Seasonal variation of stable isotopes in precipitation of Kathmandu Valley on the southem slope of Himalaya was carried out to understand the controlling mechanism of amount and temperature effect on the basis of one ...Seasonal variation of stable isotopes in precipitation of Kathmandu Valley on the southem slope of Himalaya was carried out to understand the controlling mechanism of amount and temperature effect on the basis of one year stable isotope data from 2010 to 2011. Highly depleted isotope values in major rainy period are obtained just after the onset of precipitation in summer, which ac- counts for ＂amount effect＂ due to saturation isotopic compositions in high moisture condition, whereas, the higher values in winter are indicative to regional vapors （temperature effect） recycling of various sources. An abrupt depletion of isotope values in mid- June, indicates the onset date of monsoon precipitation, by the replacement of winter air mass with southem monsoon. Thus, pre- cipitation isotopes are a tool revealing the onset date of summer monsoon and temporal features of variability, in local and regional monsoons precipitations. A comparison of long term monthly values of 5180, temperature, and precipitation with GNIP 6180 data shows the temporal variations of stable isotopes are mostly controlled by amount and temperature effects. During summer mon- soon, the amount effects are stronger for high values of precipitation （R=0.7） and altitude effect appears for low moisture in late rainy season, thus from December to June （winter to pre-monsoon） the controlling features of isotopes remains under the temper- ature effect. A temporal rate of temperature effect is derived as 0.04%0 per year which indicates a dry signal of atmospheric condition and a temperature relation 5180=（0.371±0.08）T＋（0.156±0.05） is obtained from this analysis. The meteoric water lines of Kathmandu before and after monsoon onset of 2011, are found as 5D=（4.36±0.3）5180＋（15.66±1.2） and 5D=（6.91±0.2）S180-（7.92±2.26） from lab samples result, and 5D=9.25180＋11.725 and 5D=8.535180＋16.65 from GNIP data, which lacks the consistency both for slopes and intercepts values for the study period. The mean lapse rate values of δ18O and δD from GNIP data are obtained as -0.002‰/m and -0.015 ‰/m, which indicate the altitudinal effects in regional precipitation of the southern slope of Himalayas. This study estimates new stable isotopes data in recent precipitation using simple methodology which can be important for regional precipitation monitoring systems, environmental change and paleo-climatic studies.展开更多
In order to provide a theoretical basis for apple cultivation techniques and to provide a reference for preparation of scientific management measures,the occurrence and damage status of apple little leaf in northern G...In order to provide a theoretical basis for apple cultivation techniques and to provide a reference for preparation of scientific management measures,the occurrence and damage status of apple little leaf in northern Guizhou was investigated,and fertilizer control test against the disease was also conducted.（1）Apple little leaf occurred from April to October in apple producing areas in northern Guizhou every year,with heavy incidence from April to May,light incidence from June to July,and the lightest incidence from August to October.（2） Effectiveness test showed that application of zinc sulfate fertilizer 135 g ＋ cow dung 10 kg received the best control effect,followed by zinc sulfate fertilizer 165 g ＋ cow dung 10 kg,then zinc sulfate fertilizer 105 g ＋ cow dung 10 kg and zinc sulfate fertilizer 150 g ＋ cow dung 10 kg.（3） Based on local environmental conditions,occurrence and damage situation,incidence conditions and fertilizer efficacy test,comprehensive prevention and control technology with rational supplement of zinc fertilizer could be used to control apple little leaf.展开更多
基金supported by the Ph.D.program of Institute of Tibetan Plateau Research,ITPCAS
文摘Seasonal variation of stable isotopes in precipitation of Kathmandu Valley on the southem slope of Himalaya was carried out to understand the controlling mechanism of amount and temperature effect on the basis of one year stable isotope data from 2010 to 2011. Highly depleted isotope values in major rainy period are obtained just after the onset of precipitation in summer, which ac- counts for ＂amount effect＂ due to saturation isotopic compositions in high moisture condition, whereas, the higher values in winter are indicative to regional vapors （temperature effect） recycling of various sources. An abrupt depletion of isotope values in mid- June, indicates the onset date of monsoon precipitation, by the replacement of winter air mass with southem monsoon. Thus, pre- cipitation isotopes are a tool revealing the onset date of summer monsoon and temporal features of variability, in local and regional monsoons precipitations. A comparison of long term monthly values of 5180, temperature, and precipitation with GNIP 6180 data shows the temporal variations of stable isotopes are mostly controlled by amount and temperature effects. During summer mon- soon, the amount effects are stronger for high values of precipitation （R=0.7） and altitude effect appears for low moisture in late rainy season, thus from December to June （winter to pre-monsoon） the controlling features of isotopes remains under the temper- ature effect. A temporal rate of temperature effect is derived as 0.04%0 per year which indicates a dry signal of atmospheric condition and a temperature relation 5180=（0.371±0.08）T＋（0.156±0.05） is obtained from this analysis. The meteoric water lines of Kathmandu before and after monsoon onset of 2011, are found as 5D=（4.36±0.3）5180＋（15.66±1.2） and 5D=（6.91±0.2）S180-（7.92±2.26） from lab samples result, and 5D=9.25180＋11.725 and 5D=8.535180＋16.65 from GNIP data, which lacks the consistency both for slopes and intercepts values for the study period. The mean lapse rate values of δ18O and δD from GNIP data are obtained as -0.002‰/m and -0.015 ‰/m, which indicate the altitudinal effects in regional precipitation of the southern slope of Himalayas. This study estimates new stable isotopes data in recent precipitation using simple methodology which can be important for regional precipitation monitoring systems, environmental change and paleo-climatic studies.
文摘In order to provide a theoretical basis for apple cultivation techniques and to provide a reference for preparation of scientific management measures,the occurrence and damage status of apple little leaf in northern Guizhou was investigated,and fertilizer control test against the disease was also conducted.（1）Apple little leaf occurred from April to October in apple producing areas in northern Guizhou every year,with heavy incidence from April to May,light incidence from June to July,and the lightest incidence from August to October.（2） Effectiveness test showed that application of zinc sulfate fertilizer 135 g ＋ cow dung 10 kg received the best control effect,followed by zinc sulfate fertilizer 165 g ＋ cow dung 10 kg,then zinc sulfate fertilizer 105 g ＋ cow dung 10 kg and zinc sulfate fertilizer 150 g ＋ cow dung 10 kg.（3） Based on local environmental conditions,occurrence and damage situation,incidence conditions and fertilizer efficacy test,comprehensive prevention and control technology with rational supplement of zinc fertilizer could be used to control apple little leaf.
