Study of Air Quality Objectives(AQOs)and long-term changes of air pollution plays a decisive role in formulating and refining pollution control strategies.In this study,10-year variations of six major air pollutants w...Study of Air Quality Objectives(AQOs)and long-term changes of air pollution plays a decisive role in formulating and refining pollution control strategies.In this study,10-year variations of six major air pollutants were analyzed at seven monitoring sites in Hong Kong region.The continuous decrease of annual averaged concentrations of NO_(2),SO_(2),CO,PM_(2.5)and PM_(10)and numbers of days with severe pollution conditions validated the efficiency of the series of air pollution control schemes implemented by the Hong Kong region government.However,there is still a big gap to meet the ultimate targets described by the World Health Organization.Besides,the concentration of O_(3)at roadside and urban stations increased by 135%±25%and 37%±18%from 2011 to 2020,respectively,meanwhile the highest 8 hr averaged O_(3)concentration was observed as 294μg/m^(3)at background station in 2020,which pointed out the increasing ozone pollution in Hong Kong region.There was a great decrease in the annual times of air quality health index(AQHI)laying in“high”,“very high”and“serious”categories from 2011 to 2020 with the decrease rate of 89.70%,91.30%and 89.74%at roadside stations,and 79.03%,95.98%and 72.73%at urban stations,respectively.Nevertheless,the number of days categorized as“high”or above at roadside station was twice more than that in the urban station during the past ten years.Thus,more policies and attentions should be given to the roadside air quality and its adverse health effect to pedestrians on street.展开更多
A typhoon passed through Hong Kong region suddenly and unexpectedly on 18 September 1906(the“Typhoon 1906”)and had a disastrous impact on Victoria Harbour and its surroundings in just a couple of hours.Since the yea...A typhoon passed through Hong Kong region suddenly and unexpectedly on 18 September 1906(the“Typhoon 1906”)and had a disastrous impact on Victoria Harbour and its surroundings in just a couple of hours.Since the year 1906 was the“Bingwu”year in the Chinese calendar,the typhoon is also known historically as the“Bingwu Typhoon”.Tremendous loss of lives and property resulted,and the shipping and fishing communities were devastated.Two mysteries arising from this calamitous typhoon have existed to date:1)Why the Hong Kong region Observatory was not able to provide any forewarning?2)whether the storm surge reported in some contemporary records is entirely credible?This paper will focus on both of these.In this paper,we re-analyse historical weather observations recorded in various historical documents and estimate the possible storm size,intensity and track of Typhoon 1906 using tropical cyclone models.Based on the re-analyses,the storm surges,storm tides and wave heights in Hong Kong region are also estimated using storm surge and wave models.The results reveal that Typhoon 1906 was a midget typhoon,with a radius of maximum winds of 11 km or smaller,during its passage through Hong Kong region.This explains why it was technically impossible for a forewarning to be given at that time when real-time weather observations from ships,meteorological satellites and radars were non-existent.We also estimate that the maximum storm surges(storm tides)in Hong Kong region were not higher than 0.82 m(2.43 mCD)and 1.98 m(4.15 mCD)in Victoria Harbour and Tolo Harbour respectively.These figures are found to be limited by the intensity and the storm size of the typhoon.Therefore,we conclude that the previously documented storm surge figures are not supported by the present study.展开更多
This paper reports observations of flocking behavior of birds in a well-protected secondary forest in Tai Po Kau Nature Reserve, Hong Kong Special Administrative Region, China. A total of 1025 flocks including 5255 bi...This paper reports observations of flocking behavior of birds in a well-protected secondary forest in Tai Po Kau Nature Reserve, Hong Kong Special Administrative Region, China. A total of 1025 flocks including 5255 birds and 48 species were observed between October 2002 and November 2003. Most flocks consisted of only one species. The observed flocks averaged 1.79 +/- 0.05 (SE) species and 5.13 +/- 0.18 (SE) birds. The Japanese White-eye was the most numerous species and was present in 21.6% of the observed flocks. Seasonal trends in both flock size and number of species were similar to those in overall bird density and species richness in the study area reported in a previous study.展开更多
基金supported by the Research Grants Council of Hong Kong Government(Project No.T24/504/17 and T31-603/21-N)he Environment and Conservation Fund of Hong Kong Governmentt(Project No.ECF 63/2019).
文摘Study of Air Quality Objectives(AQOs)and long-term changes of air pollution plays a decisive role in formulating and refining pollution control strategies.In this study,10-year variations of six major air pollutants were analyzed at seven monitoring sites in Hong Kong region.The continuous decrease of annual averaged concentrations of NO_(2),SO_(2),CO,PM_(2.5)and PM_(10)and numbers of days with severe pollution conditions validated the efficiency of the series of air pollution control schemes implemented by the Hong Kong region government.However,there is still a big gap to meet the ultimate targets described by the World Health Organization.Besides,the concentration of O_(3)at roadside and urban stations increased by 135%±25%and 37%±18%from 2011 to 2020,respectively,meanwhile the highest 8 hr averaged O_(3)concentration was observed as 294μg/m^(3)at background station in 2020,which pointed out the increasing ozone pollution in Hong Kong region.There was a great decrease in the annual times of air quality health index(AQHI)laying in“high”,“very high”and“serious”categories from 2011 to 2020 with the decrease rate of 89.70%,91.30%and 89.74%at roadside stations,and 79.03%,95.98%and 72.73%at urban stations,respectively.Nevertheless,the number of days categorized as“high”or above at roadside station was twice more than that in the urban station during the past ten years.Thus,more policies and attentions should be given to the roadside air quality and its adverse health effect to pedestrians on street.
文摘A typhoon passed through Hong Kong region suddenly and unexpectedly on 18 September 1906(the“Typhoon 1906”)and had a disastrous impact on Victoria Harbour and its surroundings in just a couple of hours.Since the year 1906 was the“Bingwu”year in the Chinese calendar,the typhoon is also known historically as the“Bingwu Typhoon”.Tremendous loss of lives and property resulted,and the shipping and fishing communities were devastated.Two mysteries arising from this calamitous typhoon have existed to date:1)Why the Hong Kong region Observatory was not able to provide any forewarning?2)whether the storm surge reported in some contemporary records is entirely credible?This paper will focus on both of these.In this paper,we re-analyse historical weather observations recorded in various historical documents and estimate the possible storm size,intensity and track of Typhoon 1906 using tropical cyclone models.Based on the re-analyses,the storm surges,storm tides and wave heights in Hong Kong region are also estimated using storm surge and wave models.The results reveal that Typhoon 1906 was a midget typhoon,with a radius of maximum winds of 11 km or smaller,during its passage through Hong Kong region.This explains why it was technically impossible for a forewarning to be given at that time when real-time weather observations from ships,meteorological satellites and radars were non-existent.We also estimate that the maximum storm surges(storm tides)in Hong Kong region were not higher than 0.82 m(2.43 mCD)and 1.98 m(4.15 mCD)in Victoria Harbour and Tolo Harbour respectively.These figures are found to be limited by the intensity and the storm size of the typhoon.Therefore,we conclude that the previously documented storm surge figures are not supported by the present study.
文摘This paper reports observations of flocking behavior of birds in a well-protected secondary forest in Tai Po Kau Nature Reserve, Hong Kong Special Administrative Region, China. A total of 1025 flocks including 5255 birds and 48 species were observed between October 2002 and November 2003. Most flocks consisted of only one species. The observed flocks averaged 1.79 +/- 0.05 (SE) species and 5.13 +/- 0.18 (SE) birds. The Japanese White-eye was the most numerous species and was present in 21.6% of the observed flocks. Seasonal trends in both flock size and number of species were similar to those in overall bird density and species richness in the study area reported in a previous study.
