Based on 1961-2000 NCEP/NCAR monthly mean reanalysis datasets, vapor transfer and hydrological budget over the Tibetan Plateau are investigated. The Plateau is a vapor sink all the year round. In summer, ...Based on 1961-2000 NCEP/NCAR monthly mean reanalysis datasets, vapor transfer and hydrological budget over the Tibetan Plateau are investigated. The Plateau is a vapor sink all the year round. In summer, vapor is convergent in lower levels (from surface to 500 hPa) and divergent in upper levels (from 400 to 300 hPa), with 450 hPa referred to as level of non-divergence. Two levels have different hydrologic budget signatures: the budget is negative at the upper levels from February to November, i.e., vapor transfers from the upper levels over the plateau; as to the lower, the negative (positive) budget occurs during the winter (summer) half year. Evidence also indicates that Tibetan Plateau is a 'vapor transition belt', vapor from the south and the west is transferred from lower to upper levels there in summer, which will affect surrounding regions, including eastern China, especially, the middle and lower reaches of the Yangtze. Vapor transfer exerts significant influence on precipitation in summertime months. Vapor transferred from the upper layers helps humidify eastern China, with coefficient -0.3 of the upper budget to the precipitation over the middle and lower reaches of the Yangtze (MLRY); also, vapor transferred from east side (27.5 o -32.5 o N) of the upper level has remarkable relationship with precipitation, the coefficient being 0.41. The convergence of the lower level vapor has great effects on the local precipitation over the plateau, with coefficient reaching 0.44, and the vapor passage affects the advance and retreat of the rainbelt. In general, atmospheric hydrologic budget and vapor transfer over the plateau have noticeable effects on precipitation of the target region as well as the ambient areas.展开更多
Naqsh-e-Rostam is known as an ancient periphery which is located in northwest of Persepolis in Fars Province, lran. The oldest relief at Naqsh-e-Rostam is severely damaged and dates to 1,200 B.C.. There is a rock reli...Naqsh-e-Rostam is known as an ancient periphery which is located in northwest of Persepolis in Fars Province, lran. The oldest relief at Naqsh-e-Rostam is severely damaged and dates to 1,200 B.C.. There is a rock relief thought to be elimate, originally. Four tombs belonging to Achaemenid kings are carved out of the rock face and seven oversized rock reliefs at Naqsh-e-Rostam depict the monarchs of the Sassanid Period. These works are located in orographic mountains which are exposed to the interaction with their surrounding environment. Therefore, existing deterioration as well as erosion process is mainly observed due to climatically conditions and geo-environmental factors which have caused such challenges. Transverse and micro cracks are most kinds of damages that will result in erosion in whole of these works. The focal sources which cause ground cracks have been studied with hydro geological survey. Actually considering the storage volume changing and the calculation of hydrological budget for aquifer, this conclusion drown that the ground crack in this site is the direct result of land subsidence resulting from ground water extraction.展开更多
基金The Key Project of the Ministry of Science and Technology No.2001CCB00400 China Climbing Project B-TIPEX
文摘Based on 1961-2000 NCEP/NCAR monthly mean reanalysis datasets, vapor transfer and hydrological budget over the Tibetan Plateau are investigated. The Plateau is a vapor sink all the year round. In summer, vapor is convergent in lower levels (from surface to 500 hPa) and divergent in upper levels (from 400 to 300 hPa), with 450 hPa referred to as level of non-divergence. Two levels have different hydrologic budget signatures: the budget is negative at the upper levels from February to November, i.e., vapor transfers from the upper levels over the plateau; as to the lower, the negative (positive) budget occurs during the winter (summer) half year. Evidence also indicates that Tibetan Plateau is a 'vapor transition belt', vapor from the south and the west is transferred from lower to upper levels there in summer, which will affect surrounding regions, including eastern China, especially, the middle and lower reaches of the Yangtze. Vapor transfer exerts significant influence on precipitation in summertime months. Vapor transferred from the upper layers helps humidify eastern China, with coefficient -0.3 of the upper budget to the precipitation over the middle and lower reaches of the Yangtze (MLRY); also, vapor transferred from east side (27.5 o -32.5 o N) of the upper level has remarkable relationship with precipitation, the coefficient being 0.41. The convergence of the lower level vapor has great effects on the local precipitation over the plateau, with coefficient reaching 0.44, and the vapor passage affects the advance and retreat of the rainbelt. In general, atmospheric hydrologic budget and vapor transfer over the plateau have noticeable effects on precipitation of the target region as well as the ambient areas.
文摘Naqsh-e-Rostam is known as an ancient periphery which is located in northwest of Persepolis in Fars Province, lran. The oldest relief at Naqsh-e-Rostam is severely damaged and dates to 1,200 B.C.. There is a rock relief thought to be elimate, originally. Four tombs belonging to Achaemenid kings are carved out of the rock face and seven oversized rock reliefs at Naqsh-e-Rostam depict the monarchs of the Sassanid Period. These works are located in orographic mountains which are exposed to the interaction with their surrounding environment. Therefore, existing deterioration as well as erosion process is mainly observed due to climatically conditions and geo-environmental factors which have caused such challenges. Transverse and micro cracks are most kinds of damages that will result in erosion in whole of these works. The focal sources which cause ground cracks have been studied with hydro geological survey. Actually considering the storage volume changing and the calculation of hydrological budget for aquifer, this conclusion drown that the ground crack in this site is the direct result of land subsidence resulting from ground water extraction.
