JournalTOCs

Journal of Geography and Geology
Number of Followers: 12

This is an Open Access Journal

Open Access journal
ISSN (Print) 1916-9779 - ISSN (Online) 1916-9787
Published by CCSE

[43 journals]

Classification and Mapping of Plant Communities Using Multi-Temporal and
Multi-Spectral Satellite Images
- Abstract: Classification and mapping of plant communities is an essential step for conservation and management of ecosystems and biodiversity. We adopt the Genus-Physiognomy-Ecosystem (GPE) system developed in the previous study for satellite-based classification of plant communities at a broad scale. This paper assesses the potential of multi-spectral and multi-temporal images collected by Sentinel-2 satellites for the classification and mapping of GPE types. This research was conducted in seven representative study sites in different climatic regions ranging from one warm-temperate site in Aya to six cool-temperate sites in Hakkoda, Zao, Oze, Shirakami, Kitakami and Shiranuka. The GPE types were enumerated in all study sites and ground truth data were collected with reference to extant vegetation surveys, visual interpretation of high-resolution images, and onsite field observations. We acquired all Sentinel-2 Level-1C product images available for the study sites between 2017-2019 and generated monthly median composite images consisting of ten spectral and twelve spectral-indices. The Gradient Boosting Decision Trees (GBDT) classifier was employed for the supervised classification of the satellite data with the support of ground truth data. The cross-validation accuracy in terms of kappa coefficient varied from 87% in Oze site with 41 GPE types to 95% in Hakkoda site with 19 GPE types; with average performance of 91% across all sites. The GPE maps produced in this research demonstrated a clear distribution of plant communities in all seven sites, highlighting the potential of Sentinel-2 multi-spectral and multi-temporal images with GPE classification system for operational and broad-scale mapping of plant communities.
  PubDate: Wed, 11 May 2022 02:17:13 +000
Use of Topographic Map Evidence to Locate a New Cenozoic Glacial History
Paradigm’s Deep “Hole” Rim in Northeast New Mexico and Southern
Colorado, USA
- Abstract: A recently proposed Cenozoic geology and glacial history paradigm requires a thick North American continental ice sheet to have been located within an ice sheet created and occupied deep “hole” and predicts large south-oriented meltwater floods flowed across the deep “hole’s” southern rim before rim uplift progressively diverted floodwaters toward the Mississippi River valley, which in time became the only deep “hole” southern exit (the accepted paradigm does not recognize such an ice sheet created deep “hole”). Possible locations for the new paradigm deep “hole” rim in Great Plains regions east of the Sangre de Cristo Mountains are considered with the one being the Purgatoire-Canadian River drainage divide in the Raton Mesas area along the Colorado-New Mexico border and a second being the Canadian-Pecos River (Arkansas River-Gulf of Mexico) drainage divide in San Miguel County (NM). Detailed topographic maps indicate streams of what could have been south-oriented melt water once crossed the two studied drainage divides with headward erosion of the northeast-oriented Purgatoire River drainage basin diverting south-oriented water toward the east-oriented Arkansas River (and Mississippi River valley) while headward erosion of east-oriented Canadian River tributary valleys beheaded south-oriented flow to the south-southeast oriented Pecos River (flowing to the Rio Grande River–which then flows to the Gulf of Mexico). While the Purgatoire-Canadian River drainage divide has some deep “hole” rim characteristics, those characteristics disappear in an eastward direction and the Canadian River, like the Purgatoire River, is an Arkansas River tributary. East-oriented Canadian River headwaters and tributary valley headward erosion diverted south-oriented flow from the Rio Grande River to the Mississippi River valley (via the Canadian and Arkansas Rivers), which means the new paradigm’s deep “hole” rim southern margin should be located along or near the Arkansas River-Gulf of Mexico drainage divide.
  PubDate: Fri, 04 Mar 2022 02:18:05 +000
Rainfall Characteristics during the Years of Significant Departures from
Normal in the Sudano-Sahelian Ecological Zone of Nigeria
- Abstract: The rationale examining the rainfall characteristics during the years of significant departures from normal in the Sudano-Sahelian Ecological Zone (SSEZ) of Nigeria is based on the devastating effects of extreme weather events and their subsequent implications for agriculture and food security in sub-Saharan Africa. This study designated Significant Years of Positive Departure (SYPD) and Negative Departure (SYND) of rainfall from normal using a Z-score analysis on 39 years of rainfall data (1980-2018) for Sokoto, Kano, Maiduguri, and Nguru. The results show that nine years possessed significant positive departures in rainfall versus six years of negative departures significant at α = 0.05. The frequency of occurrence of intra-seasonal dry spells outweighed that of wet spells in all the years except in 2000 (Maiduguri), 2012 (Kano and Nguru), and 2016 in Sokoto. Light rainfall contributed almost 60% of the total annual rainfall in the zone with heavy rains comprising 17.6% of the total in SYPD versus only 3% in SYND. The average length of the growing season (106 days) was higher during the SYND than the SYPD with an average of 99 days. Onset and retreat days were mostly recorded during June and September respectively in SSEZ. This study found that SYPD in Sudano-Sahelian Ecological Zone possessed more wet occurrences than dry periods resulting from below-normal rainfall. These wetter occurrences also possess food security concerns because of their timing, while the SYND years portend to drought and possible famine.
  PubDate: Thu, 17 Feb 2022 01:50:09 +000
Why is Mars the “Red Planet”' A New, Novel Hypothesis on the
Features of Mars and the Origin of the Asteroid Belt
- Abstract: Mars has always been known as the “Red Planet because it is the only planet in our solar system with a red surface. The reasons for this uniqueness have never been proposed, other than the fact that its soil and surface rocks have a high content of iron oxide. In order to attempt to resolve this issue, a novel hypothesis is proposed herewith. Formulation of this hypothesis involved considering the unique features of Mars and putting them into a rational correlating explanation. The scenario involves the collision of a formerly much larger Mars with another planet early in the solar system’s history. The crust and mantle were blown off, forming the asteroid belt, leaving the iron core intact. Upon cooling and solidification, the iron core combined with oxygen in the remaining atmosphere to form rust-colored iron oxide (rust). Methane in the early atmosphere underwent combustion, forming its current high carbon dioxide atmosphere. The combustion of methane also produced massive amounts of liquid water, explaining the dried-up erosional features of the planet’s surface, such as river valleys. The point of impact formed a long, deep canyon, Valles Marineris, and the nearby giant volcano, Olympus Mons, even in the absence of Mars’ tectonic activity. The cooled, solidified core may explain why Mars has no magnetic field. If accurate, these ideas may help space programs prepare astronauts for manned exploration of the Red Planet, as well as facilitating an understanding of its unusual features.
  PubDate: Tue, 15 Feb 2022 06:14:51 +000