Coherence-guided InSAR deformation analysis in the presence of ongoing land surface changes in the Imperial Valley, California

2021 ◽  
Vol 253 ◽  
pp. 112160
Author(s):  
Junle Jiang ◽  
Rowena B. Lohman
Science ◽  
2005 ◽  
Vol 310 (5748) ◽  
pp. 657-660 ◽  
Author(s):  
F. S. Chapin

2021 ◽  
Author(s):  
Daeha Kim ◽  
Jong Ahn Chun

<p>While the Budyko framework has been a simple and convenient tool to assess runoff (Q) responses to climatic and surface changes, it has been unclear how parameters of a Budyko function represent the vertical land-atmosphere interactions. Here, we explicitly derived a two-parameter equation by correcting a boundary condition of the Budyko hypothesis. The correction enabled for the Budyko function to reflect the evaporative demand (E<sub>p</sub>) that actively responds to soil moisture deficiency. The derived two-parameter function suggests that four physical variables control surface runoff; namely, precipitation (P), potential evaporation (E<sub>p</sub>), wet-environment evaporation (E<sub>w</sub>), and the catchment properties (n). We linked the derived Budyko function to a definitive complementary evaporation principle, and assessed the relative elasticities of Q to climatic and land surface changes. Results showed that P is the primary control of runoff changes in most of river basins across the world, but its importance declined with climatological aridity. In arid river basins, the catchment properties play a major role in changing runoff, while changes in E<sub>p</sub> and E<sub>w</sub> seem to exert minor influences on Q changes. It was also found that the two-parameter Budyko function can capture unusual negative correlation between the mean annual Q and E<sub>p</sub>. This work suggests that at least two parameters are required for a Budyko function to properly describe the vertical interactions between the land and the atmosphere.</p>


Author(s):  
Tingxiang Liu ◽  
Lingxue Yu ◽  
Kun Bu ◽  
Jiuchun Yang ◽  
Fengqin Yan ◽  
...  

2019 ◽  
Vol 11 (15) ◽  
pp. 1759 ◽  
Author(s):  
Detang Zhong ◽  
Fuqun Zhou

A key challenge in developing models for the fusion of surface reflectance data across multiple satellite sensors is ensuring that they apply to both gradual vegetation phenological dynamics and abrupt land surface changes. To better model land cover spatial and temporal changes, we proposed previously a Prediction Smooth Reflectance Fusion Model (PSRFM) that combines a dynamic prediction model based on the linear spectral mixing model with a smoothing filter corresponding to the weighted average of forward and backward temporal predictions. One of the significant advantages of PSRFM is that PSRFM can model abrupt land surface changes either through optimized clusters or the residuals of the predicted gradual changes. In this paper, we expanded our approach and developed more efficient methods for clustering. We applied the new methods for dramatic land surface changes caused by a flood and a forest fire. Comparison of the model outputs showed that the new methods can capture the land surface changes more effectively. We also compared the improved PSRFM to two most popular reflectance fusion algorithms: Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) and Enhanced version of STARFM (ESTARFM). The results showed that the improved PSRFM is more effective and outperforms STARFM and ESTARFM both visually and quantitatively.


2007 ◽  
Vol 24 (3) ◽  
pp. 527-537 ◽  
Author(s):  
Xingkui Xu ◽  
Feng Zhang ◽  
Jason K. Levy

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1525
Author(s):  
Abdullah Ayub Khan ◽  
Zaffar Ahmed Shaikh ◽  
Asif Ali Laghari ◽  
Sami Bourouis ◽  
Asif Ali Wagan ◽  
...  

In this paper, we propose a secure blockchain-aware framework for distributed data management and monitoring. Indeed, images-based data are captured through drones and transmitted to the fog nodes. The main objective here is to enable process and schedule, to investigate individual captured entity (records) and to analyze changes in the blockchain storage with a secure hash-encrypted (SH-256) consortium peer-to-peer (P2P) network. The proposed blockchain mechanism is also investigated for analyzing the fog-cloud-based stored information, which is referred to as smart contracts. These contracts are designed and deployed to automate the overall distributed monitoring system. They include the registration of UAVs (drones), the day-to-day dynamic captured drone-based images, and the update transactions in the immutable storage for future investigations. The simulation results show the merit of our framework. Indeed, through extensive experiments, the developed system provides good performances regarding monitoring and management tasks.


2021 ◽  
Author(s):  
Ran Feng ◽  
Tripti Bhattacharya ◽  
Bette Otto-bliesner ◽  
Esther Brady ◽  

<p>Earth System Models (ESMs) project drying of the northern subtropics by the end of the 21<sup>st</sup> century. However, geologic evidence from intervals with elevated concentrations of atmospheric carbon dioxide (pCO<sub>2</sub>), like the mid-Pliocene, suggest mesic subtropical conditions. Several hypotheses, including an El Niño-like SST pattern and weaker Hadley circulation, have been proposed to explain this mismatch. Here, we show that PlioMIP2 ensemble broadly capture the pattern of proxy reconstructed Pliocene hydroclimate, notably a wetter Sahel and southeast Asia. Sensitivity simulations reveal that this pattern is driven by summertime rainfall increases as a result of lowered albedo and a distinct surface warming pattern, generated by prescribed vegetation and ice sheet changes. The resultant tropospheric moistening and stationary wave pattern enhance moisture convergence into the northern subtropics. Our results suggest that mid-Pliocene hydroclimate is part of the Earth system feedback to sustained CO<sub>2</sub> concentrations similar to today.</p><p><img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gepj.0005b442a70068203111161/sdaolpUECMynit/12UGE&app=m&a=0&c=d33f4ac1a0750ab37681b00412fa7633&ct=x&pn=gepj.elif&d=1" alt=""></p>


2022 ◽  
Vol 804 ◽  
pp. 150221
Author(s):  
L. Olivera-Guerra ◽  
M. Quintanilla ◽  
I. Moletto-Lobos ◽  
E. Pichuante ◽  
C. Zamorano-Elgueta ◽  
...  

2020 ◽  
Vol 12 (15) ◽  
pp. 2406 ◽  
Author(s):  
Zhongbin Li ◽  
Hankui K. Zhang ◽  
David P. Roy ◽  
Lin Yan ◽  
Haiyan Huang

Combination of near daily 3 m red, green, blue, and near infrared (NIR) Planetscope reflectance with lower temporal resolution 10 m and 20 m red, green, blue, NIR, red-edge, and shortwave infrared (SWIR) Sentinel-2 reflectance provides potential for improved global monitoring. Sharpening the Sentinel-2 reflectance with the Planetscope reflectance may enable near-daily 3 m monitoring in the visible, red-edge, NIR, and SWIR. However, there are two major issues, namely the different and spectrally nonoverlapping bands between the two sensors and surface changes that may occur in the period between the different sensor acquisitions. They are examined in this study that considers Sentinel-2 and Planetscope imagery acquired one day apart over three sites where land surface changes due to biomass burning occurred. Two well-established sharpening methods, high pass modulation (HPM) and Model 3 (M3), were used as they are multiresolution analysis methods that preserve the spectral properties of the low spatial resolution Sentinel-2 imagery (that are better radiometrically calibrated than Planetscope) and are relatively computationally efficient so that they can be applied at large scale. The Sentinel-2 point spread function (PSF) needed for the sharpening was derived analytically from published modulation transfer function (MTF) values. Synthetic Planetscope red-edge and SWIR bands were derived by linear regression of the Planetscope visible and NIR bands with the Sentinel-2 red-edge and SWIR bands. The HPM and M3 sharpening results were evaluated visually and quantitatively using the Q2n metric that quantifies spectral and spatial distortion. The HPM and M3 sharpening methods provided visually coherent and spatially detailed visible and NIR wavelength sharpened results with low distortion (Q2n values > 0.91). The sharpened red-edge and SWIR results were also coherent but had greater distortion (Q2n values > 0.76). Detailed examination at locations where surface changes between the Sentinel-2 and the Planetscope acquisitions occurred revealed that the HPM method, unlike the M3 method, could reliably sharpen the bands affected by the change. This is because HPM sharpening uses a per-pixel reflectance ratio in the spatial detail modulation which is relatively stable to reflectance changes. The paper concludes with a discussion of the implications of this research and the recommendation that the HPM sharpening be used considering its better performance when there are surface changes.


Sign in / Sign up

Export Citation Format

Share Document