Matching soil grid unit resolutions with polygon unit map scales is important to minimize the uncertainty of regional soil organic carbon(SOC) pool simulation due to their strong influences on the modeling.A series of...Matching soil grid unit resolutions with polygon unit map scales is important to minimize the uncertainty of regional soil organic carbon(SOC) pool simulation due to their strong influences on the modeling.A series of soil grid units at varying cell sizes was derived from soil polygon units at six map scales,namely,1:50 000(C5),1:200 000(D2),1:500 000(P5),1:1 000 000(N1),1:4 000 000(N4) and 1:14 000 000(N14),in the Taihu Region of China.Both soil unit formats were used for regional SOC pool simulation with a De Nitrification-DeC omposition(DNDC) process-based model,which spans the time period from 1982 to 2000 at the six map scales.Four indices,namely,soil type number(STN),area(AREA),average SOC density(ASOCD) and total SOC stocks(SOCS) of surface paddy soils that were simulated by the DNDC,were distinguished from all these soil polygon and grid units.Subjecting to the four index values(IV) from the parent polygon units,the variations in an index value(VIV,%) from the grid units were used to assess its dataset accuracy and redundancy,which reflects the uncertainty in the simulation of SOC pools.Optimal soil grid unit resolutions were generated and suggested for the DNDC simulation of regional SOC pools,matching their respective soil polygon unit map scales.With these optimal raster resolutions,the soil grid units datasets can have the same accuracy as their parent polygon units datasets without any redundancy,when VIV < 1% was assumed to be a criterion for all four indices.A quadratic curve regression model,namely,y = – 0.80 × 10^(–6)x^2 + 0.0228 x + 0.0211(R^2 = 0.9994,P < 0.05),and a power function model R? = 10.394?^(0.2153)(R^2 = 0.9759,P < 0.05) were revealed,which describe the relationship between the optimal soil grid unit resolution(y,km) and soil polygon unit map scale(1:10 000x),the ratio(R?,%) of the optimal soil grid size to average polygon patch size(?,km^2) and the ?,with the highest R^2 among different mathematical regressions,respectively.This knowledge may facilitate the grid partitioning of regions during the investigation and simulation of SOC pool dynamics at a certain map scale,and be referenced to other landscape polygon patches' mesh partition.展开更多
Power market construction is an important part of the marketization reform in China's electric power industry and an essential part of the economic system reform in China. With the social and economic development,...Power market construction is an important part of the marketization reform in China's electric power industry and an essential part of the economic system reform in China. With the social and economic development, the contradiction between distribution of energy resources and development of regional economies gets increasingly noticeable, and a united national power market is consequentially required to optimize the allocation of energy resources over the whole country. Analyses indicate that the development of UHV grid will provide a strong material support for the united national power market by expanding market coverage, lowering load fluctuation and promoting diversif ication of power resources.展开更多
探究不同栅格分辨率下崩岗易发性评价对崩岗防控具有重要意义.为开展相关研究,以赣州市石城县为例,利用地理探测器选取降雨侵蚀力、可蚀性、岩石种类、植被高度、叶面积指数、高程、坡度、归一化植被指数指标作为评价指标,划分出15、30...探究不同栅格分辨率下崩岗易发性评价对崩岗防控具有重要意义.为开展相关研究,以赣州市石城县为例,利用地理探测器选取降雨侵蚀力、可蚀性、岩石种类、植被高度、叶面积指数、高程、坡度、归一化植被指数指标作为评价指标,划分出15、30、60、90、120 m 5种分辨率的栅格单元,以频率比(FR)为联接方法,构建频率比-随机森林(FR-RF)模型开展崩岗易发性评价.结果显示:栅格单元空间分辨率对崩岗易发性评价有一定影响,5种不同栅格分辨率下易发性结果的AUC值依次为0.840、0.830、0.830、0.820、0.810,基于随机森林模型下15 m分辨率栅格单元更适用于研究区的崩岗易发性评价(AUC值为0.840);研究区较高易发区以及高易发区主要分布在北部区域.研究结果可以为赣南地区的崩岗易发性评价提供重要参考.展开更多
基金Under the auspices of Special Project of National Key Research and Development Program(No.2016YFD0200301)National Natural Science Foundation of China(No.41571206)Special Project of National Science and Technology Basic Work(No.2015FY110700-S2)
文摘Matching soil grid unit resolutions with polygon unit map scales is important to minimize the uncertainty of regional soil organic carbon(SOC) pool simulation due to their strong influences on the modeling.A series of soil grid units at varying cell sizes was derived from soil polygon units at six map scales,namely,1:50 000(C5),1:200 000(D2),1:500 000(P5),1:1 000 000(N1),1:4 000 000(N4) and 1:14 000 000(N14),in the Taihu Region of China.Both soil unit formats were used for regional SOC pool simulation with a De Nitrification-DeC omposition(DNDC) process-based model,which spans the time period from 1982 to 2000 at the six map scales.Four indices,namely,soil type number(STN),area(AREA),average SOC density(ASOCD) and total SOC stocks(SOCS) of surface paddy soils that were simulated by the DNDC,were distinguished from all these soil polygon and grid units.Subjecting to the four index values(IV) from the parent polygon units,the variations in an index value(VIV,%) from the grid units were used to assess its dataset accuracy and redundancy,which reflects the uncertainty in the simulation of SOC pools.Optimal soil grid unit resolutions were generated and suggested for the DNDC simulation of regional SOC pools,matching their respective soil polygon unit map scales.With these optimal raster resolutions,the soil grid units datasets can have the same accuracy as their parent polygon units datasets without any redundancy,when VIV < 1% was assumed to be a criterion for all four indices.A quadratic curve regression model,namely,y = – 0.80 × 10^(–6)x^2 + 0.0228 x + 0.0211(R^2 = 0.9994,P < 0.05),and a power function model R? = 10.394?^(0.2153)(R^2 = 0.9759,P < 0.05) were revealed,which describe the relationship between the optimal soil grid unit resolution(y,km) and soil polygon unit map scale(1:10 000x),the ratio(R?,%) of the optimal soil grid size to average polygon patch size(?,km^2) and the ?,with the highest R^2 among different mathematical regressions,respectively.This knowledge may facilitate the grid partitioning of regions during the investigation and simulation of SOC pool dynamics at a certain map scale,and be referenced to other landscape polygon patches' mesh partition.
文摘Power market construction is an important part of the marketization reform in China's electric power industry and an essential part of the economic system reform in China. With the social and economic development, the contradiction between distribution of energy resources and development of regional economies gets increasingly noticeable, and a united national power market is consequentially required to optimize the allocation of energy resources over the whole country. Analyses indicate that the development of UHV grid will provide a strong material support for the united national power market by expanding market coverage, lowering load fluctuation and promoting diversif ication of power resources.
文摘探究不同栅格分辨率下崩岗易发性评价对崩岗防控具有重要意义.为开展相关研究,以赣州市石城县为例,利用地理探测器选取降雨侵蚀力、可蚀性、岩石种类、植被高度、叶面积指数、高程、坡度、归一化植被指数指标作为评价指标,划分出15、30、60、90、120 m 5种分辨率的栅格单元,以频率比(FR)为联接方法,构建频率比-随机森林(FR-RF)模型开展崩岗易发性评价.结果显示:栅格单元空间分辨率对崩岗易发性评价有一定影响,5种不同栅格分辨率下易发性结果的AUC值依次为0.840、0.830、0.830、0.820、0.810,基于随机森林模型下15 m分辨率栅格单元更适用于研究区的崩岗易发性评价(AUC值为0.840);研究区较高易发区以及高易发区主要分布在北部区域.研究结果可以为赣南地区的崩岗易发性评价提供重要参考.
