This paper focuses on the dynamic variation of groundwater level in Lhasacity. According to the data, the obvious characteristic of the groundwater level of the city is thatit is changing seasonally. Lhasa is divided ...This paper focuses on the dynamic variation of groundwater level in Lhasacity. According to the data, the obvious characteristic of the groundwater level of the city is thatit is changing seasonally. Lhasa is divided into three districts according to hydrogeologicalconditions: the alluvial plain of the Lhasa-river, the alluvial plain of the Doilung-river, and thealluvial fan of inter mountain, which presents a downward trend, a slight upward trend and basicallystabilizing trend over the years individually. The analysis indicates that meteorological andhydrological factors lead to the obvious dynamic change of the groundwater level. However, more andmore human activities and over-exploitation of the groundwater cause the downward trend inthegroundwater level.展开更多
The floristic elements and the geographical distribution are analyzed in thispaper based on statistics of elements of rare and endangered plants in Tibet. The results have beengained as following: (1) According to ...The floristic elements and the geographical distribution are analyzed in thispaper based on statistics of elements of rare and endangered plants in Tibet. The results have beengained as following: (1) According to 'the National Important Wild Conservative Plants List (List1)' and 'the National Important Wild Conservative Plants List (List 1)', there are a total of 54plant species (48 genera and 33 families); (2) The geographical elements are very complicated inTibet with 12 of 15 distribution patterns of genera classified by academician Wu; (3) There areobvious temperate genera with 28 genera accounting for 60. 4% of the total genera; (4) There areabundant endemic species accounting for 18. 52% of total species but poor endemic genera; (5) Thegeographical distribution is uneven and a great of species distribute in the areas between 1 000 mand 3 500 m above sea level; (6) To protect the rare and endangered plants efficiently, sixconservation measures are proposed, and 35 species are suggested for the conservative plants of theautonomous conservation level.展开更多
Taking Tibet as an example, the functional essentiality degrees of water resources conserving of regions were discussed in this paper. At first, based on the status of regional vegetation, whether the region has the f...Taking Tibet as an example, the functional essentiality degrees of water resources conserving of regions were discussed in this paper. At first, based on the status of regional vegetation, whether the region has the function of water conserving was made certain. And then, according to the impacted objects of water resources conserving, taking into account the demands for water and regional supply capacities of water and the requirement of environmental protection, the functional grades of regional water resources conserving of Tibet were evaluated in this paper.展开更多
文摘This paper focuses on the dynamic variation of groundwater level in Lhasacity. According to the data, the obvious characteristic of the groundwater level of the city is thatit is changing seasonally. Lhasa is divided into three districts according to hydrogeologicalconditions: the alluvial plain of the Lhasa-river, the alluvial plain of the Doilung-river, and thealluvial fan of inter mountain, which presents a downward trend, a slight upward trend and basicallystabilizing trend over the years individually. The analysis indicates that meteorological andhydrological factors lead to the obvious dynamic change of the groundwater level. However, more andmore human activities and over-exploitation of the groundwater cause the downward trend inthegroundwater level.
文摘The floristic elements and the geographical distribution are analyzed in thispaper based on statistics of elements of rare and endangered plants in Tibet. The results have beengained as following: (1) According to 'the National Important Wild Conservative Plants List (List1)' and 'the National Important Wild Conservative Plants List (List 1)', there are a total of 54plant species (48 genera and 33 families); (2) The geographical elements are very complicated inTibet with 12 of 15 distribution patterns of genera classified by academician Wu; (3) There areobvious temperate genera with 28 genera accounting for 60. 4% of the total genera; (4) There areabundant endemic species accounting for 18. 52% of total species but poor endemic genera; (5) Thegeographical distribution is uneven and a great of species distribute in the areas between 1 000 mand 3 500 m above sea level; (6) To protect the rare and endangered plants efficiently, sixconservation measures are proposed, and 35 species are suggested for the conservative plants of theautonomous conservation level.
文摘Taking Tibet as an example, the functional essentiality degrees of water resources conserving of regions were discussed in this paper. At first, based on the status of regional vegetation, whether the region has the function of water conserving was made certain. And then, according to the impacted objects of water resources conserving, taking into account the demands for water and regional supply capacities of water and the requirement of environmental protection, the functional grades of regional water resources conserving of Tibet were evaluated in this paper.