Based on the investigation data of Jiaozhou Bay waters in 1981,current situation and horizontal distribution of Cr content in bottom waters of Jiaozhou Bay mouth were studied. Results showed that in bottom waters of J...Based on the investigation data of Jiaozhou Bay waters in 1981,current situation and horizontal distribution of Cr content in bottom waters of Jiaozhou Bay mouth were studied. Results showed that in bottom waters of Jiaozhou Bay center,Cr content changed from 0. 50 to3. 78 μg/L in April. In August,Cr content changed from 0. 14 to 1. 42 μg/L in bottom waters of Jiaozhou Bay mouth. It showed that Cr content corresponded with national class-one seawater quality standard(50. 00 μg/L) at different times and spaces,and Cr content was far less than5. 00 μg/L. Therefore,under the effect of vertical water body,water quality was clean in bottom waters of Jiaozhou Bay,which was not polluted by Cr. In bottom waters of Jiaozhou Bay center in April and bottom waters of Jiaozhou Bay mouth in August,Cr transported by the river came to the bottom layer from surface layer by passing through water body in temporal-spatial change process. Under the effects of gravity and water flow,Cr continuously and quickly sank to the sea bottom. It verified the sedimentation process of Cr content.展开更多
Lake surface water temperature （SWT） is an important indicator of lake state relative to its water chemistry and aquatic ecosystem,in addition to being an important regional climate indicator.However,few literatures...Lake surface water temperature （SWT） is an important indicator of lake state relative to its water chemistry and aquatic ecosystem,in addition to being an important regional climate indicator.However,few literatures involving spatial-temporal changes of lake SWT in the Qinghai-Tibet Plateau,including Qinghai Lake,are available.Our objective is to study the spatial-temporal changes in SWT of Qinghai Lake from 2001 to 2010,using Moderate-resolution Imaging Spectroradiometer （MODIS） data.Based on each pixel,we calculated the temporal SWT variations and long-term trends,compared the spatial patterns of annual average SWT in different years,and mapped and analyzed the seasonal cycles of the spatial patterns of SWT.The results revealed that the differences between the average daily SWT and air temperature during the temperature decreasing phase were relatively larger than those during the temperature increasing phase.The increasing rate of the annual average SWT during the study period was about 0.01℃/a,followed by an increasing rate of about 0.05℃/a in annual average air temperature.The annual average SWT from 2001 to 2010 showed similar spatial patterns,while the SWT spatial changes from January to December demonstrated an interesting seasonal reversion pattern.The high-temperature area transformed stepwise from the south to the north regions and then back to the south region from January to December,whereas the low-temperature area demonstrated a reversed annual cyclical trace.The spatial-temporal patterns of SWTs were shaped by the topography of the lake basin and the distribution of drainages.展开更多
In this study, based on environmental quality monitoring data on 22 pollutants from 490 control sections, we analyzed the spatial distribution and temporal changes of water quality in ten Chinese river basins （waters...In this study, based on environmental quality monitoring data on 22 pollutants from 490 control sections, we analyzed the spatial distribution and temporal changes of water quality in ten Chinese river basins （watersheds） to reveal the trends from 2005 to 2010. We used a comprehensive water pollution index （WPI） and the proportions of this index accounted for by the three major pollutants to analyze how economic development has influenced water quality. Higher values of the index represent more serious pollution. We found that WPI was much higher for the Hai River Basin （1.83 to 5.60 times the averages in other regions）. In the Yangtze River Basin, WPI increased from upstream to downstream. The indices of some provinces toward the middle of a basin, such as Hebei Province in the Hal River Basin, Shanxi Province in the Yellow River Basin, and Anhui Province in the Huai River Basin, were higher than those of upstream and downstream provinces. In the Songhua, Liao, and South- east river basins, WPI decreased during the study period： in 2010, it decreased by 33.9%, 44.3%, and 67.2%, respectively, compared with the 2005 value. In the Pearl River, Southwest, and Inland river basins, WPI increased by 23.1%, 47.7%, and 38.5% in 2010, compared with 2005. A comparison of WPI with the GDP of each province showed that the water pollution generated by economic development was lightest in northwestern, southwestern, and northeastern China, and highest in central and eastern China, and that the water environment in some coastal regions were improving. However, some provinces （e.g., Shanxi Province） were seriously polluted.展开更多
基金Supported by the China National Natural Science Foundation(31560107)Doctoral Degree Construction Library of Guizhou Minzu University,Education Ministry’s New Century Excellent Talents Supporting Plan(NCET-12-0659)+3 种基金Innovation Group Major Program of Guizhou Province(KY[2013]405,KY[2016]029)Research Projects of Guizhou Province Ministry of Science and Technology(LH[2014]7376)Research Projects of Guizhou Minzu University([2014]02)Research Projects of Guizhou Province Ministry of Education(KY[2014]266)
文摘Based on the investigation data of Jiaozhou Bay waters in 1981,current situation and horizontal distribution of Cr content in bottom waters of Jiaozhou Bay mouth were studied. Results showed that in bottom waters of Jiaozhou Bay center,Cr content changed from 0. 50 to3. 78 μg/L in April. In August,Cr content changed from 0. 14 to 1. 42 μg/L in bottom waters of Jiaozhou Bay mouth. It showed that Cr content corresponded with national class-one seawater quality standard(50. 00 μg/L) at different times and spaces,and Cr content was far less than5. 00 μg/L. Therefore,under the effect of vertical water body,water quality was clean in bottom waters of Jiaozhou Bay,which was not polluted by Cr. In bottom waters of Jiaozhou Bay center in April and bottom waters of Jiaozhou Bay mouth in August,Cr transported by the river came to the bottom layer from surface layer by passing through water body in temporal-spatial change process. Under the effects of gravity and water flow,Cr continuously and quickly sank to the sea bottom. It verified the sedimentation process of Cr content.
基金supported by the National Basic Research Program of China(2012CB417001)the National Natural Science Foundation of China(41271125)
文摘Lake surface water temperature （SWT） is an important indicator of lake state relative to its water chemistry and aquatic ecosystem,in addition to being an important regional climate indicator.However,few literatures involving spatial-temporal changes of lake SWT in the Qinghai-Tibet Plateau,including Qinghai Lake,are available.Our objective is to study the spatial-temporal changes in SWT of Qinghai Lake from 2001 to 2010,using Moderate-resolution Imaging Spectroradiometer （MODIS） data.Based on each pixel,we calculated the temporal SWT variations and long-term trends,compared the spatial patterns of annual average SWT in different years,and mapped and analyzed the seasonal cycles of the spatial patterns of SWT.The results revealed that the differences between the average daily SWT and air temperature during the temperature decreasing phase were relatively larger than those during the temperature increasing phase.The increasing rate of the annual average SWT during the study period was about 0.01℃/a,followed by an increasing rate of about 0.05℃/a in annual average air temperature.The annual average SWT from 2001 to 2010 showed similar spatial patterns,while the SWT spatial changes from January to December demonstrated an interesting seasonal reversion pattern.The high-temperature area transformed stepwise from the south to the north regions and then back to the south region from January to December,whereas the low-temperature area demonstrated a reversed annual cyclical trace.The spatial-temporal patterns of SWTs were shaped by the topography of the lake basin and the distribution of drainages.
文摘In this study, based on environmental quality monitoring data on 22 pollutants from 490 control sections, we analyzed the spatial distribution and temporal changes of water quality in ten Chinese river basins （watersheds） to reveal the trends from 2005 to 2010. We used a comprehensive water pollution index （WPI） and the proportions of this index accounted for by the three major pollutants to analyze how economic development has influenced water quality. Higher values of the index represent more serious pollution. We found that WPI was much higher for the Hai River Basin （1.83 to 5.60 times the averages in other regions）. In the Yangtze River Basin, WPI increased from upstream to downstream. The indices of some provinces toward the middle of a basin, such as Hebei Province in the Hal River Basin, Shanxi Province in the Yellow River Basin, and Anhui Province in the Huai River Basin, were higher than those of upstream and downstream provinces. In the Songhua, Liao, and South- east river basins, WPI decreased during the study period： in 2010, it decreased by 33.9%, 44.3%, and 67.2%, respectively, compared with the 2005 value. In the Pearl River, Southwest, and Inland river basins, WPI increased by 23.1%, 47.7%, and 38.5% in 2010, compared with 2005. A comparison of WPI with the GDP of each province showed that the water pollution generated by economic development was lightest in northwestern, southwestern, and northeastern China, and highest in central and eastern China, and that the water environment in some coastal regions were improving. However, some provinces （e.g., Shanxi Province） were seriously polluted.
