المؤلفون: Tonghui Zhang, Shilin Tang, Fenfen Liu, Haibin Ye

المصدر: Water, Vol 13, Iss 435, p 435 (2021)
Water
Volume 13
Issue 4

مصطلحات موضوعية: lcsh:Hydraulic engineering, 010504 meteorology & atmospheric sciences, Geography, Planning and Development, Remote sensing reflectance, 0211 other engineering and technologies, 02 engineering and technology, Aquatic Science, 01 natural sciences, Biochemistry, suspended sediment concentration, lcsh:Water supply for domestic and industrial purposes, lcsh:TC1-978, sand excavation, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Water Science and Technology, Hydrology, geography, lcsh:TD201-500, geography.geographical_feature_category, Sediment, Excavation, Estuary, Satellite remote sensing, Environmental science, symbolic regression, Landsat

الوصف: The Hong Kong-Zhuhai-Macau Bridge crosses the Pearl River Estuary and is the largest bridge and tunnel project in the world. During the construction period of this project, the excessive suspended sediment was found in the construction region. The suspended sediment generated by sand excavation in the upstream was assumed to have a significant impact on the suspended sediment in the tunnel region. In this study, we assessed the impact of upstream sand excavation on the suspended sediment in the Hong Kong-Zhuhai-Macau Bridge construction area using Landsat OLI, ETM+, and TM data. Regional suspended sediment algorithms were developed for Landsat using a symbolic regression method based on data from in situ measurements in the study area from 2003 to 2014. A band shift was conducted on the remote sensing reflectance data from Landsat ETM+ and OLI to produce a time series of the suspended sediment concentrations that was internally consistent with that of the Landsat TM data. The suspended sediment distribution was extracted and used to compare under two different conditions, with and without sand excavation. The correlations of the time series of the suspended sediment concentrations in different regions in the surrounding waters, including the correlations between the construction regions and the sand excavation regions, were calculated. Our results indicated that the sand excavation north of the Pearl River Estuary had a limited impact on the surface suspended sediment concentrations in the Hong Kong-Zhuhai-Macau Bridge tunnel area.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fb8ca4c23a5ee80aa6e9d7db36cbebf4Test
https://www.mdpi.com/2073-4441/13/4/435Test

المؤلفون: Haigang Zhan, Shilin Tang, Tonghui Zhang

المصدر: Journal of Coastal Research. 342:451-459

مصطلحات موضوعية: 0106 biological sciences, Hydrology, In situ, geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Ecology, 010604 marine biology & hydrobiology, Estuary, engineering.material, 01 natural sciences, chemistry.chemical_compound, Oceanography, chemistry, Chlorophyll, Phytoplankton, engineering, Environmental science, Satellite, Bloom, Eutrophication, Pearl, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology

الوصف: Zhang, T.; Tang, S., and Zhan, H., 2018. Using satellite sensors and in situ observations to monitor phytoplankton blooms in the Pearl River Estuary. Eutrophication in the Pearl River Estuary (PRE) has become severe with the rapid urbanization of the Pearl River Delta in recent years. As a result, large-scale phytoplankton blooms occur frequently because of eutrophication. This study investigated a massive Cochlodinium geminatum bloom near the mouth of the Pearl River in August 2011 based on data from both in situ measurements and satellites. Both methods provided a useful approach for monitoring phytoplankton blooms. The in situ measurements illustrated a high concentration of algal cells (1.5 × 107 cells L−1) in the study area, and the bloom reached dimensions of approximately 10 to 15 km in length, 8 to 10 km in width, and 100 km2 in area based on continuous field measurements. A chlorophyll algorithm for satellite sensors was developed based on in situ chlorophyll concentrations and remote se...

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::41176cdb5289d3a536f538a8644f2b66Test
https://doi.org/10.2112/jcoastres-d-16-00188.1Test

المؤلفون: Jing Feng, Na Su, Quanlin Ma, Xueyong Zhao, Tonghui Zhang, Yuqiang Li, Wen Shang, Jinnian Tang

المصدر: Journal of Arid Land. 9:688-700

مصطلحات موضوعية: Total organic carbon, 010504 meteorology & atmospheric sciences, Agroforestry, 04 agricultural and veterinary sciences, Soil carbon, Management, Monitoring, Policy and Law, 01 natural sciences, Biomass carbon, Sand dune stabilization, Plant ecology, Agronomy, Caragana microphylla, Soil water, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Afforestation, Environmental science, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology

الوصف: Afforestation is conducive to soil carbon (C) sequestration in semi-arid regions. However, little is known about the effects of afforestation on sequestrations of total and labile soil organic carbon (SOC) fractions in semi-arid sandy lands. In the present study, we examined the effects of Caragana microphylla Lam. plantations with different ages (12- and 25-year-old) on sequestrations of total SOC as well as labile SOC fractions such as light fraction organic carbon (LFOC) and microbial biomass carbon (MBC). The analyzed samples were taken from soil depths of 0–5 and 5–15 cm under two shrub-related scenarios: under shrubs and between shrubs with moving sand dunes as control sites in the Horqin Sandy Land of northern China. The results showed that the concentrations and storages of total SOC at soil depths of 0–5 and 5–15 cm were higher in 12- and 25-year-old C. microphylla plantations than in moving sand dunes (i.e., control sites), with the highest value observed under shrubs in 25-year-old C. microphylla plantations. Furthermore, the concentrations and storages of LFOC and MBC showed similar patterns with those of total SOC at the same soil depth. The 12-year-old C. microphylla plantations had higher percentages of LFOC concentration to SOC concentration and MBC concentration to SOC concentration than the 25-year-old C. microphylla plantations and moving sand dunes at both soil depths. A significant positive correlation existed among SOC, LFOC, and MBC, implying that restoring the total and labile SOC fractions is possible by afforestation with C. microphylla shrubs in the Horqin Sandy Land. At soil depth of 0–15 cm, the accumulation rate of total SOC under shrubs was higher in young C. microphylla plantations (18.53 g C/(m2•a); 0–12 years) than in old C. microphylla plantations (16.24 g C/(m2•a); 12–25 years), and the accumulation rates of LFOC and MBC under shrubs and between shrubs were also higher in young C. microphylla plantations than in old C. microphylla plantations. It can be concluded that the establishment of C. microphylla in the Horqin Sandy Land may be a good mitigation strategy for SOC sequestration in the surface soils.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::25e89a8526726d1d5052a0d716fd9e8fTest
https://doi.org/10.1007/s40333-017-0063-xTest

المؤلفون: Tonghui Zhang, Yuhui He, Xiangfei Yue, Shuilian Wei, Lamei Zhang, Xinping Liu, Jianying Yun, Yuqiang Li, Xueyong Zhao

المصدر: Environmental Earth Sciences. 73:8699-8708

مصطلحات موضوعية: Hydrology, Soil depth, Global and Planetary Change, Soil Science, Geology, Soil science, Soil surface, Pollution, Rainfall infiltration, Effective depth, Infiltration (hydrology), Simulated rainfall, Soil water, Environmental Chemistry, Water content, Earth-Surface Processes, Water Science and Technology

الوصف: To understand the relationships among rainfall–infiltration–evaporation–replenishment in mobile dunes in the semi-arid areas of China, we used the Container of Water Distribution (100 × 100 × 120 cm3) to examine rainfall infiltration, soil water redistribution, and soil surface evaporation under natural and simulated rainfall conditions. The results showed that infiltration depth was linearly related to rainfall amount and intensity. Rainfall amounts larger than 13.4 mm, could replenish soil water at 60 cm depth after redistribution, while with rainfalls larger than 39.8 mm, infiltration depth could exceed 120 cm. Rainfall amounts larger than 50 mm produced saturated soil water at 120 cm depth, and replenishment amount accounted for 40.4 % of the total amount of rainfall. Soil surface evaporation exhibited a relatively minor change with increases in rainfall when rainfall was larger than 11.8 mm. The amount of evaporation and soil water content were significantly correlated at 0–60 cm soil depth, but not below. These results suggest that the maximum effective depth of evaporation is 60 cm below the ground surface, and that rainfall of 13.4 mm is a threshold distinguishing effective from ineffective rainfall in the mobile dunes of the Horqin Sandy Land.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::a7d6a1aa06edcb0df256237fe977381bTest
https://doi.org/10.1007/s12665-015-4125-0Test

المؤلفون: Yunhua Ma, Xinping Liu, Tonghui Zhang

المصدر: Environmental Earth Sciences. 74:727-735

مصطلحات موضوعية: Canopy, Hydrology, Global and Planetary Change, Biomass (ecology), geography, geography.geographical_feature_category, Soil Science, Geology, Plant community, Pollution, Arid, Agronomy, Germination, Spring (hydrology), Soil water, Environmental Chemistry, Intensity (heat transfer), Earth-Surface Processes, Water Science and Technology

الوصف: The composition and development of sandy land plant communities in arid and semiarid environments largely depend on rainfall pulses. However, little is known about how the intensity of small rainfall events affects the emergence and growth of annuals in spring. For this study, an experiment was designed to simulate the effect of low-intensity spring rainfall events on annuals in Horqin Sandy Land, China, in May of 2011 and 2012. It included rainfall treatments of 2 mm (applied 16 times), 4 mm (applied 8 times), and 8 mm (applied 4 times), and a control check (CK, which received natural rainfall). The soil water content, species composition, seed germination, plant density, height, and coverage, and aboveground biomass were measured. Results showed that rainfall intensity had a significant influence on the emergence and growth of annuals. A rainfall of 8 mm was the threshold for germination, whether as a single rainfall event or as accumulated rainfall. The 8-mm treatment also resulted in the greatest number of seedlings, while the 2-mm treatment provided the least. Community characteristics such as species number, density, and coverage increased with rainfall intensity; height and canopy decreased; the Shannon-Wiener index showed no obvious trend. The distribution of rain amount and frequency impacted biomass accumulation: with increased rainfall intensity and extended rainfall intervals, biomass was significantly increased compared to the control check.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::9b359e6b47a2bfafcd513595fecf3ae8Test
https://doi.org/10.1007/s12665-015-4077-4Test

المؤلفون: Tonghui Zhang, Yuhui He, Xinping Liu, Shaokun Wang, Shuxia Yao, Lamei Zhang, Xueyong Zhao, Shuilian Wei, Yunhua Ma

المصدر: Journal of Arid Land. 7:238-250

مصطلحات موضوعية: Hydrology, Growing season, Soil science, Groundwater recharge, Management, Monitoring, Policy and Law, Field capacity, Soil water, Soil horizon, Environmental science, Surface runoff, Soil salinity control, Groundwater, Earth-Surface Processes, Water Science and Technology

الوصف: Quantification of deep drainage and the response of soil water content to rainfall patterns are critical for an effective management strategy of soil water conservation and groundwater utilization. However, there has been little information on how rainfall characteristics influence soil water dynamics and deep drainage in mobile sandy lands. We used an underground chamber to examine the responses of deep drainage and soil water content in mobile sandy lands to rainfall characteristics in Inner Mongolia during the growing seasons of 2010, 2011 and 2012. Results showed that rainfall in this area was dominated by small events (≤5 mm), which increased soil water con- tent in the surface soil layers (0-40 cm), but did not increase soil water content in the deeper soil layers (greater than 40 cm). Soil water content at the 0-100 cm depth increased significantly when the total amount of rain was >20 mm. Rainfall amount, intensity and the duration of dry intervals were significantly related to the soil water content in different soil layers. Deep drainage was significantly correlated with rainfall amount and intensity, but not with the duration of dry intervals. The coefficients of deep drainage in the mobile sandy lands ranged from 61.30% to 67.94% during the growing seasons. Our results suggested that rainfall infiltration in the mobile sandy lands had considerable potential to increase soil water storage while recharging the groundwater in this region.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::bd710eae864f05605c824b49fd099fd1Test
https://doi.org/10.1007/s40333-014-0095-4Test

المؤلفون: Xueyong Zhao, ceshi, Wei Mao, Yu-Lin Li, zhang, Yingxin Huang, Tonghui Zhang

المصدر: Journal of Arid Land. 4:161-170

مصطلحات موضوعية: Geography, Nutrient, biology, Perennial plant, Ecology, Allometry, Management, Monitoring, Policy and Law, biology.organism_classification, China, Pennisetum, Earth-Surface Processes, Water Science and Technology

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::fbc5928758d79ba7dc6573caff90ba5fTest
https://doi.org/10.3724/sp.j.1227.2012.00161Test

المؤلفون: Tonghui Zhang, Xueyong Zhao, Yuqiang Li, Yulin Li, Halin Zhao, Jianyuan Cui

المصدر: Environmental Earth Sciences. 63:771-783

مصطلحات موضوعية: Hydrology, Global and Planetary Change, Topsoil, Soil Science, Geology, Silt, Pollution, Bulk density, Soil retrogression and degradation, Environmental chemistry, Soil water, Grazing, Exclosure, Cation-exchange capacity, Environmental Chemistry, Earth-Surface Processes, Water Science and Technology

الوصف: Heavy grazing is recognized as one of the main causes of vegetation and soil degradation and desertification in the semiarid Horqin sandy grassland of northern China. Soil physical and chemical properties were examined under continuous grazing and exclusion of livestock for 8 years in a representative desertified sandy grassland. Exclosure increased the mean soil organic C, total N, fine sand and silt + clay contents, inorganic C (CaCO3), electrical conductivity, and mineral contents (including Al2O3, K2O, Na2O, Fe2O3, CaO, MgO, TiO2, MnO), microelements (Fe, Mn, Zn, B, Cu, Mo), and heavy metals (Pb, Cr, Ni, As, Hg, Cd, Se), and decreased the coarse sand content, bulk density, and SiO2 in the top 100 cm of the soil. Livestock exclusion also improved available N, P, K, Fe, Mn, and Cu, exchangeable K+, and the cation exchange capacity, but decreased pH, exchangeable Na+, and available S, Zn, and Mo in the top 20 cm of the soil. The greatest change in soil properties was observed in the topsoil. The results confirm that the desertified grassland is recovering after removal of the livestock disturbance, but that recovery is a slow process.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::33796c41373aaca171c68425f4836d50Test
https://doi.org/10.1007/s12665-010-0748-3Test

المؤلفون: Yulin Li, Tonghui Zhang, Halin Zhao, Jianyuan Cui

المصدر: Agricultural Water Management. 61:1-12

مصطلحات موضوعية: geography, geography.geographical_feature_category, Soil Science, Sowing, Arid, Crop, Crop coefficient, Agronomy, Evapotranspiration, Lysimeter, Spring (hydrology), Leaf area index, Agronomy and Crop Science, Earth-Surface Processes, Water Science and Technology, Mathematics

الوصف: Gravimetric lysimeter experiments were conducted to measure the daily evapotranspiration (ETc) of spring wheat in 1998 and maize in 1999 at Naiman, Inner Mongolia, China. The weekly ETc range of spring wheat varied from 12.32 to 45.43 mm per week. The maximum ETc occurred at the 9th week after sowing during the mid-season stage, and the peak value of leaf area index (LAI) also occurred at this time. As for maize, ETc averaged 16.7 mm per week during the initial stage, approached a peak value of 48.45 mm per week at the 12th week after sowing, and declined to its minimum of 13.33 mm per week during the late-season stage. The total ETc of spring wheat and maize were 425.7 and 572.5 mm, and average daily ETc of spring wheat and maize were 4.05 and 4.09 mm during the both growth seasons. The five reference ET methods (i.e. FAO-56 Penman–Monteith (56PM), FAO-24 Penman (24Pn), FAO-24 Blaney–Criddle (24BC), FAO-24 Radiation (24Rd) and 1985 Hargreaves (Harg)) were evaluated for their capabilities to predict ET0 using daily weather data. Statistical analysis showed that the FAO-24 Penman and FAO-24 Blaney–Criddle methods may be instead of the FAO-56 Penman–Monteith method in predicting ET0 value in this region. Crop coefficients (Kc) for spring wheat and maize were calculated from the measured ETc data and the predicted ET0 data by the FAO-56 Penman–Monteith method, and their values were 0.55, 1.03, 1.19, and 0.65 during the initial, crop development, mid-season, and late-season stages for spring wheat, respectively, and the corresponding values for maize were 0.50, 1.02, 1.26 and 0.68.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::f3f80777ba5b74238992f8397876be73Test
https://doi.org/10.1016/s0378-3774Test(02)00177-4