Explaining groundwater hydrographs: separating atypical rainfall events from time trends

Soil Research ◽  
2001 ◽  
Vol 39 (4) ◽  
pp. 861 ◽  
Author(s):  
Ruhi Ferdowsian ◽  
David J. Pannell ◽  
Clare McCarron ◽  
Arjen Ryder ◽  
Lisa Crossing
Keyword(s):  
Western Australia ◽  
Time Trends ◽  
Time Trend ◽  
Agricultural Land ◽  
Explanatory Power ◽  
Dryland Salinity ◽  
Rainfall Events ◽  
Groundwater Levels ◽  
Average Rainfall ◽  
Using Data

By 1994, an estimated 1.8 million hectares of cleared land in Western Australia was affected by secondary dryland salinity to some extent. The area affected is likely to double in the coming 20 years. The cause of this salinity is excessive recharge under traditional agriculture, leading to rising groundwater levels. Monitoring changes in groundwater levels is helpful in indicating the degree of threat to agricultural land and public assets. Many researchers have studied groundwater level rises and attempted to explain them statistically. We present an approach for statistically estimating trends in groundwater levels. The approach separates the effect of atypical rainfall events from the underlying time trend and the lag between rainfall and its impact on groundwater is explicitly represented. Rainfall is represented as an accumulation of deviations from average rainfall. Application of the approach is demonstrated using data from 49 bores in Jerramungup Shire, Western Australia. The approach provides high explanatory power, particularly for deeper bores.

Dryland salinity in Western Australia: managing a changing water cycle

2003 ◽  
Vol 47 (7-8) ◽  
pp. 201-207 ◽  
Author(s):  
R.J. Taylor ◽  
G. Hoxley
Keyword(s):  
Western Australia ◽  
Surface Runoff ◽  
Agricultural Land ◽  
Management Strategies ◽  
Groundwater Discharge ◽  
Groundwater Hydrology ◽  
Dryland Salinity ◽  
Saline Groundwater ◽  
The Future ◽  
Surface And Groundwater

Clearing of agricultural land has resulted in significant changes to the surface and groundwater hydrology. Currently about 10% of agricultural land in Western Australia is affected by dryland salinity and between a quarter and a third of the area is predicted to be lost to salinity before a new hydrological equilibrium is reached. This paper develops a general statement describing the changes to the surface and groundwater hydrology of the wheatbelt of Western Australia between preclearing, the year 2000 and into the future. For typical catchments in the wheatbelt it is estimated that average groundwater recharge and surface runoff have increased about tenfold when comparing the current hydrology to that preclearing. Saline groundwater discharge and flood volumes have also increased significantly. Saline groundwater discharge and associated salt load will probably double in the future in line with the predicted increase in the area of dryland salinity. In addition, future increases in the area of dryland salinity/permanent waterlogging will probably double the volumes in flood events and further increase surface runoff in average years. The outcomes of surface and groundwater management trials have been briefly described to estimate how the hydrology would be modified if the trials were implemented at a catchment scale. These results have been used to formulate possible integrated revegetation and drainage management strategies. The future hydrology and impacts with and without integrated management strategies have been compared.

Comparison of Examinees’ and Doctors’ Judgement of Health Status Using Data in an AMHTS

1984 ◽  
Vol 23 (01) ◽  
pp. 15-22
Author(s):  
Y. Sekita ◽  
T. Ohta ◽  
M. Inoue ◽  
H. Takeda
Keyword(s):  
Health Status ◽  
Discriminant Analysis ◽  
Explanatory Power ◽  
Laboratory Data ◽  
Subjective Symptom ◽  
Health Conditions ◽  
Testing System ◽  
Multiple Discriminant Analysis ◽  
Canonical Axis ◽  
Using Data

SummaryJudgements of examinees’ health status by doctors and by the examinees themselves are compared applying multiple discriminant analysis. The doctors’ judgements of the examinees’ health status are studied comparatively using laboratory data and the examinees’ subjective symptom data.This data was obtained in an Automated Multiphasic Health Testing System. We discuss the health conditions which are significant for the judgement of doctors about the examinees. The results show that the explanatory power, when using subjective symptom data, is fair in the case of the doctors’ judgement. We found common variables, such as nervousness, lack of perseverance etc., which form the first canonical axis.

scholarly journals The Impact of Work Characteristics on Social Distancing: Implications at the Time of COVID-19

2021 ◽  
Vol 18 (10) ◽  
pp. 5074
Author(s):  
Keisuke Kokubun ◽  
Yoshinori Yamakawa
Keyword(s):  
Information Processing ◽  
Multiple Regression ◽  
Explanatory Power ◽  
Work Conditions ◽  
Multiple Regression Model ◽  
Social Characteristics ◽  
Work Characteristics ◽  
Social Distancing ◽  
Using Data ◽  
The Impact

The coronavirus disease (COVID-19) continues to spread globally. While social distancing has attracted attention as a measure to prevent the spread of infection, some occupations find it difficult to implement. Therefore, this study aims to investigate the relationship between work characteristics and social distancing using data available on O*NET, an occupational information site. A total of eight factors were extracted by performing an exploratory factor analysis: work conditions, supervisory work, information processing, response to aggression, specialization, autonomy, interaction outside the organization, and interdependence. A multiple regression analysis showed that interdependence, response to aggression, and interaction outside the organization, which are categorized as ”social characteristics,” and information processing and specialization, which are categorized as “knowledge characteristics,” were associated with physical proximity. Furthermore, we added customer, which represents contact with the customer, and remote working, which represents a small amount of outdoor activity, to our multiple regression model, and confirmed that they increased the explanatory power of the model. This suggests that those who work under interdependence, face aggression, and engage in outside activities, and/or have frequent contact with customers, little interaction outside the organization, and little information processing will have the most difficulty in maintaining social distancing.

scholarly journals A Comparison of Approaches to Regional Land-Use Capability Analysis for Agricultural Land-Planning

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 458
Author(s):  
Tara A. Ippolito ◽  
Jeffrey E. Herrick ◽  
Ekwe L. Dossa ◽  
Maman Garba ◽  
Mamadou Ouattara ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Planning ◽  
Crop Production ◽  
Agricultural Land ◽  
Arable Land ◽  
Agricultural Activity ◽  
Field Samples ◽  
Agricultural Potential ◽  
Fertility Data ◽  
Using Data

Smallholder agriculture is a major source of income and food for developing nations. With more frequent drought and increasing scarcity of arable land, more accurate land-use planning tools are needed to allocate land resources to support regional agricultural activity. To address this need, we created Land Capability Classification (LCC) system maps using data from two digital soil maps, which were compared with measurements from 1305 field sites in the Dosso region of Niger. Based on these, we developed 250 m gridded maps of LCC values across the region. Across the region, land is severely limited for agricultural use because of low available water-holding capacity (AWC) that limits dry season agricultural potential, especially without irrigation, and requires more frequent irrigation where supplemental water is available. If the AWC limitation is removed in the LCC algorithm (i.e., simulating the use of sufficient irrigation or a much higher and more evenly distributed rainfall), the dominant limitations become less severe and more spatially varied. Finally, we used additional soil fertility data from the field samples to illustrate the value of collecting contemporary data for dynamic soil properties that are critical for crop production, including soil organic carbon, phosphorus and nitrogen.

scholarly journals Mechanisms Associated with Large Daily Rainfall Events in Northeast Brazil

2011 ◽  
Vol 24 (2) ◽  
pp. 376-396 ◽  
Author(s):  
Brant Liebmann ◽  
George N. Kiladis ◽  
Dave Allured ◽  
Carolina S. Vera ◽  
Charles Jones ◽  
...  
Keyword(s):  
Daily Rainfall ◽  
Annual Rainfall ◽  
Northeast Brazil ◽  
Kelvin Wave ◽  
Rainfall Events ◽  
Independent Events ◽  
Precipitation Anomalies ◽  
Wave Trains ◽  
Using Data ◽  
Forcing Mechanisms

Abstract The mechanisms resulting in large daily rainfall events in Northeast Brazil are analyzed using data filtering to exclude periods longer than 30 days. Composites of circulation fields that include all independent events do not reveal any obvious forcing mechanisms as multiple patterns contribute to Northeast Brazil precipitation variability. To isolate coherent patterns, subsets of events are selected based on anomalies that precede the Northeast Brazil precipitation events at different locations. The results indicate that at 10°S, 40°W, the area of lowest annual rainfall in Brazil, precipitation occurs mainly in association with trailing midlatitude synoptic wave trains originating in either hemisphere. Closer to the equator at 5°S, 37.5°W, an additional convection precursor is found to the west, with a spatial structure consistent with that of a Kelvin wave. Although these two sites are located within only several hundred kilometers of each other and the midlatitude patterns that induce precipitation appear to be quite similar, the dates on which large precipitation anomalies occur at each location are almost entirely independent, pointing to separate forcing mechanisms.

scholarly journals A Review of Case Studies on Climate Change Impact on Hydrologic Cycle: An Indian Perspective

2021 ◽  
pp. 249-266
Author(s):  
P K Bhunya ◽  
Sanjay Kumar ◽  
Sunil Gurrapu ◽  
M K Bhuyan
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Hydrological Cycle ◽  
Groundwater Resources ◽  
Rainfall Events ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Change Impact ◽  
Heavy Rainfall Events ◽  
Flood Characteristics

In recent times, several studies focused on the global warming that may affect the hydrological cycle due to intensification of temporal and spatial variations in precipitation. Such climatic change is likely to impact significantly upon freshwater resources availability. In India, demand for water has already increased manifold over the years due to urbanization, agriculture expansion, increasing population, rapid industrialization and economic development. Numerous scientific studies also report increases in the intensity, duration, and spatial extents of floods, higher atmospheric temperatures, warmer sea, changes in precipitation patterns, and changing groundwater levels. This work briefly discusses about the present scenario regarding impact of climate change on water resources in India. Due to the insufficient resolution of climate models and their generally crude representation of sub-grid scale and convective processes, little confidence can be placed in any definite predictions of such effects, although a tendency for more heavy rainfall events seems likely, and a modest increase in frequency in floods. Thus to analyses this effect, this work considers real problems about the changing flood characteristics pattern in two river regions, and the effect of spatial and temporal pattern in rainfall. In addition to these, the work also examines the trend of groundwater level fluctuations in few blocks of Ganga–Yamuna and Sutlej-Yamuna Link interfluves region. As a whole, it examines the potential for sustainable development of surface water and groundwater resources within the constraints imposed by climate change.

scholarly journals Modeling a Bridge When Survey Questions Change: Evidence from the Current Population Survey Health Insurance Redesign

2019 ◽  
Vol 35 (1) ◽  
pp. 189-202
Author(s):  
Brett O’Hara ◽  
Carla Medalia ◽  
Jerry J. Maples
Keyword(s):  
Health Insurance ◽  
Current Population Survey ◽  
Time Trend ◽  
Population Survey ◽  
The United States ◽  
Community Survey ◽  
Historical Time ◽  
Current Population ◽  
Using Data ◽  
The Impact

Abstract Most research on health insurance in the United States uses the Current Population Survey Annual Social and Economic Supplement. However, a recent redesign of the health insurance questions disrupted the historical time trend in 2013. Using data from the American Community Survey, which has a parallel trend in the uninsured rate, we model a bridge estimate of the uninsured rate using the traditional questions. Also, we estimate the effect of changing the questionnaire. We show that the impact of redesigning the survey varies substantially by subgroup. This approach can be used to produce bridge estimates when other questionnaires are redesigned.

scholarly journals TERRITORIAL DIFFERENTIATION OF ANTHROPOGENIC TRANSFORMATION OF THE REPUBLIC OF TuVA

2021 ◽  
Vol 31 (1) ◽  
pp. 46-56
Author(s):  
T.N. Biche-ool
Keyword(s):  
Agricultural Land ◽  
Federal State ◽  
Economic Activities ◽  
Anthropogenic Transformation ◽  
Urban Districts ◽  
Mountain Terrain ◽  
Territorial Differentiation ◽  
The Republic ◽  
Using Data ◽  
The Impact

The assessment of territorial differentiation of anthropogenic transformation of the Republic of Tuva based on methods of geoinformation technologies, historical geography and methods of A. G. Isachenko using data from the Federal register of land categories and types of land, statistical data of the Federal state statistics service, reports of the Ministry of fuel and energy, the Ministry of economy of the Republic of Tuva, was carried out. A total of 17 districts and 2 urban districts were studied. The results of the study reflect the spatial characteristics of the impact of the population and its economic activities on the territory of the Republic of Tuva. Studies have shown that the state of modern landscapes of the Republic of Tuva is characterized mainly by low anthropogenic transformation, against which there are pockets of territories with high anthropogenic transformation - 2 urban districts, which is a consequence of the predominance of mountain terrain; difficult transport accessibility of the Republic; low population density and its extremely uneven settlement; high proportion of land occupied by forests (up to 60 %); inaccessibility of most mineral deposits. Currently, the transformation of the landscapes of the Republic of Tuva, including in high-altitude areas, is affected by the predominance of agricultural land, which occupies up to 32 % of the total area.

Sign in / Sign up

Export Citation Format

Share Document