Trends in evapotranspiration and their responses to climate change and vegetation greening over the upper reaches of the Yellow River Basin

“…The modified Penman-Monteith method [1,23,27,28], recommended by the FAO (PM-FAO) and widely identified as being efficient and effective for estimating reference evapotranspiration (ET 0 ), was used to calculate ET 0 (mm/d) [29]. The ET 0 was calculated based on the PM-FAO method for a well-watered short grass with height, albedo, and stomata resistance of 0.12 m, 0.23, and 70 s/m, respectively [30].…”

Section: Calculation Of Reference Evapotranspiration Crop Water Requmentioning

confidence: 99%

Assessment of the Irrigation Water Requirement and Water Supply Risk in the Tarim River Basin, Northwest China

Wang

Chen

et al. 2019

Sustainability

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Studying the relationship between agricultural irrigation water requirements (IWR) and water supply is significant for optimizing the sustainable management of water resources in Tarim River Basin (TRB). However, the related studies have not quantified the total IWR and the imbalance of irrigation water supply and requirements in the TRB. The study analyzed the spatial-temporal variations of IWR by a modified Penman–Monteith (PM) method during 1990–2015. Five major crops—rice, wheat, maize, cotton, and fruit trees—are chosen for calculating the IWR. It was found that the IWR increased significantly, from 193.14 × 108 m3 in 1990 to 471.89 × 108 m3 in 2015, for a total increase of 278.74 × 108 m3. For the first period (1990–2002), the total IWR remained stable at 200 × 108 m3 but started to increase from 2003 onwards. Significantly more irrigation water was consumed in the oasis regions of the Tienshan Mountains (southern slope) and the Yarkand River (plains). Furthermore, there was an intensified conflict between IWR and water supply in the major sub-basins. The ratios of IWR to river discharge (IWR/Q) for the Weigan-Kuqa River Basin (WKRB), Aksu River Basin (ARB), Kaxgar River Basin (KGRB), and Yarkand River Basin (YRB) were 0.93, 0.68, 1.05, and 0.79, respectively. The IWR/Q experienced serious annual imbalances, as high flows occurred in July and August, whereas critical high IWR occurred in May and June. Seasonal water shortages further aggravate the water stress in the arid region.

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“…According to the fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC), global warming is prevailing throughout the world, with the global temperature rising by 0.91 • C over the past 100 years, and the global warming trend will continue [1]. Various studies have indicated that climate warming is expected to intensify atmospheric circulation and hydrological circle, then alter precipitation patterns and evapotranspiration [2,3]. Furthermore, changes in precipitation and evapotranspiration will affect the balance of the surface water budget.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Dry/Wet Variations in the Poyang Lake Basin Using Standardized Precipitation Evapotranspiration Index Based on Two Potential Evapotranspiration Algorithms

Liu

2019

Water

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Global warming has resulted in unevenly distributed changes in precipitation and evapotranspiration, which has some influence on dry/wet conditions, thus exerting a tremendous impact on national life and the social economy, especially agricultural production. In order to characterize the dry/wet variations in the Poyang Lake basin during 1958–2013, based on the potential evapotranspiration (PET) estimated by the Thornthwaite (TH) and Penman–Monteith (PM) formulas, two types of Standardized Precipitation Evapotranspiration Index (SPEI), namely SPEI_th and SPEI_pm, were calculated in this study. The characteristic of dry/wet variations in the Poyang Lake basin was analyzed and a comparative analysis of two SPEIs was conducted. The results indicate that both SPEI series showed a wet trend in the Poyang Lake basin on an annual scale as well as seasonal scales during 1958–2013, except for spring and autumn. A drying trend was observed in spring, while in autumn, the dry and wet conditions in two SPEIs had opposite trends. However, all trends from two SPEIs were not significant, except for summer SPEI_pm. Meanwhile, significant positive correlations were detected between precipitation and two SPEIs, with the correlation coefficients above 0.95, whereas negative correlations were detected between PET and two SPEIs, with the correlation coefficients ranging from −0.17 to −0.85. This indicates that precipitation was the main climatic factor to determine change in dry/wet conditions in the Poyang Lake basin. Although there were obvious differences between the accumulated values of the Penman–Monteith-based PET (ET_pm) and Thornthwaite-based PET (ET_th), trends in the SPEI_pm series were generally consistent with those in the SPEI_th series, revealing that the method for PET calculation was not critical to the change in dry/wet conditions. Moreover, the results of the conditional probability of SPEI_pm and SPEI_th show that both SPEI_pm and SPEI_th could detect wet or dry events that were identified by SPEI_pm or SPEI_th.

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Trends in evapotranspiration and their responses to climate change and vegetation greening over the upper reaches of the Yellow River Basin

Cited by 134 publications

References 55 publications

Elevation‐dependent changes in reference evapotranspiration due to climate change

Elevation‐dependent changes in reference evapotranspiration due to climate change

Assessment of the Irrigation Water Requirement and Water Supply Risk in the Tarim River Basin, Northwest China

Analysis of Dry/Wet Variations in the Poyang Lake Basin Using Standardized Precipitation Evapotranspiration Index Based on Two Potential Evapotranspiration Algorithms

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