The continuous decrease of low-slope cropland resources caused by construction land crowding poses huge threat to regional sustainable development and food security.Slope spectrum analysis of topographic and geomorphi...The continuous decrease of low-slope cropland resources caused by construction land crowding poses huge threat to regional sustainable development and food security.Slope spectrum analysis of topographic and geomorphic features is considered as a digital terrain analysis method which reflects the macro-topographic features by using micro-topographic factors.However,pieces of studies have extended the concept of slope spectrum in the field of geoscience to construction land to explore its expansion law,while research on the slope trend of cropland from that perspective remains rare.To address the gap,in virtue of spatial analysis and geographically weighted regression(GWR)model,the cropland use change in the Yangtze River Basin(YRB)from 2000 to 2020 was analyzed and the driving factors were explored from the perspective of slope spectrum.Results showed that the slope spectrum curves of cropland area-frequency in the YRB showed a first upward then a downward trend.The change curve of the slope spectrum of cropland in each province(municipality)exhibited various distribution patterns.Quantitative analysis of morphological parameters of cropland slope spectrum revealed that the further down the YRB,the stronger the flattening characteristics,the more obvious the concentration.The province experienced the greatest downhill cropland climbing(CLC)was Shannxi,while province experienced the highest uphill CLC was Zhejiang.The most common cropland use change type in the YRB was horizontal expansion type.The factors affecting average cropland climbing index(ACCI)were quite stable in different periods,while population density(POP)changed from negative to positive during the study period.This research is of practical significance for the rational utilization of cropland at the watershed scale.展开更多
无线传感器网络的节点运行往往受限于能量供给。对太阳能进行采集并转换成电能存储,可以延长节点的使用寿命。对太阳能进行能量预测,可以更好地规划和使用采集到的能量,这有助于节省能源、避免浪费,提升无线传感器网络的生存周期。针对...无线传感器网络的节点运行往往受限于能量供给。对太阳能进行采集并转换成电能存储,可以延长节点的使用寿命。对太阳能进行能量预测,可以更好地规划和使用采集到的能量,这有助于节省能源、避免浪费,提升无线传感器网络的生存周期。针对太阳能预测,提出一种基于自回归积分移动平均-长短期记忆(Autoregressive Integrated Moving Average-Long Short Term Memory,ARIMA-LSTM)组合模型的能量预测方法。首先,采用ARIMA模型来对太阳辐照数据进行预测,提取数据中的线性分量;然后将过滤后的残差代入LSTM神经网络模型,得到非线性分量的预测;最后将二者进行相加,得到最终的预测结果。仿真实验显示,组合模型比起现有的单一模型,能够有效地提高预测的精度。展开更多
基金supported in part by the Key Laboratory of Natural Resources Monitoring and Supervision in Southern Hilly Region,Ministry of Natural Resources(NRMSSHR2023Y02)Yunnan Key Laboratory of Plateau Geographic Processes and Environmental Changes(PGPEC2304)+1 种基金Yunnan Normal University,China.This study was also sponsored by the Scientific Research Project of Education Department of Hubei Province(Grant No.B2022262)the Philosophy and Social Sciences Research Project of Education Department of Hubei Province(Grant No.22G024).
文摘The continuous decrease of low-slope cropland resources caused by construction land crowding poses huge threat to regional sustainable development and food security.Slope spectrum analysis of topographic and geomorphic features is considered as a digital terrain analysis method which reflects the macro-topographic features by using micro-topographic factors.However,pieces of studies have extended the concept of slope spectrum in the field of geoscience to construction land to explore its expansion law,while research on the slope trend of cropland from that perspective remains rare.To address the gap,in virtue of spatial analysis and geographically weighted regression(GWR)model,the cropland use change in the Yangtze River Basin(YRB)from 2000 to 2020 was analyzed and the driving factors were explored from the perspective of slope spectrum.Results showed that the slope spectrum curves of cropland area-frequency in the YRB showed a first upward then a downward trend.The change curve of the slope spectrum of cropland in each province(municipality)exhibited various distribution patterns.Quantitative analysis of morphological parameters of cropland slope spectrum revealed that the further down the YRB,the stronger the flattening characteristics,the more obvious the concentration.The province experienced the greatest downhill cropland climbing(CLC)was Shannxi,while province experienced the highest uphill CLC was Zhejiang.The most common cropland use change type in the YRB was horizontal expansion type.The factors affecting average cropland climbing index(ACCI)were quite stable in different periods,while population density(POP)changed from negative to positive during the study period.This research is of practical significance for the rational utilization of cropland at the watershed scale.
文摘无线传感器网络的节点运行往往受限于能量供给。对太阳能进行采集并转换成电能存储,可以延长节点的使用寿命。对太阳能进行能量预测,可以更好地规划和使用采集到的能量,这有助于节省能源、避免浪费,提升无线传感器网络的生存周期。针对太阳能预测,提出一种基于自回归积分移动平均-长短期记忆(Autoregressive Integrated Moving Average-Long Short Term Memory,ARIMA-LSTM)组合模型的能量预测方法。首先,采用ARIMA模型来对太阳辐照数据进行预测,提取数据中的线性分量;然后将过滤后的残差代入LSTM神经网络模型,得到非线性分量的预测;最后将二者进行相加,得到最终的预测结果。仿真实验显示,组合模型比起现有的单一模型,能够有效地提高预测的精度。
