A Framework for a Subwatershed-Scale Screening Tool to Support Development of Resiliency Solutions and Flood Protection Priority Areas in a Low-Lying Coastal Community

Flood risk analysis is the instrument for local officials to create a sound strategy and adaptation plans for the impacts of inundation due to heavy rains, climate change and sea level rise. Hence, cities with aging infrastructure are retrofitting their stormwater management systems to mitigate the impacts. However determining the most at risk areas and the options for corrections is more challenging. As a result, there is an urgent need to develop a screening tool to analyze watersheds and identify the most at-risk areas. High-quality, open source data and sophisticated spatial analysis techniques allow engineers to create innovative ways to conduct watershed wide inundation analysis. In this study, the investigators developed a screening tool to identify at-risk properties by combining readily available data on topography, groundwater, surface water, tidal information for coastal communities, soils, open space, and rainfall data. Once the screening tool is developed, the means to identify and prioritize improvements to be funded with scarce capital funds is the next step. A tool box of solutions was developed to address flood risk and vulnerability. Testing of the screening tool was conducted in Broward County, Florida and shows encouraging results. Comparison with FEMA Flood maps and repetitive loss mapping indicates that the process works in a coastal community. The framework appears to be viable across cities that may be inundated with water due to sea-level rise, rainfall, runoff upstream, and other natural events.

Clinical Study on the Treatment of Low Anal Fistula in Infants and Young Children by Anal Gland Excision and Virtual Hanging Procedure

Objective:To compare the efficacy of anal adenectomy with virtual hanging wire and anal fistulotomy in the treatment of low anal fistula in infants and children.Methods:60 children with low anal fistula who were admitted to our hospital from October 2021 to March 2022 and met the inclusion criteria were randomly divided into two groups of 30 cases each;the treatment group was treated with anal adenectomy and virtual hanging wire surgery,and the control group was treated with anal fistula resection.The clinical efficacy after treatment was compared.Results:The total effective rate of both groups was 96.67%and the difference between the two groups was not statistically significant(P>0.05).The postoperative pain score of the treatment group was lower than that of the control group(P<0.05).The length of hospitalization and healing time of the treatment group was lower than that of the control group(P<0.05).The anal function of the patients in both groups was normal,and there was no adverse reaction.Conclusion:Anal gland excision and virtual hanging surgery for the treatment of low anal fistula in infants and children have the advantages of mild pain,reduced length of hospitalization,short healing time,and better patient experience as compared to anal fistula excision.

高分辨率光学卫星影像高精度在轨实时云检测的流式计算

本文重点阐述基于机器视觉的智能摄影测量的效率基础问题之二:高精度影像在轨实时云检测方法。随着技术发展,数据获取能力不断提升,待处理的数据量呈爆炸式增长;同时,对处理精度需求的提升,导致所需计算量的不断增长,二者凸显了智能摄影测量面临的效率问题。对光学卫星影像而言,高达50%的平均云覆盖率严重制约了高效精准在轨智能摄影测量的实现。针对于此,本文结合机器视觉中"自底向上"的图像理解控制策略,提出一种可供借鉴的基于流式计算的高分辨率光学卫星影像高精度在轨实时云检测方法,采用适合在轨搭载的嵌入式GPU实现实时流式计算,为后续的智能摄影测量处理提供输入。本文方法采用不依赖外存的快速处理机制,对持续流入的数据实时分块,通过负载均衡机制将数据块依次分发至各个单元并行处理,从而实现"流入、处理、流出"的实时处理。利用高分二号数据对本文方法进行试验验证,结果表明本文方法在显著提高云覆盖区域检测精度的同时,综合加速比达14,可满足在轨实时处理需求。

Simulation study on the influence of magnetic field in the near-anode region on anode power deposition of ATON-type Hall thruster

The highest deposition of power and temperature is always near the cusp of the ATON-type Hall thruster.This shows that when there are electrons gathering at the cusp,the distribution of heat load will be uniform,which will potentially damage the reliability.Therefore,we optimize the magnetic field near the anode.We changed the magnetic field characteristics in the near-anode region with an additional magnetic screen,and performed numerical simulation with particle-incell simulation.The simulation results show that the magnetic field of the thruster with the additional magnetic screen can alleviate the over-concentration of power deposition on the anode and reduce the power deposition in the anode by 20%,while ensuring that the overall magnetic field characteristics do not change significantly.

Stream-computing of High Accuracy On-board Real-time Cloud Detection for High Resolution Optical Satellite Imagery

This paper focuses on the time efficiency for machine vision and intelligent photogrammetry, especially high accuracy on-board real-time cloud detection method. With the development of technology, the data acquisition ability is growing continuously and the volume of raw data is increasing explosively. Meanwhile, because of the higher requirement of data accuracy, the computation load is also becoming heavier. This situation makes time efficiency extremely important. Moreover, the cloud cover rate of optical satellite imagery is up to approximately 50%, which is seriously restricting the applications of on-board intelligent photogrammetry services. To meet the on-board cloud detection requirements and offer valid input data to subsequent processing, this paper presents a stream-computing of high accuracy on-board real-time cloud detection solution which follows the “bottom-up” understanding strategy of machine vision and uses multiple embedded GPU with significant potential to be applied on-board. Without external memory, the data parallel pipeline system based on multiple processing modules of this solution could afford the “stream-in, processing, stream-out” real-time stream computing. In experiments, images of GF-2 satellite are used to validate the accuracy and performance of this approach, and the experimental results show that this solution could not only bring up cloud detection accuracy, but also match the on-board real-time processing requirements.

Estimating the impact of land use change on surface energy partition based on the Noah model

It is well known that land use has an important impact on surface energy partition. It is important to study the evolving trend of the partition of sensible heat flux （SHF） and latent heat flux （LHF） from the net radiance （NR） with land use change in the context of regional climate changes. In this paper, we studied the response of energy partition to land use using the Noah model. First, the Noah model simulation results of SHF and LHF between 2003 and 2005 were comprehensively validated using the observation data from the Changbai Mountain Station, the Xilinhot Station, and the Yucheng Station. The study domains represent three different types of land use change： excessive deforestation, grassland degeneration aggravation, and groundwater level decline, respectively. The study period was subsequently extended from 2015 through 2034, using four projected land use maps and forcing data from Princeton （2000-2004）. The simulation results show that during the land use conversions, the annual average of LHF drops by 10.7%, rises by 10.1%, and drops by 11.5% for the Changbai Mountain, Inner Mongolia, and Northern China stations, respectively while the annual average of SHF rises by 10.6%, drops by 10.1%, and drops by 11.3% for the three areas.

Principles and methods for the validation of quantitative remote sensing products

We first discuss the relativity of "true value and homogeneity" for quantitative remote sensing products (QRSPs), and then propose the definitions of "eigenaccuracy" and "eigenhomogeneity" under practical conditions. The eigenaccuracy and eigenhomogeneity for land surface crucial parameters such as albedo, leaf area index (LAI), and surface temperature are analyzed based on a series of experiments. Secondly, we point out the differences and similarities between the scale-free phenomena of the QRSPs and the measurements of the coastline length (1-dimensional) and the curved surface area (2-dimensional). An information fractal algorithm for the QRSPs is presented. In a case study for the LAI, when the fractal dimension is 2.16, the ratio of the LAI retrieval values obtained respectively from remote sensing data of 30 m and 6 km pixel resolution can actually reach as high as 2.86 for the same 6 km pixel using the same retrieval model. Finally, we propose an operational validation method "one test and two matches" and multipoint observation when the real situation does not allow carrying out scanning measurement without gap and overlap on the ground surface.

LUCC and its impact on run-off yield in the Bai River catchment—upstream of the Miyun Reservoir basin

Aims The Miyun Reservoir is the most important drinking water source for Beijing—the capital of China with a population of more than 16 million.Since the 1980s,the inflow to the reservoir has been decreasing,which seriously threatens the security of water use in Beijing.Our goal was to analyze the impact of land use and cover change(LUCC)on run-off yield in the upstream of the Miyun Reservoir.Methods In this study,the Soil andWater Assessment Tool(SWAT)was used to simulate the impacts of LUCC on the run-off yield in the Bai River catchment—upstream of the Miyun Reservoir basin in northern China.The investigation was conducted using two 6-year historical streamflow records:from 1986 to 1991 and from 2000 to 2005.A split sample procedure was used for model calibration and validation.The data from 1986 to 1988 and from 2000 to 2002 were used for calibration,while those from 1989 to 1991 and from 2003 to 2005 for validation.The SWAT calibration was based on monthly measured discharge at Zhangjiafen station at the catchment outlet from Bai River catchment.Additionally,the influence of LUCC on the surface run-off was distinguished from that of climate change on the surface runoff through SWAT scenarios modeling,the twoway analysis of variance(ANOVA),and the rainfall–run-off double-mass analysis in the Bai River catchment.Important Findings We found that the SWAT model could be used successfully to accurately simulate run-off yield and different LUCC patterns affecting water quantity in this catchment.During calibraion for the two periods the simulated monthly run-off satisfactorily matched the observed values,with the Nash–Sutcliffe coefficient>0.9 and 0.7 and a coefficient of determination of 0.9 and 0.65 at the outlet station(Zhangjiafen station),while during validation for the two periods the obtained values were 0.85,0.65 and 0.9,0.65,respectively.During the period of 1986–91,both the SWAT scenarios modeling and the analysis of the two-way ANOVA method showed that LUCC and climate change had some impact on run-off,and the impact of climate change was more significant than that of LUCC.Compared with the period during 1986–91,the run-off yield in the period during 2000–05 significantly decreased.The obtained results from the rainfall–run-off double-mass analysis indicate that since 1998 LUCC has had an increasing influence on the run-off,while the response of the run-off to rainfall has been decreasing.Since 1998,the LUCC has been a major driving force for run-off change in Bai River catchment.

Intercomparison of two trapezoid-based soil moisture downscaling methods using three scaling factors

This paper compared two soil moisture downscaling methods using three scaling factors.Level 3 soil moisture product of advanced microwave scanning radiometer for EOS(AMSR-E)is downscaled from 25 to 1 km.The downscaled results are compared with the soil moisture observations from polarimetric scanning radiometer(PSR)microwave radiometer and field sampling.The results show that(1)the scaling factor of normalized soil thermal inertia(NSTIs)and vegetation temperature condition index(VTCI)are better than soil evaporative efficiency in reflecting soil moisture;(2)for method 1,NSTIS is the best in the downscaling of soil moisture.For method 2,VTCI is the best;(3)no significant differences of the correlation coefficients(R2)and the biases were found between the two methods for the same scaling factors.However,method 2 shows a better potential than method 1 in the time-series applications of the downscaling of soil moisture;(4)compared with the relationship between the area-averaged soil moisture of AMSR-E and that of PSR,R2 of the 6 sets of the downscaled soil moisture almost do not decrease,which suggests the validity of the downscaling of soil moisture with the two downscaling methods using the three scaling factors.