Spatial and temporal distribution of rainfall erosivity in New Zealand

Soil Research ◽  
2015 ◽  
Vol 53 (7) ◽  
pp. 815 ◽  
Author(s):  
Andreas Klik ◽  
Kathrin Haas ◽  
Anna Dvorackova ◽  
Ian C. Fuller
Keyword(s):  
New Zealand ◽  
Temporal Distribution ◽  
Annual Rainfall ◽  
Rainfall Erosivity ◽  
High Resolution Data ◽  
Topographic Features ◽  
Erosion Processes ◽  
Precipitation Records ◽  
First Time

Rainfall and its kinetic energy, expressed by rainfall erosivity, drives soil erosion processes by water. One of the most commonly used erosivity parameters is the rainfall-runoff erosivity factor R of the Revised Universal Soil Loss Equation. The goal of this study was to investigate for the first time the spatial distribution of annual rainfall erosivity in New Zealand. High-resolution data from 35 weather stations were used to calculate the R-factors. Based on these results, region-specific equations were developed and were applied by using long-term precipitation records from 597 stations. The values were interpolated with a geographic information system to generate a map showing spatial variations of rainfall erosivity. Annual R-values vary across both islands by a factor of 30, from <550 MJ mm ha–1 h–1 in parts of Central Otago to >16 000 MJ mm ha–1 h–1 in the Southern Alps. These large differences are related to climatic and topographic features. Nevertheless, the data show a high correlation to the precipitation. In most parts of New Zealand, highest erosivity values occurred in December and January, whereas the lowest values were observed in August.

Uprooting in boreal spruce forests: long-term variation in disturbance rate

1993 ◽  
Vol 23 (11) ◽  
pp. 2383-2388 ◽  
Author(s):  
Bengt Gunnar Jonsson ◽  
Mats Dynesius
Keyword(s):  
Retrospective Studies ◽  
Temporal Distribution ◽  
Long Period ◽  
Term Variation ◽  
Forest Floor Disturbance ◽  
Disturbance Pattern ◽  
Fall Direction ◽  
First Time ◽  
High Winds

Uprooted trees provide many kinds of exposed and colonizable substrates and may mediate coexistence of plant species. Here we present, for the first time, the temporal forest floor disturbance pattern caused by uprooted trees over a long period of time (120 years). There was a significant correlation between the frequency of high winds and number of uprooted trees, and the fall direction was closely related to the main direction of high winds. The temporal distribution was strongly aggregated, with many uprootings in the 1890s and the 1970s, resulting in large variations in disturbance rate between different decades. This implies periods with low availability of exposed soil. To interpret traits among species dependent on the disturbance as adaptations to some mean rate may thus be strongly misleading. However, the occurrence and importance of such bottleneck periods is hard to evaluate, as studies of the process of uprooting have only documented numbers and rates of uprooted trees and not the availability of exposed soil. We recommend more retrospective studies to evaluate long-term variation in disturbance regime parameters and studies on the temporal availability of exposed and colonizable soil.

scholarly journals Radar and Rain Gauge Analysis of the Extreme Rainfall during Hurricane Danny’s (1997) Landfall

2007 ◽  
Vol 135 (5) ◽  
pp. 1869-1888 ◽  
Author(s):  
Jeffrey M. Medlin ◽  
Sytske K. Kimball ◽  
Keith G. Blackwell
Keyword(s):  
Inner Core ◽  
Temporal Distribution ◽  
Extreme Rainfall ◽  
Rain Gauge ◽  
Rainfall Amount ◽  
Mobile Bay ◽  
Maximum Rainfall ◽  
Torrential Rainfall ◽  
First Time

Abstract As a minimal hurricane, Danny moved over Mobile Bay around 0900 UTC 19 July 1997 and became stationary by midmorning, while situated within a synoptic col. Danny then evolved into an asymmetric storm with an intensely convective rainband that produced torrential rainfall through 1200 UTC 20 July 1997. Danny’s center remained &lt;100 km from the National Weather Service (NWS) Weather Surveillance Radar-1988 Doppler (WSR-88D) in Mobile, Alabama, for over 48 h, allowing long-term surveillance of the storm’s inner core. This event marked the first time the tropical Z–R relationship was employed on an operational WSR-88D system during tropical cyclone landfall. A radar-estimated maximum rainfall accumulation of 1097 mm (43.2 in.) was analyzed over southwestern Mobile Bay. A NWS cooperative rain gauge located on Dauphin Island, Alabama, measured 896 mm (35.28 in.). An adjacent standard rain gauge measured the highest rainfall amount of 932 mm (36.71 in.). This paper investigates the spatial and temporal distribution and potential magnitude of Danny’s torrential rainfall episode over coastal Alabama. It is shown that both gauges and radar seriously underestimated event rainfall. An estimate is given for what could have been the true event rainfall amount. In the case of the radar, the WSR-88D Algorithm Testing and Display System is used to obtain a better estimate of rainfall using higher dBZ caps than the operational 50 dBZ. In the case of the tipping-bucket rain gauge, wind and mechanical error estimates were applied in order to quantify rainfall underestimation.

Modeling winter season fluxes of water and energy in a temperate montane forest

2021 ◽  
Author(s):  
Tomas Vogel ◽  
Michal Dohnal ◽  
Jana Votrubova ◽  
Jaromir Dusek ◽  
Miroslav Tesar
Keyword(s):  
Winter Season ◽  
Temporal Distribution ◽  
Montane Forest ◽  
Surface Fluxes ◽  
Mountainous Areas ◽  
Near Surface ◽  
High Resolution Data ◽  
Highly Sensitive ◽  
Headwater Catchment

&lt;p&gt;Winter regimes affect&amp;#160;significantly the long-term water and energy balance of mountainous areas in Central Europe. A recently developed numerical model is used to study near-surface fluxes of water and energy in the Liz catchment &amp;#8212; a small headwater catchment of the Otava River, situated in the Southern Bohemia. The results of the numerical simulations are compared with high-resolution data recorded at the site of interest. The forest floor of the catchment is mostly covered by snow during winter. However, the snowpack is usually exposed to several snowmelt episodes over the season. The intensity, duration and frequency of these episodes is irregular and seems to be highly sensitive to changing climate. Increasing frequency of winter periods with limited or missing snow cover affects both water flow and heat transport in the catchment. Changes in the temporal distribution of snowmelt are reflected in changing runoff patterns.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

The Relationship of Debris Flow Hazards and Rainfall Erosivity in the Bailong River Basin of Southern Gansu Province, China

2014 ◽  
Vol 1073-1076 ◽  
pp. 1614-1619
Author(s):  
Peng Zhang ◽  
He Ping Shu ◽  
Jin Zhu Ma ◽  
Gang Wang ◽  
Li Ming Tian
Keyword(s):  
Soil Erosion ◽  
River Basin ◽  
Debris Flows ◽  
Temporal Distribution ◽  
Gansu Province ◽  
Annual Precipitation ◽  
Annual Rainfall ◽  
Rainfall Erosivity ◽  
Erosive Rainfall ◽  
Bailong River Basin

Rainfall is one of the main factors that drive soil erosion, leading to environmental problems such as increased frequency and severity of debris flows, and ecosystem damage. Rainfall erosivity represents the potential of rainfall to cause soil erosion, and is determined by a combination of rainfall intensity. The spatial and temporal distribution of rainfall erosivity was analyzed to get its relationship with the debris flows in the Bailong River Basin in China's Gansu Province. The mean annual amount of erosive rainfall accounts for 36.0-47.1% of annual precipitation. The annual mean rainfall erosivity amounts to 798.8 MJ mm ha-1 h-1 yr-1 in the Bailong River Basin. A positive correlation between annual precipitation and annual rainfall erosivity was demonstrated at all 18 rainfall stations. However, further research is required to reveal the key factors that explain soil erosion and debris flows.

scholarly journals Detailed Analysis of Spatial–Temporal Variability of Rainfall Erosivity and Erosivity Density in the Central and Southern Pannonian Basin

2021 ◽  
Vol 13 (23) ◽  
pp. 13355
Author(s):  
Tanja Micić Ponjiger ◽  
Tin Lukić ◽  
Biljana Basarin ◽  
Maja Jokić ◽  
Robert L. Wilby ◽  
...  
Keyword(s):  
Temporal Variability ◽  
Large Scale ◽  
Pannonian Basin ◽  
Temporal Trends ◽  
Mitigation Measures ◽  
Annual Rainfall ◽  
Rainfall Erosivity ◽  
Erosion Risk ◽  
Erosion Processes ◽  
Starting Point

Estimation of rainfall erosivity (RE) and erosivity density (ED) is essential for understanding the complex relationships between hydrological and soil erosion processes. The main objective of this study is to assess the spatial–temporal trends and variability of the RE and ED in the central and southern Pannonian Basin by using station observations and gridded datasets. To assess RE and ED, precipitation data for 14 meteorological stations, 225 grid points. and an erosion model consisting of daily, monthly, seasonal, and annual rainfall for the period of 1961–2014 were used. Annual RE and ED based on station data match spatially variable patterns of precipitation, with higher values in the southwest (2100 MJ·mm·ha−1·h−1) and southeast (1650 MJ·mm·ha−1·h−1) of the study area, but minimal values in the northern part (700 MJ·mm·ha−1·h−1). On the other hand, gridded datasets display more detailed RE and ED spatial–temporal variability, with the values ranging from 250 to 2800 MJ·mm·ha−1·h−1. The identified trends are showing increasing values of RE (ranging between 0.20 and 21.17 MJ·mm·ha−1·h−1) and ED (ranging between 0.01 and 0.03 MJ·ha−1·h−1) at the annual level. This tendency is also observed for autumn RE (from 5.55 to 0.37 MJ·mm·ha−1·h−1) and ED (from 0.05 to 0.01 MJ·ha−1·h−1), as for spring RE (from 1.00 to 0.01 MJ·mm·ha−1·h−1) and ED (from 0.04 to 0.01 MJ·ha−1·h−1), due to the influence of the large-scale processes of climate variability, with North Atlantic Oscillation (NAO) being the most prominent. These increases may cause a transition to a higher erosive class in the future, thus raising concerns about this type of hydro-meteorological hazard in this part of the Pannonian Basin. The present analysis identifies seasons and places of greatest erosion risk, which is the starting point for implementing suitable mitigation measures at local to regional scales.

scholarly journals Early Eocene Palynology from Mead Stream, New Zealand

2021 ◽  
Author(s):  
◽  
Thomas Foster Cooper
Keyword(s):  
Organic Matter ◽  
New Zealand ◽  
Energy Transport ◽  
Limited Range ◽  
Early Eocene ◽  
High Resolution Data ◽  
Early Eocene Climatic Optimum ◽  
Carbon Isotope Excursion ◽  
Extreme Salinity ◽  
First Time

<p>This study documents the first detailed palynological analysis of early Eocene strata from the Lower Marl unit at Mead Stream, southern Marlborough, New Zealand. Examination of marine palynomorph assemblages and palynofacies analysis were used to improve biostratigraphic resolution and investigate paleoclimate across the Early Eocene Climatic Optimum (EECO; ~53–49 Ma)—a period characterised by the highest temperatures of the Paleogene. Early Eocene New Zealand dinocyst zones from NZE2–NZE4, and the Charlesdowniea coleothrypta zone are established across the Lower Marl for the first time in this study. Marine palynomorph assemblages originating in outer-neritic conditions and deposited on the upper slope represent low energy transport along the margin of a terrestrial discharge plume. Palynomorph assemblages do not provide insight into sea surface temperature (SST) trends. Palynomorph assemblages may reflect extremely low surface productivity. Cycles in organic matter between marine-dominant limestones to terrestrial-dominant marls, controlled by changes in temperature and seasonal precipitation, may represent orbital forcing by way of precession cycles; however the limited range of high resolution data from this study cannot statistically confirm this. An overall increase of allochthonous organic matter across the Lower Marl is likely representative of long-term background warming, culminating in peak EECO temperatures. The base of a hyperthermal, represented by carbon isotope excursion (CIE) previously identified at Mead Stream has been redefined in this study. High abundances of warm water, extreme salinity taxa coincide with the onset of this warming event.</p>

scholarly journals Assessing the sources of uncertainty associated with the calculation of rainfall kinetic energy and erosivity – application to the Upper Llobregat Basin, NE Spain

2011 ◽  
Vol 15 (3) ◽  
pp. 679-688 ◽  
Author(s):  
G. Catari ◽  
J. Latron ◽  
F. Gallart
Keyword(s):  
Kinetic Energy ◽  
Temporal Variability ◽  
Rainfall Intensity ◽  
Spatial Scales ◽  
Annual Rainfall ◽  
Rainfall Erosivity ◽  
Sources Of Uncertainty ◽  
Eastern Pyrenees ◽  
Erosion Modelling

Abstract. The diverse sources of uncertainty associated with the calculation of rainfall kinetic energy and rainfall erosivity, calculated from precipitation data, were investigated at a range of temporal and spatial scales in a mountainous river basin (504 km2) in the south-eastern Pyrenees. The sources of uncertainty analysed included both methodological and local sources of uncertainty and were (i) tipping-bucket rainfall gauge instrumental errors, (ii) the efficiency of the customary equation used to derive rainfall kinetic energy from intensity, (iii) the efficiency of the regressions obtained between daily precipitation and rainfall erosivity, (iv) the temporal variability of annual rainfall erosivity values, and the spatial variability of (v) annual rainfall erosivity values and (vi) long-term erosivity values. The differentiation between systematic (accuracy) and random (precision) errors was taken into account in diverse steps of the analysis. The results showed that the uncertainty associated with the calculation of rainfall kinetic energy from rainfall intensity at the event and station scales was as high as 30%, because of insufficient information on rainfall drop size distribution. This methodological limitation must be taken into account for experimental or modelling purposes when rainfall kinetic energy is derived solely from rainfall intensity data. For longer temporal scales, the relevance of this source of uncertainty remained high if low variability in the types of rain was supposed. Temporal variability of precipitation at wider spatial scales was the main source of uncertainty when rainfall erosivity was calculated on an annual basis, whereas the uncertainty associated with long-term erosivity was rather low and less important than the uncertainty associated with other model factors such as those in the RUSLE, when operationally used for long-term soil erosion modelling.

Spatiotemporal Distribution of Rainfall Erosivity in the Bailong River Basin, Gansu Province

2014 ◽  
Vol 936 ◽  
pp. 2377-2382 ◽  
Author(s):  
Peng Zhang ◽  
Gang Wang ◽  
Li Ming Tian ◽  
Ya Li Zhang
Keyword(s):  
River Basin ◽  
Temporal Distribution ◽  
Gansu Province ◽  
Annual Rainfall ◽  
Rainfall Erosivity ◽  
Distance Weighting ◽  
Erosive Rainfall ◽  
Annual Amount ◽  
Inverse Distance ◽  
Bailong River Basin

Rainfall erosivity is one of the key parameters that determine soil erosion, sediment yield, and water quality, thus its importance has grown in modeling of the environmental effects of climate change. The spatial and temporal distribution of rainfall erosivity in the Bailong River Basin in China's Gansu Province were analyzed. We derived a rainfall erosivity map based on data from 18 meteorological stations in and around the basin using the inverse distance weighting interpolation approach. The annual mean rainfall erosivity within the Bailong River Basin was 798.8 MJ mm ha-1h-1yr-1. The mean annual amount of erosive rainfall accounts for 36.0 to 47.1% of annual precipitation, depending on the station. Rainfall erosivity was greatest from June to September, and rainfall during this period accounts for 77.7% to 84.8% of the total annual rainfall erosivity.

scholarly journals Early Eocene Palynology from Mead Stream, New Zealand

2021 ◽  
Author(s):  
◽  
Thomas Foster Cooper
Keyword(s):  
Organic Matter ◽  
New Zealand ◽  
Energy Transport ◽  
Limited Range ◽  
Early Eocene ◽  
High Resolution Data ◽  
Early Eocene Climatic Optimum ◽  
Carbon Isotope Excursion ◽  
Extreme Salinity ◽  
First Time

<p>This study documents the first detailed palynological analysis of early Eocene strata from the Lower Marl unit at Mead Stream, southern Marlborough, New Zealand. Examination of marine palynomorph assemblages and palynofacies analysis were used to improve biostratigraphic resolution and investigate paleoclimate across the Early Eocene Climatic Optimum (EECO; ~53–49 Ma)—a period characterised by the highest temperatures of the Paleogene. Early Eocene New Zealand dinocyst zones from NZE2–NZE4, and the Charlesdowniea coleothrypta zone are established across the Lower Marl for the first time in this study. Marine palynomorph assemblages originating in outer-neritic conditions and deposited on the upper slope represent low energy transport along the margin of a terrestrial discharge plume. Palynomorph assemblages do not provide insight into sea surface temperature (SST) trends. Palynomorph assemblages may reflect extremely low surface productivity. Cycles in organic matter between marine-dominant limestones to terrestrial-dominant marls, controlled by changes in temperature and seasonal precipitation, may represent orbital forcing by way of precession cycles; however the limited range of high resolution data from this study cannot statistically confirm this. An overall increase of allochthonous organic matter across the Lower Marl is likely representative of long-term background warming, culminating in peak EECO temperatures. The base of a hyperthermal, represented by carbon isotope excursion (CIE) previously identified at Mead Stream has been redefined in this study. High abundances of warm water, extreme salinity taxa coincide with the onset of this warming event.</p>

scholarly journals Assessment of Soil Erosion Hazard in Prambanan District Using RUSLE (Revised Universal Soil Loss Equation)

2021 ◽  
Vol 884 (1) ◽  
pp. 012010
Author(s):  
S. A Mulya ◽  
N. Khotimah
Keyword(s):  
Soil Loss ◽  
Hazard Index ◽  
Universal Soil Loss Equation ◽  
Annual Rainfall ◽  
Rainfall Erosivity ◽  
Slope Length ◽  
Erosion Hazard ◽  
Erosion Processes ◽  
Factor C ◽  
Soil Loss Equation

Abstract Prambanan District which located in Daerah Istimewa Yogyakarta Province has the potential for land degradation due to erosion processes. With the characteristics of annual rainfall more than 2000 mm / year, topography with a slope of more than 20% in upland areas, as well as the conversion of upland to dryland agriculture are factors that can trigger the erosion process more quickly. If the rate of erosion speed exceeds the ability of the soil to regenerate the soil body, its productivity will be disrupted and accelerate the formation of critical soil. Therefore, it is necessary to know the estimated rate of erosion, tolerable distribution of erosion, and the potential danger of erosion that occurs. The purpose of this study was to (1) predict the rate of erosion, (2) calculate the permissible erosion value, (3) identify the rate & index of erosion hazard. Data were collected using field surveys and soil sampling using stratified random sampling techniques with land units as the unit of analysis. The value of erosion was predicted using the Revised Universal Soil Loss Equation (RUSLE) method. The RUSLE method is described by the following equation, A=R*K*L*S*C*P, where; A as estimated averages annual loss of soil, R is the rainfall erosivity factor, K is the soil erodibility factor, LS is the slope length factor, C is the cover management factor, & P is the conservation practice factor. The results showed that the erosion value ranged from 0.39 - 268.55 tons/ha/year. Permissible erosion ranges from 8.4 – 15 tons/ha/year for Latosol and 27.4 ton/ha/year for Regosol. The Rate of Erosion Hazard is dominated by moderate erosion, covering an area of 1330.7 ha or 31.8% of the total area. The Erosion Hazard Index is dominated by the low class (<1.0) which is covered over 2703.1 ha or 64.61% of the total area.

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