SPATIAL PROPERTIES OF LIGHTNING-CAUSED FOREST FIRES

Some 2088 lightning-caused forest fires that occurred between 1960 and 1971 in northern Idaho are described and analyzed relative to the properties of pattern, central tendency, and spatial variability. Pattern analysis reveals that randomness characterizes both the distribution of total fires and of annual mean areal centers. A model is proposed relating the latitudinal and longitudinal behavior of mean areal centers to shifts in storm tracks and resultant adjustments in fuel-moisture conditions. Rank correlation analysis reveals that northwest shifts in mean areal centers are associated with higher fuel-moisture conditions whereas southeast movements in mean areal centers are related to reduced fuel-moisture conditions. No significant differences were revealed in the variability of the annual standard distances of fire distribution, nor was there any association between temperature and azimuthal adjustments in mean areal centers.     

THE LOCATION OF LIGHTNING-CAUSED WILDLAND FIRES,NORTHERN IDAHO

Elevation, timber type, size and density of stand, position on slope, and slope aspect were assessed as to their effects upon the location of 2088 lightning-caused forest fires in a 1.4 million-hectare tract of northern Idaho. χ² analysis revealed that relative fire frequency was greatest between 1050 and 1650 m on the upper 1/3 of those slopes which lie perpendicular to dominant storm tracks and which are covered with Hemlock, Alpine Fir and Spruce.     

QUANTITATIVE LINEARS ANALYSIS IN MINERAL EXPLORATION

Surficial spatial variation in air photo linears is evaluated as a mineral search methodology having potential in differentiating between ore-bearing and non-ore-bearing areas. Linear density, bearing, length, and pattern were compared in equal sized plots of mineralized and adjacent non-mineralized ground in each of 10 study areas. Variance and discriminant analysis indicate that the variables of density and pattern are useful in the prediction and classification of areas as either mineralized or non-mineralized.     

Planning for Peri-urban Agriculture: a geographically-specific,evidence-based approach from Sydney

Agriculture on the fringes of cities across the Global North is increasingly perceived as making an important contribution to urban sustainability. As Australian cities continue to expand and encroach on their peri-urban peripheries, there is rising concern about loss of farmland to housing. Such concerns are especially urgent in the Sydney Basin, due to population growth, and topographical and land-use constraints. Accounting for the Basin's farmlands, however, remains opaque, not unrelated to difficulties in acquiring reliable data on the area and value of Sydney's agricultural industries. The problem is not simply that there are no data available but rather that the nature of existing data is (often hotly) contested. Critical questions for urban planners therefore remain unanswered, including: is peri-urban agriculture as important as advocates suggest? Are metropolitan food supplies under threat? If peri-urban farmland is important, what should be done to preserve it? In collating and analysing existing Australian Bureau of Statistics (ABS) and non-ABS data on Sydney agriculture between 1992 and 2011, we outline the need for more reliable and consistent longitudinal data to enable better planning for Sydney's farmland into the future. Notwithstanding limitations of available data sources, our findings reveal trends in Sydney Basin agriculture that invite debate on many assumptions about the nature of peri-urban agriculture. These findings emphasise the importance of geographically specific, evidence-based analysis as a basis for planning for peri-urban agriculture.     

Net groundwater inflow in an enclosed lake: from synoptic variations to climatic projections

Using lake Stechlin in northeastern Germany as an example of a small groundwater‐feed lake without surface inflows and outflows, we estimated the temporal scales and the variability ranges of the net groundwater contribution to the lake water budget. High‐resolution water level measurements by a bottom‐mounted pressure logger provided the background for the estimation of the total lake water budget. This method has demonstrated reliability for estimation of lake level variations during periods ranging from subdiurnal to perennial. The typical amplitudes of the synoptic‐to‐perennial variability characterizing the groundwater climate of lake Stechlin are estimated by comparing the two subsequent years 2006 and 2007; one of these years shows an extremely high, and the other an extremely low, annual precipitation–evaporation balance. The net groundwater flow, estimated as the difference between the total water budget and the precipitation–evaporation balance at the surface, revealed synoptic effects of lake water exfiltration into the groundwater aquifer following strong precipitation events. Perennial variations between wet and dry years superimposed seasonal oscillations. The probable origin of the latter is seasonality in the groundwater level on the watershed, although the exact amplitudes are subject to further quantification on account of seasonality in the evaporation estimation error. The results emphasize the non‐stationary behaviour of groundwater flow on timescales shorter than climatic ones. The analysis yielded a net quantitative relationship between groundwater flow and water balance at the lake surface: The water level changes in the lake due to evaporation and precipitation are damped to 60% because of the lake–groundwater exchange by means of intermittent infiltration and exfiltration events. Assuming the remaining 40% of the surface water budget may potentially result in perennial water level variability, we estimated an effect of the precipitation decrease on the lake water budget as predicted by the regional climate scenarios for the next century. Copyright © 2012 John Wiley & Sons, Ltd.     

The Effects of Quality Control on Decreasing Error Propagation in the LandScan USA Population Distribution Model: A Case Study of Philadelphia County

LandScan USA is a 90 m population distribution model that is used for a variety of applications, including emergency management. Models should have a measure of accuracy; however, the accuracy of population distribution models is difficult to determine due to the inclusion of multiple input datasets and the lack of quantifiable, observable (validated) data to confirm model output. Validated data enables quantification of: (1) overall model accuracy and (2) changes in model output at different levels of quality control. This article examines the effect of quality control for two national school datasets incorporated as input in LandScan USA for Philadelphia County, Pennsylvania; which had a local, validated school dataset available. The effect of each stage of quality control efforts utilized throughout the LandScan USA process were assessed to determine what level of quality control was required to have a statistically significant change of the model's population distribution. The typical level of quality control for LandScan USA resulted in 36% of schools being moved to the correct location and 20% of missing student enrollments were found, compared to 87% and 98% respectively for the validated dataset. The costs of increasing quality control resulted in a six-fold increase in labor time; however, the additional quality control did not produce statistically significant improvements in the LandScan USA model. Thus, typical quality control efforts for schools in LandScan USA produced a population distribution similar to the validated level of quality control, and can be applied with confidence for policy, planning, and emergency situations.     

A Study of the Earth-Affecting CMEs of Solar Cycle 24

Using in situ observations from the Advanced Composition Explorer (ACE), we have identified 70 Earth-affecting interplanetary coronal mass ejections (ICMEs) in Solar Cycle 24. Because of the unprecedented extent of heliospheric observations in Cycle 24 that has been achieved thanks to the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instruments onboard the Solar Terrestrial Relations Observatory (STEREO), we observe these events throughout the heliosphere from the Sun to the Earth, and we can relate these in situ signatures to remote sensing data. This allows us to completely track the event back to the source of the eruption in the low corona. We present a summary of the Earth-affecting CMEs in Solar Cycle 24 and a statistical study of the properties of these events including the source region. We examine the characteristics of CMEs that are more likely to be strongly geoeffective and examine the effect of the flare strength on in situ properties. We find that Earth-affecting CMEs in the first half of Cycle 24 are more likely to come from the northern hemisphere, but after April 2012, this reverses, and these events are more likely to originate in the southern hemisphere, following the observed magnetic asymmetry in the two hemispheres. We also find that as in past solar cycles, CMEs from the western hemisphere are more likely to reach Earth. We find that Cycle 24 lacks in events driving extreme geomagnetic storms compared to past solar cycles.     

Upscaling site‐scale ecohydraulic models to inform salmonid population‐level life cycle modeling and restoration actions – Lessons from the Columbia River Basin

With high‐resolution topography and imagery in fluvial environments, the potential to quantify physical fish habitat at the reach scale has never been better. Increased availability of hydraulic, temperature and food availability data and models have given rise to a host of species and life stage specific ecohydraulic fish habitat models ranging from simple, empirical habitat suitability curve driven models, to fuzzy inference systems to fully mechanistic bioenergetic models. However, few examples exist where such information has been upscaled appropriately to evaluate entire fish populations. We present a framework for applying such ecohydraulic models from over 905 sites in 12 sub‐watersheds of the Columbia River Basin (USA), to assess status and trends in anadromous salmon populations. We automated the simulation of computational engines to drive the hydraulics, and subsequent ecohydraulic models using cloud computing for over 2075 visits from 2011 to 2015 at 905 sites. We also characterize each site's geomorphic reach type, habitat condition, geomorphic unit assemblage, primary production potential and thermal regime. We then independently produce drainage network‐scale models to estimate these same parameters from coarser, remotely sensed data available across entire populations within the Columbia River Basin. These variables give us a basis for imputation of reach‐scale capacity estimates across drainage networks. Combining capacity estimates with survival estimates from mark–recapture monitoring allows a more robust quantification of capacity for freshwater life stages (i.e. adult spawning, juvenile rearing) of the anadromous life cycle. We use these data to drive life cycle models of populations, which not only include the freshwater life stages but also the marine and migration life stages through the hydropower system. More fundamentally, we can begin to look at more realistic, spatially explicit, tributary habitat restoration scenarios to examine whether the enormous financial investment on such restoration actions can help recover these populations or prevent their extinction. Copyright © 2017 John Wiley & Sons, Ltd.