lectures – Page 2 – EARTH,SPACE & BEYOND

Integrating GIS into Forest Resources Spatial Management and Planning (1) – Introduction

March 15, 2017March 14, 2017 by S.T. PradopoNo Comments

This article is summarized and concluded from articles as follow: (1) Making GIS Work in Forest Management by Manij Upadhyay, unpublished work. (2) A Hierarchical Approach to Spatial Forest Planning by Ugo Feunekes and Andrew Cogswell, USDA Forest Service, Proceeding (3) HCVF/A Identify Within Ecoregion; Integrating Conservation Planning into Regional Spatial Planning by Barano Siswa Sulistyawan, WWF Indonesia, (4) Assessing participatory GIS for community-based natural resources management: claiming community forests in Cameroon by Michael K. McCall and Peter A. Minang, The Geography Journal Volume 171 No.(4) pages 283-306, 2010 Introduction Integrating GIS into Forest Resources Spatial Management and Planning (1) - As Indonesia becomes the third highest biodiversity country, it is important for Indonesian to conserve its forest resources. Since, without any simultaneous conservation strategies and sustainable use of forest resources, all advantageous for nation development will be vanished no more than a few years. Concerns over the impacts of forest operations on the forest landscape have compelled a number of agencies to take initiatives to address these issues (Feunekes and Cogswell, 1993)....

THIESSEN POLYGON AND ISOHYET CONTOUR METHODS FOR MEASURE AND COMPARE THE PRECIPITATION MEAN

March 14, 2017March 14, 2017 by S.T. PradopoNo Comments

THIESSEN POLYGON AND ISOHYET CONTOUR METHODS FOR MEASURE AND COMPARE THE PRECIPITATION MEAN A brief practical report Below is the example of the precipitation mean measurement using thiessen polygon, and isohyet contour methods. Both methods is commonly used in climatology. The result of thiessen polygon and isohyet contour methods shown in figures below : Tabel 1. Measurement of precipitation depth using Thiessen Polygon Station 24-hours Total Area Weighted ppt (mm) unit (%) (mm) A 78 0.05 0.3 24.04438964 B 115 1.7 10.5 1205.302096 C 140 3.8 23.4 3279.901356 D 165 2.1 12.9 2136.251541 E 150 0.95 5.9 878.5450062 F 90 3.4 21.0 1886.559803 G 175 1.8 11.1 1942.046856 H 155 2.42 14.9 2312.577065 Total 1068 16.22 13665.22811 ∑ Pn The average of preciputation depth = ∑ area = 13665.23 / 16.22 = 842.4925 mm Tabel 2. Measurement of precipitation depth using Isohyet Contour Station Group Total Area Weighted ppt Median unit (%) (mm) 80 - 90 85 0.02 0.092208391 7.837713232 90 - 100 95 0.27 1.244813278 118.2572614 100 - 110 105 2.1 9.681881051 1016.59751 110 - 120 115 2.5 11.52604887 1325.49562 120 - 130 125 3.5 16.13646842 2017.058552 130 - 140 135 5.2 23.97418165 3236.514523 140 - 150 145 3.7 17.05855233 2473.490088 150 - 160 155 1.9 8.759797142 1357.768557 160 - 170 165 0.7 3.227293684 532.5034578 170 - 180 175 1.8 8.298755187 1452.282158 Total 1300 21.69 13537.80544 ∑ Pn The average of precipitation depth = ∑ area = 13537.8 / 21.69 = 624.15 mm CONCLUSION The result showed the difference between both measurement. This may happen when we use a bigger grid size. The accuracy decrease since the grid cannot cover the area border precisely . Thiessen Polygon Method is simpler than isohyets contour. Isohyet method is more complex and may...

UNDERSTANDING OUR PLANET Q/A #6 – What geologic processes might cause the forces that can hold a region out of isostatic equilibrium?

January 13, 2017March 17, 2017 by S.T. PradopoNo Comments

UNDERSTANDING OUR PLANET Q/A #6 - What geologic processes might cause the forces that can hold a region out of isostatic equilibrium? - On a geological scale, isostasy can be observed where the Earth's strong lithosphere exerts stress on the weaker asthenosphere which, over geological time flows laterally such that the load of the lithosphere is accommodated by height adjustments. It was ascertained that disturbances of the isostatic equilibrium are the result of the active geotectonic process and that isostatic forces are passive as tectonic factor. In the geological time scale the readjustment takes place instantaneously, therefore isostatic anomalies of gravity may be considered as direct indications of the modern tectonic activity. However, some continental collisions are far more complex than this, and the region may not be in isostatic equilibrium. Certain areas (such as the Himalayas) are not in isostatic equilibrium, in the case of the Himalayas, by proposing that their elevation is being "propped-up" by the force of the...

UNDERSTANDING OUR PLANET Q/A #5 – Why asthenosphere is important to understand the dynamic of Earth’s crust?

January 12, 2017March 17, 2017 by S.T. PradopoNo Comments

UNDERSTANDING OUR PLANET Q/A #5 - Why asthenosphere is important to understand the dynamic of Earth’s crust? - Asthenosphere is part of the upper mantle which is partially molten, a relatively narrow, and mobile zone of the mantle. The asthenosphere is a weak zone, formed of mostly solid rock (with perhaps a little magma mixed in), and flows very slowly, in a manner similar to the ice at a bottom of a glacier. The rigid lithosphere is believed to "float" or move about on the slowly flowing asthenosphere....

UNDERSTANDING OUR PLANET Q/A #4 – What facts make it probable that Earth’s core is composed of mostly iron?

January 11, 2017March 17, 2017 by S.T. PradopoNo Comments

UNDERSTANDING OUR PLANET Q/A - What facts make it probable that Earth’s core is composed of mostly iron? - The analogy for this fact is big magnet theory. The magnetic field of the Earth is more or less like that would be produced if there were a giant bar magnet at the center of the Earth. This assumption is obtained according to the fact that the earth is dynamic. Pressure and movement attached to metal (iron) will make a magnetic power to such metal. Since the earth have a magnetic field (gravitation), it is assumed that beneath the earth must be metal material. In this case, the most powerful metal to be given a magnetic power is iron. The Earth's field sometimes switches polarity and compasses would point South. This happened last about 780,000 years ago and could happen again any millenia now. These facts confirm the existence of a fluid outer core made of pure metal. It is the motions in...