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Geographical Information Based Evaluation System for Drought
Dilip Kumar,
Sushil Kr. Himanshu
Issue:
Volume 3, Issue 4, December 2017
Pages:
49-53
Received:
9 December 2016
Accepted:
23 February 2017
Published:
14 December 2017
Abstract: Drought is one of the major natural hazards affecting the environment and economy of countries worldwide. As a natural hazard, drought is best characterized by multiple climatological and hydrological parameters. An understanding of the relationships between these two sets of parameters is necessary to develop measures for mitigating the impacts of droughts. Droughts are recognized as an environmental disaster and have attracted the attention of environmentalists, ecologists, hydrologists, meteorologists, geologists, and agricultural scientists.. Low rainfall has mainly caused droughts and subsequent reduction in agricultural production. Droughts have been a recurring feature of the Indian climate, therefore, study of historical droughts may help in the delineation of major areas facing drought risk and thereby, management plans can be formulated by the government authorities to cope with the disastrous effects of this hazard. In recent years, Geographic Information System (GIS) and Remote Sensing (RS) have played a key role in studying different types of hazards, either natural or man-made. This paper emphasizes upon the application of RS and GIS in the field of drought risk evaluation. The study area taken is a part of the Jamnagar district of Gujarat between latitude 22°19′46′′N to 22°46′01′′N and longitude 70°20′56′′E to 70°47′34′′E. The study was conducted with satellite images of year 1977, 1990 and 1999. Data has been acquired mainly from two sources, firstly Normalized Difference Vegetation Index (NDVI) obtained from satellite sources and secondly rainfall obtained from ground rainfall stations record. In the present paper, an effort has been made to derive drought risk areas facing agricultural as well as meteorological drought by use of Normalized Difference Vegetation Index (NDVI) from Landsat images. NDVI values reflect the different geographical conditions quite well. The NDVI and rainfall was found to be highly correlated. It is therefore concluded that temporal variations of NDVI are closely linked with precipitation.
Abstract: Drought is one of the major natural hazards affecting the environment and economy of countries worldwide. As a natural hazard, drought is best characterized by multiple climatological and hydrological parameters. An understanding of the relationships between these two sets of parameters is necessary to develop measures for mitigating the impacts of...
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Study of Nutrient Salts, Chlorophyll-a and Physicochemical Condition in El-Mex Bay Water, Alexandria, Egypt
Mohamed A. Okbah,
Mamdouh S. Masoud,
Gehan M. El Zokm,
Alyaa A. Abd El-Salam
Issue:
Volume 3, Issue 4, December 2017
Pages:
54-64
Received:
24 January 2017
Accepted:
17 February 2017
Published:
18 December 2017
Abstract: The present work aimed to study the physicochemical parameters and nutrient salts of El Mex Bay area to evaluate its composition since El- Mex Bay exposed to several kinds of human activities and receive different types of industrial pollutants. Various pollutants are dumped daily by industrial, agricultural and domestic sources over Alexandria coasts through several outfalls, El-Mex Bay one of these disposal sites (El-Mex Pumping Station). Surface and bottom water samples were collected seasonally during the period from September (summer) 2012 to April (spring) 2013. Salinity variation appeared in water quality changes, it ranged from 2.25‰ to 38.87‰ and from 26.21‰ to 39.64‰ at the surface and bottom water, respectively. Dissolved oxygen levels indicated poor aeration conditions along the water column, it is lower in most stations at surface layer (ND-3.15 mgl-1) than that in the bottom layer (0.79 – 6.28 mgl-1). The pH values of the study area at surface ranged (7.05 - 8.73), while at the bottom water ranged (7.18 - 8.45). Inorganic nitrogen species in El-Mex Bay water decreased in the order of NH4+ > NO3- > NO2-. The measured nutrient content varied greatly as follows: NH4+, 4.73±5.70 to 99.27±72.53 µM; NO2-, 0.72±0.43 to 4.34±3.43 µM; NO3-, 1.33±1.01 to 31.68±24.59 µM Regional and seasonal variations of total nitrogen concentration in El-Mex Bay surface and bottom water ranged from 28.26± 14.87 to 335.12±226.66 µM. The concentrations of reactive phosphate (PO4) and total phosphorus (TP) were in the ranges of 0.05-17.36 µM and 0.11-28.01 µM, respectively. As a result of nutrient enrichment, phytoplankton growth was very intensive, reflected by an abnormally high concentration of chlorophyll-a (annual average: 13.64±10.69 μg l−1 at surface and 3.96 ±2.42 μg l-1 at bottom water).
Abstract: The present work aimed to study the physicochemical parameters and nutrient salts of El Mex Bay area to evaluate its composition since El- Mex Bay exposed to several kinds of human activities and receive different types of industrial pollutants. Various pollutants are dumped daily by industrial, agricultural and domestic sources over Alexandria coa...
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Effect of Exclosure Age on Carbon Sequestration Potential of Restorations in Tigray Region, N. Ethiopia
Samson Shimelse,
Tamrat Bekele,
Sileshi Nemomissa
Issue:
Volume 3, Issue 4, December 2017
Pages:
65-80
Received:
23 November 2017
Accepted:
11 December 2017
Published:
8 January 2018
Abstract: Conversion of degraded free grazing lands into exclosures is one option to promote natural regeneration of plants and to restore degraded ecosystems in Ethiopia. The present study investigated the change in ecosystem carbon stocks (ECS) and the enhancement of plant species richness and diversity following the establishment of exclosures on free grazing lands in Tigray, Ethiopia. Exclosures of 10, 15, and 20 years old were selected and each exclosure was paired with an adjacent free grazing land. A total of 120 quadrants were sampled using a stratified preferential sampling design technique with flexible systematic model. The differences in carbon stocks and vegetation composition between an exclosure and free grazing lands were assessed using a paired t-test. Data analyses also included descriptive statistics, inferential statistics using one way ANOVA, t-test and Chi-square test. All exclosures displayed higher ECS, and plant species richness, diversity and aboveground standing biomass than the free grazing lands. Differences in ECS between exclosures and free grazing lands varied between 32.96 and 61.0 t. ha-1 increasing with exclosure age. Over a period of 20 years, the carbon dioxide sequestered in the investigated exclosures was 223.88 t. ha-1. Differences in plant species richness and aboveground standing biomass between exclosures and free grazing lands also increased with exclosure age. The results of the present study confirm that establishment of exclosures on degraded free grazing lands in the Northern Highlands of Ethiopian is a viable option to restore ECS. The study showed that ECS in exclosures, in free grazing lands and the change in ECS following the establishment of exclosures on free grazing lands can be predicted using easily measurable biophysical and management-related indicators. Such information is necessary for the establishment of baseline information for carbon sequestration projects, for evaluation of whether exclosure establishment should be expanded, and for policymakers to take into account the value of exclosures in their management decisions. Although the study showed that exclosures are effective to restore ECS, expansion of exclosures would increase grazing pressure on the remaining free grazing area. Therefore, the decision to establish additional exclosures should also include an economical analysis and an evaluation of the social consequences of such a decision.
Abstract: Conversion of degraded free grazing lands into exclosures is one option to promote natural regeneration of plants and to restore degraded ecosystems in Ethiopia. The present study investigated the change in ecosystem carbon stocks (ECS) and the enhancement of plant species richness and diversity following the establishment of exclosures on free gra...
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An Allometric Growth Estimation of Grapes (Vitis vinifera L) from High Mountainous Region of Gilgit-Baltistan, Pakistan
Shaheen Kausar,
Sidra Asad,
Chandni Kiran,
Tika Khan
Issue:
Volume 3, Issue 4, December 2017
Pages:
81-84
Received:
7 June 2017
Accepted:
7 July 2017
Published:
14 January 2018
Abstract: Grapes (Vitis vinifera), besides their medicinal and health importance, plays an important role in livelihood of poor populations living across mighty mountain ranges of Himalaya, Karakoram and Hindukush. Allometric study is necessary to understand quantitative correlations of tree growth. Hundred plant samples (n=100) from ten populations (N=10) were studied at an elevation of 1854 meters asl. Ten (N=10) different population studied revealed that mean leaf length is 10.9 cm (max. 13.4, min. 9.1 cm) followed by mean leaf width 8.4 cm (max. 9.3, min. 7.1 cm). total mean leaf area was 92.2 cm2 (max. 122.6, min. 70.9 cm2). Mean stem length recorded was 26.8 feet (max. 35, min. 16 feet) followed by mean stem width 8.44 cm (max. 12.8, min. 3.1 cm). one thousand seeds were measured and mean seed weight recorded was 0.043 mg (max. 0.047, min. 0.039). similarly mean weight of hundred (n=100) seeds recorded was 4.29 g. research was summarized with the fact that stem length grows 98.97% faster than its width increase. Which means 1 cm with increase corresponds almost 100 cm increase in length. Similarly, leaf length increase is 23% higher to its growth in width. Ignorance towards a rich varietal base is on erosion.
Abstract: Grapes (Vitis vinifera), besides their medicinal and health importance, plays an important role in livelihood of poor populations living across mighty mountain ranges of Himalaya, Karakoram and Hindukush. Allometric study is necessary to understand quantitative correlations of tree growth. Hundred plant samples (n=100) from ten populations (N=10) w...
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