scholarly journals Flash Flooding in Arid/Semiarid Regions: Dissecting the Hydrometeorology and Hydrology of the 19 August 2014 Storm and Flood Hydroclimatology in Arizona

2017 ◽  
Vol 18 (12) ◽  
pp. 3103-3123 ◽  
Author(s):  
Long Yang ◽  
James Smith ◽  
Mary Lynn Baeck ◽  
Efrat Morin ◽  
David C. Goodrich
Keyword(s):  
North American ◽  
Hydrological Modeling ◽  
Rainfall Variability ◽  
Flash Floods ◽  
Flood Frequency ◽  
North American Monsoon ◽  
The North ◽  
Flood Response ◽  
Central Arizona

The hydroclimatology, hydrometeorology, and hydrology of flash floods in the arid/semiarid southwestern United States are examined through empirical analyses of long-term, high-resolution rainfall and stream gauging observations, together with hydrological modeling analyses of the 19 August 2014 storm based on the Kinematic Runoff and Erosion Model (KINEROS2). The analyses presented here are centered on identifying the structure and evolution of flood-producing storms, as well as the interactions of space–time rainfall variability and basin characteristics in determining the upper-tail properties of rainfall and flood magnitudes over this region. This study focuses on four watersheds in Maricopa County, Arizona, with contrasting geomorphological properties. Flash floods over central Arizona are concentrated in both time and space, reflecting controls of the North American monsoon and complex terrain. Thunderstorm systems during the North American monsoon, as represented by the 19 August 2014 storm, are the dominant flood agents that determine the upper tail of flood frequency over central Arizona and that also shape the envelope curve of floods for watersheds smaller than 250 km2. Flood response for the 19 August 2014 storm is associated with storm elements of comparable spatial extent to the drainage area and slow movement for the three compact, headwater watersheds. Flood response for the elongated and relatively flat Skunk Creek highlights the importance of the spatial distribution of rainfall for transmission losses in arid/semiarid watersheds.

scholarly journals Vegetation Dynamics within the North American Monsoon Region

2011 ◽  
Vol 24 (6) ◽  
pp. 1763-1783 ◽  
Author(s):  
Giovanni Forzieri ◽  
Fabio Castelli ◽  
Enrique R. Vivoni
Keyword(s):  
North American ◽  
Vegetation Dynamics ◽  
Vegetation Index ◽  
North American Monsoon ◽  
Terrain Attributes ◽  
The North ◽  
Short Period ◽  
Long Term Trends ◽  
Northwestern Mexico

Abstract The North American monsoon (NAM) leads to a large increase in summer rainfall and a seasonal change in vegetation in the southwestern United States and northwestern Mexico. Understanding the interactions between NAM rainfall and vegetation dynamics is essential for improved climate and hydrologic prediction. In this work, the authors analyze long-term vegetation dynamics over the North American Monsoon Experiment (NAME) tier I domain (20°–35°N, 105°–115°W) using normalized difference vegetation index (NDVI) semimonthly composites at 8-km resolution from 1982 to 2006. The authors derive ecoregions with similar vegetation dynamics using principal component analysis and cluster identification. Based on ecoregion and pixel-scale analyses, this study quantifies the seasonal and interannual vegetation variations, their dependence on geographic position and terrain attributes, and the presence of long-term trends through a set of phenological vegetation metrics. Results reveal that seasonal biomass productivity, as captured by the time-integrated NDVI (TINDVI), is an excellent means to synthesize vegetation dynamics. High TINDVI occurs for ecosystems with a short period of intense greening tuned to the NAM or with a prolonged period of moderate greenness continuing after the NAM. These cases represent different plant strategies (deciduous versus evergreen) that can be adjusted along spatial gradients to cope with seasonal water availability. Long-term trends in TINDVI may also indicate changing conditions favoring ecosystems that intensively use NAM rainfall for rapid productivity, as opposed to delayed and moderate greening. A persistence of these trends could potentially result in the spatial reorganization of ecosystems in the NAM region.

scholarly journals Intensification of the North American Monsoon Rainfall as Observed From a Long‐Term High‐Density Gauge Network

2019 ◽  
Vol 46 (12) ◽  
pp. 6839-6847 ◽  
Author(s):  
Eleonora M. C. Demaria ◽  
Pieter Hazenberg ◽  
Russell L. Scott ◽  
Menberu B. Meles ◽  
Mary Nichols ◽  
...  
Keyword(s):  
North American ◽  
Monsoon Rainfall ◽  
High Density ◽  
North American Monsoon ◽  
The North

scholarly journals Defining Intraseasonal Rainfall Variability within the North American Monsoon

2006 ◽  
Vol 19 (17) ◽  
pp. 4243-4253 ◽  
Author(s):  
Phil J. Englehart ◽  
Arthur V. Douglas
Keyword(s):  
North American ◽  
Linear Trend ◽  
Monsoon Season ◽  
Rainfall Variability ◽  
Daily Rainfall ◽  
Principal Component ◽  
Seasonal Rainfall ◽  
North American Monsoon ◽  
The North ◽  
The Pacific

Abstract This study provides an empirical description of intraseasonal rainfall variability within the North American monsoon (NAM) region. Applying particular definitions to historical daily rainfall observations, it demonstrates that distinct intraseasonal rainfall modes exist and that these modes differ considerably from the monsoon core region in northwest Sonora (SON), California, to its northward extension in southeast Arizona (AZ). To characterize intraseasonal rainfall variability (ISV), separate P-mode principal component (PC) analyses were performed for SON and AZ. The results indicate that in each area, much of the ISV in rainfall can be described by three orthogonal modes. The correlations between ISV modes and total seasonal rainfall reinforce the notion of differing behaviors between the monsoon’s core and extension. For SON all three ISV modes exhibit significant correlation with seasonal rainfall, with the strongest relationship in evidence for the ISV mode, which is related to rainfall intensity. For AZ, total rainfall exhibits the strongest correlation with the ISV mode, which emphasizes season length and rainfall consistency. Examination of longer-period behavior in the ISV modes indicates that, for SON, there is a positive linear trend in intensity, but a countervailing trend toward a shorter monsoon season along with less consistent rainfall in the form of shorter wet spells. For AZ, the evidence for trend in the ISV modes is not nearly as compelling, though one of the modes appears to exhibit distinct multidecadal variability. This study also evaluates teleconnectivity between ENSO, the Pacific decadal oscillation (PDO), and the NAM’s intraseasonal rainfall variability. Results indicate that part of the intraseasonal rainfall variability in both SON and AZ is connected to ENSO while only SON exhibits a teleconnection with the long-period fluctuations of the PDO.

scholarly journals Flash Flooding in Arid/Semiarid Regions: Climatological Analyses of Flood-Producing Storms in Central Arizona during the North American Monsoon

2019 ◽  
Vol 20 (7) ◽  
pp. 1449-1471 ◽  
Author(s):  
Long Yang ◽  
James Smith ◽  
Mary Lynn Baeck ◽  
Efrat Morin
Keyword(s):  
United States ◽  
North American ◽  
Large Scale ◽  
North American Monsoon ◽  
Time Variability ◽  
Southwestern United States ◽  
Flash Flooding ◽  
The North ◽  
Synoptic Conditions ◽  
Central Arizona

Abstract Flash flooding in the arid/semiarid southwestern United States is frequently associated with convective rainfall during the North American monsoon. In this study, we examine flood-producing storms in central Arizona based on analyses of dense rain gauge observations and stream gauging records as well as North American Regional Reanalysis fields. Our storm catalog consists of 102 storm events during the period of 1988–2014. Synoptic conditions for flood-producing storms are characterized based on principal component analyses. Four dominant synoptic modes are identified, with the first two modes explaining approximately 50% of the variance of the 500-hPa geopotential height. The transitional synoptic pattern from the North American monsoon regime to midlatitude systems is a critical large-scale feature for extreme rainfall and flooding in central Arizona. Contrasting spatial rainfall organizations and storm environment under the four synoptic modes highlights the role of interactions among synoptic conditions, mesoscale processes, and complex terrains in determining space–time variability of convective activities and flash flood hazards in central Arizona. We characterize structure and evolution properties of flood-producing storms based on storm tracking algorithms and 3D radar reflectivity. Fast-moving storm elements can be important ingredients for flash floods in the arid/semiarid southwestern United States. Contrasting storm properties for cloudburst storms highlight the wide spectrum of convective intensities for extreme rain rates in the arid/semiarid southwestern United States and exhibit comparable vertical structures to their counterparts in the eastern United States.

scholarly journals Do Long-Term Natural Disasters Influence Social Trust? Empirical Evidence from China

2021 ◽  
Vol 18 (14) ◽  
pp. 7280
Author(s):  
Yao Li ◽  
Haoyang Li ◽  
Jianqing Ruan
Keyword(s):  
Natural Disasters ◽  
Natural Disaster ◽  
Social Trust ◽  
Geographical Location ◽  
Household Survey ◽  
Flood Frequency ◽  
Psychological Characteristics ◽  
The North ◽  
The Impact

The natural environment is one of the most critical factors that profoundly influences human races. Natural disasters may have enormous effects on individual psychological characteristics. Using China’s long-term historical natural disaster dataset from 1470 to 2000 and data from a household survey in 2012, we explore whether long-term natural disasters affect social trust. We find that there is a statistically significant positive relationship between long-term natural disaster frequency and social trust. We further examine the impact of long-term natural disaster frequency on social trust in specific groups of people. Social trust in neighbors and doctors is stronger where long-term natural disasters are more frequent. Our results are robust after we considering the geographical difference. The effect of long-term natural disasters remains positively significant after we divide the samples based on geographical location. Interestingly, the impact of long-term flood frequency is only significant in the South and the impact of long-term drought frequency is only significant in the North.

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