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Rapid urbanization leads to changes in urban micro meteorology, such as the urban heat island effect and rain island effect, which eventually brings about urban waterlogging and other problems. In this study, the data of precipitation, temperatures and impervious surfaces with long series and high resolution are used to study the rain island effect in Jinan City, China. MK-Sen’s slope estimator, Pettitt test and Pearson correlation analysis are used to quantitatively analyze the impact of urban expansion on extreme climate indices. The results show that Jinan City has experienced rapid urbanization since the 1978 economic reform, and the impervious surface areas have increased from 311.68 km2 (3.04%) in 1978 to 2389.50 km2 (23.33%) in 2017. Urban expansion has a significant impact on temperature, with large variations in extreme temperature indices over the intensive construction area relative to the sparse construction area. The extreme temperature indices have a significant correlation with impervious surfaces. Jinan City shows a certain degree of rain island effect, which seems to be spatially correlated with the urban heat island effect. The frequency of short-duration precipitation events significantly increases and the intensity of precipitation events generally increases. The magnitude and frequency of extreme precipitation indices in the intensive construction area significantly increase when compared to that in the sparse construction area, and they have a significant correlation with impervious surfaces. There is a tendency that Jinan City’s rainfall center moves towards to the intensive construction area.
Yanjun Zhao; Jun Xia; Zongxue Xu; Lei Zou; Yunfeng Qiao; Peng Li. Impact of Urban Expansion on Rain Island Effect in Jinan City, North China. Remote Sensing 2021, 13, 2989 .
AMA StyleYanjun Zhao, Jun Xia, Zongxue Xu, Lei Zou, Yunfeng Qiao, Peng Li. Impact of Urban Expansion on Rain Island Effect in Jinan City, North China. Remote Sensing. 2021; 13 (15):2989.
Chicago/Turabian StyleYanjun Zhao; Jun Xia; Zongxue Xu; Lei Zou; Yunfeng Qiao; Peng Li. 2021. "Impact of Urban Expansion on Rain Island Effect in Jinan City, North China." Remote Sensing 13, no. 15: 2989.
Soil water content (SWC) is an important factor restricting crop growth and yield in cropland ecosystems. The observation and simulation of soil moisture contribute greatly to improving water-use efficiency and crop yield. This study was conducted at the Shandong Yucheng Agro-ecosystem National Observation and Research Station in the North China Plain. The study period was across the winter wheat (Triticum aestivum L.) growth stages from 2017 to 2019. A cosmic-ray neutron probe was used to monitor the continuous daily SWC. Furthermore, the crop leaf area index (LAI), yield, and aboveground biomass of winter wheat were determined. The root zone quality model 2 (RZWQM2) was used to simulate and validate the SWC, crop LAI, yield, and aboveground biomass. The results showed that the simulation errors of SWC were minute across the wheat growth stages and mature stages in 2017–2019. The root mean square error (RMSE) and relative root mean square error (RRMSE) of the SWC simulation at the jointing stage of winter wheat were 0.0296 and 0.1605 in 2017–2018, and 0.0265 and 0.1480 in 2018–2019, respectively. During the rain-affected days, the RMSE (0.0253) and RRMSE (0.0980) for 2017–2018 were significantly lower than those of 2018–2019 (0.0301 and 0.1458, respectively), indicating that rain events decreased the model accuracy in the dry years compared to the wet years. The simulated LAIs were significantly higher than the measured values. The simulated yield value of winter wheat was 5.61% lower and 3.92% higher than the measured yield in 2017–2018 and in 2018–2019, respectively. The simulated value of aboveground biomass was significantly (45.48%) lower than the measured value in 2017–2018. This study showed that, compared with the dry and cold wheat growth period of 2018–2019, the higher precipitation and temperature in 2017–2018 led to a poorer simulation of SWC and crop-growth components. This study indicated that annual abnormal rainfall and temperature had a significant influence on the simulation of SWC and wheat growth, especially under intensive climate-change stress conditions.
Kun Du; Yunfeng Qiao; Qiuying Zhang; Fadong Li; Qi Li; Shanbao Liu; Chao Tian. Modeling Soil Water Content and Crop-Growth Metrics in a Wheat Field in the North China Plain Using RZWQM2. Agronomy 2021, 11, 1245 .
AMA StyleKun Du, Yunfeng Qiao, Qiuying Zhang, Fadong Li, Qi Li, Shanbao Liu, Chao Tian. Modeling Soil Water Content and Crop-Growth Metrics in a Wheat Field in the North China Plain Using RZWQM2. Agronomy. 2021; 11 (6):1245.
Chicago/Turabian StyleKun Du; Yunfeng Qiao; Qiuying Zhang; Fadong Li; Qi Li; Shanbao Liu; Chao Tian. 2021. "Modeling Soil Water Content and Crop-Growth Metrics in a Wheat Field in the North China Plain Using RZWQM2." Agronomy 11, no. 6: 1245.
Water is the key limiting factor in socioeconomic and ecological development, but it is adversely affected by climate change. The novel virtual water (VW) concept and water, energy, food, biodiversity, and human health (WEFBH) nexus approach are powerful tools to assess the sustainability of a region through the lens of climate change. Climate change-related challenges and water are complex and intertwined. This paper analyzed the significant WEFBH sectors using the multicriteria decision-making (MCDM) and analytic hierarchy process (AHP) model. The AHP model demonstrated quantitative relationships among WEFBH nexus sustainability indicators in the Greater Horn of Africa countries. Besides, the net VW imports and water footprints of major staple crops were assessed. The composite WEFBH nexus indices varied from 0.10 to 0.14. The water footprint of crops is increasing period by period. The results also revealed that most countries in the study area are facing WEFBH domains unsustainability due to weak planning or improper management strategies. The strong policy constancy among the WEFBH sector is vital for dissociating the high-water consumption from crop production, energy, environmental, and human health system. Thus, this study enhances insights into the interdependencies, interconnectedness, and interactions of sectors thereby strengthening the coordination, complementarities, and synergies among them. To attain sustainable development, we urgently call all public and private entities to value the amount of VW used in their daily activities and design better policies on the complex WEFBH nexus and future climate change.
Hubert Hirwa; Qiuying Zhang; Yunfeng Qiao; Yu Peng; Peifang Leng; Chao Tian; Sayidjakhon Khasanov; Fadong Li; Alphonse Kayiranga; Fabien Muhirwa; Auguste Itangishaka; Gabriel Habiyaremye; Jean Ngamije. Insights on Water and Climate Change in the Greater Horn of Africa: Connecting Virtual Water and Water-Energy-Food-Biodiversity-Health Nexus. Sustainability 2021, 13, 6483 .
AMA StyleHubert Hirwa, Qiuying Zhang, Yunfeng Qiao, Yu Peng, Peifang Leng, Chao Tian, Sayidjakhon Khasanov, Fadong Li, Alphonse Kayiranga, Fabien Muhirwa, Auguste Itangishaka, Gabriel Habiyaremye, Jean Ngamije. Insights on Water and Climate Change in the Greater Horn of Africa: Connecting Virtual Water and Water-Energy-Food-Biodiversity-Health Nexus. Sustainability. 2021; 13 (11):6483.
Chicago/Turabian StyleHubert Hirwa; Qiuying Zhang; Yunfeng Qiao; Yu Peng; Peifang Leng; Chao Tian; Sayidjakhon Khasanov; Fadong Li; Alphonse Kayiranga; Fabien Muhirwa; Auguste Itangishaka; Gabriel Habiyaremye; Jean Ngamije. 2021. "Insights on Water and Climate Change in the Greater Horn of Africa: Connecting Virtual Water and Water-Energy-Food-Biodiversity-Health Nexus." Sustainability 13, no. 11: 6483.
It is important to strengthen the studies on the response of soil respiration components to tillage practices and natural precipitation in cropland. Therefore, soil heterotrophic respiration (RH) and autotrophic (RA) respiration were monitored by a root exclusion method in the North China Plain (NCP). The tillage practices included no-tillage (NT) and conventional tillage (CT), and the study periods were the summer maize growth stages in 2018 and 2019. RH, RA, soil water content and temperature were measured continuously for 113 days by an automatic sampling and analysis system. The soil RH values on bright days and rain-affected days were higher under NT in 2018 (14.22 and 15.06 g CO2 m−2 d−1, respectively) than in 2019 (8.25 and 13.30 g CO2 m−2 d−1, respectively). However, the RA values on bright days and rain-affected days were lower under NT in 2018 (4.74 and 4.97 g CO2 m−2 d−1, respectively) than in 2019 (5.67 and 6.93 g CO2 m−2 d−1, respectively). Moreover, NT decreased RH but increased RA compared to CT in 2019. Compared to bright days, the largest increase in both RH and RA after rain pulses was under CT in 2019 (6.75 and 1.80 g CO2 m−2 d−1, respectively). Soil water content and soil temperature were higher in 2018 than in 2019. Moreover, NT increased soil water content and decreased soil temperature on bright days compared to CT in 2019. Furthermore, soil temperature accounted for more variations in RH on bright days and rain-affected days, but soil water content had a greater influence on RA on bright days. However, after precipitation, higher soil water content decreased RA under NT in 2018, while soil water content was positively related to RA under CT in 2019. This study determined the differential response of RH and RA to tillage practices and natural precipitation pulses, and we confirmed that excessively dry soil increases soil carbon loss after rain events in the NCP.
Kun Du; Fadong Li; Peifang Leng; Zhao Li; Chao Tian; Yunfeng Qiao; Zhaoxin Li. Differential Influence of No-Tillage and Precipitation Pulses on Soil Heterotrophic and Autotrophic Respiration of Summer Maize in the North China Plain. Agronomy 2020, 10, 2004 .
AMA StyleKun Du, Fadong Li, Peifang Leng, Zhao Li, Chao Tian, Yunfeng Qiao, Zhaoxin Li. Differential Influence of No-Tillage and Precipitation Pulses on Soil Heterotrophic and Autotrophic Respiration of Summer Maize in the North China Plain. Agronomy. 2020; 10 (12):2004.
Chicago/Turabian StyleKun Du; Fadong Li; Peifang Leng; Zhao Li; Chao Tian; Yunfeng Qiao; Zhaoxin Li. 2020. "Differential Influence of No-Tillage and Precipitation Pulses on Soil Heterotrophic and Autotrophic Respiration of Summer Maize in the North China Plain." Agronomy 10, no. 12: 2004.
Nansi Lake has been seriously affected by intensive anthropogenic activities in recent years. In this study, an extensive survey on spatial variation, pollution assessment as well as the possible sources identification of major nutrients (Total phosphorus: TP, Total nitrogen: TN, and Total organic carbon: TOC) in the surface sediments of Nansi Lake was conducted. Results showed that the mean contents of TP, TN and TOC were 1.13-, 5.40- and 2.50- fold higher than their background values respectively. Most of the TN and TOC contents in the surface sediments of Nansi Lake were four times as high or higher and twice as high or higher than the background values except the Zhaoyang sub-lake, and the spatial distribution of TN and TOC contents were remarkably similar over a large area. Nearly all the TP contents in the surface sediments of Nansi Lake were all higher than its background values except most part of the Zhaoyang sub-lake. Based on the enrichment factor (EF) and the organic pollution evaluation index (Org-index), TP, TOC and TN showed minor enrichment (1.13), minor enrichment (2.50) and moderately severe enrichment (5.40), respectively, and most part of the Dushan sub-lake and the vicinity of the Weishan island were in moderate or heavy sediments organic pollution, while the other parts were clean. Moreover, according to the results of multivariate statistical analysis, we deduced that anthropogenic TN and TOC were mainly came from industrial sources including enterprises distributed in Jining, Yanzhou and Zoucheng along with iron and steel industries distributed in the southern of the Weishan sub-lake, whereas TP mainly originated from runoff and soil erosion coming from agricultural lands located in Heze city and Weishan island, the local aquacultural activities as well as the domestic sewage discharge of Jining city.
Longfeng Wang; Jun Xia; Jingjie Yu; Liyuan Yang; Chesheng Zhan; Yunfeng Qiao; Hongwei Lu. Spatial Variation, Pollution Assessment and Source Identification of Major Nutrients in Surface Sediments of Nansi Lake, China. Water 2017, 9, 444 .
AMA StyleLongfeng Wang, Jun Xia, Jingjie Yu, Liyuan Yang, Chesheng Zhan, Yunfeng Qiao, Hongwei Lu. Spatial Variation, Pollution Assessment and Source Identification of Major Nutrients in Surface Sediments of Nansi Lake, China. Water. 2017; 9 (6):444.
Chicago/Turabian StyleLongfeng Wang; Jun Xia; Jingjie Yu; Liyuan Yang; Chesheng Zhan; Yunfeng Qiao; Hongwei Lu. 2017. "Spatial Variation, Pollution Assessment and Source Identification of Major Nutrients in Surface Sediments of Nansi Lake, China." Water 9, no. 6: 444.