China is an energy starved country that has faced a severe energy crisis for the last few decades. In response to China’s increasing dependence on non-renewable fuels, the Chinese government has discussed current and potential biomass energy resources as well as energy conversion and promotion policies. Bioethanol production has proven to be environmentally friendly and energy-efficient and is a potentially important source of renewable fuels. However, the uneven distribution of water and the implementation of the Three Red Lines water conservation policies may limit the development of bioethanol in China. From the perspective of water footprint (WF), this paper analyzes the water requirements of producing bioethanol from crop straws, and shows that water consumption in the bioethanol conversion stage is less than that in the crop growth stage; in other words, producing bioethanol from crop straws may be more water-efficient than that from grains or non-grain crop because water that would be consumed for grain growth is already being allocated to the agricultural sector. There is an abundance of crop straws of approximately 150.71 million tons that can be used for bio-ethanol production in China; if converted, 41.83 billion L ethanol would be produced annually, and an amount equal to 4 times China’s fuel ethanol production in 2014. According to a crop straws and water resource conditions, the provinces of Jilin, Shandong, Henan and Sichuan are the best for developing bioethanol from crop straws however, variations in the local availability of water resources and crop straws prevent us from drawing immediate conclusions about which crop straws would be most suitable for bioethanol production in China.
This study reports petrography, geochemistry, geochronology, and Lu–Hf isotopic analyses of Xiaofangshen, Lingshansibei, and Shidonggou plutons, which are located in the northern Liaoning Province, eastern segment of the northern margin of the North China Craton. In this study, we discuss their formation ages, petrogenesis, and tectonic environment. Petrographic characteristics suggest that these plutons are composed mainly of granitic rocks and are widely altered by later deformation. Zircon U–Pb dating results suggest formation ages of 248.2 ± 1.4 Ma, 245.1 ± 1.5 Ma, and 230.6 ± 2.5 Ma for the Xiaofangshen, Lingshansibei, and Shidonggou plutons, respectively. The geochemical characteristics indicate that both the Xiaofangshen and Lingshansibei plutons are metaluminous, high‐K calc‐alkaline‐shoshonitic granites that formed in a crustal thickening environment; the Shidonggou pluton is peraluminous, calc‐alkaline I‐type granite that formed in a post‐orogenic environment. All granitic plutons in the study area are enriched in large‐ion lithophile elements and light rare earth elements (REEs) and depleted in high‐field‐strength elements and heavy REEs. Combined with geochemical characteristics of the plutons and previous studies on the region, we conclude that the eastern part of the Palaeo‐Asian Ocean closed in the Late Permian to Early Triassic. The orogeny of the eastern segment of the northern margin of the North China Craton continued until the early Late Triassic.
Abstract The uneven changes in potential evapotranspiration (PET) in response to temperature rise are called the ‘evapotranspiration paradox’ phenomenon, which is expected to intensify further under a warming climate. In this paper, we explored the spatial–temporal changes in the future ‘evapotranspiration paradox’ phenomenon over China and its 10 major river sub‐regions under different climate change scenarios. Thus, this paper uses four global climate model outputs under seven shared socioeconomic pathway‐based scenarios (SSP1‐1.9, SSP1‐2.6, SSP2‐4.5, SSP3‐7.0, SSP4‐3.4, SSP4‐6.0 and SSP5‐8.5) from the sixth phase of the Coupled Model Intercomparison Project (CMIP6). Considering the latest IPCC's 6th Assessment Report (AR6), this research emphasizes the 2021–2040 (near‐term), 2041–2060 (mid‐term) and 2081–2100 (long‐term) periods to anticipate the ‘evapotranspiration paradox’ phenomenon. In this study, PET is estimated based on the modified Penman–Monteith (P‐M) method (considering CO 2 ). Furthermore, the paradox phenomenon in this study is defined considering two pivotal conditions: the surface temperature increases but the evaporation decreases (Type I), and the temperature decreases but the evaporation still tends to increase (Type II). The results show that there were only Type I ‘evapotranspiration paradoxes’ that existed in the historical period, which were dominant especially before the 1990s. Nearly 50% of the areas experienced the Type I ‘evapotranspiration paradox’ phenomenon that occurred during 1975–1994 and 1995–2014. Spatially, it covered 100% of the area of the Southeast River (SER) and the Liaohe River (LR) during 1975–1994 and the area of the SER, the HAR, the HHR and the LR during 1995–2014. In the future, the interdecadal growth rate of PET in China is projected to be the highest under the SSP5‐8.5 and the lowest under the SSP3‐7.0 with spatial variation. Importantly, the largest areas of approximately 36% and 45% with the Type I phenomenon are inclined to occur under the SSP1‐1.9 and SSP4‐6.0, respectively, over the long‐term period (2081–2100). The area with the Type I phenomenon will be less than 20% in the near‐term, and it is less than 12% in the mid‐term period. For the Type II evapotranspiration paradox, the uppermost 45% of the area is expected to experience the Type II phenomenon under SSP1‐1.9 during the mid‐term period, while it is 30% under SSP1‐2.6 during the long‐term period. However, this study's findings provide the scientific basis for formulating adaptation and mitigation strategies to combat ‘evapotranspiration paradox’‐related extremes at regional scales.
Abstract Drought has a paramount impact on global agriculture and food security. However, the study on future cropland areas that can incur drought is inadequate. This paper uses input parameters from 7 CMIP6 models for 7 future scenarios (SSP1‐1.9, SSP1‐2.6, SSP4‐3.4, SSP2‐4.5, SSP4‐6.0, SSP3‐7.0, and SSP5‐8.5) to measure South Asian cropland exposure to drought and its underlying factors. Some defined epochs such as 2021–2040 (near‐term), 2041–2060 (mid‐term), 2081–2100 (long‐term), and 1995–2014 (reference period) are designed to explore diverse outlooks of the change. The Standardized Precipitation Evapotranspiration Index and the Run theory methods are applied to detect drought. Results indicate an intensified cropland (under SSP4‐3.4, SSP3‐7.0, and SSP5‐8.5) in the Indo‐Gangetic Plain region of South Asia, where mostly the variation occurs among scenarios and periods. Notably, the future cropland exposed to drought will increase in the 2021–2040, and 2041–2060 periods, but it intends to decline during the 2081–2100. Relatively, the exposed cropland will upturn highest by 49.2% (SSP3‐7.0) in the mid‐term period and decrease by −8.2% (SSP5‐8.5) in the end future. Spatially, distributed cropland in the central, south‐west, and portion of the northeast of South Asia are subjective to be exposed largely, but it can drop greatly across the eastern part by the end future. Importantly, the climate change effect plays a grounding role in future exposure change over the region during the near to mid‐term periods, while the cropland change effect is predominant in the long‐term perspectives. However, these findings signify the urgency of policymaking focusing on drought mitigation to ensure food security.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)