Saline ice meltwater can be used for irrigation and leaching of salts in salt-affected soil regions.A laboratory experiment was conducted using soil columns to investigate the redistribution of soil moisture, salt and...Saline ice meltwater can be used for irrigation and leaching of salts in salt-affected soil regions.A laboratory experiment was conducted using soil columns to investigate the redistribution of soil moisture, salt and sodium adsorption ratio(SAR) in saline-sodic soil under the infiltration of saline ice meltwater.Soils were treated using saline water of three irrigation volumes(1 600, 2 400 and 3 200 mL) at four salinity levels.These four salinity levels included salt free(0 g L^(-1)), low salinity level(1.4 g L^(-1)), moderate salinity level(2.7 g L^(-1)) and high salinity level(4.1 g L^(-1)).The prepared saline water was frozen into ice, and then the ice was put on the surface of soil columns.After 96 h, the infiltration rate and soil moisture content of saline ice treatments were greater than those of salt-free ice treatments, increasing with the increase of ice salinity.Infiltration of saline ice meltwater increased soil moisture content in the upper layers for all treatments.Both salt contents and SAR values in the upper soil layers decreased in all saline ice treatments and were lower than those in salt-free ice treatment.However, this trend was reversed in the deeper(below 20 cm) soil layers.The highest desalting rate and lowest SAR were observed in high-salinity treatment under three irrigation volumes in the 0–15 cm soil layer,especially under irrigation volume of 2 400 mL.These results indicate that saline ice(0–20 cm) meltwater irrigation is beneficial to saline-sodic soil reclamation, and the best improvement effect would be achieved when using high-salinity ice under optimal irrigation volume.展开更多
There is a lack of information of whether the behavior pattern and physical condition of the Hooded Crane (Grus monacha) have been limited by conditions encountered at stopover sites in Changgou village,which is adjac...There is a lack of information of whether the behavior pattern and physical condition of the Hooded Crane (Grus monacha) have been limited by conditions encountered at stopover sites in Changgou village,which is adjacent to Zhalong Nature Reserve in northeastern China,one of the most important stopover sites of this crane.The objective of our research was to investigatethe impact of human-caused disturbances on the Hooded Cranes.We investigated three behavior activities of the Hooded Cranes,i.e.,flying time,flushing distance and the duration of vigilance.The results indicate that the auditory stimuli caused by local people provoked the most pronounced disturbances to the Hooded Crane.Human-caused disturbances not only frequently interrupt the feeding process of the cranes,but also lead to an increase of 200％ in the duration of their vigilance and a significant increase in flying time from 0.4 to 0.7 h (p ＜ 0.05).In addition,high-intensity noise can cause larger flushing distances; foraging cranes will flush away by about 600 m when disturbed by the honking of vehicles.Whistles or shouts by local farmers in the field generated the largest sound intensity,about 120 dB,which caused a flushing distance of over 700 m.In order to reduce the negative effect of human-caused disturbances on these cranes,it is imperative to define a buffer zone around sensitive areas during the fall stopover period.To solve the conflict between the interest of farmers and the demand for crops on the part of the cranes requires financial compensation to the farmers for the crops consumed by the Hooded Crane in order to enhance the conservation of this vulnerable bird species.展开更多
A perforating hole is a channel through which the oil and gas in a reservoir pass into the production well bore.During the process of perforating due to explosion,the surrounding sandstone will be damaged to a certain...A perforating hole is a channel through which the oil and gas in a reservoir pass into the production well bore.During the process of perforating due to explosion,the surrounding sandstone will be damaged to a certain extent,which will increase the well bore skin and lead to the decrease of production consequently.In this work a mechanical model of perforating damage is developed to describe the influences of perforating due to explosion on the porosity and permeability of the surrounding sandstone near the compaction zone.Based on this developed model,the important data related to the damage of sandstone,such as matrix effective stress,plastic deformation,volumetric strain,and so on,can be numerically simulated.Especially the behaviors of plasticity kinematic hardening at high strain rate due to impact loads,which are the important characteristics in the sandstone,is taken into account in this developed model.Both numerical and testing results show that the damage due to perforation in the sandstone can be accurately predicted by the developed model together with the porosity and permeability evolving model of perforation in a compaction zone.As a practical application,a methodology for the analysis of damage of porosity and permeability around a perforation tunnel is supposed based on the developed model and the core flow efficiency test of interparticle pore spaced sandstone target in China Shengli Oilfield and the computed tomography test.展开更多
Grand Lake O’The Cherokees, the third largest reservoir located in northeastern Oklahoma, provides recreational services, water supply, hydroelectric power, and flood control to residents of Oklahoma and neighboring ...Grand Lake O’The Cherokees, the third largest reservoir located in northeastern Oklahoma, provides recreational services, water supply, hydroelectric power, and flood control to residents of Oklahoma and neighboring states. Grand Lake has experienced major problems?with eutrophication, harmful algal blooms, and dissolved oxygen (DO) depletion during summer. To better understand the dynamics of DO depletion in the hypolimnion of Grand Lake, a three-layer steady state vertical DO model for summer-stratified conditions was used to investigate dissolved oxygen profiles both above and below the thermocline. The DO model was used to determine the relative effects of atmospheric reaeration and phytoplankton production as a source of DO and phytoplankton respiration, decomposition of organic matter, and nitrification as loss terms for DO. Additionally, the importance of sediment oxygen demand (SOD) for hypolimnetic oxygen depletion was investigated at the sediment water-interface under stratified conditions. Observed water quality data, kinetic coefficients from the literature, and physical, biological, and chemical data collected throughout 2013 and 2015 along the spatial gradient of riverine, transition, lacustrine zones and a site close to the Grand Lake Pensacola Dam were used?in the pre-processing calculations to derive estimates of kinetic rates as input parameters to the model. The estimated predictions from the model showed reasonable agreement with the observed vertical profiles of DO. Conclusions from this study indicate that phytoplankton production, high light limitation, and phosphorus were the major terms that controlled DO production in the surface layer, while nitrification and organic carbon decomposition were the major sinks of DO consumption in the bottom layer. Interestingly, SOD did not play a significant role in DO depletion in the water column.展开更多
Flood forecasting is an essential tool for mitigating flood risks and enhancing disaster preparedness,particularly in vulnerable urban and agricultural areas where timely and accurate predictions can significantly red...Flood forecasting is an essential tool for mitigating flood risks and enhancing disaster preparedness,particularly in vulnerable urban and agricultural areas where timely and accurate predictions can significantly reduce damage and ensure public safety.This paper presents a comprehensive approach to forecasting the water level of downstream network systems,including reservoirs and irrigation districts,during the flood season.The proposed methodology utilizes the Long Short-Term Memory(LSTM)deep learning technique to accurately predict flood water level patterns.Historical water level and rainfall data from a network comprising four rainfall gauging stations with long-term records and one water level gauging station within the case study area are processed and analyzed to improve prediction accuracy.The results demonstrate that the proposed LSTM model with SGDM technique effectively captures regime dynamics,providing valuable insights for decision-makers in flood risk management.The model achieves high accuracy in predicting flood peaks,both in magnitude and timing,with determination coefficient𝑅R^(2)values of 0.92 for 24-hour forecasts and 0.81 for 48-hour forecasts.The Root Mean Square Errors(RMSEs)for the entire flood season are 0.23 m for 24-hour forecasts and 0.35 m for 48-hour forecasts,within a water level range of approximately 2.0 m to 8.0 m during the intentional flood period at the control stations.The forecasted flow accuracy P are 84.85%and 87.60%for 24-hour and 48-hour forecasts,respectively.These findings highlight the potential of the LSTM model to enhance forecast performance,contributing to more efficient and sustainable water distribution systems while improving flood risk management practices.展开更多
基金supported by the National Key Research and Development Program of China(No.2016YFC0501200)the National Natural Science Foundation of China(Nos.41571210 and 41601583)the Natural Science and Technology Basic Work of China(No.2015FY110500)
文摘Saline ice meltwater can be used for irrigation and leaching of salts in salt-affected soil regions.A laboratory experiment was conducted using soil columns to investigate the redistribution of soil moisture, salt and sodium adsorption ratio(SAR) in saline-sodic soil under the infiltration of saline ice meltwater.Soils were treated using saline water of three irrigation volumes(1 600, 2 400 and 3 200 mL) at four salinity levels.These four salinity levels included salt free(0 g L^(-1)), low salinity level(1.4 g L^(-1)), moderate salinity level(2.7 g L^(-1)) and high salinity level(4.1 g L^(-1)).The prepared saline water was frozen into ice, and then the ice was put on the surface of soil columns.After 96 h, the infiltration rate and soil moisture content of saline ice treatments were greater than those of salt-free ice treatments, increasing with the increase of ice salinity.Infiltration of saline ice meltwater increased soil moisture content in the upper layers for all treatments.Both salt contents and SAR values in the upper soil layers decreased in all saline ice treatments and were lower than those in salt-free ice treatment.However, this trend was reversed in the deeper(below 20 cm) soil layers.The highest desalting rate and lowest SAR were observed in high-salinity treatment under three irrigation volumes in the 0–15 cm soil layer,especially under irrigation volume of 2 400 mL.These results indicate that saline ice(0–20 cm) meltwater irrigation is beneficial to saline-sodic soil reclamation, and the best improvement effect would be achieved when using high-salinity ice under optimal irrigation volume.
文摘There is a lack of information of whether the behavior pattern and physical condition of the Hooded Crane (Grus monacha) have been limited by conditions encountered at stopover sites in Changgou village,which is adjacent to Zhalong Nature Reserve in northeastern China,one of the most important stopover sites of this crane.The objective of our research was to investigatethe impact of human-caused disturbances on the Hooded Cranes.We investigated three behavior activities of the Hooded Cranes,i.e.,flying time,flushing distance and the duration of vigilance.The results indicate that the auditory stimuli caused by local people provoked the most pronounced disturbances to the Hooded Crane.Human-caused disturbances not only frequently interrupt the feeding process of the cranes,but also lead to an increase of 200％ in the duration of their vigilance and a significant increase in flying time from 0.4 to 0.7 h (p ＜ 0.05).In addition,high-intensity noise can cause larger flushing distances; foraging cranes will flush away by about 600 m when disturbed by the honking of vehicles.Whistles or shouts by local farmers in the field generated the largest sound intensity,about 120 dB,which caused a flushing distance of over 700 m.In order to reduce the negative effect of human-caused disturbances on these cranes,it is imperative to define a buffer zone around sensitive areas during the fall stopover period.To solve the conflict between the interest of farmers and the demand for crops on the part of the cranes requires financial compensation to the farmers for the crops consumed by the Hooded Crane in order to enhance the conservation of this vulnerable bird species.
文摘A perforating hole is a channel through which the oil and gas in a reservoir pass into the production well bore.During the process of perforating due to explosion,the surrounding sandstone will be damaged to a certain extent,which will increase the well bore skin and lead to the decrease of production consequently.In this work a mechanical model of perforating damage is developed to describe the influences of perforating due to explosion on the porosity and permeability of the surrounding sandstone near the compaction zone.Based on this developed model,the important data related to the damage of sandstone,such as matrix effective stress,plastic deformation,volumetric strain,and so on,can be numerically simulated.Especially the behaviors of plasticity kinematic hardening at high strain rate due to impact loads,which are the important characteristics in the sandstone,is taken into account in this developed model.Both numerical and testing results show that the damage due to perforation in the sandstone can be accurately predicted by the developed model together with the porosity and permeability evolving model of perforation in a compaction zone.As a practical application,a methodology for the analysis of damage of porosity and permeability around a perforation tunnel is supposed based on the developed model and the core flow efficiency test of interparticle pore spaced sandstone target in China Shengli Oilfield and the computed tomography test.
文摘Grand Lake O’The Cherokees, the third largest reservoir located in northeastern Oklahoma, provides recreational services, water supply, hydroelectric power, and flood control to residents of Oklahoma and neighboring states. Grand Lake has experienced major problems?with eutrophication, harmful algal blooms, and dissolved oxygen (DO) depletion during summer. To better understand the dynamics of DO depletion in the hypolimnion of Grand Lake, a three-layer steady state vertical DO model for summer-stratified conditions was used to investigate dissolved oxygen profiles both above and below the thermocline. The DO model was used to determine the relative effects of atmospheric reaeration and phytoplankton production as a source of DO and phytoplankton respiration, decomposition of organic matter, and nitrification as loss terms for DO. Additionally, the importance of sediment oxygen demand (SOD) for hypolimnetic oxygen depletion was investigated at the sediment water-interface under stratified conditions. Observed water quality data, kinetic coefficients from the literature, and physical, biological, and chemical data collected throughout 2013 and 2015 along the spatial gradient of riverine, transition, lacustrine zones and a site close to the Grand Lake Pensacola Dam were used?in the pre-processing calculations to derive estimates of kinetic rates as input parameters to the model. The estimated predictions from the model showed reasonable agreement with the observed vertical profiles of DO. Conclusions from this study indicate that phytoplankton production, high light limitation, and phosphorus were the major terms that controlled DO production in the surface layer, while nitrification and organic carbon decomposition were the major sinks of DO consumption in the bottom layer. Interestingly, SOD did not play a significant role in DO depletion in the water column.
基金funding from the Vietnam Ministry of Natural Resources and Environment entitled“To Study and Develop Hydrological Forecasting and Flood Warning Technologies for Small River Basins,Applying the Tests to Some Small River Basins in the North-West Region”,Code number:TNMT.2023.06.14.
文摘Flood forecasting is an essential tool for mitigating flood risks and enhancing disaster preparedness,particularly in vulnerable urban and agricultural areas where timely and accurate predictions can significantly reduce damage and ensure public safety.This paper presents a comprehensive approach to forecasting the water level of downstream network systems,including reservoirs and irrigation districts,during the flood season.The proposed methodology utilizes the Long Short-Term Memory(LSTM)deep learning technique to accurately predict flood water level patterns.Historical water level and rainfall data from a network comprising four rainfall gauging stations with long-term records and one water level gauging station within the case study area are processed and analyzed to improve prediction accuracy.The results demonstrate that the proposed LSTM model with SGDM technique effectively captures regime dynamics,providing valuable insights for decision-makers in flood risk management.The model achieves high accuracy in predicting flood peaks,both in magnitude and timing,with determination coefficient𝑅R^(2)values of 0.92 for 24-hour forecasts and 0.81 for 48-hour forecasts.The Root Mean Square Errors(RMSEs)for the entire flood season are 0.23 m for 24-hour forecasts and 0.35 m for 48-hour forecasts,within a water level range of approximately 2.0 m to 8.0 m during the intentional flood period at the control stations.The forecasted flow accuracy P are 84.85%and 87.60%for 24-hour and 48-hour forecasts,respectively.These findings highlight the potential of the LSTM model to enhance forecast performance,contributing to more efficient and sustainable water distribution systems while improving flood risk management practices.
