Scientific- Research Quarterly of Geographical Data (SEPEHR)

Scientific- Research Quarterly of Geographical Data (SEPEHR)

Estimating density and percent canopy cover of alluvial fans in South Western Miami using aerial imagery captured by drone

Document Type : Research Paper

Authors
Sepide Imeni 1
Hassan Sadough 2
Shahram Bahrami 3
Ahmad Reza Mehrabian 4
Kazem Nosrati 5
1 Ph. D Candidate of geomorphology, Department of natural geography, Faculty of earth sciences, ShahidBeheshti University, Tehran
2 Professor, Department of natural geography, Faculty of earth sciences, ShahidBeheshti University, Tehran
3 Associate professor, Department of natural geography, Faculty of earth sciences, ShahidBeheshti University, Tehran
4 Assistant professor, Department of plant science and biotechnologhy, Faculty of biological science and technology, ShahidBeheshti University, Tehran
5 Associate professor, Department of natural geography, Faculty of earth science, ShahidBeheshti University, Tehran
10.22131/sepehr.2020.47880
Abstract
Extended Abstract
Introduction
 Geomorphologists have always considered geomorphological processes such as weathering, erosion, and sedimentation, and tectonic processes as the main factor creatingdifferent landforms in the ecosystem. Moreover, a large part of the earth’s surface is affected by the presence and existence of organisms, thus these biological species play a major role in environmental changes and consequently in the creation of landforms. In fact, geomorphology is one of the important factors affecting vegetation heterogeneity in the scope of landscape. Alluvial fans are among the important and majorgeomorphologicalforms in which two natural parameters of landform and vegetation coexist. Various methods are used to study vegetation density. Vegetation variables are commonly estimated using land surveying, but satellite images have made more accurate methods of rangeland management and alsoestimationof plant quantities in inaccessible areas possible. However, usingdata obtained from satellite imageries for partial measurements has some limitations due to unavailabilityof high spatial resolution images such as QuickBird satellite images or high expenses of retrieving such imagery.In the present study, plant variables were investigated using large-scale aerial imagery and field sampling. Plant density and percent canopy cover were also determined in the study area using the same methods.
 Materials & Methods
Study area
The area under study is located in the northeastern regions of Semnan province, northernShahroud city. The study area includes three alluvial fans including Saran, Moghatelan and Hot-Sokhteh.
Methods
Based on field observations, Google Earth images, and drainage pattern, alluvial fans were divided into active (young surfaces) and inactive (old surfaces) parts. Six sites (P1 to P6) including upstream, downstream, active and inactive parts of the alluvial fans under study were selected in order to determine the density and percent of canopy cover in channels, interfluves (in old surfaces), bars and swales  (in young surfaces). The aerial image was acquired using a Dji Phantom 4 Pro Drone with a relative flying height of 100 m, and a 20 megapixel, FC6210 digital camerain December 2018 (Table 1 and Fig. 3). The canopy covers in alluvial fan landforms (including channels, interfluves, bars and swales) were measured using large-scale images (1: 500) acquiredby drone. In the next stage, 50 rectangle and squareshaped plots were selected to determine the density and percent canopy cover of the aforementioned landforms in the upstream and downstream of the three alluvial fans; 5 squareshaped plots with a dimension of 10*10 m were selected from the interfluves, 45 rectangularshaped plots with a dimension of 3*10 m were selected from the channels, swales and bars. Then, percent canopy cover was calculated in each plot and the average percent canopy cover was finally calculated for the 50 plots of each site.
 Experimental studies
In order to investigate physical and chemical characteristics of soil and its effects on the density and vegetation type across alluvial fans, 48 soil samples were collected from a depth of 0-20 cm in the three alluvial fanseach including active and inactive parts, bars, swales, channels, and interfluves. PH, EC, phosphorus (P), absorbable potassium (K) and sodium (Na), calcium carbonate (CaCO3), Saturation percentage (Sp), water retention capacity of soil (WHC), soil texture, and total organic carbon (OCT) were also measured in the samples.
 Sampling vegetation and identifying plant species
In order to identify plant species, field work was carried out in June 2019. Plant species of the study area were identified and a sample was collected, dried and pressed. Systematic random sampling was used in the specified types. In fact, a 200-meter transect was selected in each site, and 8 plots with a dimension of 8 * 8 m were identified along each transect including channels, interfluves, swales, and bars of the upstream and downstream alluvial fans. Therefore, 43 vegetation sampling plots were selected along the 200-meter transect.
 Results & Discussion
In the active surfaces of both upstream and downstream alluvial fans, density and percent canopy cover of bars arehigher than those of swales, because of the higher amount of silt and clay in bars. Larger plant species such as shrubs and sub-shrubs requiringfine-textured soil grow in these bars. On the other hand, swales have a higher amount of organic materials and calcium carbonate. EC and PH are lower in the bars as compared to the swales. Water-holding capacity (WHC) and Saturation percentage (Sp) of the soil are higher in the swales as compared to the bars. There are more absorbable potassium and phosphorus in the bars. However, vegetation density and percent canopy cover in swales are lower than those of bars despite their high soil fertility and moisture. This is probably due to the lower stability of the swales whichresults in their higher exposure to unstable currents during occasional storms and floods.
Overall, plant species adapted to the specific environmental conditions are settled in each landform. PerovskiaAbrotanoides is the dominant plant species in active surfaces ofbars. The vegetation type is more limited in the swales of active surfaces including species likePoabulbosa and Bromusdanthoniae.
In inactive surfaces of alluvial fans, elementsrequired for soil fertility (organic materials, calcium carbonate, absorbable potassium and sodium, phosphorus, pH, saturated moisture of the soil, and soil retention) are higher in the interfluves as compared to channels. The relative higher fertility of interfluves can be attributed to their gentle slopes, higher stability and hence higher possibility of soil formation. Long-term exposure of sediments or alluviums to weathering elements on relatively flat surfaces of interfluves has resulted in the formation of more clay and silt, and thereby denser vegetation in interfluves compared to channels. Herbaceous and shrub species, which require fine-textured soils, settle in interfluves. On the other hand, vegetation density of channels with higher amounts of sand and pebbles is lower likely due to their steep slopes as well as their higher level of erosion. However, percent of canopy cover is higher in channels as compared to interfluves. Channels have a relatively higher level of moisturesince they are in the shade and in vicinity of groundwater. Hence, shrubsare settled in these landforms. These species havea denser canopy cover, and deeper roots and require coarser soil texture.
Artemisia sieberi is the dominant plant species in inactive surfacesofinterfluves.This species is a sun-loving plant requiring lots ofsunshine to grow.Apart from Artemisia sieberi, other plants such as Astragalus sp., Acanthophyllum sp., Peganumharmala, AmygdalusScoparia and convolvulus acanthocladus have also settled in the interfluves.
 Conclusion
Analyzing vegetation density and percent canopy cover of alluvial fans and their related landforms indicated that bushes are more frequent in the interfluves of old surfaces as compared to other parts of these fans. Despitelower vegetation densityin bars of young fans and channels of old fans, they have a larger type of vegetation (mainly shrubs) and thus, a higherpercent canopy cover. Generally, this study has revealed that bushes are more frequent in the old alluvial fans, especially upstream parts of the fans as compared to other areas. Overall, the results indicate that geomorphological processes such as aggradation and degradation affect the texture and fertility of soil as well as type and density of vegetation.
Keywords
Geomorphology
Processes
Plant species
Alluvial fan
Drone
Miami
1.بهرامی، بیرامعلی، فیله ‌کش، قهرمان؛ شهرام، فرشته، اسماعیل، کاوه؛ 1397، بررسی تأثیر ژئومورفولوژی در نوع و تراکم پوشش گیاهی مخروط افکنه ‌های فشتنق -   سبزوار، مجله جغرافیا و توسعه، شماره  52، صص 193- 210.
2.چناری،‌ عرفانی فرد، دهقانی، پورقاسمی؛ افروز، سیدیوسف، مریم، حمیدرضا؛ 1396، برآورد مساحت تاج تک درختان بنه با استفاده از DSM تصاویر هوایی پهپاد در جنگل تحقیقاتی بنه استان فارس، نشریه پژوهش ‌های علوم و فناوری چوب و جنگل، جلد بیست و چهارم، شماره چهارم، صص 117- 130.
3.رویان، سپهری، سلمان‌ ماهینی؛ ملوک، عادل، عبدالرسول؛  1395، برآورد فراوانی و تراکم گیاهی مراتع با استفاده از عکس ‌های هوایی ارتفاع پایین، مجله بوم ‌شناسی کاربردی، شماره 17،صص 1- 9.
4.فکری، عارف،  1396، مقایسه ترکیب و تنوع گونه ای در مراتع داخل و خارج قرق تحقیقاتی ارشق در استان اردبیل، پایان نامه کارشناسی ارشد گروه منابع طبیعی دانشگاه محقق اردبیلی، 76 صفحه.
5.مصداقی، منصور، 1380، توصیف و تحلیل پوشش گیاهی، انتشارات جهاد دانشگاهی مشهد، 287 صفحه.
6.میرداودی، زاهدی، شکوبی، ترکان؛ حمیدرضا، حجت الله، مسعود، جواد؛ 1385، شناخت عوامل اکولوژیکی مؤثر بر پوشش گیاهی مراتع با استفاده از تجزیه تحلیل‌ های چند متغیره (مطالعه موردی:  جنوب استان مرکزی)، فصلنامه علمی- پژوهشی، جلد 12، شماره 3، صص211- 201 .
7.نصرتی، کاظم، 1392، روش‌های کاربردی در پژوهش علمی، چاپ اول، انتشارات جهاد دانشگاهی واحد شهید بهشتی، 204 صفحه.
8.   Bahrami, S, Ghahraman, K., 2019. Geomorphological controls on soil fertility of semi-arid alluvial fans: A case study of the Joghatay Mountains, Northeast Iran. Catena 176, 145-158.
9.   Bahrami, S., FatemiAghda, S.M., Bahrami, K., Motamedi Rad, M., Poorhashemi, S., 2015. Effects of weathering and lithology on the quality of aggregates in the alluvial fans of Northeast Rivand, Sabzevar, Iran. Geomorphology 241: 19-30.
10. Baker, A. K. M., Fitzpatrick, R. W., Koehne, S. R., 2004. High resolution low altitude aerial photography for recording temporal changes in dynamic surficial environments. Regolith: 21-25.
11. Bor, N.L. 1970. Flora Iranica, AkademischeDruck-u.Verlagsanstalt. Graz: Austria. Vol. 70.
12. Browicz, K and Zohary, D. 1996. The genus Amygdalus L. (Rosaceae): Species relationships, distribution and evolution under domestication, Genetic Resources and Crop Evolution volume 43: 229-247.
13. Can Birdal, Anıl.,Avdan, Uğur., Türk, Tarık. 2017. Estimating tree heights with images from an unmanned aerial vehicle. Geomatics, natural hazards and risk, VOL. 8, NO.2, 1144- 1156.
14. Cassel, D.K., Nielsen, D.R., 1986. Field capacity and available water capacity. In: Klute, A. (Ed.),  Methods of Soil Analysis part 1. Soil Physical Properties.Agron.Monogr. 9. ASA and SSSA, Madison, WI, pp. 901-924.
15. Carter, M. R., and Gregorich, E.G. 2008. Soil sampling and methods analysis, Canadian society of soil science, second edition.
16. Chianucci, F., Disperati, L., Guzzi, D., Bianchini, D., Nardino, V., Lastri, C., Rindinella, A., and Corona, P. 2016. Estimation of canopy attributes in beech forests using true colour digital images from a small fixed-wing UAV. International J. Applied Earth Obsevation and Geoinformation., 47: 60-68.
17. Corenblit, D., Baas, A.C.W., Bornette, G., Darrozes, J., Delmotte, S., Francis, R.A., Gurnell, A.M., Julien, F., Naiman, R.J., Steiger, J., 2011. Feedbacks between geomorphology and biota controlling Earth surface processes and landforms: A review of foundation concepts and current understandings, Earth-Science Reviews 106: 307–331.
18. D’Odorico, P., Caylor, K., Okin, G.S and Scanlon, T.M. 2007. On soil moisture - vegetation feedbacks and their possible effects on the dynamics of dryland ecosystems, Journal of Geophysical Research, 112 p.
19. El-Hadidi, M. N. 1972. Flora Iranica, AkademischeDruck-u.Verlagsanstalt. Graz: Austria. Vol. 98.
20. El-Keblawy, Ali., A. Abdelfattah, Mahmoud and Khedr, Abdel-Hamid A., 2015. Relationships between landforms, soil characteristics and dominant xerophytes in the hyper-arid northern United Arab Emirates, Journal of Arid Environments, 117, pp. 28-36.
21. Field, J.J., 1994. Surficial processes, channel change, and geological methods of flood- hazard assessment on fluvially dominated alluvial fans in Arizona. (Ph.D thesis), University of Arizona (258 pp.).
22. Greene, R.S. B., Valentin, C and Esteves, M. 2001. Runoff and erosion processes, in banded vegetation patterning in arid and semiarid environment, edited by D. J. Tongway, C. Valentin, and J. Seghieri, Springer, New York, p. 52–77.
23. Grierson, A.J. C and Rechinger, K.H. 1982. Flora Iranica, AkademischeDruck-u.Verlagsanstalt. Graz: Austria. Vol. 154.
24. Guerra-Hernández, Juan., González-Ferreiro, Eduardo., Sarmento, Alexandre., Silva, João., Nunes, Alexandra., C. Correia, Alexandra., Fontes, Luis., Tomé, Margarida., Díaz-Varela, Ramón. 2016. Using high resolution UAV imagery to estimate tree variables in Pinuspinea plantation in Portugal. Forest Systems, 25(2), eSC09, 5 pages.
25. Hedge, I. C. 1982. Flora Iranica, AkademischeDruck-u.Verlagsanstalt. Graz: Austria. Vol. 150/ T.
26. Johnson, R.A and Wichern, D.W., 1992. Applied multivariate statistical analysisPrentice-Hall: Englewood Cliffs, Pearson Education, six edition, 184- 188.
27. Khokthong, Watit., Clara Zemp, Delphine., Irawan., Bambang., Sundawati, Leti., Kreft, Holger., Hölscher, Dirk. 2019. Drone-Based Assessment of Canopy Cover for Analyzing Tree Mortality in an Oil Palm Agroforest, Frontiers in Forests and Global Change, Volume 2 | Article 12, 1- 10.
28. Knudsen, D., Peterson, G. A., Pratt, P. F., 1982.  Lithium, Sodium and potassium. In: Page, A.L., Miller, R.H., Keeney, D.R. (Eds), Methods of Soil Analysis, Part 2- Chemical and MicrobiologicalProperties (second edition). Madison, Wisconsin. American Society of Agronomy: 225-246.
29. Kroetsch, D., 2008. Particle size distribution: Soil sampling and methods of analysis. 2nd ed. CRC Press, Boca Raton, FL: 713- 725.
30. Lane, S.N., Borgeaud, L., Vittoz, P., 2016.  Emergent geomorphic- vegetation interactions on a subalpine alluvial fan.Earth surface processes and landforms.Earth Surf.Process. Landforms 41: 72–86.
31. Larsen, A., Nardin, W., Bätz, N., Falcini, F., Larissa, N., Nienhuis, J., 2016. Biogeomorphology: conceptualising and quantifying processes, rates and feedbacks. EGU general assembly Vienna, Austria, 7–12 April 2019.
32. Mclean, E.O., 1982. Soil pH and lime requirement. In: Page, A.L., Miller, R.H., Keeney, D.R. (Eds), Methods of Soil Analysis, Part 2- Chemical and Microbiological Properties (second edition). Madison, Wisconsin. American Society of Agronomy: 199-224.
33. Moghaddam, M. R., 2005. Quantitative Plant Ecology.University of Tehran, 701 p.
34. Mohseni, N., Hosseinzadeh, S. R., Sepehr, A., Golzarian, M. R., Shabani, F., 2017. Variations in spatial patterns of soil-vegetation properties and the emergence of multiple resilience thresholds within different debris flow fan positions, Geomorphology 290: 365-375.
35. Murray, B and Fonstad, MA. 2007. Preface: Complexity (and simplicity) in landscapes. Geomorphology 91: 173–177.
36. Navarro, José Antonio., Algeet, Nur.,Fernández-Landa, Alfredo., Esteban, Jessica., Rodríguez-Noriega, Pablo., Luz Guillén-Climent, María. 2019. Integration of UAV, Sentinel-1, and Sentinel-2 Data for Mangrove Plantation Aboveground Biomass Monitoring in Senegal, Remote Sens. 11, 77; 1- 23.
37. Nelson, R.E., 1982. Carbonate and gypsum. In: Page, A.L., Miller, R.H., Keeney, D.R. (Eds.), Methods of Soil Analysis: Chemical and Microbiological Properties. American Society of Agronomy Inc.,, Wisconsin, pp. 181–197.
38. Nosrati, K., 2013. Assessing soil quality indicator underdifferent land use and soil erosion usingmultivariate statistical techniques.Environmental Monitoring andAssessment 185:2895- 2907.
39. Osterkamp, WR, Hupp, CR and Stoffel, M. 2012. The interactions between vegetation and erosion: new directions for research at the interface of ecology and geomorphology. Earth Surface Processes and Landforms 37: 23–36.
40. Panagiotidis, Dimitrios.,Abdollahnejad, Azadeh., Surový, Peter., Chiteculo, Vasco. 2016. Determining tree height and crown diameter from high-resolution UAV imagery. INTERNATIONAL JOURNAL OF REMOTE SENSING, Volume 38, Issue 8-10 , 1- 19.
41. Podlech, D. 1999. Flora Iranica, AkademischeDruck-u.Verlagsanstalt. Graz: Austria. Vol. 174.
42. Rechinger, K. H. 1963. Flora Iranica, AkademischeDruck-U. Verlagsanstalt. Graz: Austria. Vol. 1.
43. Rechinger, K. H. 1988. Flora Iranica, AkademischeDruck-U. Verlagsanstalt. Graz: Austria. Vol. 163.
44. Schönbeck-Temesy, E. 1970. Flora Iranica, AkademischeDruck-U. Verlagsanstalt. Graz: Austria. Vol. 69.
45. Schoenau, j.j., O’Halloran, I. P., 2008. Sodium Bicarbonate-Extractable Phosphorus: Carter, M.R., Gregorich E.G. (Eds.), Soil Sampling and Methods of Analysis. CRC Press, Taylor & Francis Group, Boca Raton: 115- 121.
46. Skjemstad, J.O and Baldock, J.A., 2008. Total and organic carbon. In: Carter, M.R., Gregorich, E.G. (Eds.), Soil Sampling and Methods of Analysis. CRC Press, Taylor & Francis Group, Boca Raton, pp. 225-237.
47. Thomas, G.W., 1996. Soil pH and Soil Acidity. In:  Sparks, D.L. (Ed.), Methods of Soil Analysis, Part 3 – Chemical Methods. Soil Science Society of America, Madison, Wisconsin, USA: 475-490.
48. Townend, J., Reeve, M.J., 2001. Water release characteristic. In: Smith, K.A., Mullins, C.E. (Eds.), Soil and Environmental Analysis: Physical Analysis. CRC Press, New York, pp. 95-140.
49. Twidale, C. R. 2004. River patterns and their meaning. Earth-Science Reviews, Volume 67, Issues 3- 4,  Pages 159-218.
50. Walkley, A., Black, I.A., 1834. An Examination of the Degtjareff Method for Determining Soil Organic Matter, and A Proposed Modification of the Chromic Acid Titration Method: Soil Science, vol. 37: 28-34.
51. Wendelbo, P. 1965. Flora Iranica, AkademischeDruck-U. Verlagsanstalt. Graz: Austria. Vol. 10.
52.          Ye Seul, Lim., PhuHien, La., Jong Soo, Park., MiHee, Lee., Mu Wook, Pyeon., Jee-In, Kim. 2015. Calculation of Tree Height and Canopy Crown from Drone Images Using Segmentation. Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography, Vol. 33, No. 6, 605-613.