Chunyu Dong

Sun Yat-Sen University | SYSU · Center for Water Resources and Environment

Southern California is a biodiversity hotspot and home to over 23 million people. Over recent decades the annual wildfire area in the coastal southern California region has not significantly changed. Yet how fire regime will respond to future anthropogenic climate change remains an important question. Here, we estimate wildfire probability in south...

Free Access to the Final Version: https://authors.elsevier.com/a/1gk477sfVZAEgd (Available before 30, April, 2023) Urban vegetation is valuable in alleviating local heatwaves. However, drought may decrease vegetation health and limit this cooling effect. Here we use the satellite-based Normalized Difference Vegetation Index (NDVI) and Palmer Droug...

Climate warming has intensified drought severity in many areas of the globe. Dryland mountain ecosystems are sensitive to climate variability. However, the response of mountainous vegetation to drought has high uncertainties due to the rugged terrain and varied local climate and is still not well understood. In this study, the Qilian Mountains (QLM...

Saltwater intrusion is a natural mixture process between watershed freshwater and seawater that frequently occurs in estuaries. Station-based monitoring of saltwater intrusion is time-consuming and labor-intensive. To enable quick monitoring of saltwater intrusion, this study developed new remote sensing algorithms for water surface salinity measur...

Snow is an important component of the hydrological cycle. As a major part of the cryosphere, snow cover also represents a valuable terrestrial water resource. In the context of climate change, the dynamics of snow cover play a crucial role in rebalancing the global energy and water budgets. Remote sensing, hydrological modeling and in situ observat...

Natural hazards could have devastating consequences globally, making hazard assessment and spatial prediction crucial for enhancing the resilience of urbanized regions. However, current disaster prediction and assessment research often neglect the compound effects between multiple geohazards highly in urbanized regions. To address the concern, we e...

The Pearl River Estuary (PRE) frequently experiences the impacts of typhoons, storm surges, and saltwater intrusion. While previous research has mainly focused on saltwater intrusion during the dry season, there is limited research on saltwater intrusion caused by storm surges in the PRE. In this study, we systematically investigate the effects of...

The prediction of water quality in urban rivers plays a crucial role in supporting water environment management. This study collected real-time water quality monitoring data from four stations in the Fenjiang River Basin of Foshan City, spanning from 2016 to 2021. Then the Wavelet Packet Denoising (WPD) technique was applied to reduce noise interfe...

Accurate snow cover data are critical for understanding the Earth’s climate system, and exploring hydrological processes and regional water resource management over High Mountain Asia (HMA). However, satellite-based remote sensing observations of snow cover have inevitable data gaps originating from cloud cover, sensor, orbital limitations and othe...

The prediction of water quality in urban rivers plays a crucial role in supporting water environment management. This study collected and organized real-time water quality monitoring data from four water quality monitoring stations in the Fenjiang River Basin of Foshan City, spanning from 2016 to 2021. To reduce noise interference in historical mon...

Vegetation resistance and resilience to drought are linked to the stability of terrestrial ecosystems under climate change. However, the factors driving the spatial heterogeneity in drought resistance and resilience remain poorly understood. In the study, we utilized multiple satellite-derived vegetation indices to calculate and analyze changes in...

Waterlogging disasters severely restrict crop production. The middle and lower Yangtze River region (MLYRR) is an important grain-producing region in China but suffers from severe waterlogging disasters. In this study, an agriculture-specific index called the accumulative humidity index was introduced to analyze the spatiotemporal characteristics o...

Extreme heat, also known as the silent killer that conceal its lethal effect behind heat-related deaths, has become one of the deadliest natural hazards globally. However, the evaluation of heat risks in many countries remains incomplete, overlooking an important component on population health conditions in the evaluation framework. Drawing on the...

Over the past four decades, annual area burned has increased significantly in California and across the western USA. This trend reflects a confluence of intersecting factors that affect wildfire regimes. It is correlated with increasing temperatures and atmospheric vapour pressure deficit. Anthropogenic climate change is the driver behind much of t...

As a major component of the cryosphere, permafrost plays important roles in the climate system and land surface processes of the Earth. Owing to the rapidly warming climate, permafrost over the globe has degraded in recent decades. However, quantifying the distribution and temporal changes in permafrost is challenging. In this study, we modified th...

The Hawaiian Islands have been identified as a global biodiversity hotspot. We examine the Normalized Difference Vegetation Index (NDVI) using Climate Data Records products (0.05 × 0.05°) to identify significant differences in NDVI between neutral El Niño-Southern Oscillation years (1984, 2019) and significant long-term changes over the entire time...

Satellite-based normalized difference vegetation index (NDVI) time series data are useful for monitoring the changes in vegetation ecosystems in the context of global climate change. However, most of the current NDVI products cannot effectively reconcile high spatial resolution and continuous observations in time. Here, to produce a global-scale, l...

Satellite-based Normalized Difference Vegetation Index (NDVI) time-series data are useful for monitoring the changes of vegetation ecosystems in the context of global climate change. However, there are currently no ideal NDVI datasets that reconcile long-term series with high spatial resolution. Here, we have developed a simple and novel data downs...

（Free access before May 25, 2022: https://authors.elsevier.com/a/1escN7qzSxbUa） The accurate spatial information of snow cover is useful for understanding the impact of global warming, and it is of high significance for hydrological disaster prediction, water resources management, and climate change research. The Normalized Difference Snow Index (N...

Flash floods are one of the most severe natural disasters throughout the world, and are responsible for sizeable social and economic losses, as well as countless injuries and death. Risk assessment, which identifies areas susceptible to flooding, has been shown to be an effective tool for managing and mitigating flash floods. The study aims to intr...

A combination of drought and high temperatures ("global-change-type drought") is projected to become increasingly common in Mediterranean climate regions. Recently, Southern California has experienced record-breaking high temperatures coupled with significant precipitation deficits, which provides opportunities to investigate the impacts of high te...

Plain Language Summary In this study, we investigated California vegetation responses to the recent prolonged 2012–2016 drought, which was potentially the driest 4‐year span in the last 1,200 years. The overall vegetation of the state has been presumed to be severely affected. However, Normalized Difference Vegetation Index (NDVI) satellite data re...

Rapid warming has reduced seasonal snow cover and changed the hydrological regimes over many areas of the globe. Temperature increase cannot only stimulate snowmelt but also favors a shift of wintertime precipitation towards rainfall, especially in Western and Central Europe that has temperate and humid winters. We assume that the mid-season (Janua...

California's climate has become warmer since the early 20th century and is experiencing marked aridity in this century. Satellite-based climate and vegetation data, along with surface-based data, were used to investigate the changing hydroclimate and its impacts on both wildland and urban vegetation. Drying has been more evident in southern Califor...

The complex interactions in desert ecosystems between functional types and environmental conditions could be reflected by plant water use patterns. However, the mechanisms underlying the water use patterns as well as the water sources of Tamarix laxa in the mega-dunes of the Badain Jaran Desert, China, remain unclear. This study investigated the wa...

Chunyu Dong. How Do We Measure Future Snow Cover?, Science Trends, 2018. Available at: https://sciencetrends.com/how-do-we-measure-future-snow-cover/ http://doi.org/10.31988/SciTrends.25792

Ecosystems in Mediterranean climates are adapted to seasonal drought. Multi‐annual drought, however, may significantly affect Mediterranean ecosystems and, further, may affect their constituent communities in different ways with differences in responses emerging during severe drought and over the course of long‐term climate change. This study inves...

It is generally concluded that the climate in California has become drier during the past two decades. However, there is evidence of a distinct north-south pattern of hydroclimatic variability due to a climatic dipole in the western United States. In this study, analysis of MODIS-derived Normalized Difference Vegetation Index (NDVI) and a newly con...

Cloud cover and snow misclassi cations are the two major limitations for the hydrological application of MODIS snow data. Ground-based meteorological data have the inherent potential to provide the means to reconstruct snow cover for regions in which MODIS snow maps are obstructed by clouds, and to reduce misclassi ed snow observations. In this stu...

A camera network has been applied to monitor snow height and snow interception with high temporal resolution in montane forest environments (800-1200 m a.s.l.) in southwestern Germany. A typical feature of this region is the high temporal variability of weather conditions, with frequent snow accumulation and ablation processes and recurrent snow in...

California’s Mediterranean ecosystem has been identified as one of the Earth’s biodiversity hotspots. The high degree of rapid urbanization along the southern California coastline has resulted in the loss of significant natural areas over the last century and protected areas that do exist may be further threatened by climate change, drought, and fi...

A camera network with hourly resolution was used to monitor the complex snow processes in montane forest environments. We developed a semi-automatic procedure to interpret snow depths from the digital images, which exhibited high consistency with manual measurements and station-based recordings. To extract snow interception dynamics, six binary cla...

Cloud cover and snow misclassifications are the two major limitations for the hydrological application of MODIS snow data. Ground-based meteorological data have the inherent potential to provide the means to reconstruct snow cover for regions in which MODIS snow maps are obstructed by clouds, and to reduce misclassified snow observations. In this s...

MODIS snow data are appropriate for a wide range of eco-hydrological studies and applications in the fields of snow-related hazards, early warning systems and water resources management. However, the high spatio-temporal resolution of the remotely sensed data is often biased by snow misclassifications, and cloud cover frequently limits the availabi...

Snow is an important component of the hydrological cycle. As a major part of the cryosphere, snow cover also represents a valuable terrestrial water resource. In the context of climate change, the dynamics of snow cover play a crucial role in rebalancing the global energy and water budgets. Remote sensing, hydrological modeling and in situ observat...

An investigation of temporal dynamics and spatial patterns of dryness/wetness conditions over the eastern part of Northwest China (including Shaanxi, Ningxia, the eastern part of Gansu, and a part of southern Inner Mongolia) during the period 1960–2009 is presented. The analysis of this study is threefold. First, the dryness/wetness conditions over...

The formation mechanisms of the mega-dunes and lakes in the hinterland of Badain Jaran Desert, China, is the focus of extensive academic research in the field of geoscience, and an often debated topic is whether atmospheric precipitation on the mega-dune can infiltrate to recharge groundwater. In the present study, the probability distribution func...

Methods for reconstruction of river runoff have been an important component of paleo-climatology and paleo-hydrology. The lower Heihe River was studied from 2002 to 2008 to reconstruct the annual average runoff at the Zhengyi Gorges hydrological station using measured data and improved water and energy balance equations. The results indicate that t...

Based on the positioning observation of precipitation in the hinterland of the Badain Jaran desert and data from four surrounding gauges in the vicinity of the desert, the characteristic of precipitation in the hinterland of the desert is examined. The effect of megadunes on precipitation is primitively analyzed. The difference in precipitation amo...

Based on the daily data from 1960-2009 of 14 meteorological stations in Heihe River basin and the surrounding areas, spatital and temporal distributions of the reference evapotranspiration in Heihe River basin were analyzed after calculated with the Penman-Monteith method recommended by FAO. Nondimensional relative sensitivity coefficients of refer...

本文通过定位观测的方式获取了2010年以来巴丹吉林沙漠腹地温、湿、风、降水、蒸发等常规气候要素以及水位、水温等水文要素的第一手数据，在此基础上开展了湖泊水量平衡计算以及各湖泊和地下水水位的时空变化过程分析，发现降水远不能满足湖泊蒸发损失，湖泊和地下水位春季最高，夏季最低，变化趋势与年内降水分布相反，冬季基本无降水时，各区域水位均快速上升，表明湖泊和地下水主要接受稳定的地下水补给，但其水位年内季节波动可能主要受控于蒸发量变化。在巴丹吉林沙漠和腾格里沙漠各区域开展了近地表沙层含水量、盐分、氢氧稳定同位素变化分析，发现降水仅能下渗到1m以内的沙层，降水的δD和δ18O值明显偏正，地下水及其附近沙层水分的δD和δ18O值则明显偏负，表明降水和地下水来源不同。在室内沙层持水量实验表明，沙层在无蒸发自由...

The meteorological data of 9 stations around the Badain Jaran desert are analyzed by through the liner regression method, 5 year moving average and Mann-Kendall abrupt test to get the feature of climate change in this area in the past 50 years. The data includes monthly mean temperature, mean maximum temperature, mean minimum temperature, precipita...

Based on the observational data of monthly mean air temperature, precipitation and relative humidity from 1960 to 2009 recorded by 4 weather stations, Ejin Banner and Guaizihu, which are located on the northern margin of the Badain Jaran Desert, Alashan right banner and Yabrai, which are located on the southern margin. The fundamental change charac...

The Badain Jaran Desert is a unique geomorphic unit with the world's highest sand hill and more than 100 lakes. However, there are different opinions on the boundary and the area of it, leading to the question whether its area is the second or the third in China. According to latest research achievements and extensive fieldwarks in 2009, questions...