المستودع الرقمي لـقسم التربة والمياه

Abstract F01 The third assessment report of intergovernmental panel on climate change (IPCC) represented a consensus among the world’s leading climate scientists that rapid climate changes were occurring on a global scale and define climate change as “any change in climate over time, whether due to natural variability or as a result of human activity”. Climate change indicators should give an overview of the climate and it’s development. Climate change indicators are primarily used to simplify the complex reality and to communicate, more succinctly of critical information regarding climate trends. In establishing indicators, a distinguish can be made between primary indicators based on analysis of directly observed meteorological data, and secondary indicators based on responses of the living world to climate changes which provoke in living organisms. Precipitation data in the region were obtained from the Libyan National Climate Center (LNCC). The runoff collected in dams records were obtained from General Water Authority (GWA). The research has assessed a few of potential indicators for western region of Libya and has established several potentially valuable data sources which satisfy or partially satisfy the requirements that a good indicators should have. The runoff monitoring began 1972 when there is no awareness of climate change, but the importance of this data has now been realized. Both the meteorological data and water resource monitoring data have been shown to provide useful information on climate change in Libya. Clearly the climate in Libya is changing, as it always has, and as it always will. The indicators examined in this study suggest that despite a maritime location buffered by the Mediterranean sea from extremes of climate. Libya is mirroring, albeit at a some what delayed the climate change rate, not as the trends apparent at global scale. This study show importance of climatological data and water resource data records, and importance of depending on charting of climate data for more accuracy in predicting climate change. Key words: Climate, Climate change, Climate change indicators, Libya. Western region, arabic 12 English 67
Abdulfatah F Aboufayed(1-2014)

Soil ecosystem services (ES) (e.g., provisioning, regulation/maintenance, and cultural) and ecosystem disservices (ED) are dependent on soil diversity/pedodiversity (variability of soils), which needs to be accounted for in the economic analysis and business decision-making. The concept of pedodiversity (biotic + abiotic) is highly complex and can be broadly interpreted because it is formed from the interaction of atmospheric diversity (abiotic + biotic), biodiversity (biotic), hydrodiversity (abiotic + biotic), and lithodiversity (abiotic) within ecosphere and anthroposphere. Pedodiversity is influenced by intrinsic (within the soil) and extrinsic (outside soil) factors, which are also relevant to ES/ED. Pedodiversity concepts and measures may need to be adapted to the ES framework and business applications. Currently, there are four main approaches to analyze pedodiversity: taxonomic (diversity of soil classes), genetic (diversity of genetic horizons), parametric (diversity of soil properties), and functional (soil behavior under different uses). The objective of this article is to illustrate the application of pedodiversity concepts and measures to value ES/ED with examples based on the contiguous United States (U.S.), its administrative units, and the systems of soil classification (e.g., U.S. Department of Agriculture (USDA) Soil Taxonomy, Soil Survey Geographic (SSURGO) Database). This study is based on a combination of original research and literature review examples. Taxonomic pedodiversity in the contiguous U.S. exhibits high soil diversity, with 11 soil orders, 65 suborders, 317 great groups, 2026 subgroups, and 19,602 series. The ranking of “soil order abundance” (area of each soil order within the U.S.) expressed as the proportion of the total area is: (1) Mollisols (27%), (2) Alfisols (17%), (3) Entisols (14%), (4) Inceptisols and Aridisols (11% each), (5) Spodosols (3%), (6) Vertisols (2%), and (7) Histosols and Andisols (1% each). Taxonomic, genetic, parametric, and functional pedodiversity are an essential context for analyzing, interpreting, and reporting ES/ED within the ES framework. Although each approach can be used separately, three of these approaches (genetic, parametric, and functional) fall within the “umbrella” of taxonomic pedodiversity, which separates soils based on properties important to potential use. Extrinsic factors play a major role in pedodiversity and should be accounted for in ES/ED valuation based on various databases (e.g., National Atmospheric Deposition Program (NADP) databases). Pedodiversity is crucial in identifying soil capacity (pedocapacity) and “hotspots” of ES/ED as part of business decision making to provide more sustainable use of soil resources. Pedodiversity is not a static construct but is highly dynamic, and various human activities (e.g., agriculture, urbanization) can lead to soil degradation and even soil extinction. arabic 7 English 46
Elena A. Mikhailova , Hamdi A. Zurqani , Christopher J. Post , Mark A. Schlautman, Gregory C. Post (3-2021)

Sunshine duration (SD) is an essential atmospheric indicator which is used in many agriculture, ‎architects and solar energy applications. In many situations where data of sunshine duration may not be ‎available due to temporal and financial constraints, developing alternative indirect methods based on ‎theoretical considerations for determining SD are essentially required. In this study, seven models were ‎developed using stepwise regression technique to estimate monthly sunshine duration for Libya. The ‎predictors which were used as inputs differ from one model to another and they included monthly ‎cloudiness index, total day length, mean relative humidity, depth of precipitation, mean maximum ‎temperature, altitude and longitude over 16 meteorological stations spread across Libya during the ‎period of 1961 – 2000 . The evaluation of the developed models was performed using a set of data of ‎four meteorological stations representing different physiogeographic and climatic zones during 2001 ‎and against Abdelwahed and Snyder (2015) equations which were developed for estimating sunshine ‎duration for Libya. The statistical parameters of evaluation criteria included mean absolute error (MAE), ‎root mean square error (RMSE), (RMSE %) and Nash and Sutcliffe Efficiency (NSE). The linear regression ‎equation relating predicted with measured data with intercept equals zero and determination coefficient ‎‎(R2) were also used for evaluation purpose. According to the performance indicators, it was detected ‎that six of the developed models were superior to the model with one parameter (cloudiness index) in ‎estimating the sunshine hours. It was also found that all the developed models have better performance ‎in estimating the sunshine duration as compared with Abdelwahed and Snyder (2015) equations. ‎However, due to its few required variables, a model with two parameters (cloudiness index and total ‎day length) is sufficient and can be used with confidence in estimating sunshine duration for Libya. ‎ Keywords: Sunshine duration, Stepwise regression, Statistical model.‎ arabic 15 English 69
ِAhmed Ibrahim Ekhmaj, Milad Omran Alwershefani(12-2016)

تم استخدام طريقة كريكينج من النوع الاعتيادي (OK)وطريقة مقلوب المسافة الموزونة (IDW) للتنبؤ المكاني لتلوث مياه الخزانات الجوفية الضحلة لمنطقة طرابلس بمياه البحر عام 2016 .استعملت نسبة سيمبسون كمؤشر لتلوث المياه الجوفية بمياه البحر على عدد 42 عينة. طبقت طريقة كريكنج من النوع الاعتيادي على البيانات قبل وبعد إجراء التحويل اللوغاريتمي، وتم تقدير التركيبة المكانية عبر استخدام النماذج الكروية والأسية والكأسية. وقد استخدمت تقنية التحقق المتقاطع لتقييم عملية الاستنباط الناتجة عن استخدام طريقة (OK) وطريقة (IDW) بقيم أس تتراوح بين (1،5). تم تقييم أداء نماذج الفاريوجرام (Variogram) باستخدام معامل التحديد ( R2) ومجموع مربعات البواقي (RSS)، واستخدم كل من الجذر التربيعي لمربع الخطأ (RMSE) ومتوسط الخطأ النسبي (MRE) لتقييم دقة النتائج المتحصل عليها من تقنية التحقق المتقاطع. أظهرت النتائج أن أداء نماذج الفاريوجرام قبل التحويل اللوغاريثمي كان أكثر دقة، من ذلك المتحصل عليها بعد التحويل اللوغاريثمي، وأن أفضلهم أداءً هو النموذج الكأسي قبل عملية التحويل اللوغاريثمي بقيمة 0.463، 4.30 ،وذلك لكل من(R2) و(RSS) ،على التوالي. كما بينت النتائج وفقاً لتقنية التحقق المتقاطع أن طريقة (OK) عبر استخدام النموذج الكأسي قبل التحويل اللوغاريثمي وطريقة (IDW) بأس مسافة يساوي 1 أعطت النتائج الأكثر دقة، مع الأفضلية لطريقة (OK) بقيم 0.535، 0.246، 0.249 وذلك لكل من (RMSE)، (MRE) و(R2)، على التوالي. وقد أوضحت الخريطة المتحصل عليها من تطبيق طريقة (OK) باستخدام النموذج الكأسي، أنه على الرغم من أن 55.76 %من مساحة منطقة الدراسة صنفت مياهها الجوفية بأنها ذات تلوث طفيف بمياه البحر، إلا أن هناك زيادة في خطورة تلوث المياه الجوفية في الحدود الجنوبية شرقية والشمالية الغربية منها. الكلمات المفتاحية: المياه الجوفية، تداخل مياه البحر، نسبة سيمبسون، الإحصاء المكاني، التحقق. arabic 261 English 5
أحمد إبراهيم خماج, عبدالرحمن أحمد الرياني(10-2020)

Many soil regulating ecosystem services (ES) are linked to Earth’s atmosphere, but associated monetary values often are unknown or difficult to quantify. Atmospheric deposition of calcium (Ca2+) and magnesium (Mg2+) are abiotic flows (wet, dry, and total) from the atmosphere to land surfaces, which potentially can become available to sequester carbon (C) as soil inorganic carbon (SIC). However, these processes typically have not been included in economic valuations of ecosystem services. The primary objective of this study was to demonstrate an approach for valuing non-constrained potential SIC sequestration from atmospheric Ca2+ and Mg2+ deposition based on the concept of the avoided social cost of carbon dioxide emissions (SC-CO2). Maximum monetary values associated with the non-constrained potential SIC sequestration were compiled for the contiguous United States (U.S.) by soil order, land resource region (LRR), state, and region using available deposition data from the National Atmospheric Deposition Program (NRSP-3). For the entire contiguous U.S., an average annual monetary value for the non-constrained potential SIC sequestration due to atmospheric Ca2+ and Mg2+ deposition was $135M (i.e., $135 million U.S. dollars, where M = million = 106). Mollisols, Alfisols, and Entisols were soil orders with the highest average annual monetary values for non-constrained potential SIC sequestration. When normalized by land area, however, Vertisols had the highest average annual monetary values followed by Alfisols and Mollisols for non-constrained potential SIC sequestration. From a more agricultural perspective, the LRRs with the highest average annual monetary values for non-constrained potential SIC sequestration were the Western Range and Irrigated Region (D), the Central Feed Grains and Livestock Region (M), and the Central Great Plains Winter Wheat and Range Region (H). When normalized by area, the LRRS with the highest average annual monetary values were the Southwest Plateaus and Plains Range and Cotton Region (I) and the Florida Subtropical Fruit, Truck Crop and Range Region (U). Among the U.S. states, the highest average annual monetary values for non-constrained potential SIC sequestration were Texas, Kansas, and New Mexico, but when normalized by area the highest values by state were Kansas, Iowa, and Texas. Geographical regions in the contiguous U.S. with the highest average annual monetary values for non-constrained potential SIC sequestration were the South Central, Midwest, and West; when normalized by area, the highest values by region were South Central, Midwest, and Northern Plains. Constraints on maximum monetary values, based on physical, chemical, biological, economic, social, and political limitations, need to be considered and quantified to obtain more precise and accurate accounting of the ES associated with SIC sequestration due to atmospheric Ca2+ and Mg2+ deposition. arabic 14 English 112
Elena A. Mikhailova, Hamdi A. Zurqani, Christopher J. Post, Mark A. Schlautman(5-2020)

Soil textural information is an important component underlying other soil health indicators. Soil texture analysis is a common procedure, but it can be labor intensive and expensive. Soil texture data typically are available from the Soil Survey Geographic (SSURGO) database, which may be an option for determining soil health texture groups (SHTG). The SSURGO database provides soil texture information in the soil map unit (SMU) name, taxonomic class category (family), and detailed values (≤ 2 mm soil fraction) of percent sand, silt and clay by soil horizon. The objective of this study was to examine the possibility of using SSURGO data for SHTG at the 147-ha Cornell University Willsboro Research Farm in New York state as an alternative for soil texture data determined manually on collected soil core samples. Comparative results revealed that representative values for soil texture from the SSURGO database generally matched measured mean values for all SMUs. arabic 11 English 65
Elena Mikhailova, Christopher Post, Mark Schlautman, John Galbraith, Hamdi Zurqani(9-2019)

Soil databases are very important for assessing ecosystem services at different administrative levels (e.g., state, region etc.). Soil databases provide information about numerous soil properties, including soil inorganic carbon (SIC), which is a naturally occurring liming material that regulates soil pH and performs other key functions related to all four recognized ecosystem services (e.g., provisioning, regulating, cultural and supporting services). However, the ecosystem services value, or “true value,” of SIC is not recognized in the current land market. In this case, a negative externality arises because SIC with a positive value has zero market price, resulting in the market failure and the inefficient use of land. One potential method to assess the value of SIC is by determining its replacement cost based on the price of commercial limestone that would be required to amend soil. The objective of this study is to assess SIC replacement cost value in the contiguous United States (U.S.) by depth (0–20, 20–100, 100–200 cm) and considering different spatial aggregation levels (i.e., state, region, land resource region (LRR) using the State Soil Geographic (STATSGO) soil database. A replacement cost value of SIC was determined based on an average price of limestone in 2014 ($10.42 per U.S. ton). Within the contiguous U.S., the total replacement cost value of SIC in the upper two meters of soil is between $2.16T (i.e., 2.16 trillion U.S. dollars, where T = trillion = 1012) and $8.97T. States with the highest midpoint total value of SIC were: (1) Texas ($1.84T), (2) New Mexico ($355B, that is, 355 billion U.S. dollars, where B = billion = 109) and (3) Montana ($325B). When normalized by area, the states with the highest midpoint SIC values were: (1) Texas ($2.78 m−2), (2) Utah ($1.72 m−2) and (3) Minnesota ($1.35 m−2). The highest ranked regions for total SIC value were: (1) South Central ($1.95T), (2) West ($1.23T) and (3) Northern Plains ($1.01T), while the highest ranked regions based on area-normalized SIC value were: (1) South Central ($1.80 m−2), (2) Midwest ($0.82 m−2) and (3) West ($0.63 m−2). For land resource regions (LRR), the rankings were: (1) Western Range and Irrigated Region ($1.10T), (2) Central Great Plains Winter Wheat and Range Region ($926B) and (3) Central Feed Grains and Livestock Region ($635B) based on total SIC value, while the LRR rankings based on area-normalized SIC value were: (1) Southwest Plateaus and Plains Range and Cotton Region ($3.33 m−2), (2) Southwestern Prairies Cotton and Forage Region ($2.83 m−2) and (3) Central Great Plains Winter Wheat and Range Region ($1.59 m−2). Most of the SIC is located within the 100–200 cm depth interval with a midpoint replacement cost value of $2.49T and an area-normalized value of $0.34 m−2. Results from this study provide a link between science-based estimates (e.g., soil order) of SIC replacement costs within the administrative boundaries (e.g., state, region etc.). arabic 19 English 114
Garth Groshans, Elena Mikhailova, Christopher Post, Mark Schlautman, Hamdi Zurqani, Lisha Zhang(12-2018)

A “soil carbon hotspot” (SCH) is a geographic area having an abundance of soil carbon, and therefore higher ecosystem services value based on avoided social costs of CO2 emissions. Soil organic carbon (SOC), soil inorganic carbon (SIC), and total soil carbon (TSC) are critical data to help identify SCH at the farm scale, but monetary methods of hotspot evaluation are not well defined. This study provides a first of its kind quantitative example of farm-scale monetary value of soil carbon (C), and mapping of SCH based on avoided social cost of CO2 emissions using both Soil Survey Geographic (SSURGO) database and field measurements. The total calculated monetary value for TSC storage at the Willsboro Farm based on the SSURGO database was about 7.3 million U.S. dollars ($7.3 M), compared to $2.8 M based on field data from averaged soil core results. This difference is attributed to variation in soil sampling methodology, laboratory methods of soil C analyses, and depth of reported soil C results. Despite differences in total monetary valuation, observed trends by soil order were often similar for SSURGO versus field methods, with Alfisols typically having the highest total and area-normalized monetary values for SOC, SIC, and TSC. Farm-scale C accounting provides a more detailed spatial resolution of monetary values and SCH, compared to estimates based on country-level reports in soil survey databases. Delineation and mapping of SCH at the farm scale can be useful tools to define land management zones, to achieve social profit for farmers, and to realize United Nations (UN) Sustainable Development Goals (SDGs) based on avoided social cost of CO2 emissions. arabic 24 English 105
Elena Mikhailova, Christopher Post, Mark Schlautman, Gregory Post, Hamdi Zurqani(1-2020)