نقشه‌برداری رقومی شاخص کیفیت خاک (مطالعه موردی: قروه، استان کردستان)

نوع مقاله : مقاله کامل علمی پژوهشی

نویسندگان

1 دانش‌آموخته کارشناسی‌ارشد، گروه علوم و مهندسی خاک، دانشگاه کردستان

2 دانشیار، گروه علوم و مهندسی خاک، دانشگاه کردستان،

3 استادیار، گروه مدیریت مناطق خشک و بیابانی، دانشگاه اردکان

چکیده

سابقه و هدف: کیفیت خاک یکی از خصوصیات بسیار مهم خاک بوده که بررسی تغییرات مکانی آن، جهت مدیریت و تخریب خاک مهم می‌باشد. رویکرد کمی کردن کیفیت خاک با استفاده از شاخص‌های کیفیت، جهت فهم بهتر اکوسیستم‌های خاک به طور گسترده‌ای به‌کار برده شده است. شاخص کیفیت خاک از طریق اندازه‌گیری یکسری خصوصیات خاک محاسبه می‌شود که اندازه‌گیری این خصوصیات گران و زمان‌بر می‌باشد که یکی از راه‌ها جهت این کاهش هزینه و زمان، استفاده از تکنیک نقشه‌برداری رقومی خاک است که می‌تواند خصوصیات خاک را با استفاده از داده‌های کمکی و مدل‌های داده‌کاوی به صورت رقومی پیش‌بینی کند. هدف از این تحقیق استفاده از مدل جنگل تصادفی و داده‌های کمکی برای نقشه‌برداری شاخص کیفیت خاک می‌باشد.
مواد و روش‌ها: بر اساس نقشه ژئومورفولوژی، 17 پروفیل خاک و 105 نمونه اوگر از عمق 20-0 سانتی‌متری در منطقه قروه استان کردستان (با وسعت 6500 هکتار) برداشت شد و بافت خاک، کربن آلی، ظرفیت تبادل کاتیونی، هدایت الکتریکی، اسیدیته، کربنات کلسیم معادل، ازت کل، فسفر در دسترس، شدت تنفس میکروبی، نسبت جذب سطحی سدیم (SAR)، جرم مخصوص ظاهری و درصد سنگریزه اندازه‌گیری و محاسبه شدند و سپس شاخص کیفیت وزنی تجمعی خاک محاسبه شد. متغیرهای محیطی در این پژوهش نقشه ژئومورفولوژی، پارامترهای سرزمین و داده‌های تصویر +ETM بودند. نقشه ژئومورفولوژی بر اساس روش زینک تهیه شد. پارامترهای سرزمین ( شامل 10 پارامتر)، شاخص تعدیل شده خاک (SAVI)، شاخص روشنایی (BI) و شاخص گیاهی نرمال شده (NDVI) به ترتیب با استفاده از نرم‌افزار SAGA و ArcGIS10.3 محاسبه و استخراج گردید. جهت ارتباط بین شاخص کیفیت خاک و متغیرهای کمکی از مدل جنگل تصادفی استفاده شد و با استفاده از روش اعتبارسنجی دوجانبه و پارامترهای آماری شامل ضریب تبیین، میانگین خطا و میانگین ریشه مربعات خطا مورد ارزیابی قرار گرفت.
یافته‌ها: بر اساس آنالیز واریانس مشترک (سهم هر ویژگی) جرم مخصوص ظاهری خاک، شن، ظرفیت تبادل کاتیونی و رس دارای بیشترین وزن (1/0 ≥) و سنگریزه و SAR دارای کمترین وزن (05/0 ≤) در میان ویژگی‌های کیفیت خاک بودند. برای پیش‌بینی شاخص کیفیت خاک، متغیرهای کمکی شامل شیب، شاخص SAVI، شاخص خیسی، شاخص MrVBF، فاکتور LS، ارتفاع، شاخص NDVI و نقشه ژئومورفولوژی مهم‌ترین بودند. نتایج این تحقیق نشان داد که مدل جنگل تصادفی با 65/0، 042/0 و 062/ به ترتیب0برای ضریب تبیین، میانگین خطا و میانگین ریشه مربعات خطا دارای دقت نسبتا مناسب برای پیش‌بینی شاخص کیفیت خاک بودند. شاخص کیفیت خاک در محدوه بین 65/0 -3/0 قرار داشت و میانگین مقادیر آن در واحدهای ژئومورفولوژی (مناطق مرتفع شمال، شمال‌غربی و شمال‌شرقی) با شیب زیاد و عمق کم خاک (Mo131، Mo141 و Hi231) کمترین و در واحدهای با شیب کم و عمق زیاد خاک (Pi111،Pi311، Pi322،Pi211 و Pi312) بیشترین بود که از لحاظ آماری هم این اختلافات معنی‌داری می‌باشند.
نتیجه‌گیری: در پژوهش حاضر از مدل جنگل تصادفی جهت بررسی تغییرات مکانی شاخص کیفیت خاک در منطقه قروه استان کردستان استفاده شد. شرایط ژئومورفولوژیک منطقه مطالعاتی بسیاری از خصوصیات خاک و متعاقبا شاخص کیفیت خاک را در منطقه تاثیر قرار داده است. مدل جنگل تصادفی برآورد نسبتا دقیقی از شاخص کیفیت خاک داشت. لذا پیشنهاد می‌گردد جهت نقشه‌برداری خصوصیات خاک از تکنیک‌های پدومتری (همچون جنگل تصادفی) و داده‌های کمکی از قبیل نقشه ژئومورفولوژی، اجزاء سرزمین و تصاویر ماهواره‌ای استفاده شود.

کلیدواژه‌ها


عنوان مقاله [English]

Digital mapping of soil quality index (Case study; Ghorveh, Kurdistan Province)

نویسندگان [English]

  • leila rasouly 1
  • Kamal Nabiollahi 2
  • Ruhollah Taghizadeh 3
1 Department ofSoil Science and Engineering, Faculty of Agriculture, University of Kurdistan
2 University of Kurdistan
3 Ardakan University
چکیده [English]

Background and objectives: Soil quality is one of the most important soil properties which investigation of it's changes is essential to soil management and degradation. Quantifying soil quality using soil quality index to improve understanding of soil ecosystems is have been wieldy used. The soil quality index is calculated by measuring some soil characteristics which measuring these properties is expensive and time consuming. Therefore, one of the solutions is the use of digital soil mapping technique that can digitally predict soil properties using auxiliary data and data mining models. The purpose of this research is using a random forest model and auxiliary data for mapping the soil quality index.
Materials and Methods: Based on the geomorphology map, 17 soil profiles and 105 auger samples were taken from a depth of 0-20 cm in the Ghorveh area of Kurdistan Province ( covers 6500 ha) and soil texture, organic carbon, cation exchange capacity, electrical conductivity, pH, carbonate calcium equivalent, total nitrogen, available phosphorus, microbial respiration rate, sodium adsorption ratio (SAR), bulk density, and gravel percentage were measured and calculated then the soil additive weighted index was calculated. Environmental variables in this research were map geomorphology, terrain attributes and data of ETM+ image. Geomorphology map was prepared based on zinc method. Terrain attributes (including 10 parameters), soil adjust vegetative index index (SAVI), and normalized difference vegetative index (NDVI), and brightness index (BI) were computed and extracted using SAGA and Arc GIS software, respectively. To make a relationship between soil quality index and auxiliary data, random forest (RF) model were applied and using cross validation method and statistic criteria including coefficient of determination (R2), mean error (ME) and root mean square error (RMSE) was validated.
Results and Discussion: According to the communality (share of each soil indicator), bulk density, sand, cation exchange capacity and clay had the highest weight (≥ 0.1) and gravel and SAR had the lowest weight (≤0.05) among the soil quality properties. To predict soil quality index, auxiliary variables including slope, SAVI index, wetness index, MrVBF index, LS factor, elevation, NDVI index and geomorphology map were the most important. The results of this study showed that the random forest model with 0.65, 0.042 and 0.062 for determination of coefficient (R2), mean error (ME), and root mean square root (RMSE) had a fairly suitable accuracy for prediction of soil quality index. The soil quality index was ranged between 0.3-0.65 and its mean values in geomorphologic units with low gradient and low soil depth (Mo131, Mo141 and Hi231) were the lowest and in geomorphologic units with low slope and high soil depth (Pi111, Pi311, Pi322, Pi211 and Pi312) were the highest which these differences were statistically significant.
Conclusion: In this research, a randomized forest model was used to study the spatial variation of soil quality index in Ghorveh area of Kurdistan province. The geomorphologic conditions of the study area have affected many soil characteristics and subsequently the soil quality index in the region. The soil quality index content was the lowest in highlands of north, northwest and northeast with high slope and low soil depth. The slope was the most important auxiliary variables to predict soil quality index in the region. Based on the results of statistical indices, random forest model also had relatively accurate estimation of the soil quality index. Therefore, it is suggested to map soil properties podometric techniques (such as randomized forest) and auxiliary data such as geomorphologic map, terrain attributes, and satellite images were applied.

کلیدواژه‌ها [English]

  • Soil quality
  • geomorphology map
  • Landsat
  • terrain attributes
  • random forest
1.Adhikari, K., Minasny, B., Greve, B.G., and Greve, M.H. 2014. Constructing a soil class map of Denmark based on the FAO legend using digital techniques. Geoderma. 214-215: 101-113.
2.Akpa, S.I.C., Odeh, I.O.A., Bishop, F.A., Hartemink, A.E., and Amapu, I.Y.2016. Total soil organic carbon and carbon sequestration potential in Nigeria. Geoderma. 271: 202-215.3.Anderson, E., and John, P. 1982.Soil respiration, P 831-870. In: A. Klute (ed.), Methods of Soil Analysis. Part 2: Chemical and microbiological properties, 2nd ed. Agronomy Monograph. 9: ASA, Madison, WI.
4.Andrews, S.S., Mitchell, J.P., Mancinelli, R., Karlen, K.L., Hartz, T.K., Horwath, W.R., Pettygrove, G.S., Scow, K.M., and Munk, D.S. 2002. On-farm assessment of soil quality in California's central valley. Agron. J. 94: 12-23.
5.Andrews, S.S., Karlen, D.L., and Cambardella, C.A. 2004. The soil management assessment framework: a quantitative soil quality evaluation method. Soil Sci. Soc. Amer. J. 68: 1945-1962.
6.Askari, M.S., O Rourke, S.M.,and Holden, M.M. 2015. Evaluation of soil quality for agricultural production using visible–near-infrared spectroscopy. Geoderma. 243-244: 80-91.
7.Benedetto, A. 2010. Water content evaluation in unsaturated soil using GPR signal analysis in the frequency domain. J. Appl. Geophys. 71: 26-35.
8.Blake, G.R., and Hartage, K.H. 1986. Bulk density, P 363-382. In: A. Klute (ed.), Methods of Soil Analysis. Part 1: physical and Mineralogical Methods,
2nd ed. Agronomy Monograph. 9: ASA, Madison, WI.
9.Biswas, S., Hazra, G.C., Purakayastha, T.J., Saha, N., Mitran, T., Roy, S.S., Basak, N., and Mandal, B. 2017. Establishment of critical limits of indicators and indices of soil quality in rice-rice cropping systems under different soil orders. Geoderma. 292: 34-48.
10.Bower, C.A., Reitemeier, R.F., and Fireman, M. 1952. Exchangeable cation analysis of saline and alkali soils. Soil Science. 73: 251-262.
11.Ceddia, M.B., Vieira, S.R., Villela, L.O., Mota, L.S., Anjos, H.C., and Carvalho, F.D. 2009. Topography and spatial variability of soil physical properties. Scientia Agricola. 66: 338-352.
12.Chau, J.F., Bagtzoglou, A.C., and Willig, M.R. 2011. The effect of soil texture on richness and diversity of bacterial communities. Environmental Forensics. 12: 333-341.
13.Chen, Y.D., Wang, H.Y., Zhou,J.M., Xing, L., Zhu, B.S., Zhao,Y.C., and Chen, X.Q. 2013. Minimum data set for assessing soil quality in farmland of northeast China. Pedosphere. 23: 564-576.
14.Das, B., Chakraborty, D., Singh,V.K., Ahmed, M., Singh, A.K., and Barman, A. 2016. Evaluating Fertilization Effects on Soil Physical Properties Using a Soil Quality Index in an Intensive Rice-Wheat Cropping System. Pedosphere. 26: 6. 887-894.
15.Doran, J.W., and Parkin, B.T. 1994. Defining and assessing soil quality.P 3-21. In: J.W. Doran, D.C. Coleman, D.F. Bezdicek, B.A. Stewart, (eds.), Defining Soil Quality for a Sustainable Environment. American Society of Agronomy, Inc., Soil Science Society of America, Inc., Madison, WI.
16.Gee, G.W., and Bauder, J.W. 1986. Particle size analysis, P 383-411. In: A. Klute. (ed). Methods of Soil Analysis. Part 1: Physical and mineralogical methods, second edition. American Society of Agronomy,Inc., Soil Science Society of America, Inc., Madison, WI.
17.Guo, L., Sun, Z.H., Ouyang, Z.H., Han, D., and Li, F. 2017. A comparison of soil quality evaluation methods for Fluvisol along the lower Yellow River. Catena. 152: 135-143.
18.Jafari, A., Finke, P.A., de Wauw,J.V., Ayoubi, S., and Khademi, H.2012. Spatial prediction of USDA- great soil groups in the arid Zarand region, Iran: comparing logistic regression approaches to predict diagnostic horizons and soil types. Europ. J. Soil Sci. 63: 284-298.
19.Jayachandran, K., Gamare, J.S., Nair, P.R., Xavier, M., and Aggarwal,S.K. 2012. A novel biamperometric methodology for thorium determination by EDTA complexometric titration. Radiochimica Acta, 100: 311-314.
20.Jiang, P., and Thelen, K.D. 2004. Effect of soil and topographic properties on crop yield in a north-central corn soybean cropping system. Agron. J.
96: 252-258.
21.Jones, B.J. 2001. Laboratory guide for conducting soil tests and plant analysis. Boca Raton, London, New York & Washington, D.C. CRC Press, 384p.
22.Karlen, D.L., and Scott, D.E. 1994.A framework for evaluating physical and chemical indicators of soil quality.P 53-72. In: J.W. Doran, D.C. Coleman, D.F. Bezdicek, B.A. Stewart (eds.), Defining Soil Quality for a Sustainable Environment. American Society of Agronomy, Inc., Soil Science Society of America, Inc., Madison, WI.
23.Karlen, D.L., Gardner, J.C., and Rosek, M.J. 1998. A soil quality framework for evaluating the impact of CRP. J. Prod. Agric. 11: 56-60.
24.Lal, R. 1994. Methods and Guidelines for Assessing Sustainable Use of Soil and Water Resources in the Tropics.
The Ohio State University, 78p.
25.Lin, Y., Deng, H., Du, K., Li, j., Lin, H., Chen, C., Fisher, L., and Wu, C. 2017. Soil quality assessment in different climate zones of China’s Wenchuan earthquake affected region. Soil & Tillage Research. 165: 315-324.
26.Manrique, .LA., Jones, C.A., and Dyke, P.T. 1991. Predicting cation exchange capacity from soil physical and chemical properties. Soil Sci. Soc. Amer. J.50: 787-794.
27.McBratney, A.B., Santos, M.L.M., and Minasny, B. 2003. On digital soil mapping. Geoderma. 117: 3-52.
28.McLean, E.O. 1982. Soil pH and lime requirement, P 199-224. 9. In: A.L. Page, R.H. Miller, and D.R. Keeney (eds.), Methods of Soil Analysis, Part 2: Chemical and Microbiological Properties, 2nd ed. American Society of Agronomy, Inc., Soil Science Society of America, Inc., Madison, WI.
29.Nabiollahi, K., Taghizadeh-Mehrjardi, M., Kerry, R., and Moradian, Sh. 2017. Assessment of soil quality indices for salt-affected agricultural land in Kurdistan Province. Iran. Ecological Indicators. 83: 482-494.
30.Nabiollahi, K., Golmohammadi, F., Taghizadeh-Mehrjardi, M., and Kerry, R. 2018a. Assessing the effects of slope gradient and land use change on soil quality degradation through digital mapping of soil quality indices and soil loss rate, Geoderma. 318: 482-494.
31.Nabiollahi, K., Taghizadeh-Mehrjardi, M., and Eskandari, Sh. 2018b. Assessing and monitoring the soil quality of forested and agricultural areas using soil-quality indices and digital soil-mapping in a semi-arid environment. Archive of Agrononomy and Soil Science. 64: 5. 482-494.
32.Nelson, D.W., and Sommers, L.E. 1982. Total carbon, organic carbon and organic matter. P 539-594. In: A.L. Page, R.H., Miller, and D.R., Keeney (eds.), Methods of Soil Analysis, Part 2: Chemical and Microbiological Properties. American Society of Agronomy, Inc., Soil Science Society of America, Inc., Madison, WI.
33.Olsen, S.R., and Sommers, L. 1982. phosohorus, P 403-430. In: A.L. Page (ed.). Methods of soil analysis,Agron. No. 9, Part 2: Chemical and microbiological properties, American Society of Agronomy, Inc., Soil Science Society of America, Inc., Madison, WI.
34.Pahlavan-Rad, M.R., Toomanian, N., Khormali, F., Brungard, C.W., Komaki, C.B., and Bogaert, P. 2014. Updating soil survey maps using random forest and conditioned Latin hypercube sampling in the loess derived soils of northern Iran. Geoderma. 232-234: 97-106.
35.Pahlavan-Rad, M.R., and Akbarimoghaddam, A. 2018. Spatial variability of soil texture fractions and pH in a flood plain (Case study from eastern Iran). Catena. 160: 275-281.
36.Rezaei, S., and Gilkes, R. 2005. The effects of landscape attributes and plant community on soil physical properties in rangelands, Geoderma. 125: 167-176.
37.Soil Survey Staff, 2014. Keys to Soil Taxonomy, 12th edn. United States Department of Agriculture, Washington, 360p.
38.Taghizadeh-Mehrjardi, R. 2016. Modern concepts in Soil Science (Pedometric). Ardakan University Press, 311p. (In Persian)
39.Taghizadeh-Mehrjardi R., Nabiollahi K., and Kerry, R. 2016. Digital mapping of soil organic carbon at multiple depths using different data mining techniques in Baneh region, Iran. Geoderma.253-254: 67-77.
40.Toomanian, N., Jalalian, A., Khademi, H., Karimian Eghbal, M., and Papritz, A., 2006. Pedodiversity and pedogenesis in Zayandeh-rud Valley, central Iran. Geomorphology. 81: 376-393.
41.Were, K., Bui, D.T., Dick, Q.B., and Singh, B.R. 2015. A comparative assessment of support vector regression, artificial neural networks, and random forests for predicting and mapping soil organic carbon stocks across an Afromontane landscape. Ecological Indicators. 52: 394-403.
42.Wischmeier, W.H., and Smith, D.D. 1978. Predicting rainfall erosion losses: a guide to conservation planning. U.S. Dep. Agric. Handb. No. 537. Pp: 1-69.
43.Zhang, Y., Xu, X., Li, Z., Liu, M., Xu, C., Zhang, R., and Luo, W. 2019. Effects of vegetation restoration on soil quality in degraded karst landscapes of southwest China. Science Total Environment. 650: 2657-2665.