0850-B4

Investigation of effective factors for path tracing using Geographical Information Systems in Kheyroud Forest (Iran- Mazandaran Province)

S.Ata o. Hosseini, N. Sarikhani, K. Solaymani, Gh. Djalali ¹

Abstract:

In this research, main factors for path tracing was investigated by studying principle-digitized maps including slope, slope direction, soil, volume per hectare and ecological capacity units by using GIS technique. Namkhaneh district in Kheyroud Forest (Training and Research Forest of Natural Resources Faculty of Tehran University) at the east of Nowshahr-Mazandaran province because of having complete and exact geographical information was selected as the area of this research. Digital maps were produced and analyzed by GIS technique and Arcview software. Maps of soil, slope, directions of slope, bedrock and volume per hectare were categorized to needed classes and then surfaces of each classes was prepared separately. By overlaying those maps in Arcview, some ecological units were selected and an ecological capacity map was ready to analyze. These units were arranged in some tables to divide the research area to different units for path tracing. Finally, by using slope, aspect (direction of slope), soil (drainage), volume per hectare and ecological capacity maps, It was decided to select the best area to plan forest road with effective factors as above in Namkhaneh district. With taking into consideration technical points for planning forest road by using GIS technique optimal forest road was designed as soon as possible. Surely, using GIS technique and computerized analyzing cause to economize in time, costs and to minimize environmentally damages.

Introduction:

According to the statistic data issued by Forest and Rangelands Organization of Iran (2000), only 7 percent of the country's land is covered by forests form which the portion of the North is less than 1 percent. Considering this limited forest cover in the North necessitates a fundamental management and planning in this field. Optimum planning of forest roads network is the basis and foundation for reasonable and practical preparation of forestry management to manage it and exploit safely and sustainablly. Precise tracing of the path to plan the access roads networks for conservation and exploitation of the forest is the basis for forest management. Keeping these points in mind, it is necessary to take technical principles into consideration for designing the path. Forest as the main factor in soil conservation, water storage, wild habitat and biotic storage, tourism, entertainment and recreation and finally as a productive resource has many material and spiritual values. The facts relating to the effective role of forest in preventing soil erosion and mass movement and considering the related socio-economic problems can affect a person's thought regarding exploitation from this God-given gift.(7) To prepare the existing topographic maps in our country, aerial photographs taken by country-wide flights in 1956 and in the latest maps, aerial photographs taken in 1995 have been used, however this can obviate small part of the needed information for path tracing in the forests. Thus, Geographical Information System can be used to increase information layers digitally and to put them together. This system is used for a set of information series and modeling methods, which play their role through offering Geographical Information structure, analysis, offering quantitative information from geographic places in different forms and graphical and digital methods. Geographical Information System capabilities can be used for reasonable decision making through increasing precision and decreasing expenses to implement path tracing and optimum recognition of the land. A variety of studies in different fields of forestry, watershed management and pedology have been implemented in the research area. To reach the given goals in this study, fairly complete recognition of the suitable areas to perform the path, slope map of the zone, geographical direction of the slopes, the type of soil and bed rock, current type of the mass, stock per hectare and finally their analysis were needed. After the above-mentioned factors in the study zone, the whole surface of the zone was studied rather precisely for path tracing. In this study the most area in the slope map was related to the 20-45 percent class and the prevailing direction was western aspect. The forest type was mainly Beech-Hornbeam, the most of which were settled on deep dark brown soils with Marn bedrock and fairly good to good drainage. The average stock per hectare was 370 cubic meter in this district. Ultimately, by composing some of these factors and through overlaying produced maps the ecological capabilities of different places were classified as homogenous units and were analyzed for path tracing.

Material and Methods:

Study Zone: The resaerch area is located on 10th kilometer of Nowshahr(Mazandaran Province), between North latitude of 36‎ْ27َ and 36‎ْ40َ and eastern longitude of 51‎ْ32َ and 51‎ْ43َ including 7 districts which their area figure out to 8800 hectares. A district with the area of 1075 hectares called Namkhaneh(3). The precipitation rate fluctuates between 1300 to 1600 (mm) and the minimum rainfall occurs in the middle of summer (Weather Forecasting Organization 1999).Its geological structure is made of limestone belonging to the third era of geology and due to geomorphologic phenomena such as Dolin in the zone, there is a proper drainage all over this district. Five southeastern parcels out of 27 parcels in the study zone are so called protective parcels. They are excluded from the forest road network planning due to their excessive dip and their area amounts to 285 hectares. According to the statistics data (Forest and Rangelands Organization 1999) the extent of main (First Degree) and tributary roads in Namkhaneh district amounts to 11340 (m), the length density of which is 14/36 (m/ha).

Research Method: In this study Arcview software was employed to produce maps and analyze Database. Paying attention to the references and history of the research, the recognition of the soil of the zone and bedrock conditions, the zone dip condition, geographical direction of the slopes, the amount of stock per hectare and the percent forest type were needed. So it was decided to collect them as digital information. Dip(slope)maps and geographical directions of slopes were prepared using GIS capabilities and by digital elevation model (DEM). Dip map was classified based on the percentage using topographic map of the zone and was extracted by Arcview software and by defining the geographical directions of the slopes in the software, its map was also achieved in separation with its classes. The type map of different soils in the study zone was very important and was extracted from the pedology studies of Kheyroud Forest (9). Using the prepared digital maps for all districts of this Forest, the border of research district was separated in Arcview software and the map of soil types in Namkhaneh district and soil drainage condition were provided. Some of the characteristics were achieved from last project booklet such as stock per hectare and forest type percent were used to produce the map by software. After regulating the achieved data and Database from the study zone, dip percentage maps, soil type and its drainage, percent type of the growing stock, number of trees per hectare and geographical directions of the slopes were composed and a number of ecological homogenous units were extracted.

Results:

The following maps and tables were produced and extracted for further study and discussion:

1- Digital map of the study zone topography.
2- Slope map separated into three classes (0-25, 25-40, >40%).
3- The map of the geographical direction of slopes separated into five classes (North, South, East, West and Plate).
4- Map of the soil drainage condition, which was prepared, based on the map of soil types and classified into three categories (good, medium and poor).
5- Map of present forest type was prepared using growing elements of the parcels and three major types were specified (Beech, Beech-Hornbeam and Hornbeam)
6- Map of tree number per hectare using GIS capabilities(0-150, 150-300, 300-450)
7- Map of the ecological capacity categories, the product of the analysis of classified homogenous units of the research area.

To study the effective factors in tracing the proper paths, the frequency rate of the areas of each specified class on the research area map was studied and the tables of the their codes cover areas were extracted:

1- Table of slope percentage factor, area and frequency percentage of each class:

2- Table of soil type factor and its characteristics,. Classified in accordance with area and frequency percentage of different categories:

3-Table of geographical direction factor, area and frequency percentage for each category:

4- Table of the factor of Tree number per hectare, area and frequency percentage for each category

Table of volume per hectare, area and frequency percentage for each category

5- An example of homogenous units table (from 136 units) and ecological capacity in separation:

Discussion:

Investigation and studying of path tracing in forestry is very important and necessary environmentally and socio-economically. Precise tracing of the path to plan the access roads networks for conservation and exploitation of the forest is the basis for forest management. Keeping these points in mind. According to the statistic data that issued by Forest and Ranglands Organization (2000) only 7000 (km) were constructed and used. Based on the total forest cover area in the north of Iran that is 1/9 million hectare, it is needed having 38000 (km) optimally distributed with 20 (m/ha) density. For planning of this length of forest roads a very long time and much money should be spend. If we use new technology such as GIS technique, the information and exact data will prepare to analyze for path tracing. Effective factors including (DEM) Digital Elevation Model, soil map, bedrock map, drainage map were classified carefully. By considering them, the major soil type was deep dark brown forest soil with fairly good drainage condition that was suitable for path tracing in this district. The bedrock was Marn about 44/6 %, so it was a problem on hazardous slopes and north direction. The most slope percent was between 25-40% and geographical direction was West that was a dry side and drainage condition, infiltration of soil was good. So there was no treat to path tracing on most part of this district. With these factors the costs of construction and maintenance were decreased logically. As a whole, it was concluded that research area had some suitable factors to pass tracing for planning forest roads. Finally, using GIS caused precision increase, expense decrease in path tracing, building and maintenance. The most important of all was "saving the time of performance and soil conservation". In this study, logical justification of the speed and precision of Geographical Information System was approved clearly.

References:

1-Acar, H.H. (1997) Preparation of forest transport plans in mountainous regions , Turkish Journal of Agriculture and forestry, 21:2, pp. 201-206

2-Amiri, M.J. (2000) Forest Road Planning Using Ecological Capacity In Gilan Province, M.Sc. Thesis, Tarbiat Modarres University, Natural Resources Faculty, pp.83

3- Goudarzi, M. (1999) Study of variants for Completing of Forest road Network in Namkhaneh District, M.Sc. Thesis, Tehran University, Natural Resources Faculty, pp.110

4-Makhdoum, M. (1999) The Basis of Land-use Evaluation, Tehran University Publication, No. 2203, pp.289

5-Modyri, M. (1999) Geographical Information System, Geogrphical Publication, pp.228

6-Nosrati, K. (1993) Quantitative and qualitative Studying of Shafaroud Forest Road Networks (Gilan province) M.Sc. Thesis, Tehran University, Natural Resources Faculty, pp.111

7-Sarikhani, N. and Madjnonian, B. (1996) Technical Characteristics of Forest Road construction, Management and Programming Organization Publication, pp.175

8-Sarikhani, N. (1996) Forest road Construction guidebook, Tehran University, Faculty of Natural Resources of Karadj, pp. 180

9-Sarmadyan, F. and Djafari, M. (2001) Soil Investigation of Kheyroud Training and Research Forest of Karadj Faculty of Natural Resources, Iran Natural Resources Scientific and Research journal, 4:2, pp.,110

10- Tan, J. (1992) planning a forest road network by spatial data handeling- network routing system, Acta Forestalia Fennica, no. 227, pp.85-90

¹ S.Ata o. Hosseini - Scientific board member of Forestry Department- IRAN- Sari - P.O. Box # 737
E- mail: [email protected]
N. Sarikhani - Ph.D. of Forest Engineering
K. Solaymani - Ph.D. of Remote sensing and GIS
Gh. Djalali - Ph.D. of Forestry

Bibliography of Author:

I was born on Augest 18^th 1968 in Teran(IRAN). I was graduated in 1989 from Natural Resources Faculty of Tehran University as B.Sc. degree and then I have done some projects about "Forest Road Planning in the North of Iran" including Sari and Nowshahr(Mazandaran Province). So I passed my M.Sc. degree in Natural Resources Faculty Tarbiat Modarres University in 1992 on Forest Engineering field and my thesis was about " The Effect of Forest Road Construction on Landslide in Kheyroud Forest". Now I am Ph.D. student of Forest Engineering and Scientific board member of Forestry Department of Mazandaran University (Natural Resources Faculty of Sari).