desertization การใช้

• Reasons of wind - erosion and desertization in wulanchabu league
• Culture of kubuqi desert and succession of land desertization
• Origins of desertization land and its countermeasures in tongliao
• Developmental tendency of desertization land and control measures in hexi region , gansu province
• That is to say , where the moisture deficit is heavy , desertization degree is serious and aggravation trend is obvious
• The driving forces of desertization development are main problems in recent study and prevention of desertization
• But now , our country lacks intact , objective understanding to forming mechanism , especially driving mechanism of the desertization
• These are the material bases for the desertization expanding that the earth ' s surface vegetation is sparsed , made - ups material is loosed , and sand source is abundant in mu us region
• Desertization , land degradation in arid , semi - arid and dry sub - humid area , is one of the environmental problems concerned by human society . it has a direct relationship with the existence and development of mankind
• The result also indicates that the influence power of the wind subsides to desertization with the gradual reduction of the number of sand - blowing winds on one hand . on the other hand , the number of sand - blowing winds , esp
• Through utilizing the geographical information system from the relevant angle of space , by analysis of the natural factors , human factors , land utilization and their functions on the desertization , the driving mechanism of desertization were studied systematically
• And the precipitation decrease progressively and evaporation capacity greater and greater in mu us region . and the results indicate that it is more outstanding of the relationship between the moisture deficit and the current desertization situation and degree of aggravating of the main counties in this area
• The arid and windy climate condition is one of the important factors of the desertization although there are a lot of natural factors to influence the desertization . because of the regional obvious aridity ization caused by global change that the greenhouse effect cause , the temperature of mu us region increase nearly by 1 . 12 in forty years from 1961 to 2000 , which is above the average temperature - growth of the global
• And mu us region , which located on the northwestern part of the loess plateau , is far from the sea and has a relatively dry climate , is one of the regions with serious desertization as well as ecological fragility . so , this study has not only important theory meaning but also obvious realistic meaning and high practical value
• The first is that the area of desertization land of the whole area tends towards stability , and the proportion of desertization land area in the whole area of land is 85 . 98 % in the middle period of the 1980s while 86 . 07 % in the end stage of the 1990s . the second is that the desertization degree of every county is aggravated to some extents . and the composite index of desertization of the whole district is from 0 . 107 in the middle period of the 1980s to 0 . 159 in the end of the 1990s , while the degree of the desertization rises from the middle rank to the heavy rank
• According to the relevant materials of field investigating and existing land desertization , various image characteristics of different desertization degrees were summed up . this study has realized translating by hand to the desertification land supported by expert system on the basis of the categorised system after choosing the classified training areas and adopting the translated method through the eyes