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MEI Li TONG Siqin YIN Shan BAO Yuhai HUANG Xiaojun ALATENG Tuya WANG Yongfang GUO Enliang YUAN Zhihui NASHUN Dalai GAO Suriguga LIU Xinyi YE Zhigang 《地理学报(英文版)》2023,33(1):169-194
Water use efficiency (WUE) is an important variable to explore coupled relationships in carbon and water cycles. In this study, we first compared the spatial variations of annual gross primary productivity (GPP) and evapotranspiration (ET) using four GPP and ET products. Second, we selected the products closest to the flux towers data to estimate WUE. Finally, we quantitatively analyzed the impact of climate change and soil water content on WUE. The results showed that: (1) Four GPP and ET products provided good performance, with GOSIF-GPP and FLDAS-ET exhibiting a higher correlation and the smallest errors with the flux tower data. (2) The spatial pattern of WUE is consistent with that of GPP and ET, gradually decreasing from the northeast to the southwest. Higher WUE values appeared in the northeast forest ecosystem, and lower WUE values occurred in the western Gobi Desert, with a value of 0.28 gC m?2 mm?1. The GPP and ET products showed an increasing trend, while WUE showed a decreasing trend (55.15%) from 2001 to 2020. (3) The spatial relationship between WUE and driving factors reveal the variations in WUE of Inner Mongolia are mainly affected by soil moisture between 0 and 10 cm (SM0-10cm), vapor pressure deficit (VPD), and precipitation, respectively. (4) In arid regions, VPD and precipitation exhibit a major influence on WUE. An increase in VPD and precipitation has a negative and positive effect on WUE, with threshold values of approximately 0.36 kPa and 426 mm, respectively. (5) In humid regions, SM0-10cm, VPD, SM10-40cm, and SM40-100cm exert a significant impact on WUE, especially SM0-10cm, and weakens with increasing soil depths, these differences may be related to physiological structure and living characteristics of vegetation types in different climate regimes. Our results emphasize the importance of VPD and soil moisture in regional variability in WUE. 相似文献
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本文研究了海水中溶油对骨条藻、角毛藻,三角褐指藻、金藻、甲藻、杜氏盐藻的生长影响。结果表明杜氏盐藻、三角褐指藻、甲藻等在含油海水中9天左右达到最高含量,且在17天左右仍维持最高含量,表明这些藻的耐油性较好。这些耐油藻使海水中石油含量下降3—6倍,表明它们对海水中溶油有净化作用。 相似文献
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The impact of irrigation water supply rate on agricultural drought disaster risk: a case about maize based on EPIC in Baicheng City,China 总被引:2,自引:0,他引:2
This study presents a methodology for risk analysis, assessment, and combination of drought disasters under the different irrigational levels in Baicheng City, which is supported by run theory, copula functions, crop growth model, and technique of natural disaster risk assessment from the viewpoints of climatology, geography, hydrology, agricultural science, disaster science, environmental science, and so on. Along with the global warming, the occurrences of water-related disasters become more frequent and more serious. It is necessary to determine the laws of the relationship between irrigational ability and the loss caused by drought. Drought events were identified by using run theory; the drought frequency was calculated by using copula function; the loss of every drought event was simulated by using EPIC model; and the relationship curves under the different irrigational supply conditions between the drought frequency and the yield reduction rate of the drought event were fitted to assess the impact of irrigational supply rate on the loss caused by drought. The results show that in the range of crop water demand, the loss caused by drought decreases as the result of the increase in irrigational supply rate; however, their variations are not proportional. The loss caused by the certain frequency drought event under the certain irrigational supply condition could be calculated by the curve of drought disaster risk assessment constructed by this study. The results obtained from this study are specifically intended to support local and national governmental agencies on agricultural disaster management. 相似文献
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寒区土壤温度场观测多采用垂直埋管方式,常用管材有铁管、PVC管、PPR管、PE管等,在实践中发现同一地点不同材质测管所测温度场存在较大差异.为研究几种常用测温管材测试值的差异性,2014年11月3日至2015年4月29日对四种材质垂直埋管与土壤直埋传感器的测温方式进行了现场比对试验.结果表明:(1)不同材质垂直埋管因其物理性质的差异,在测温过程中对温度场有不同程度的影响,PVC管和PPR管的测温值分别偏高于相应土层温度约0.8℃和0.3℃,而铁管和PE管则分别偏低于相应土层温度约0.4℃和0.6℃.(2)管材中温度场数据与土壤温度场数据相关性由高到低排序为:铁管 > PPR管 > PVC管 > PE管.(3)通过最小二乘法,求得铁管-土壤各层埋深温度场的转换系数,并得到铁管-土壤温度场拟合方程,经证实相关性显著. 相似文献
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静冰力学模型试验的相似比尺问题探讨 总被引:4,自引:0,他引:4
分析冰盖形成的热力学模型, 推导出室内模型试验的相似比尺. 模拟野外降温过程, 在低温实验室内进行静冰压力模型试验, 研究实验室模拟静冰压力产生过程的可行性. 结果表明: 实验室模拟最大冰厚39.8 cm, 试验历时387.4 h, 冰的冻结过程符合天然规律; 实验室目前难以模拟融化过程中天然状态的太阳辐射, 有待进一步改进降温制度. 模拟试验的冰压力最大值出现在升温阶段, 与温升率相关, 温升率越大, 静冰压力值越大; 当环境温度升至0 ℃左右时, 静冰压力达到最大值, 随后迅速消散, 符合水库冰过程观测结果. 相似文献
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牟氏角毛藻的有机渗出物及其对铜的络合作用 总被引:1,自引:0,他引:1
对牟氏角毛藻(chaetoceros muelleri)进行一次性的培养过程,不同时间取藻培养液过滤,测定滤液中的COD及铜络合容量CC_(cu)值。结果表明,牟氏角毛藻在生长过程中向体外渗出有机物,在指数生长期渗出的有机物量很少;细胞渗出有机物明显增加;出现在静止期之后。牟氏角毛藻的细胞渗出物对铜具有络合能力,CCcu值从初始到192小时,由1.65×10~(-7)mol/dm~3增加到2.20×10~(-7)mol/dm~3。铜络合物的条件稳定常数在整个培养过程中无明显改变,logKcuL变化范围从7.27到7.74。过滤藻液的COD值从初始到192小时由0.81mg/dm~3增加到1.58mg/dm~3。 相似文献