探究基于高分六号水体提取模型,能为水体监测提供新的数据源和技术支撑。首先,基于卓乃湖的高分六号WFV数据分析水体与其他地物反射率的差异,从而构建了一种新的水体指数——红边水体指数(read side water index,RSWI);然后,利用混淆矩...探究基于高分六号水体提取模型,能为水体监测提供新的数据源和技术支撑。首先,基于卓乃湖的高分六号WFV数据分析水体与其他地物反射率的差异,从而构建了一种新的水体指数——红边水体指数(read side water index,RSWI);然后,利用混淆矩阵生成的总体精度和Kappa系数,分别与归一化差异水体指数、改进的阴影水体指数和单波段阈值法进行了对比精度检验;最后,选取可可西里地区不同类型面积大于100 km^(2)的6个典型湖泊进行普适性分析。结果表明:与其他方法相比,RSWI和近红外波段构成的决策树模型有效消除了湖底沉积物对水体的影响,更完整地提取浅水区水体,总体精度达93.78%,Kappa系数为0.87;另外,RSWI水体模型对不同类型的湖泊具有较好的稳定性和普适性。展开更多
针对传统水体指数模型易受水体边界浅水区的水体底质的影响,导致在提取水体时容易产生水体错分和遗漏等问题,该文以汤河水库、桐湖和近海浅水区为研究对象,基于Landsat影像的典型地物光谱信息构建了一种新型多波段水体指数(new multi ba...针对传统水体指数模型易受水体边界浅水区的水体底质的影响,导致在提取水体时容易产生水体错分和遗漏等问题,该文以汤河水库、桐湖和近海浅水区为研究对象,基于Landsat影像的典型地物光谱信息构建了一种新型多波段水体指数(new multi band water index,NMBWI)。与传统水体指数模型归一化差异水体指数(normalized difference water index,NDWI)、改进的归一化差异水体指数(modified normalized difference water index,MNDWI)、增强型水体指数(enhanced water index,EWI)及修订型归一化水体指数(revised normalized difference water index,RNDWI)进行了对比分析,结果表明:NMBWI对于水体边界的浅水区水体强化效果更佳,提取的水域范围更为完整,总体精度和Kappa系数总体优于传统水体指数模型且NMBWI对不同类型水体边界的浅水区水体提取具有较好的普适性和稳定性。展开更多
For the backfill hydraulic support as the key equipment for achieving integration of backfilling and coal mining simultaneously in the practical process, its characteristics will directly influence the backfill body&#...For the backfill hydraulic support as the key equipment for achieving integration of backfilling and coal mining simultaneously in the practical process, its characteristics will directly influence the backfill body's compression ratio. Horizontal roof gap, as a key parameter of backfilling characteristics, may impact the backfilling effect from the aspects of control of roof subsidence in advance, support stress, backfilling process and the support design. Firstly, the reason why horizontal roof gap exists was analyzed and its definition, causes and connotation were introduced, then adopting the Pro/E 3D simulation software, three typical 3D entity models of backfill hydraulic supports were built, based on the influence of horizontal roof gap on backfilling effect, and influence rules of four factors, i.e. support height, suspension height, suspension angle and tamping angle, were emphatically analyzed on horizontal roof gap. The results indicate that, the four factors all have significant impacts on horizontal roof gap, but show differences in influence trend and degree, showing negative linear correlation, positive linear correlation, positive semi-parabolic correlation and negative semi-parabolic correlation, respectively. Four legs type is the most adaptive to the four factors, while six legs(II) type has the poorest adaptability, and the horizontal roof gap is small under large support height, small suspension height, small suspension angle and large tamping angle situation. By means of optimizing structure components and their positional relation and suspension height of backfill scrape conveyor in the process of support design and through controlling working face deployment, roof subsidence in advance, mining height and backfilling during engineering application, the horizontal roof gap is optimized. The research results can be served as theoretical basis for support design and guidance for backfill support to have better performance in backfilling.展开更多
文摘探究基于高分六号水体提取模型,能为水体监测提供新的数据源和技术支撑。首先,基于卓乃湖的高分六号WFV数据分析水体与其他地物反射率的差异,从而构建了一种新的水体指数——红边水体指数(read side water index,RSWI);然后,利用混淆矩阵生成的总体精度和Kappa系数,分别与归一化差异水体指数、改进的阴影水体指数和单波段阈值法进行了对比精度检验;最后,选取可可西里地区不同类型面积大于100 km^(2)的6个典型湖泊进行普适性分析。结果表明:与其他方法相比,RSWI和近红外波段构成的决策树模型有效消除了湖底沉积物对水体的影响,更完整地提取浅水区水体,总体精度达93.78%,Kappa系数为0.87;另外,RSWI水体模型对不同类型的湖泊具有较好的稳定性和普适性。
文摘针对传统水体指数模型易受水体边界浅水区的水体底质的影响,导致在提取水体时容易产生水体错分和遗漏等问题,该文以汤河水库、桐湖和近海浅水区为研究对象,基于Landsat影像的典型地物光谱信息构建了一种新型多波段水体指数(new multi band water index,NMBWI)。与传统水体指数模型归一化差异水体指数(normalized difference water index,NDWI)、改进的归一化差异水体指数(modified normalized difference water index,MNDWI)、增强型水体指数(enhanced water index,EWI)及修订型归一化水体指数(revised normalized difference water index,RNDWI)进行了对比分析,结果表明:NMBWI对于水体边界的浅水区水体强化效果更佳,提取的水域范围更为完整,总体精度和Kappa系数总体优于传统水体指数模型且NMBWI对不同类型水体边界的浅水区水体提取具有较好的普适性和稳定性。
基金Project(2014ZDPY02) supported by the Fundamental Research Funds for the Central Universities,ChinaProject supported by Qinglan Plan of Jiangsu Province,ChinaProject(SKLCRSM12X01) supported by State Key Laboratory of Coal Resources and Safe Mining(China University of Mining & Technology)
文摘For the backfill hydraulic support as the key equipment for achieving integration of backfilling and coal mining simultaneously in the practical process, its characteristics will directly influence the backfill body's compression ratio. Horizontal roof gap, as a key parameter of backfilling characteristics, may impact the backfilling effect from the aspects of control of roof subsidence in advance, support stress, backfilling process and the support design. Firstly, the reason why horizontal roof gap exists was analyzed and its definition, causes and connotation were introduced, then adopting the Pro/E 3D simulation software, three typical 3D entity models of backfill hydraulic supports were built, based on the influence of horizontal roof gap on backfilling effect, and influence rules of four factors, i.e. support height, suspension height, suspension angle and tamping angle, were emphatically analyzed on horizontal roof gap. The results indicate that, the four factors all have significant impacts on horizontal roof gap, but show differences in influence trend and degree, showing negative linear correlation, positive linear correlation, positive semi-parabolic correlation and negative semi-parabolic correlation, respectively. Four legs type is the most adaptive to the four factors, while six legs(II) type has the poorest adaptability, and the horizontal roof gap is small under large support height, small suspension height, small suspension angle and large tamping angle situation. By means of optimizing structure components and their positional relation and suspension height of backfill scrape conveyor in the process of support design and through controlling working face deployment, roof subsidence in advance, mining height and backfilling during engineering application, the horizontal roof gap is optimized. The research results can be served as theoretical basis for support design and guidance for backfill support to have better performance in backfilling.
