The comparison of hydrographs measured and simulated by the GSH model under four simulated rainfall events.The total precipitation of rainfall event in a, b, c, and d were 206 mm, 90 mm, 20.3 mm and 16.9 mm, respectively; RI is rain intensity.
Mentions: The hydrograph simulated by the GSH model was compared to the observed data as shown in Fig (5A–5D). Under low intensity rainfall (i.e., 16.9 mm and 20.3 mm rainfall events), no peak in discharged is observed for either the measured or GSH-simulated hydrographs (Fig 5D). Small discharge peaks observed in Fig 1C were not simulated by the GSH model owing to the very low discharges (<0.02 m3s-1). These could be viewed as the base flow of the original hydrograph. Note that the relative errors of the simulated total runoff are less than 10% (Table 4). Under more intense rainfall (90 mm, with an average recurrence interval (ARI) of 1 year), the relative errors in simulated peak discharge and total runoff are 8.5% and 0.9%, respectively. Under extreme rainfall (206 mm, with an ARI of 30 years), the simulated hydrograph displays a relative error of 3.8% in peak discharge and 13.6% in total runoff (Table 4). The non-dimensional efficiency criterion of Nash and Sutcliffe (E) was 0.88 for rainfall of 90 mm and 0.92 for rainfall of 206 mm. These results demonstrate that the calibration and validation of the GSH model was representative of watershed response.

Bottom Line: The simulated total runoff generated from the two rainfall events displayed limited variation for the conversion of dry croplands to forest, while it strongly decreased after paddy fields were converted to forest.The effect of paddy terraces on runoff generation was dependent on the rainfall characteristics and antecedent moisture (or saturation) conditions in the fields.The reduction in simulated runoff generated from intense rainfall events suggested that afforestation and terracing might be effective in managing runoff and had the potential to mitigate flooding in southwestern China.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Wan-Shou-Shan, Beijing, 100091, P. R. China.

ABSTRACT
The "Grain for Green Project" is a country-wide ecological program to converse marginal cropland to forest, which has been implemented in China since 2002. To quantify influence of this significant vegetation change, Guansihe Hydrological (GSH) Model, a validated physically-based distributed hydrological model, was applied to simulate runoff responses to land use change in the Guansihe watershed that is located in the upper reaches of the Yangtze River basin in Southwestern China with an area of only 21.1 km2. Runoff responses to two single rainfall events, 90 mm and 206 mm respectively, were simulated for 16 scenarios of cropland to forest conversion. The model simulations indicated that the total runoff generated after conversion to forest was strongly dependent on whether the land was initially used for dry croplands without standing water in fields or constructed (or walled) paddy fields. The simulated total runoff generated from the two rainfall events displayed limited variation for the conversion of dry croplands to forest, while it strongly decreased after paddy fields were converted to forest. The effect of paddy terraces on runoff generation was dependent on the rainfall characteristics and antecedent moisture (or saturation) conditions in the fields. The reduction in simulated runoff generated from intense rainfall events suggested that afforestation and terracing might be effective in managing runoff and had the potential to mitigate flooding in southwestern China.

No MeSH data available.


Related in: MedlinePlus