Autumn continuous overcast and rainfall weather affects normal rice harvest and often causes higher rice output which is not accompanied by a higher income,and it is one of main agrometeorological disasters in harvest...Autumn continuous overcast and rainfall weather affects normal rice harvest and often causes higher rice output which is not accompanied by a higher income,and it is one of main agrometeorological disasters in harvesting period of middle and late rice in Hubei Province. Especially in recent years,plantation area of single-season rice in Hubei Province is larger,and it is mostly harvested from last dekad of September to middle dekad of October,and the opportunity of encountering autumn continuous overcast and rainfall in harvesting period is larger. From later period of last dekad of September to first and middle dekads of October,2017,continuous overcast and rainfall weather occurred in most areas of east Hubei Province,which caused serious influence on the harvesting of semilate rice. In this paper,adverse influence on semilate rice harvest by the autumn continuous overcast and rainfall was investigated and analyzed,and the suggestions on defending and reducing the harm of continuous overcast and rainfall in the harvesting period of semilate rice were proposed.展开更多
[Objective] The aim was to study the variation characteristics of longest continuous rainfall days in Shenyang in recent 48 years. [Method] Based on the data of longest continuous rainfall days in Shenyang from May to...[Objective] The aim was to study the variation characteristics of longest continuous rainfall days in Shenyang in recent 48 years. [Method] Based on the data of longest continuous rainfall days in Shenyang from May to September in 1961-2008, the variation characteristics of longest continuous rainfall days in Shenyang in recent 48 years was analyzed by means of one-dimensional linear trend estimation and wavelet analysis method. [Result] In recent 48 years, the longest continuous rainfall days in Shenyang showed decrease trend from May to September except for June in which it showed increased; the total longest continuous rainfall days showed decrease trend, and the maximum value appeared in 1986, while the minimum value could be found in 1997; from periodic variation, the total longest continuous rainfall days had the period of 2-3 years, and there also existed the period of 5-7 years after 1980; the total longest continuous rainfall days were more from the beginning of 1960s to the middle of 1990s and less thereafter. [Conclusion] The study could provide theoretical foundation for the deep research on climate change in Shenyang.展开更多
This paper deals with a stochastic representation of the rainfall process. The analysis of a rainfall time series shows that cumulative representation of a rainfall time series can be modeled as a non-Gaussian random ...This paper deals with a stochastic representation of the rainfall process. The analysis of a rainfall time series shows that cumulative representation of a rainfall time series can be modeled as a non-Gaussian random walk with a log-normal jump distribution and a time-waiting distribution following a tempered a-stable probability law. Based on the random walk model, a fractional Fokker-Planck equation （FFPE） with tempered a-stable waiting times was obtained. Through the comparison of observed data and simulated results from the random walk model and FFPE model with tempered a-stable waiting times, it can be concluded that the behavior of the rainfall process is globally reproduced, and the FFPE model with tempered a-stable waiting times is more efficient in reproducing the observed behavior.展开更多
A substantial amount of the Indian economy depends solely on agriculture.Rainfall,on the other hand,plays a significant role in agriculture–while an adequate amount of rainfall can be considered as a blessing,if the ...A substantial amount of the Indian economy depends solely on agriculture.Rainfall,on the other hand,plays a significant role in agriculture–while an adequate amount of rainfall can be considered as a blessing,if the amount is inordinate or scant,it can ruin the entire hard work of the farmers.In this work,the rainfall dataset of the Vellore region,of Tamil Nadu,India,in the years 2021 and 2022 is forecasted using several machine learning algorithms.Feature engineering has been performed in this work in order to generate new features that remove all sorts of autocorrelation present in the data.On removal of autocorrelation,the data could be used for performing operations on the time-series data,which otherwise could only be performed on any other regular regression data.The work uses forecasting techniques like the AutoRegessive Integrated Moving Average(ARIMA)and exponential smoothening,and then the time-series data is further worked on using Long Short Term Memory(LSTM).Later,regression techniques are used by manipulating the dataset.The work is benchmarked with several evaluation metrics on a test dataset,where XGBoost Regression technique outperformed the test.The uniqueness of this work is that it forecasts the daily rainfall for the year 2021 and 2022 in Vellore region.This work can be extended in the future to predict rainfall over a bigger region based on previously recorded time-series data,which can help the farmers and common people to plan accordingly and take precautionary measures.展开更多
The bottom ash is increasingly used as a substitute aggregate material in road construction in China,and road salting is the major salt source in groundwater.Continuous rainfall releases soluble salts from the bottom ...The bottom ash is increasingly used as a substitute aggregate material in road construction in China,and road salting is the major salt source in groundwater.Continuous rainfall releases soluble salts from the bottom ash subgrade into the surrounding soil and groundwater,resulting in potential hazards.Different methods were employed to simulate and collect runoff water during rainfall events,including batch leaching test,dynamic leaching test and constant head test,to assess environmental impact of bottom ash as road basement materials under continuous rainfall conditions.This study simulated the seepage of bottom ash backfill roads under different rainfall intensities,rainfall times,and rainfall pH values.A comprehensive sampling and laboratory testing program was undertaken to characterize the environmental impact of soluble salts from bottom ash.The obtained results reveal that the leaching concentrations of Cl^(−)and SO_(4)^(2−)exceed the limit specified in the class V standard of surface water,which are 2.06–2.17 times and 1.08–1.25 times,respectively.By examining the long-term environmental influence under the condition of continuous rainfall,the leaching of Cl^(−)mainly occurs in the early leaching stage,and the maximum leaching concentration reaches 19,700 mg/L.The release concentration of Cl^(−)begins to be lower than the class V standard of surface water when continuous rainfall approaches the total rainfall for 13 months.The cumulative release of Cl^(−)in the bottom ash is 2.8–5.4 mg/g.Both rainfall intensity and rain pH affect the release of Cl^(−).The obtained results derived from the constant head tests indicate that stagnant water caused by rainfall deteriorates the release of soluble salt into the groundwater in only 1 day,especially at the early stage of 12 h.This work provides some basic information about how to minimize damage to the surrounding environment caused by the leaching of salt in bottom ash.展开更多
文摘Autumn continuous overcast and rainfall weather affects normal rice harvest and often causes higher rice output which is not accompanied by a higher income,and it is one of main agrometeorological disasters in harvesting period of middle and late rice in Hubei Province. Especially in recent years,plantation area of single-season rice in Hubei Province is larger,and it is mostly harvested from last dekad of September to middle dekad of October,and the opportunity of encountering autumn continuous overcast and rainfall in harvesting period is larger. From later period of last dekad of September to first and middle dekads of October,2017,continuous overcast and rainfall weather occurred in most areas of east Hubei Province,which caused serious influence on the harvesting of semilate rice. In this paper,adverse influence on semilate rice harvest by the autumn continuous overcast and rainfall was investigated and analyzed,and the suggestions on defending and reducing the harm of continuous overcast and rainfall in the harvesting period of semilate rice were proposed.
文摘[Objective] The aim was to study the variation characteristics of longest continuous rainfall days in Shenyang in recent 48 years. [Method] Based on the data of longest continuous rainfall days in Shenyang from May to September in 1961-2008, the variation characteristics of longest continuous rainfall days in Shenyang in recent 48 years was analyzed by means of one-dimensional linear trend estimation and wavelet analysis method. [Result] In recent 48 years, the longest continuous rainfall days in Shenyang showed decrease trend from May to September except for June in which it showed increased; the total longest continuous rainfall days showed decrease trend, and the maximum value appeared in 1986, while the minimum value could be found in 1997; from periodic variation, the total longest continuous rainfall days had the period of 2-3 years, and there also existed the period of 5-7 years after 1980; the total longest continuous rainfall days were more from the beginning of 1960s to the middle of 1990s and less thereafter. [Conclusion] The study could provide theoretical foundation for the deep research on climate change in Shenyang.
文摘This paper deals with a stochastic representation of the rainfall process. The analysis of a rainfall time series shows that cumulative representation of a rainfall time series can be modeled as a non-Gaussian random walk with a log-normal jump distribution and a time-waiting distribution following a tempered a-stable probability law. Based on the random walk model, a fractional Fokker-Planck equation （FFPE） with tempered a-stable waiting times was obtained. Through the comparison of observed data and simulated results from the random walk model and FFPE model with tempered a-stable waiting times, it can be concluded that the behavior of the rainfall process is globally reproduced, and the FFPE model with tempered a-stable waiting times is more efficient in reproducing the observed behavior.
基金This researchwas partially funded by the“Intelligent Recognition Industry Service Research Center”from the Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education(MOE)in Taiwan and Ministry of Science and Technology in Taiwan(Grant No.MOST 109-2221-E-224-048-MY2).
文摘A substantial amount of the Indian economy depends solely on agriculture.Rainfall,on the other hand,plays a significant role in agriculture–while an adequate amount of rainfall can be considered as a blessing,if the amount is inordinate or scant,it can ruin the entire hard work of the farmers.In this work,the rainfall dataset of the Vellore region,of Tamil Nadu,India,in the years 2021 and 2022 is forecasted using several machine learning algorithms.Feature engineering has been performed in this work in order to generate new features that remove all sorts of autocorrelation present in the data.On removal of autocorrelation,the data could be used for performing operations on the time-series data,which otherwise could only be performed on any other regular regression data.The work uses forecasting techniques like the AutoRegessive Integrated Moving Average(ARIMA)and exponential smoothening,and then the time-series data is further worked on using Long Short Term Memory(LSTM).Later,regression techniques are used by manipulating the dataset.The work is benchmarked with several evaluation metrics on a test dataset,where XGBoost Regression technique outperformed the test.The uniqueness of this work is that it forecasts the daily rainfall for the year 2021 and 2022 in Vellore region.This work can be extended in the future to predict rainfall over a bigger region based on previously recorded time-series data,which can help the farmers and common people to plan accordingly and take precautionary measures.
基金the projects of the National Natural Science Foundation(No.52170141,No.52236008)the Key Research and Development Program of Zhejiang Province(No.2022C03092)Natural Science Foundation of Zhejiang Province(No.LZ23E060004)。
文摘The bottom ash is increasingly used as a substitute aggregate material in road construction in China,and road salting is the major salt source in groundwater.Continuous rainfall releases soluble salts from the bottom ash subgrade into the surrounding soil and groundwater,resulting in potential hazards.Different methods were employed to simulate and collect runoff water during rainfall events,including batch leaching test,dynamic leaching test and constant head test,to assess environmental impact of bottom ash as road basement materials under continuous rainfall conditions.This study simulated the seepage of bottom ash backfill roads under different rainfall intensities,rainfall times,and rainfall pH values.A comprehensive sampling and laboratory testing program was undertaken to characterize the environmental impact of soluble salts from bottom ash.The obtained results reveal that the leaching concentrations of Cl^(−)and SO_(4)^(2−)exceed the limit specified in the class V standard of surface water,which are 2.06–2.17 times and 1.08–1.25 times,respectively.By examining the long-term environmental influence under the condition of continuous rainfall,the leaching of Cl^(−)mainly occurs in the early leaching stage,and the maximum leaching concentration reaches 19,700 mg/L.The release concentration of Cl^(−)begins to be lower than the class V standard of surface water when continuous rainfall approaches the total rainfall for 13 months.The cumulative release of Cl^(−)in the bottom ash is 2.8–5.4 mg/g.Both rainfall intensity and rain pH affect the release of Cl^(−).The obtained results derived from the constant head tests indicate that stagnant water caused by rainfall deteriorates the release of soluble salt into the groundwater in only 1 day,especially at the early stage of 12 h.This work provides some basic information about how to minimize damage to the surrounding environment caused by the leaching of salt in bottom ash.
