Due to irrational human activities and extreme climate,the Qinghai-Xizang Plateau,China,faces a serious threat of desertification.Desertification has a detrimental effect on the ecological environment and socioeconomi...Due to irrational human activities and extreme climate,the Qinghai-Xizang Plateau,China,faces a serious threat of desertification.Desertification has a detrimental effect on the ecological environment and socioeconomic development.In this study,the desertification sensitivity index(DSI)model was established by integrating the spatial distance model and environmentally sensitive area index evaluation method,and then the model was used to quantitatively analyze the spatial and temporal characteristics of desertification sensitivity of the Qinghai-Xizang Plateau from 1990 to 2020.The results revealed that:(1)a general increasing tendency from southeast to northwest was identified in the spatial distribution of desertification sensitivity.The low-sensitivity areas were mostly concentrated in the Hengduan and Nyaingqêntanglha mountains and surrounding forest and meadow areas.The high-sensitivity areas were located mainly in the Kunlun and Altun mountains and surrounding decertified areas.The center of gravity of all types of desertification-sensitive areas moved to the northwest,and the desertification sensitivity showed a decreasing trend as a whole;(2)the area of highly sensitive desertification areas decreased by 8.37%,with extreme sensitivity being the largest change among the sensitivity types.The desertification sensitivity transfer was characterized by a greater shift to lower sensitivity levels(24.56%)than to higher levels(2.03%),which demonstrated a declining trend;(3)since 1990,the change in desertification sensitivity has been dominated by the stabilizing type Ⅰ(29.30%),with the area of continuously increasing desertification sensitivity accounting for only 1.10%,indicating that the management of desertification has achieved positive results in recent years;and(4)natural factors have had a more significant impact on desertification sensitivity on the Xizang Plateau,whereas socioeconomic factors affected only localized areas.The main factors influencing desertification sensitivity were vegetation drought tolerance and aridity index.Studying spatiotemporal variations in desertification sensitivity and its influencing factors can provide a scientific foundation for developing strategies to control desertification on the Qinghai-Xizang Plateau.Dividing different desertification-sensitive areas on the basis of these patterns of change can facilitate the formulation of more targeted management and protection measures,contributing to ecological construction and sustainable economic development in the area.展开更多
Sensitivity assessment is useful for monitoring land desertification. Research into how to prevent and control desertification is also important. In the arid region of northwest China, desertification is becoming wors...Sensitivity assessment is useful for monitoring land desertification. Research into how to prevent and control desertification is also important. In the arid region of northwest China, desertification is becoming worse and is a serious problem that affects local sustainable development. Based on remote-sensing and geographic information system technology, this study establishes a 'soil-terrain-hydrology-climate-vegetation' desertification sensitivity comprehensive evaluation system to reflect the spatiotemporal changes of land desertification, and proposes a spatial distance model to calculate a desertification sensitivity index. The spatiotemporal change characteristics of land desertification sensitivity in northwest China are quantitatively assessed from 2000 to 2017. Moreover, the main driving factors are analyzed using the geographical detector method. The results show the following.(1) Terrain, soil, climate, vegetation and hydrology affect and restrict each other, and constitute the background conditions of the distributions and changes of sensitivity to desertification in northwest China.(2) Desertification sensitivity generally displays a low distribution characteristic on the periphery of the area and a high one in the interior. The low-sensitivity regions are mainly in the five major mountain ranges(Altai Mountains, Tianshan Mountains, Kunlun Mountains, Altun Mountains and Qilian Mountains), while the high-sensitivity regions are mainly in regions such as the Junggar Basin, the Tarim Basin and the Inner Mongolia Plateau, as well as the Taklimakan Desert, Badain Jaran Desert and Tengger Desert. The spatial distribution of desertification sensitivity is obviously regional, and the high-and low-sensitivity regions have clear boundaries and a concentrated distribution.(3) With regard to spatiotemporal evolution, changes in desertification sensitivity since 2000 have been predominantly stable, and the overall sensitivity has displayed a slowly decreasing trend, indicating that potential desertification regions are decreasing annually and that some achievements have been made in the control of regional desertification.(4) Soil and climate play a direct role in the driving factors of desertification in northwest China, and these have been found to be the most important influential factors. Vegetation is the most active and basic factor in changing the sensitivity. In addition, topography and hydrology play a role in restricting desertification changes. Socio-economic factors are the most rapid factors affecting regional desertification sensitivity, and their impacts tend to be gradually increasing. In general, desertification has been effectively controlled in northwest China, and positive results have been achieved in such control. However, against the backdrop of intensified global climate change, increasingly prominent human activities and new normals of socio-economic development, the monitoring, assessment and control of desertification in China still have a long way to go.展开更多
Sensitivity evaluation of rocky desertification is to recognize the areas prone to be rock-deserted,so as to assess the sensitivity degree of rocky desertification to human activities.To perform the sensitivity evalua...Sensitivity evaluation of rocky desertification is to recognize the areas prone to be rock-deserted,so as to assess the sensitivity degree of rocky desertification to human activities.To perform the sensitivity evaluation of rocky desertification,we should be on the basis of the mechanism of rocky desertification formation for analyzing its regional distribution difference in the sensitivity and further for finding out the rocky desertification-susceptive areas and their possible degrees.Employing remote sensing and geological information system techniques,we regarded the 1∶ 50 000 topographic map and the TM image in 2000 of Guizhou Province,together with the hydrologic map,soil map,geologic map,rock formation map,administrative map and other geological information as data sources to generate the degree data of rocky desertification sensitivity of Guizhou Province in 1962 and 2000,based on which we determined the corresponding degree transfer matrix and adopted Markov model to simulate the dynamic change process of rocky desertification sensitivity and its future evolution trend.In various sensitivity types of rocky desertification in Guizhou Province,only the insensitive type showed a declined acreage,from the proportion of total land acreage of 61.35% in 1962 to 55.55% in 2000.Various sensitivity types inter-conversed,resultantly the acreage of mildly sensitive type increased most.The prediction results showed that the acreage of insensitive type of rocky desertification in Guizhou Province will assume a remarkable decline trend,of mildly sensitive type will present a remarkably increasing trend and of slightly sensitive type basically will maintain a stable level in the future tens of years.Acreages of both highly sensitive and extremely sensitive type of rocky desertification expanded to some extent,suggesting that the rocky desertification risk in Guizhou Province is in an aggravating process.展开更多
基金funded by the National Natural Science Foundation of China(42371219)the Key Natural Science Foundation of Gansu Province(24JRRA135)the Oasis Scientific Research Achievements Breakthrough Action Plan Project of Northwest Normal University(NWNU-LZKX-202302).
文摘Due to irrational human activities and extreme climate,the Qinghai-Xizang Plateau,China,faces a serious threat of desertification.Desertification has a detrimental effect on the ecological environment and socioeconomic development.In this study,the desertification sensitivity index(DSI)model was established by integrating the spatial distance model and environmentally sensitive area index evaluation method,and then the model was used to quantitatively analyze the spatial and temporal characteristics of desertification sensitivity of the Qinghai-Xizang Plateau from 1990 to 2020.The results revealed that:(1)a general increasing tendency from southeast to northwest was identified in the spatial distribution of desertification sensitivity.The low-sensitivity areas were mostly concentrated in the Hengduan and Nyaingqêntanglha mountains and surrounding forest and meadow areas.The high-sensitivity areas were located mainly in the Kunlun and Altun mountains and surrounding decertified areas.The center of gravity of all types of desertification-sensitive areas moved to the northwest,and the desertification sensitivity showed a decreasing trend as a whole;(2)the area of highly sensitive desertification areas decreased by 8.37%,with extreme sensitivity being the largest change among the sensitivity types.The desertification sensitivity transfer was characterized by a greater shift to lower sensitivity levels(24.56%)than to higher levels(2.03%),which demonstrated a declining trend;(3)since 1990,the change in desertification sensitivity has been dominated by the stabilizing type Ⅰ(29.30%),with the area of continuously increasing desertification sensitivity accounting for only 1.10%,indicating that the management of desertification has achieved positive results in recent years;and(4)natural factors have had a more significant impact on desertification sensitivity on the Xizang Plateau,whereas socioeconomic factors affected only localized areas.The main factors influencing desertification sensitivity were vegetation drought tolerance and aridity index.Studying spatiotemporal variations in desertification sensitivity and its influencing factors can provide a scientific foundation for developing strategies to control desertification on the Qinghai-Xizang Plateau.Dividing different desertification-sensitive areas on the basis of these patterns of change can facilitate the formulation of more targeted management and protection measures,contributing to ecological construction and sustainable economic development in the area.
基金National Natural Science Foundation of China,No.41861040, No.41761047, No.41961027。
文摘Sensitivity assessment is useful for monitoring land desertification. Research into how to prevent and control desertification is also important. In the arid region of northwest China, desertification is becoming worse and is a serious problem that affects local sustainable development. Based on remote-sensing and geographic information system technology, this study establishes a 'soil-terrain-hydrology-climate-vegetation' desertification sensitivity comprehensive evaluation system to reflect the spatiotemporal changes of land desertification, and proposes a spatial distance model to calculate a desertification sensitivity index. The spatiotemporal change characteristics of land desertification sensitivity in northwest China are quantitatively assessed from 2000 to 2017. Moreover, the main driving factors are analyzed using the geographical detector method. The results show the following.(1) Terrain, soil, climate, vegetation and hydrology affect and restrict each other, and constitute the background conditions of the distributions and changes of sensitivity to desertification in northwest China.(2) Desertification sensitivity generally displays a low distribution characteristic on the periphery of the area and a high one in the interior. The low-sensitivity regions are mainly in the five major mountain ranges(Altai Mountains, Tianshan Mountains, Kunlun Mountains, Altun Mountains and Qilian Mountains), while the high-sensitivity regions are mainly in regions such as the Junggar Basin, the Tarim Basin and the Inner Mongolia Plateau, as well as the Taklimakan Desert, Badain Jaran Desert and Tengger Desert. The spatial distribution of desertification sensitivity is obviously regional, and the high-and low-sensitivity regions have clear boundaries and a concentrated distribution.(3) With regard to spatiotemporal evolution, changes in desertification sensitivity since 2000 have been predominantly stable, and the overall sensitivity has displayed a slowly decreasing trend, indicating that potential desertification regions are decreasing annually and that some achievements have been made in the control of regional desertification.(4) Soil and climate play a direct role in the driving factors of desertification in northwest China, and these have been found to be the most important influential factors. Vegetation is the most active and basic factor in changing the sensitivity. In addition, topography and hydrology play a role in restricting desertification changes. Socio-economic factors are the most rapid factors affecting regional desertification sensitivity, and their impacts tend to be gradually increasing. In general, desertification has been effectively controlled in northwest China, and positive results have been achieved in such control. However, against the backdrop of intensified global climate change, increasingly prominent human activities and new normals of socio-economic development, the monitoring, assessment and control of desertification in China still have a long way to go.
基金Supported by Programs for Science and Technology Development of Guizhou Province(20073017,20083022)National Basic Research Program of China(973Program,2006CB403200)~~
文摘Sensitivity evaluation of rocky desertification is to recognize the areas prone to be rock-deserted,so as to assess the sensitivity degree of rocky desertification to human activities.To perform the sensitivity evaluation of rocky desertification,we should be on the basis of the mechanism of rocky desertification formation for analyzing its regional distribution difference in the sensitivity and further for finding out the rocky desertification-susceptive areas and their possible degrees.Employing remote sensing and geological information system techniques,we regarded the 1∶ 50 000 topographic map and the TM image in 2000 of Guizhou Province,together with the hydrologic map,soil map,geologic map,rock formation map,administrative map and other geological information as data sources to generate the degree data of rocky desertification sensitivity of Guizhou Province in 1962 and 2000,based on which we determined the corresponding degree transfer matrix and adopted Markov model to simulate the dynamic change process of rocky desertification sensitivity and its future evolution trend.In various sensitivity types of rocky desertification in Guizhou Province,only the insensitive type showed a declined acreage,from the proportion of total land acreage of 61.35% in 1962 to 55.55% in 2000.Various sensitivity types inter-conversed,resultantly the acreage of mildly sensitive type increased most.The prediction results showed that the acreage of insensitive type of rocky desertification in Guizhou Province will assume a remarkable decline trend,of mildly sensitive type will present a remarkably increasing trend and of slightly sensitive type basically will maintain a stable level in the future tens of years.Acreages of both highly sensitive and extremely sensitive type of rocky desertification expanded to some extent,suggesting that the rocky desertification risk in Guizhou Province is in an aggravating process.
