Historical changes in the distribution and functions of large wood in Puget Lowland rivers

2002 ◽  
Vol 59 (1) ◽  
pp. 66-76 ◽  
Author(s):  
Brian D Collins ◽  
David R Montgomery ◽  
Andrew D Haas
Keyword(s):  
Land Use ◽  
Field Data ◽  
Field Studies ◽  
Archival Data ◽  
Large Wood ◽  
Valley Bottom ◽  
Lowland Rivers ◽  
European Settlement ◽  
River Pattern ◽  
Channel Unit

We examined changes in wood abundance and functions in Puget Lowland rivers from the last ~150 years of land use by comparing field data from an 11-km-long protected reach of the Nisqually River with field data from the Snohomish and Stillaguamish rivers and with archival data from several Puget Lowland rivers. Current wood abundance is one to two orders of magnitude less than before European settlement in the Snohomish and Stillaguamish basins. Most importantly, wood jams are now rare because of a lack of very large wood that can function as key pieces and low rates of wood recruitment. These changes in wood abundance and size appear to have fundamentally changed the morphology, dynamics, and habitat abundance and characteristics of lowland rivers across scales from channel unit to valley bottom. Based on our field studies, rivers had substantially more and deeper pools historically. Archival data and field studies indicate that wood jams were integral to creating and maintaining a dynamic, anastomosing river pattern with numerous floodplain channels and abundant edge habitat and routed floodwaters and sediment onto floodplains. Establishing the condition of the riverine landscape before European settlement sets a reference against which to evaluate contemporary conditions and develop restoration objectives.

Anthropocene streams and base-level controls from historic dams in the unglaciated mid-Atlantic region, USA

2011 ◽  
Vol 369 (1938) ◽  
pp. 976-1009 ◽  
Author(s):  
Dorothy Merritts ◽  
Robert Walter ◽  
Michael Rahnis ◽  
Jeff Hartranft ◽  
Scott Cox ◽  
...  
Keyword(s):  
Land Use ◽  
Urban Areas ◽  
Bank Erosion ◽  
Primary Control ◽  
Atlantic Region ◽  
Valley Bottom ◽  
Base Level ◽  
European Settlement ◽  
Dam Breaching ◽  
The Impact

Recently, widespread valley-bottom damming for water power was identified as a primary control on valley sedimentation in the mid-Atlantic US during the late seventeenth to early twentieth century. The timing of damming coincided with that of accelerated upland erosion during post-European settlement land-use change. In this paper, we examine the impact of local drops in base level on incision into historic reservoir sediment as thousands of ageing dams breach. Analysis of lidar and field data indicates that historic milldam building led to local base-level rises of 2–5 m (typical milldam height) and reduced valley slopes by half. Subsequent base-level fall with dam breaching led to an approximate doubling in slope, a significant base-level forcing. Case studies in forested, rural as well as agricultural and urban areas demonstrate that a breached dam can lead to stream incision, bank erosion and increased loads of suspended sediment, even with no change in land use. After dam breaching, key predictors of stream bank erosion include number of years since dam breach, proximity to a dam and dam height. One implication of this work is that conceptual models linking channel condition and sediment yield exclusively with modern upland land use are incomplete for valleys impacted by milldams. With no equivalent in the Holocene or late Pleistocene sedimentary record, modern incised stream-channel forms in the mid-Atlantic region represent a transient response to both base-level forcing and major changes in land use beginning centuries ago. Similar channel forms might also exist in other locales where historic milling was prevalent.

F. E. J. Fry's Field Studies: Good Field Data Provoke New Questions

1990 ◽  
Vol 119 (4) ◽  
pp. 574-584 ◽  
Author(s):  
Thomas H. Whillans ◽  
Henry A. Regier ◽  
W. Jack Christie
Keyword(s):  
Field Data ◽  
Field Studies

scholarly journals Characteristics Study of Land for Agriculture in Sembalun

2017 ◽  
Vol 1 (2) ◽  
pp. 207
Author(s):  
Azmi Annisa Irradhiyah
Keyword(s):  
Land Use ◽  
Soil Texture ◽  
Soil Structure ◽  
Field Data ◽  
Agricultural Land ◽  
Mechanical Analysis ◽  
Class I ◽  
Slope Length ◽  
Study Population ◽  
Objective Research

This research aims to get the data, manage, analyze and discuss the characteristics of the study of Agricultural Land in Sembalun visits: 1 ) Characteristics of agricultural land, 2) Level of agricultural land suitability. This type of research is quantitative. This study population across the districts in East Lombok, amounting to 20 District of the District Keruak, Jerowaru, Sakra, Sakra West, Sakra East, Terara, Montong Ivory, Sikur, Masbagik, Pringgasela, Sukamulia, Suralaga, Selong, Labuhan Haji, Pringgabaya , Suela, Aikmel, Wanasaba Sembalun and Sambelia. Sampling in this study using Purvosive Sampling. Samples are Sembalun subdistrict. Mechanical Analysis by objective research of agricultural land characteristics observed descriptively and databulasi of the field data belongs to the growing requirements of agriculture which can be seen from the slope, soil structure, slope length, slope shape, texture soil, land use criteria. The research found that: 1) Characteristics of agricultural land in Sembalun, had several criteria: a slope in the category Sembalun including steep or less suitable for agriculture by 46-65% kemiringin slope, soil to soil Sembalun criteria granular, blocky or appropriate agricultural land and have long used the medium to long 15-50m, soil texture Sembalun criteria belong to the category of rough because it is composed by sand-plated, dusty sand, slope shape in Sembalun belong to the variation convex with dignity 2 for observation location along notching it is always a convex slope, land use Sembalun belong to the criterion of berlukar / mixed farms with dignity 2. Because along the way, the land berlukar / mixed farms. 2) Suitability of farmland in Sembalun based on the results of pengharkatan to 6 land characteristics, the number value obtained was 12 with class suitability for agricultural land belonging to the class I (land suitable for agriculture).

scholarly journals A remote-sensing-based intensity–duration threshold, Faifa Mountains, Saudi Arabia

2019 ◽  
Vol 19 (6) ◽  
pp. 1235-1249 ◽  
Author(s):  
Sita Karki ◽  
Mohamed Sultan ◽  
Saleh Alsefry ◽  
Hassan Alharbi ◽  
Mustafa Kemal Emil ◽  
...  
Keyword(s):  
Field Data ◽  
Mass Movement ◽  
Google Earth ◽  
Archival Data ◽  
Backscatter Coefficient ◽  
Duration Threshold ◽  
Radar Imagery ◽  
Temporal And Spatial ◽  
Precipitation Events ◽  
Red Sea Hills

Abstract. Construction of intensity–duration (ID) thresholds and early-warning and nowcasting systems for landslides (EWNSLs) are hampered by the paucity of temporal and spatial archival data. This work represents significant steps towards the development of a prototype EWNSL to forecast and nowcast landslides over the Faifa Mountains in the Red Sea Hills. The developed methodologies rely on readily available, temporal, archival Google Earth and Sentinel-1A imagery, precipitation measurements, and limited field data to construct an ID threshold for Faifa. The adopted procedures entail the generation of an ID threshold to identify the intensity and duration of precipitation events that cause landslides in the Faifa Mountains, and the generation of pixel-based ID curves to identify locations where movement is likely to occur. Spectral and morphologic variations in temporal Google Earth imagery following precipitation events were used to identify landslide-producing storms and generate the Faifa ID threshold (I =4.89D−0.65). Backscatter coefficient variations in radar imagery were used to generate pixel-based ID curves and identify locations where mass movement is likely to occur following landslide-producing storms. These methodologies accurately distinguished landslide-producing storms from non-landslide-producing ones and identified the locations of these landslides with an accuracy of 60 %.

scholarly journals A Remote Sensing–based Intensity-Duration Curve, Faifa Mountains, Saudi Arabia

2018 ◽  
Author(s):  
Sita Karki ◽  
Mohamed Sultan ◽  
Saleh A. Al-Sefry ◽  
Hassan M. Alharbi ◽  
Mustafa Kemal Emil ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Saudi Arabia ◽  
Early Warning ◽  
Field Data ◽  
Early Warning Systems ◽  
Google Earth ◽  
Archival Data ◽  
Warning Systems ◽  
Temporal And Spatial ◽  
Red Sea Hills

Abstract. Construction of intensity-duration (ID) curves and early warning systems for landslides (EWSL) are hampered by the paucity of temporal and spatial archival data. We developed methodologies that could be used for the construction of an ID curve that could be used for the construction of an EWSL over the Faifa Mountains in the Red Sea Hills. The developed methodologies relies on temporal, readily available, archival Google Earth and Sentinel-1 imagery, precipitation measurements, and limited field data. These methodologies accurately distinguished landslide-producing storms from non–landslide producing ones and identified the locations of these landslides with an accuracy of 60 %.

scholarly journals Evaluation of dynamic passing gap acceptance on two-lane highways using field data

2017 ◽  
Vol 44 (11) ◽  
pp. 871-880 ◽  
Author(s):  
Udai Hassein ◽  
Maksym Diachuk ◽  
Said Easa
Keyword(s):  
Regression Models ◽  
Field Data ◽  
Field Studies ◽  
Gap Acceptance ◽  
Data Logger ◽  
Driver Behaviour ◽  
Age And Gender ◽  
Time To Collision ◽  
And Gender ◽  
Acceptance Model

Gap availability is an important element of safe passing on two-lane highways. Time gaps are used to determine passing behaviour based on human factors. In this paper, the decision whether to accept or reject an available passing gap is modelled using logistic regression technique that included driver characteristics (age and experience) and the gap size. Field studies were conducted to collect experimental data regarding passing driver behaviour. The data were collected using dual camera Car DVRs and a GPS data logger device that records the instantaneous speed and position of the three vehicles involved in the passing maneuver: passing vehicle, impeding vehicle, and opposing vehicle. Regression models that include driver age and gender (required as input to the gap acceptance model) were established for initial passing time, starting gap, ending gap, and time to collision. The gap acceptance model was implemented in Simulink and the results revealed that driver characteristics significantly affect gap acceptance decisions.

Pedology and Land Use

1977 ◽  
Vol 72 ◽  
pp. 24-30
Author(s):  
John Bintliff
Keyword(s):  
Land Use ◽  
Field Data ◽  
Soil Map ◽  
Potential Map

From intensive field data a soil map and a land use potential map have been compiled. They should be considered together, and in relation to the cumulative site maps (Figs. 34–6).

Dynamics of seepage mobile inventory in forest and agricultural soils - Results from a comparative multi-year lysimeter study

2020 ◽  
Author(s):  
Katharina Lehmann ◽  
Robert Lehmann ◽  
Kai Uwe Totsche
Keyword(s):  
Land Use ◽  
Agricultural Soils ◽  
Field Studies ◽  
Critical Zone ◽  
Soil Monitoring ◽  
Event Scale ◽  
Weather Events ◽  
Physico Chemical

<p>The mobile inventory in soil seepage is of fundamental importance for soil development and for functioning of subsurface ecosystem compartments. The mobile inventory may encompass inorganic, organo-mineral and organics, dissolved and colloidal, but also particulate matter and microbiota. Still unknown are the conditions and factors that trigger the release and export of seepage-contained mobile matter within soil, and its translocation through the subsurface of the critical zone. Long-term and high-resolution field studies that includes the mobile particulate inventory are essentially lacking. To overcome this knowledge gap, we established long-term soil monitoring plots in the Hainich Critical Zone Exploratory (HCZE; NW-Thuringia, central Germany). Soil seepage from 22 tension-supported lysimeters in topsoil and subsoil, covering different land use (forest, pasture, cropland) in the topographic recharge area of the HCZE, was collected and analyzed by a variety of analytical methods (physico-/chemical and spectroscopic) on a regular (biweekly) and event-scale cycle. With our study we proved that substances up to a size of 50 µm are mobile in the soils. The material spectra comprised minerals, mineral-organic particulates, diverse bioparticles and biotic detritus. Atmospheric forcing was found to be the major factor triggering the translocation of the mobile inventory. Especially episodic infiltration events during hydrological winter seasons (e.g. snow melts) with high seepage volume influences seepage hydrochemistry (e.g. pH, EC) and is important for transport of mobile matter to deeper compartments. Seasonal events cause mobilization of significant amounts of OC. On average, 21% of the total OC of the seepage was particulate (>0.45 µm). Furthermore, our results suggest that the formation environment and the geopedological setting (soil group, parent rock, land use) are controlling factors for the composition and the amount of soil-born mobile inventory. Our study provides evidence for the importance of the mobile inventory fraction >0,45 µm for soil element dynamics and budgets and highlights the role of weather events on soil and subsoil development and subsurface ecosystem functioning.</p>

Riparian tree fall directionality and modeling large wood recruitment to streams

2006 ◽  
Vol 36 (5) ◽  
pp. 1243-1254 ◽  
Author(s):  
Daniel J Sobota ◽  
Stanley V Gregory ◽  
John Van Sickle
Keyword(s):  
Pacific Northwest ◽  
Field Data ◽  
Riparian Forest ◽  
Large Wood ◽  
Riparian Trees ◽  
The Pacific ◽  
Riparian Tree ◽  
Individual Trees ◽  
Fall Direction ◽  
Recruitment Model

Directionality of tree fall in riparian forests can strongly influence predictions of large wood recruitment to streams, yet accuracy of this model parameter has rarely been assessed with field data. We measured fall directions of 1202 riparian trees distributed among 21 stream sites across the Pacific Northwest, USA. Fall directions were oriented towards the stream at 16 sites, upstream at four sites, and not distinguishable from random at one site. Average tree fall direction across sites was correlated with valley constraint (Spearman r = –0.53; p = 0.02), but variability of fall directions was not correlated with this variable. When grouped by species (six conifers and one deciduous), individual trees exhibited stronger tendency to have fallen towards the channel on steep hillslopes (>40%) than on moderately sloped landforms (<40%). Integration of field data into an established recruitment model indicated that 1.5 to 2.4 times more large wood (by number of tree boles) would be recruited to stream reaches with steep hillslopes than to reaches with moderate side slopes or flat banks, if riparian forest conditions are assumed to be constant. We conclude that stream valley topography should be considered in models that use tree fall directions in predictions of large wood recruitment to streams.

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