A multi-level evaluation index system is established with farmland protection as the target layer,farmland quantity,farmland quality andfarmland sustainable development as the criterion layer.And the index layer inclu...A multi-level evaluation index system is established with farmland protection as the target layer,farmland quantity,farmland quality andfarmland sustainable development as the criterion layer.And the index layer includes the quantity change of farmland,per capita farmland area,multiple cropping index,total grain yield,unit grain yield,per capita grain security coefficient,and unit machinery dynamical input.Both expert eval-uation method and factor analysis method are used to determine the weight of index.According to the data in farmland area,grain yield and eco-nomic development in Urumqi-Changji Economic Zone in the years 1996-2007,a comprehensive evaluation model of intensive farmland use inUrumqi-Changji Economic Zone is established after data standardization.The overall implementation effect of farmland protection policy is ana-lyzed by integrating the farmland quantity,farmland quality and sustainable development.Result shows that implementation effect of farmland pro-tection shows an upward trend in general in Urumqi-Changji Economic Zone in the years 1996-2007,with a fluctuation in the years 2000-2003and a stable rising phase from 2004 till now.The maximum value is 0.779 in the year 2007;the minimum value is 0.242 in the year 1996;and themean value in the years 1996-2007 is 0.454.Farmland protection at first strictly controls the farmland quantity,then pays attention to farmlandquality,and finally focuses on the sustainable use of farmland.展开更多
叶面积指数(Leaf Area Index, LAI)作为植被结构和生长状况的重要指标和生态参数,能够较好地反映植被的生长状况与分布情况,本文基于LAI反映城市绿色空间的分布状况,以乌鲁木齐市作为研究区,使用2016~2022年的Sentinel-2系列遥感数据反...叶面积指数(Leaf Area Index, LAI)作为植被结构和生长状况的重要指标和生态参数,能够较好地反映植被的生长状况与分布情况,本文基于LAI反映城市绿色空间的分布状况,以乌鲁木齐市作为研究区,使用2016~2022年的Sentinel-2系列遥感数据反演了乌鲁木齐市夏季LAI时间序列数据。引入景观指数分析乌鲁木齐市2016~2022年不同等级绿色空间的组分与结构变化特征;使用结合Sen斜率估计的M-K趋势检验分析了乌鲁木齐市夏季LAI的变化趋势;并通过地理探测器分析了不同驱动因子对LAI的驱动作用。结果表明:(1)建成区内部多为低密度植被区域覆盖,高密度植被覆盖区域集中于城市边缘;(2)乌鲁木齐市的绿色空间面积主要呈减少趋势。(3)影响乌鲁木齐市绿色空间的驱动因子主要为土地利用类型和降水量;(4)交互探测表明驱动因子交互作用影响力强于单个驱动因子。展开更多
The sediments, at bore-hole T-3 in the upper reaches of the Urumqi River, are 10.7 mthick, and are composed mainly of till, slope-washed materials, solifluction and glacial-waterdeposits. The borehole can be divided i...The sediments, at bore-hole T-3 in the upper reaches of the Urumqi River, are 10.7 mthick, and are composed mainly of till, slope-washed materials, solifluction and glacial-waterdeposits. The borehole can be divided into six sections based on the pollen distribution, magneticsusceptibility , δ<sup>13</sup>C determinations and the diatoms distribution. There were three cold and dryperiods during the past 10.0 Ka （10<sup>3</sup> years）: before 9.3 KaBP, from 8.1 to 5.6 KaBP and 3.0 to 1.0KaBP. The three warmer periods were from 9.3 to 8.1 KaBP, 5.6 to 3.0 KaBP and since 1.0 KaBP.The Holocene maximum was between 5.6 and 3 KaBP. However, the vegetation compositions,mainly C<sub>3</sub> plants, the magnetic susceptibility and the δ<sup>13</sup>C were little changed in the study region inthe past 10 Ka. Indications are that the climate was relatively cold and stable during the past 10Ka.展开更多
基金Supported by the Xinjiang Social Science Fund Project (07JYB029)
文摘A multi-level evaluation index system is established with farmland protection as the target layer,farmland quantity,farmland quality andfarmland sustainable development as the criterion layer.And the index layer includes the quantity change of farmland,per capita farmland area,multiple cropping index,total grain yield,unit grain yield,per capita grain security coefficient,and unit machinery dynamical input.Both expert eval-uation method and factor analysis method are used to determine the weight of index.According to the data in farmland area,grain yield and eco-nomic development in Urumqi-Changji Economic Zone in the years 1996-2007,a comprehensive evaluation model of intensive farmland use inUrumqi-Changji Economic Zone is established after data standardization.The overall implementation effect of farmland protection policy is ana-lyzed by integrating the farmland quantity,farmland quality and sustainable development.Result shows that implementation effect of farmland pro-tection shows an upward trend in general in Urumqi-Changji Economic Zone in the years 1996-2007,with a fluctuation in the years 2000-2003and a stable rising phase from 2004 till now.The maximum value is 0.779 in the year 2007;the minimum value is 0.242 in the year 1996;and themean value in the years 1996-2007 is 0.454.Farmland protection at first strictly controls the farmland quantity,then pays attention to farmlandquality,and finally focuses on the sustainable use of farmland.
文摘叶面积指数(Leaf Area Index, LAI)作为植被结构和生长状况的重要指标和生态参数,能够较好地反映植被的生长状况与分布情况,本文基于LAI反映城市绿色空间的分布状况,以乌鲁木齐市作为研究区,使用2016~2022年的Sentinel-2系列遥感数据反演了乌鲁木齐市夏季LAI时间序列数据。引入景观指数分析乌鲁木齐市2016~2022年不同等级绿色空间的组分与结构变化特征;使用结合Sen斜率估计的M-K趋势检验分析了乌鲁木齐市夏季LAI的变化趋势;并通过地理探测器分析了不同驱动因子对LAI的驱动作用。结果表明:(1)建成区内部多为低密度植被区域覆盖,高密度植被覆盖区域集中于城市边缘;(2)乌鲁木齐市的绿色空间面积主要呈减少趋势。(3)影响乌鲁木齐市绿色空间的驱动因子主要为土地利用类型和降水量;(4)交互探测表明驱动因子交互作用影响力强于单个驱动因子。
文摘The sediments, at bore-hole T-3 in the upper reaches of the Urumqi River, are 10.7 mthick, and are composed mainly of till, slope-washed materials, solifluction and glacial-waterdeposits. The borehole can be divided into six sections based on the pollen distribution, magneticsusceptibility , δ<sup>13</sup>C determinations and the diatoms distribution. There were three cold and dryperiods during the past 10.0 Ka （10<sup>3</sup> years）: before 9.3 KaBP, from 8.1 to 5.6 KaBP and 3.0 to 1.0KaBP. The three warmer periods were from 9.3 to 8.1 KaBP, 5.6 to 3.0 KaBP and since 1.0 KaBP.The Holocene maximum was between 5.6 and 3 KaBP. However, the vegetation compositions,mainly C<sub>3</sub> plants, the magnetic susceptibility and the δ<sup>13</sup>C were little changed in the study region inthe past 10 Ka. Indications are that the climate was relatively cold and stable during the past 10Ka.
