Zhenhong Li

Chang'an University · College of Geological Engineering and Geomatics

For mapping Earth surface movements at larger scale and smaller amplitudes, many new synthetic aperture radar instruments (Sentinel-1A/B, Gaofen-3, ALOS-2) have been developed and launched from 2014–2017, and this trend is set to continue with Sentinel-1C/D, Gaofen-3B/C, RADARSAT Constellation planned for launch during 2018–2025. This poses more ch...

Early warning systems (EWSs) to detect and monitor landslides are a great challenge. They are important due to the high cost of catastrophic landslides and are challenging because of the difficulty in identifying a diverse range of landslide-triggering factors. While there has been a very limited number of successes, recent advances in Earth observ...

Real-time centimetre-level precise positioning from Global Navigation Satellite Systems (GNSS) is critical for activities including landslide, glacier and coastal erosion monitoring, flood modelling, precision agriculture, intelligent transport systems, autonomous vehicles and the Internet of Things. This may be achieved via the real-time kinematic...

Plain Language Summary Large earthquakes result in stress changes, which can induce or retard regional seismic activity or even trigger other earthquakes. Therefore, understanding historical and recent earthquakes and their associated stress changes are crucial in the evaluation of future seismic hazards. One of the most popular and intuitive ways...

Earthquake triggered landslides often pose a great threat to human life and property. Emerging research has been devoted to documenting coseismic landslides failed during or shortly after earthquakes, however, the long-term seismic effect that causes unstable landslides only to accelerate, moderately or acutely, without immediate failures is largel...

Landslides are one of the most serious natural hazards along the Sichuan-Tibet transportation corridor, which crosses the most complicated region in the world in terms of topography and geology. Landslide susceptibility mapping (LSM) is in high demand for risk assessment and disaster reduction in this mountainous region. A new model, namely Convolu...

Land surface temperature (LST) and sea surface temperature (SST) are key parameters for understanding global change and human activities. However, the existing surface temperature products are usually discontinuous at the sea and land boundary. In this study, we use Sentinel-3 sea and land surface temperature radiometer (SLSTR) to measure continuou...

On April 6, 2021, the Baihetan dam launched impoundment, and the reservoir water surface elevation dramatically increased from 660 m to 812 m until October 2021, which may induce large-scale landslides in reservoir bank. Accurate landslides susceptibility evaluation during impoundment is crucial for controlling the possible disasters and taking ear...

The Mw 6.3 Yutian earthquake, occurred in northwestern Tibet on 25 June 2020, is one of the major events sequentially occurring in the region following the 2008 Mw 7.2, 2012 Mw 6.2, and 2014 Mw 6.9 earthquakes, and is of great significance for studying the tectonic activity and assessing future seismic hazards in the region. In this study, we used...

Generating spatial crop yield information is of great significance for academic research and guiding agricultural policy. Most existing public yield datasets have a coarse spatial resolution. Although these datasets are useful for analyzing regional temporal and spatial change, they cannot deal with spatial heterogeneity, which happens to be the mo...

Landslides are major geological hazards and frequently occur in mountainous areas with steep slopes, often causing significant loss. Interferometric Synthetic Aperture Radar (InSAR) has been widely used in landslide measurement over the last three decades. However, InSAR only can measure one-dimensional displacements (i.e. those in the radar’s line...

Earth observation technologies have great potential in the investigation, monitoring and assessment of various geohazards. Stacking is an efficient InSAR method for estimating deformation rates and helps in the generation and update of the geohazard inventories. However, it relies on the assumption that the atmospheric statistics are stationary, wh...

On 5 September 2022, an Mw 6.6 earthquake struck Luding County, Sichuan Province, China, which triggered a large number of geohazards such as landslides and collapses, leading to serious casualties and economic losses. Rapid access to landslide susceptibility maps and the actual distribution map of coseismic landslides is critical for disaster mana...

Chlorophyll content is a key trait for understanding the functioning of agroforestry ecosystems and has important implications for leaf and canopy photosynthesis. However, fine-scale monitoring of canopy chlorophyll content (CCC) of individual fruit trees is rather challenging. This study aims to use a 3D radiative transfer model (RTM) and proposes...

Extensive coastal deltas in the world are subsiding due to natural or anthropogenic activities. As the widest and youngest river delta in the world, serious coastal subsidence in the Yellow River Delta (YRD) has exacerbated the relative sea level rise (RSLR) and increased the risk of soil salinization and coastal flooding. However, there are rarely...

Landslides pose a greater potential risk to the Sichuan-Tibet Transportation Project, and extensive landslide inventory and mapping are essential to prevent and control geological hazards along the Sichuan-Tibet Transportation Corridor (STTC). Recently proposed landslide detection methods mainly focused on new landslides with high vegetation. In ad...

On 22 July 2020, an Mw 6.3 earthquake occurred in Nima County, central Qinghai-Tibet Plateau, China. We used the synthetic aperture radar interferometry (InSAR) technique with Sentinel-1 images to retrieve the line of sight (LOS) coseismic deformation fields which indicate that the maximum surface displacement reached ~30 cm. We then processed a se...

The Loess Plateau is a typical ecologically sensitive area that can easily be perturbed by the effects of human activities and global climate change. Therefore, it is necessary to develop tools to monitor the environmental quality in the LP quickly and accurately. To reveal the spatio-temporal changes in environmental quality in the LP from 2000 to...

The 5 September 2022 Mw 6.6 Luding earthquake is the largest earthquake occurring on the Xianshuihe fault, Eastern Tibet in the past 40 years, and is of great significance for investigating the tectonic activity and assessing future seismic hazards in the region. Methods: In this study, we used Sentinel-1 and ALOS-2 synthetic aperture radar (SAR) i...

Snow is an important environmental variable influencing weather and climate. The GPS-IR technique is a very effective technique for monitoring snow depth. A GPS-IR snow depth estimation corrected model is proposed to address the impact of the Signal to Noise Ratio (SNR) amplitude attenuation and snow surface roughness variation that are not conside...

The Lashagou landslide group in Gansu Province, China, is a typical shallow loess landslide group caused by artificial slope cutting. In April 2018, local sliding of the landslide group damaged houses and blocked the G310 highway, leading to the relocation of the Lashagou village, which aroused widespread concern. Unfortunately, the spatiotemporal...

The Jinsha River flows through one of the most geologically complex regions in western China with extremely high altitudes and capricious climates. Frequent landslides (e.g., the Baige landslides on 11 October and 3 November 2018) occurred along its stretch which posed severe damage to bridges, dams, and roads, and put the safety of local residents...

Atmospheric effects are among the primary error sources affecting the accuracy of interferometric synthetic aperture radar (InSAR). The topography-dependent atmospheric effect is particularly noteworthy in reservoir areas for landslide monitoring utilizing InSAR, which must be effectively corrected to complete the InSAR high-accuracy measurement. T...

Turbidity maximum zone (TMZ) plays a crucial role in estuarine ecosystems, exerting effects on erosion, environment evolution and socioeconomic activities in the coastal area. However, the long-term understanding of the TMZ in large river estuary such as the Yellow River estuary is still lacking. In this study, we focus on the TMZ distribution, var...

Ground subsidence and uplift caused by the annual thawing and freezing of the active layer are important variables in permafrost studies. Global positioning system interferometric reflectometry (GPS-IR) has been successfully applied to retrieve the continuous ground surface movements in permafrost areas. However, only GPS signals were used in previ...

Traversing the Qinghai–Tibetan Plateau, the Sichuan–Tibet Railway is by far the most difficult railway project in the world. The Qinghai–Tibetan Plateau features the most active crustal dynamics on earth, the strongest coupling effects of endogenic and exogenic dynamics, and the environment most sensitive to global climate change. The project area...

Real-time precise point positioning (RTPPP) has obtained much attention and has been widely used in recent years, yet it depends very much on real-time precise satellite orbit and clock products. However, precise products cannot be received in regions where the Internet and mobile communication are restricted or even unavailable. We proposed a meth...

With frequent launches of Synthetic Aperture Radar (SAR) satellites, Interferometric SAR (InSAR) technology has been presented with unprecedented opportunities along with many new challenges for deformation mapping. In this paper, we concisely demonstrate the current development of SAR satellites and the principle of the InSAR technique, and then s...

Wide area landslide detection is a major international research hotspot in the field of geological hazards, and the integration of multi-temporal optical satellite images and spaceborne in-terferometric synthetic aperture radar (InSAR) appears to be an effective way to realize this. In this paper, a technical framework is presented for wide area la...

Wide area landslide detection is a major international research hotspot in the field of geological hazards, and the integration of multi-temporal optical satellite images and spaceborne in-terferometric synthetic aperture radar (InSAR) appears to be an effective way to realize this. In this paper, a technical framework is presented for wide area la...

Landslide susceptibility mapping (LSM) is an important element of landslide risk assessment, but the process often needs to span multiple platforms and the operation process is complex. This paper develops an efficient user-friendly toolbox including the whole process of LSM, known as the SVM-LSM toolbox. The toolbox realizes landslide susceptibili...

Inland water is an important part of the Earth’s water cycle. Mapping inland water is vital for understanding surface hydrology and climate change. Spaceborne global navigation satellite systems reflectometry (GNSS-R) has been proven to be an effective technique to detect inland water bodies. This paper proposes a new method to map inland water bod...

The Sichuan-Tibet traffic corridor is an important transportation strategy in China that plays a key role in the economic prosperity, long-term stability, and the "Belt and Road" strategy in western China. However, the complex terrain, climate environment and active geological tectonic movements along the Sichuan-Tibet traffic corridor lead to extr...

Synthetic aperture radar (SAR) signal can penetrate clouds and some vegetation canopies in all weather, and therefore, provides an important measurement tool for change detection and sustainable development of coastal wetland environments and ecosystems. However, there are a few quantitative estimations about the spatiotemporal coherence change wit...

Ankang Airport is constructed on an expansive soil-fill platform in Shaanxi Province, Central China. Since its completion in 2020, it has suffered surface deformation caused by the consolidation and settlement of the fill layer and instability of the expansive soil slope. Exploring the special deformation law of expansive soil regions by remote sen...

China is one of the largest apple-producing countries in the world, with large orchards and diverse climates. Accurately forecasting the first-flowering time of apple trees can assist orchard managers in their deciding when to apply anti-freeze. The temperature-driven sequential model from previous studies can be used to forecast the flowering phen...

Tidal flats are one of the most productive ecosystems on Earth, providing essential ecological and economical services. Because of the increasing anthropogenic interruption and sea level rise, tidal flats are under great threat. However, updated and large-scale accurate tidal flat maps around the Bohai and Yellow Seas are still relatively rare, hin...

Although deep learning techniques have achieved noticeable success in aircraft detection, the scale heterogeneity, position difference, complex background interference and speckle noise, keep aircraft detection in large-scale SAR images challenging. To solve these problems, we propose the geospatial transformer framework and implement it as a three...

Timely monitoring of above-ground biomass (AGB) is essential for indicating the crop growth status and predicting grain yield and carbon dynamics. Non-destructive remote sensing techniques with a large spatial coverage have become a promising method for crop biomass monitoring. However, most existing crop biomass models have only been tested at a s...

On 1 May 2020, the Sardoba Reservoir in Uzbekistan breached its western wall, and the uncontrolled release of water caused casualties, environmental damages and economic losses. We investigate the dam failure based on three sets of Earth observation data, including: (i) satellite altimetry products, i.e., ICESat-2 data, with the aim of understandin...

Lakes Frome, Callabonna, Blanche and Gregory are playa lakes on the eastern and northern sides of the Flinders Ranges, South Australia. Between 2007 and 2019 we surveyed key topographic features of the lakes, including shorelines, lake floors and the alluvial sills that separate the lakes with differential GPS (DGPS). We combine these observations...

After a coal mine is closed, the coal rock mass could undergo weathering deterioration and strength reduction due to factors such as stress and groundwater, which in turn changes the stress and bearing capacity of the fractured rock mass in the abandoned goaf, leading to secondary or multiple surface deformations in the goaf. Currently, the spatiot...

Precision agriculture (PA) technologies offer a potential solution to food security and environmental challenges but, will only be successful if adopted by farmers. Adoption in China lags behind that in some developed agricultural economies despite scientifically proven benefits of PA technologies for Chinese agriculture. Adoption is dependent on f...

In this paper, DMSP/OLS and NPP/VIRS nighttime light as well as Landsat multispectral remote sensing images are utilized for quantitative analysis of built-up area, urban boundary shape and extension trend in Qingdao over the past 25 years. Combined with the land use classification, road network, POI, DEM and multi-source driving factors and CA-Mar...

Rapid Interpretation and Analysis of the 2022 Eruption of Hunga TongaHunga Ha'apai Volcano with Integrated Remote Sensing Techniques

Apple is one of the most important cash crops in China. However, negative economic, environmental and social impacts are associated with its production. This study aims to apply a holistic systems perspective to understand existing problems associated with apple production in China and use this information to improve its sustainability. A structure...

Leaf base and inclination angles are two critical three-dimensional structural parameters in agronomy and remote sensing for breeding and modeling. Terrestrial laser scanning (TLS) has been proved to be a promising tool to quantify leaf base and inclination angles. However, previous TLS studies often focused on leaf base and inclination angles of c...

The 3-D ionospheric electron density is an important parameter for characterizing the ionosphere. Synthetic aperture radar (SAR), an advanced Earth observation technology, has shown its potential for observing 2-D vertical total electron content (VTEC). However, retrieval of 3-D electron density is limited by the SAR imaging geometry. To solve this...

开展铁路沿线滑坡易发性评价对川藏交通廊道工程建设及运维过程中的风险管理具有重要意义.提出一种层数自适应、通道加权的卷积神经网络（layer adaptive weighted convolutional neural network,LAW-CNN），对川藏交通廊道沿线滑坡易发性进行评价.依据野外调查和影响因素分析筛选出影响滑坡发生的影响因子，绘制滑坡编目，构造用于易发性评价的实验数据集；针对卷积神经网络的权重初值、网络层数等超参数难以优化设置的问题，提出基于影响因子信息熵的通道加权方法和网络层数优选策略，通过多通道加权和层数自适应分类卷积的方式提出滑坡易发性制图的LAW-CNN架构；搜索最优LAW-CNN网络结构并训练网络参数，获取研究区滑坡发生概率并进行易发性分级评价.所提的LAW-CN...

Landslides occur frequently in the western mountainous areas of China, causing huge losses every year. InSAR technology can efficiently and accurately identify potential landslides and is a powerful tool for landslide hazards mitigation. However, the successful application of InSAR technology is limited by several factors, such as geometric distort...

On 20 July 2021, parts of China’s Henan Province received the highest precipitation levels ever recorded in the region. Floods caused by heavy rainfall resulted in hundreds of casualties and tens of billions of dollars’ worth of property loss. Due to the highly dynamic nature of flood disasters, rapid and timely spatial monitoring is conducive for...

Deep groundwater (confined groundwater) is the major water source in Cangzhou, situated in the North China Plain. Long-term deep groundwater overexploitation has resulted in substantial groundwater storage (GWS) depletion. Quantifying the influence of long-term overexploitation on deep groundwater resources is extremely important to maintain the su...

With the rapid process of urbanization, the urban heat island (UHI), the phenomenon where urban regions become hotter than their surroundings, is increasingly aggravated. The UHI is affected by multiple factors overall. However, it is difficult to dissociate the effect of one aspect by widely used approaches such as the remote-sensing-based method....

The spatial distribution of coastal wetlands affects their ecological functions. Wetland classification is a challenging task for remote sensing research due to the similarity of different wetlands. In this study, a synergetic classification method developed by fusing the 10 m Zhuhai-1 Constellation Orbita Hyperspectral Satellite (OHS) imagery with...

Rapid socio-economic changes in China, such as land conversion and urbanization, are creating new scopes for the application of precision agriculture (PA).An experiment to assess the economic benefits of two precision agriculture methods was applied for one year – precision seeding and precision seeding with land leveling. Whilst the results for th...

Sichuan Tibet railway is a national landmark major project, which has very important strategic significance. There are a series of high-risk hidden disasters in the Sichuan Tibet railway corridor, including high-level collapse, landslide, ice avalanche and ice lake break debris flow. Due to the complex geological conditions and natural environment,...

Objectives: The Sichuan‑Tibet railway is not only a state key project in China, but also the most difficult super project in railway construction history due to the most complex terrain and the active geological structure. Interferometric synthetic aperture radar (InSAR) has proved to be a critical tool for detecting and monitoring geohazards becau...

Staring spotlight images with a spatial resolution of up to tens of centimeters are good data sources for urban applications including displacement mapping. However, phase discontinuities, layover, and shadowing effect are also associated with staring spotlight interferograms, adding to the difficulties in height estimation and spatial phase unwrap...