SPATIOTEMPORAL CHANGE DETECTION OF THE ALPINE MEADOWS AT HOLCOMB VALLEY, SAN BERNARDINO MOUNTAIN NATIONAL FOREST, USING GIS AND REMOTE SENSING TECHNIQUES

Holcomb Valley, with a general elevation between 2200-2257m, is in the Northeast of Big Bear Lake in the San Bernardino Mountains. Holcomb Valley is covered by Alpine meadows, unlike most mountain landscapes, which are rarely found in Mediterranean climates such as California. The cultural-environmental history of the San Bernardino Mountains in the past century speaks of intense anthropogenic activities such as timbering, grazing, gold mining, and extreme climate changes (i.e., drought, fires, floods). A study is conducted to identify and calculate the changes in the Alpine meadows at Holcomb Valley. The climatical data has been acquired to compute and visualize precipitation, temperature patterns, and drought index at the study site. The USGS LANDSAT satellite imageries and NAIP Orthophotos are used to visualize and quantify the change in the condition and the size of the Holcomb Valley meadow habitat. This study uses two different methods for 43 years from 1997-2021 and 20 years from 2000-2020. For the 43 years study, the GIS Remote Sensing technology of NDVI is used to visualize and quantify the change in the health of the vegetation and the size change in the meadows. The NAIP Orthophotos are used for polygon digitization and quantification of size change in meadows for the 20 years period. The results will show the types and amount of change in the meadow habitats at Holcomb Valley

Geographic Analysis of West Nile Virus in the Upper Minnesota River Valley: A GIS and Multi-temporal Remote Sensing Approach

Throughout human evolution civilizations have been faced with implications from infectious diseases caused by various environmental factors. This connection was recognized as far back as the 5th century by Hippocrates and since several key advances have been realized and will be addressed in this an environmental and physical geography of disease. Arthropod or vector-borne viruses are among the most common pathogens introduced into the modern human population. West Nile Virus is considered endemic in most parts of the world and appeared in the United States in 1999 with 62 confirmed cases in an urban New York location. Since its first appearance in the United States the proliferation has been rapid and exponential with many contributing factors influencing its spread. This research will examine factors contributing to the increased prevalence of West Nile Virus (WNV) in the Upper Minnesota River Valley, Minnesota, USA between the years 2002 to 2012. A historical walk through the diverse world of medical geographic research will be analyzed as well. This will allow the basis for this research to be clearly defined and built upon. The advent and ever-increasing functionality of remote sensing and geographical information science (GIS) technologies enables a detailed analysis of factors to be undertaken with such an environmentally connected pathogen. This paper utilizes GIS and remote sensing techniques to analyze changes in climate, land cover, population and disease patterns that are impacting the prevalence and distribution of the disease

Assessment of drought impacts on vegetation health: a case study in Kedah

Prolonged drought in the early of 2014 has caused Malaysia to experience water supply shortage which directly affects both health and growth of vegetation. Thus this study aims to assess the risk vegetation areas that were impacted during 2014's drought by integrating the Standardized Precipitation Index (SPI) and Normalized Differentiation Vegetation Index (NDVI) methods. These two methods were able to assess the risk areas for the vegetation by measuring its health and classifying them according to its severity while considering the rainfall reduction at the specific time and location. The results obtained from this study shows that the central and north west of Kedah was vulnerable to the occurrence of drought. Kedah was more impacted by the dry event during the northeast monsoon. This study is significant as a fundamental input for further research and as an alternative approach by the application of space technology

The influence of grazing on surface climatological variables of tallgrass prairie

Mass and energy exchange between most grassland canopies and the atmosphere are mediated by grazing activities. Ambient temperatures can be increased or decreased by grazers. Data have been assembled from simulated grazing experiments on Konza Prairie Research Natural Area and observations on adjacent pastures grazed by cattle show significant changes in primary production, nutrient content, and bidirectional reflectance characteristics as a function of grazing intensity. The purpose of this research was to provide algorithms that would allow incorporation of grazing effects into models of energy budgets using remote sensing procedures. The approach involved: (1) linking empirical measurements of plant biomass and grazing intensities to remotely sensed canopy reflectance, and (2) using a higher resolution, mechanistic grazing model to derive plant ecophysiological parameters that influence reflectance and other surface climatological variables

Evaluation and application of multi-source satellite rainfall product CHIRPS to assess spatio-temporal rainfall variability on data-sparse Western margins of Ethiopian Highlands

The spatio-temporal characteristic of rainfall in the Beles Basin of Ethiopia is poorly understood, mainly due to lack of data. With recent advances in remote sensing, satellite derived rainfall products have become alternative sources of rainfall data for such poorly gauged areas. The objectives of this study were: (i) to evaluate a multi-source rainfall product (Climate Hazards Group Infrared Precipitation with Stations: CHIRPS) for the Beles Basin using gauge measurements and (ii) to assess the spatial and temporal variability of rainfall across the basin using validated CHIRPS data for the period 1981-2017. Categorical and continuous validation statistics were used to evaluate the performance, and time-space variability of rainfall was analyzed using GIS operations and statistical methods. Results showed a slight overestimation of rainfall occurrence by CHIRPS for the lowland region and underestimation for the highland region. CHIRPS underestimated the proportion of light daily rainfall events and overestimated the proportion of high intensity daily rainfall events. CHIRPS rainfall amount estimates were better in highland regions than in lowland regions, and became more accurate as the duration of the integration time increases from days to months. The annual spatio-temporal analysis result using CHIRPS revealed: a mean annual rainfall of the basin is 1490 mm (1050-2090 mm), a 50 mm increase of mean annual rainfall per 100 m elevation rise, periodical and persistent drought occurrence every 8 to 10 years, a significant increasing trend of rainfall (similar to 5 mm year(-1)), high rainfall variability observed at the lowland and drier parts of the basin and high coefficient of variation of monthly rainfall in March and April (revealing occurrence of bimodal rainfall characteristics). This study shows that the performance of CHIRPS product can vary spatially within a small basin level, and CHIRPS can help for better decision making in poorly gauged areas by giving an option to understand the space-time variability of rainfall characteristics

The function of remote sensing in support of environmental policy

Limited awareness of environmental remote sensing’s potential ability to support environmental policy development constrains the technology’s utilization. This paper reviews the potential of earth observation from the perspective of environmental policy. A literature review of “remote sensing and policy” revealed that while the number of publications in this field increased almost twice as rapidly as that of remote sensing literature as a whole (15.3 versus 8.8% yr−1), there is apparently little academic interest in the societal contribution of environmental remote sensing. This is because none of the more than 300 peer reviewed papers described actual policy support. This paper describes and discusses the potential, actual support, and limitations of earth observation with respect to supporting the various stages of environmental policy development. Examples are given of the use of remote sensing in problem identification and policy formulation, policy implementation, and policy control and evaluation. While initially, remote sensing contributed primarily to the identification of environmental problems and policy implementation, more recently, interest expanded to applications in policy control and evaluation. The paper concludes that the potential of earth observation to control and evaluate, and thus assess the efficiency and effectiveness of policy, offers the possibility of strengthening governance

Assessing water availability under pastoral livestock systems in drought-prone Isiolo District, Kenya

Water availability / Water demand / Surface water / Groundwater / Wells / Salinity / Livestock / Grazing / Land use / Water supply / Drainage / GIS / Databases / Cost recovery