Automated Land Evaluation System Research Articles

Land suitability Assessment Rubber Commodities ( Hevea brasiliensis) In Nias Selatan District Scale 1: 250,000

South Nias district was the new district developed of Nias district in 2003. South Nias was part of area hit earthquake and tsunami in 2004 and 2005. The district was the producer of rubber which second superiority commodities after coconut. There were 29,125 Ha of rubber area in South Nias (Statistic of Sumatera Utara Province. 2021). This research activity was carried out in 6 subdistricts in Nias Regency in January 2019 - November 2019. Assessment of land suitability was needed in order to know a directions of superiority commodities development area. This assessment was conducted by using ALES (Automated Land Evaluation System). SDPLE (Standard Procedure for Land Evaluation) data was imported to ALES program. Land evaluation result was show in spatial form. This form made by imported tabulation data to GIS (Geographical Information System) form. Suitability land maps (scale 1 : 250.000) present based on each commodities by ArcView program.
 Keywords : Suitability land; rubber; South Nias

The application of LSE software: A new approach for land suitability evaluation in agriculture

Land suitability evaluation has been considered one of the viable approaches for limiting conflicts regarding agricultural land use and stabilizing specialized croplands for the sustainable development of mountainous regions. There are various land assessment tools that have been applied worldwide. Recently, new software called LSE (Land Suitability Evaluation) was developed and applied. This article aimed to assess the performance of LSE and the automated land evaluation system (ALES) software by comparing the results generated from ALES and LSE. This study was carried out to compare and verify the outputs of ALES and LSE software in determining the appropriate lands for orange and tea cultivation in western Nghe An, Vietnam. Fifteen ecological criteria were used to evaluate the land suitability for orange cultivation, and 10 ecological criteria were used to evaluate land suitability for tea cultivation. The study results show that the land evaluation process of LSE software has some outstanding advantages, such as high flexibility, time savings, and higher objectivity, confidence and accuracy. It is a new tool for land evaluators, scientists, and managers to use in determining land suitability and land use planning. The overall land suitability evaluation revealed that lands very suitable for orange cultivation cover 64,505.9 ha and that those suitable for tea plantation cover 69,388.8 ha, fully meeting the regional cultivation planning up to 2030 in the western Nghe An region.

Aptitud forestal de las tierras no agrícolas del norte de la provincia de Buenos Aires (Argentina)

El objetivo de este trabajo fue clasificar, cuantificar y cartografiar la aptitud forestal de las tierras no agrícolas del N-NE de la provincia de Buenos Aires. Para ello se aplicó el software Automated Land Evaluation System (ALES) propuesto por la FAO. Las especies consideradas fueron: E. camaldulensis, E. dunnii; E. saligna, E. tereticornis, E. viminalis y los géneros Salix spp. y Populus spp. Se utilizaron las Cartas de Suelos de la provincia de Buenos Aires escala 1:50.000 del INTA. Como criterios diagnósticos se utilizaron la profundidad de fluctuación de la napa freática, el pH, la textura del horizonte superficial y el drenaje, entre otros. El balance de superficies indica que existen 92.089 ha de tierras aptas para implantar E. camaldulensis de las cuales el 13% se consideran sin limitantes. Para E. tereticornis existen 91.841 ha aptas, donde el 13% son muy aptas. La superficie de tierras aptas para E. saligna y E. viminalis alcanzó las 40.718 ha de las cuales el 30% son muy aptas. Estas dos especies presentan restricciones climáticas en el área evaluada debido a la susceptibilidad al frío en el período de implantación. Para E. dunnii, con 40.718 ha, no se identificaron tierras muy aptas. En cuanto al género Populus, el potencial de tierras disponibles es de 42.000 ha, siendo el 29% muy aptas. Para el género Salix la superficie fue de 47.243 ha. Estos resultados muestran que existe una importante superficie de tierras potencialmente aptas para el desarrollo de una cuenca forestal en la región sin competencia con la agricultura.

GIS-based Analysis of Indigenous and Technical Knowledge of Soil Suitability Evaluation of Cocoa, Citrus and Oil Palm in Ejisu-Juabeng District, Ashanti Region, Ghana

A study was carried out to assess local knowledge about soil suitability in four villages in the Ejisu- Juabeng District in the Ashanti region of Ghana. This study described two approaches in soil mapping using geopedologic approach promoted by Zinck (1988) and the farmer approach using their spatial knowledge and experience. Both maps were assessed for their suitability for cocoa, oil palm and citrus. First, farmers created their soil map and then assessed the soil suitability for a selected number of tree crops which are important for them economically. Secondly, on the other side which is the side of the expert, the approach for soil suitability classification was performed using the Automated Land Evaluation System (ALES) which uses the Food and Agriculture Organization (FAO) framework for land evaluation that defines suitability by employing matching (comparison) between land quality/land characteristics and land use requirement. The expert and farmer suitability maps were then compared using spatial analysis within the Geographic Information Systems (GIS) environment to determine levels of spatial correlation and the level of agreement among the maps. Farmers’ suitability maps for cocoa accounted for 81% of the study area, citrus and oil palm accounted for 71% and 26% respectively. In the expert suitability map 66% of the study area was suitable for cocoa, citrus and oil palm accounted for 41%and 39% respectively. The overall accuracy from the map comparison was 67% for cocoa, 43% for citrus and 14% for oil palm. The results of spatial correlation between expert and local soil suitability map units reflect differences and similarities in the ways both systems classify soils. Critical is the evaluation of topsoil characteristics, as the understanding and monitoring of topsoil dynamics are fundamental for land use decision-making by farmers. Merging technical and local thinking is indispensable to formulate sustainable land management schemes for agricultural production

ASSESSING LAND CAPABILITY POTENTIALITIES OF THE WESTERN DESERT FRINGES FOR AGRICULTURAL DEVELOPMENT USING REMOTE SENSING TECHNIQUES AND GEOGRAPHIC INFORMATION SYSTEMS” ENVIRONMENTAL ECONOMIC STUDY ON FAYOUM GOVERNORATE, BENISUEF AND MINYA

Egypt's national development plans aim primarily at increasing the area of ​​agricultural land, which is an important national goal to control the gap between food production and consumption. Agricultural development affects economically and environmentally at the national level. The objective of the study is the environmental and economic assessment of sustainable development, Human and environmental and economic impact studies. In this study, the techniques of remote sensing and geographic information systems have been used to develop scenarios of land use change and future forecasting for the most suitable places where agricultural development is carried out in the Western Desert Fringes. The statistical approach, sensing and geographic information systems have been used to assess and develop the economic conditions to reach the scenarios of land validity for development and ways of future expansion. Satellite processing programs such as ENVI-5.2, GIS 10.2 ARC-GIS, and the Automated Land Evaluation System (ALES). Many field visits were required to verify the data and economic data were used to estimate average production costs per feddanFor most crops, as well as estimating the average net yield of feddan of field crops to calculate the economic effect of the net yield of feddan of field crops to see the economic gains in the study area. The results of the research showed the techniques of remote sensing in monitoring the changes of the desert lands for 2001 - 2014, proved that the reclaimed agricultural lands increased at the expense of the desert lands where the size of the reclaimed area in 2001 (111,644 acres) and in 2014, the size of the reclaimed agricultural area (273,539 feddans) showed the results of ALES in determining the suitability and suitability of the land for sustainable development through criteria for predicting the appropriate soil and water crops for agricultural development, (Wheat, sugar beet) and summer crops (including peanuts and tomatoes). The research recommendations included the expansion of the use of saline, thirst and heat tolerant crop cultivars, which are compatible with the harsh desert environment in the Western Desert Fringes, to encourage scientific research in the field of development prior to the implementation of any projects.

ASSESSMENT OF COMMODITIES AREA GAMBIER (Uncaria gambir Roxb.) IN PAKPAK BHARAT SCALE 1 : 50.000

Gambier (Uncaria gambier Roxb.) is a cultivated plant regeneration in Pakpak Bharat. Gambir extract benefits as well as the pharmaceutical industry and traditional is quite interested so that market opportunities gambier quite open for the domestic market and abroad. Land potential and development opportunities gambir high enough, it is in the use of plantation area of 1,224 ha and optimization of dry land area of 16 049, 6 hectares (Pakpak Bharat in Figures, 2013). Gambier development in Pakpak Bharat tends to increase, so it is necessary to study the suitability of land to see the direction of the development of the appropriate location. This assessment was conducted by using ALES (Automated Land Evaluation System). SDPLE (Standard Procedure for Land Evaluation) data was imported to ALES program. Land evaluation result was show in spatial form. This form made by imported tabulation data to GIS (Geographical Information System) form. Suitability land maps (scale 1 : 250.000) present based on each commodities by ArcView program.

EVALUASI LAHAN FISIK DAN EKONOMI KOMODITAS PERTANIAN UTAMA TRANSMIGRAN DI LAHAN MARJINAL KERING MASAM RANTAU PANDAN SP-4, PROVINSI JAMBI

Most of the land used for transmigration resettlement activities outside of Java Island is marginal land that requires highproduction inputs and susceptible to degradation. One of the need to be taken into consideration in the choice of location is land suitability. The objective of this study is to determine the land suitability of agricultural transmigration area with a case study of Transmigration Settlement Unit (UPT) of RantauPandan SP-4, Jambi Province, for cultivation of food crops, vegetables and perennial crops and analyse the level of biophysical and economical feasibility of several commodities. The actual land suitability assessment for the three agricultural commodities indicate the dominance land suitability classes of S3 (marginally suitable) with terrain, nutrient retention and nutrients available become dominant limiting factors. Economic land suitability analysis indicate that the biggest gross margin is rubber, while the smallest is rice. Results of analysis are used to determine the spatial land use recommendations on transmigration location. Results of analysis are not always in line with the transmigration pattern of land allocation. Nonetheless, these results suggested to be applied, for considerations of land conservation as well as farmers' welfare.Keywords: land suitability, automated land evaluation system, land quality, land characteristic

Land use planning of paddy field using geographic information system and land evaluation in West Lombok, Indonesia

Planning analysis to increase rice production either through intensiḀcation of existing paddy Ḁeld area or ex-tensiḀcation in potential land area was conducted in West Lombok Regency, West Nusa Tenggara Province, Indonesia. Existing paddy Ḁeld was delineated using high-resolution data from IKONOS imagery of 2012. Land use and land cover outside existing paddy Ḁeld were interpreted using SPOT-5 imagery of 2012. ἀe Automated Land Evaluation System (ALES) was used for land suitability analysis for paddy. ἀe results are interpreted in terms of the potential of paddy Ḁeld intensiḀcation in existing paddy Ḁeld area and the potential of extensiḀcation in land potentially used for paddy Ḁeld. ἀe result of analysis showed that in West Lombok Regency, there are still possible to do intensiḀcation and extensiḀca-tion of paddy Ḁeld to increase rice production in order to improve regional food security.

Assessment of optimum land use and water requirements for agricultural purpose in some soils South Paris Oasis, Western Desert, Egypt

The current work is aimed to realizing land suitability and water use efficiency and determining the optimum land use system. The main aims were to identify the physiographic futures and calculate the crop water requirements for specific crops. The study area was observed through a soil survey inventory in Paris Oasis, Western Desert, Egypt. Ten soil profiles plus a number of auger observations and mini pits were selected to represent the different mapping units. A fieldwork and morphological description were carried out, and soil samples were collected for demonstrating the physical and chemical soil properties. Based on satellite data that can integrate with GIS utility, field work, and laboratory analysis, the physiographic map was generated. The study found that the main land type units are plateaus, hills, dunes, and depression floor. Concerning the second aim, the main land qualities of different mapping units were rated and matched to obtain the current and potential land suitability using automated land evaluation system. This research concluded that the best crops adapted with the soil conditions and could be feasible for economic use are clover, wheat, beans, sugar beet, onions, maize, sunflower, tomato, potato, groundnut, pea, lentil, barley, sesame, and carrots. Crop water requirements were determined in variable rate according to the actual plant requirements using the aid of FAO–Cropwat model. Irrigation schedule and consumptive use of suitable crops were calculated and adopted. The crop water requirements for each selected crop were determined as follow: 828.0, 596.7, 410.3, 679.95, 409.52, 791.60, 712.2, 902.93, 456.55, 529.95, 231.4, 217.95, 303.93, 502.65, and 274.35 mm, respectively.

Land Suitability Evaluation for Tea and Food Crops in Kabarole District, Western Uganda

The study was conducted in Busoro Sub County in Kabarole District to assess the physical and economic suitability of the land for tea, maize and bananas. Physical suitability was evaluated using a soil map for the study area. Soil types with their parameters of Cation Exchange Capacity, base saturation, pH, organic matter, nitrogen, potassium, and phosphorous were studied. Climate of the area was studied using annual monthly rainfall and temperature values for the area for more than thirty years. Production costs, market prices and annual yields per hectare for tea, maize and bananas were computed. Using Net Present Value approach, the economic suitability of each crop was computed. The economic and physical parameters were entered into a model built in Automated Land Evaluation System (ALES) software using the decision trees. Overall suitability evaluation results were produced for each of the respective crops. Results of the study indicated that different soil types (management units) had varying suitability among the three crops. Tea registered higher overall economic suitability followed by bananas and then maize. However, bananas presented a higher overall physical suitability on all soil types followed by tea and maize. The study recommends conducting a mini agro-ecological zonation in planning and decision for maximum utilization of the land resources for a potential LUT is an important in ensuring improved agricultural livelihoods and household income.

CHARACTERISTICS AND LAND POTENTIAL FOR VEGETABLE DEVELOPMENT IN TEMANGGUNG DISTRICT, CENTRAL JAVA

Vegetables are mostly grown in mountainous areas with an altitude >400 m a.s.l., such as Temanggung, Central Java. The steep slope farming considers very little environmental suitability and sustainability. This study was conducted in 2004, covering a total area of 87,223 ha. Soil samples were analyzed for soil texture, pH, C, N, P, K, CEC, exchangeable cations, and base saturation. Soil characteristics data were used for land suitability evaluation for vegetables crops using the Automated Land Evaluation System (ALES) program. The results showed that 36,992 ha (42.4%) of the area is located in the elevation of 400-700 m a.s.l. and about 46,786 ha (53.6%) with elevation >700 m a.s.l. The district is dominated by volcanic parent materials (83.31%), deriving Andisols with shallow ( 15% covering 40,600 ha (46.55%) area. The district’s annual rainfall ranges from 2,375-3,054 mm with 7-9 wet months (rainfall >200 mm) and <3 dry months (rainfall <100 mm). Land suitability analysis indicated that <15% of the total area is very suitable (S1) for vegetables. The majority of the land is moderately suitable (S2) and marginally suitable (S3) for asparagus, garlic, green beans, chili, long beans, potatoes, cabbage and tomatoes, with limiting factors of steep slope, coarse to stony texture, high nutrient retention and low water availability. Other limiting factors include high rainfall, weak aggregates of the Andisols, and steep slopes, causing a high erosion hazard, unless proper soil conservation measures are implemented. Selection and implementation of locally adaptable conservation techniques and P nutrient management are important for sustainable vegetable farming in this area.

Analisis Kesesuaian Lahan Tingkat Satuan Pemukiman Menggunakan Automated Land Evaluation System (Ales): Studi Kasus Rantau Pandan Sp-1, Provinsi Jambi

Landuse planning according to biophysical and economical land suitability as well as basic allocation for transmigration should be done in order to improve the well-being of transmigrants. Suitability should be analyzed for the selection of commodities which are the most appropriate biophysically and profitable economically. The study was done in the settlements unit of Rantau Pandan SP-1, Jambi Province. The study was conducted to determine the suitability of each part of land for cultivation of food crops, vegetables and perennial crops and to see the biophysical suitability and economical feasibility. The goal is to recommend the most appropriate type of cultivation. This study integrate the Arc-View GIS and Automated Land Evaluation System (ALES) in the analysis of land suitability. The results showed that four agricultural commodities were observed showing land suitability class domination of S3 (marginally suitable) with the most dominant limiting factors were erosion and nutrient retention. The results of the analysis have been used for the determination of land use recommendations in the transmigration sites, presented spatially. Recommendations given based on the results of the analysis were not always in line with the land use recomended by government on dry land transmigration. Nonetheless, these results was suggested to be applied, either by considerations of conservation land and the consideration of economic benefit and farmers welfare. Key words: Land evaluation, transmigration, dry land farming, geographic information system

Assessing crop water requirements on the bases of land suitability of the soils South El Farafra Oasis, Western Desert, Egypt

The aims of this study are: (1) producing a geometrically corrected physiographic soil map scale 1:50,000 reduced to the attached map; (2) crop water requirements calculation for the suitable crops in this area. To fulfill the first aim, ten soil profiles were selected to represent the different mapping units. Morphological description was carried out and soil samples were collected for physical and chemical analysis. Based on the Enhanced Thematic Mapper Plus images and the geographic information system, coupled with the field work and laboratory analysis data, the physiographic soil map was produced. Satellite images interpretation indicated that the investigated area includes the main physiographic units are plateaus, hilland, mountain, and depression floor. With respect to the second aim, the main land qualities of the different mapping units and the crop requirement were rated and matched to obtain the current and potential land suitability using Automated Land Evaluation system. The most suitable crops for the studied area were: clover, wheat, beans, sugar beet, onions, maize, sunflower, tomato, potato, groundnut, pea, lentil, barley, sesame, and carrots. The crop water requirements for the selective crops were calculated using CROPWAT 8.0 for Windows program as: 781.80, 571.70, 383.20, 641.55, 395.45, 771.80, 693.90, 880.32, 432.00, 510.30, 205.05, 201.30, 284.20, 487.95, and 254.85 mm, respectively.

Use of satellite data and GIS for assessing the agricultural potentiality of the soils South Farafra Oasis, Western Desert, Egypt

Overpopulation and food security are the main global problems alert decision makers. In developing countries, such problem put extra pressure for horizontal expansion for agricultural development. The rapid sprawl of urbanized areas on the alluvial land of the River Nile and delta to accommodate the population growth has encouraged governmental and private sector for agricultural expansion in the desert. Unless there are reliable information and accurate studies for land and soil suitability, there will be a collapse of such investment. To evaluate the potential suitability of soil for agriculture development in areas of the western desert, satellite images, geographic information, and field survey including soil profiles and artesian water samples with laboratory analysis were integrated to classify the soils according their suitability for specific crop. The main land qualities of the different mapping units and the crop requirement were rated and matched to obtain the current and potential land suitability using Automated Land Evaluation System “ALES”. The study found that the main physiographic units are plateaus, hilland, mountain, and depression floor. But there are three limiting parameters for land suitability which are the lack of nutrient elements, wind erosion vulnerability, and soil texture. The study concluded that the best crops adapted with the soil conditions and could be feasible for economic use are: (1) native vegetation such as agol, sand trees, sammar, halfaa, bawaal, qordaob, bardi, and qortom; (2) filed crops such as onion, garlic, watermelon and wheat; and (3) fruits such as olive and date palms.

Use of spatial analyses techniques to suggested irrigation scheduling in Wadi El Natrun Depression, Egypt

The main objective of this study is to produce a geometrically corrected physiographic-soil map scale 1:50.000 reduced to the attached map scale 1:250.000 for the studied area as a base for optimum land use and its crop water requirements in Wadi El Natrun Depression. To fulfill this objective, eight soil profiles were chosen to represent the different mapping units. Morphological description was carried out and soil samples collected for physical and chemical analysis. The physiographic-soil map was produced based on the aerial photo-interpretation, land surveying, geographic information system, and laboratory analyses data. Where the aerial photographs were acquired in 1991, a recent Landsat ETM+image of the study area acquired during the year 2009 was used for updating the landform units. The obtained data reveal that the main landforms in the depression include flat sand sheet (6.82%), gently undulating sand sheet (30.31%), almost flat sand sheet (4.95%), undulating sand sheet (17.31%), undulating sand ripples (13.13%), undulating sandy gravel plain (20.23%), and wet sabkha (7.26%). The main land qualities of the different mapping units and the crop requirement were rated and matched to obtain the current and potential land suitability using automated land Evaluation system “ALES”. Then, the crop water requirements were calculated by using (Crop wat 4.2) program. The crop water requirements of Clover, Wheat, Beans, Sugar beet, Onion, Maize, Sunflower, Tomato, and Groundnut are 659.70, 482.40, 320.00, 534.60, 327.42, 569.50, 606.40, 751.20, and 453.10 mm, respectively.

Crop water requirements in selective wetland areas, West Suez Canal, Egypt

The present research aims to generate a geometrical corrected physiographic map with a scale (1:50,000) and calculating crop water requirements for the suitable crops in this area. To fulfill these requirements, eight soil profiles were chosen to represent the different mapping units. Morphological description was carried out and soil samples were collected for the physical and chemical analyses. Based on satellite ETM+ images of the area and the geographic information system integrated with field work and laboratory routine analyses data, the physiographic soil map was produced. In this study, two main landscape units were identified, named: Coastal plain (the Fluvio Marine deposits) and Young sub-deltaic deposits. Subsequently, the main land qualities of different mapping units with the corresponding crop requirement were rated and matched to obtain the current and potential land suitability using automated land evaluation system (ALES). In this study, it is found that the most suitable crops for the study area in regard to its crop water requirements were: Clover, wheat, beans, onion, maize, sunflower, tomato and potato. Key words: Soil mapping, water requirements, West Suez Canal, East Delta

Developing a Base Model of an Automated Land Evaluation System for Paddy Rice Production

Developing a Base Model of an Automated Land Evaluation System for Paddy Rice Production

Aplicação de um sistema automatizado (ALES - Automated Land Evaluation System) na avaliação das terras das microrregiões de Chapecó e Xanxerê, Oeste Catarinense, para o cultivo de grãos

A avaliação de terras é o processo que permite estimar o uso potencial da terra com base em seus atributos. Grande variedade de modelos analíticos pode ser usada neste processo. No Brasil, os dois sistemas de avaliação das terras mais utilizados são o Sistema de Classificação da Capacidade de Uso da Terra e o Sistema FAO/Brasileiro de Aptidão Agrícola das Terras. Embora difiram em vários aspectos, ambos exigem o cruzamento de inúmeras variáveis ambientais. O ALES (Automated Land Evaluation System) é um programa de computador que permite construir sistemas especialistas para avaliação de terras. As entidades avaliadas pelo ALES são as unidades de mapeamento, as quais podem ser de caráter generalizado ou detalhado. A área objeto desta avaliação é composta pelas microrregiões de Chapecó e Xanxerê, no Oeste catarinense, e engloba 54 municípios. Os dados sobre os solos e sobre as características da paisagem foram obtidos no levantamento de reconhecimento dos solos do Estado, na escala de 1:250.000. O presente estudo desenvolveu o sistema especialista ATOSC (Avaliação das Terras do Oeste de Santa Catarina) e, na sua construção, incluiu-se a definição dos requerimentos dos tipos de utilização da terra, bem como foi feita a subseqüente comparação destes com os atributos de cada unidade de mapeamento. Os tipos de utilização da terra considerados foram: feijão, milho, soja e trigo, em cultivos solteiros, sob condições de sequeiro e de manejo característicos destas culturas no Estado. As informações sobre os recursos naturais compreendem os atributos climáticos, de solos e das condições da paisagem que interferem na produção destas culturas. Para cada tipo de utilização da terra foram especificados, no ATOSC, o código, o nome e seus respectivos requerimentos de uso da terra. Os requerimentos de cada cultura foram definidos por uma combinação específica das características das terras selecionadas, que determina o nível de severidade de cada um deles em relação à cultura. Estabeleceram-se quatro níveis de severidade que indicam aumento do grau de limitação ou diminuição do potencial para determinado tipo de uso da terra, a saber: limitação nula ou ligeira (favorável); limitação moderada (moderadamente favorável), limitação forte (pouco favorável); e limitação muito forte (desfavorável). Na árvore de decisão, componente básico do sistema especialista, são implementadas as regras que permitirão o enquadramento das terras em classes de adequação definidas, baseado na qualidade dos requerimentos de acordo com o tipo de uso. O ATOSC facilitou o processo de comparação entre as características das terras das microrregiões de Chapecó e Xanxerê e os requerimentos de uso considerados, por permitir efetuar automaticamente a avaliação das terras, reduzindo, assim, o tempo gasto neste processo. As terras das microrregiões de Chapecó e Xanxerê foram enquadradas, em sua maior parte, nas classes de adequação pouco favorável (3) e desfavorável (4) para os cultivos considerados. Os principais fatores limitantes identificados nestas microrregiões foram a fertilidade natural e o risco de erosão, para o feijão e o milho, e condições de mecanização e risco de erosão, para a soja e o trigo.

Assessing soil erosion in a Pyrenean mountain catchment using GIS and fallout 137Cs

The soil and vegetation in some areas of the central Pyrenean middle mountains are in poor condition. The main cause of degradation has been identified as soil erosion due to intensive use, including deforestation, overgrazing and extensive agriculture since the Middle Ages, followed by land abandonment starting at the beginning of the 20th century and intensifiying during the early 1950s. In this work, a raster geographical information system (GIS) combined with an expert evaluation system and fallout 137Cs were used to assess soil erosion in the Arnas catchment in the southern Pyrenees, where changes in land use were quite rapid at the beginning of the last century. A soil survey was carried out in the Arnas catchment to identify the soil types and to determine physico-chemical properties related to soil erodibility. A grid pattern was established across the study area and 77 sites were sampled. The GIS was used to integrate the information derived from an automated land evaluation system that, in turn, identified the erosion risk of areas by combining data on various soil properties and physiographic and bioclimatic factors. According to the map of erosion risks generated for the catchment, there were three distinct areas with different soil erosion features where fallout 137Cs was used to assess the soil redistribution pattern. The depth distributions of 137Cs were measured along three transects that represented the three main areas. The 137Cs content in the soils on the shrub slope transect was smallest and significantly different from the deeper and better developed soils on the forest slope, indicating different patterns of soil mobilization. The relationship of some basic soil properties was also examined, such as organic matter and texture, in terms of the patterns of radioisotope distribution and soil erosion. In the catchment, soil redistribution was affected by physiographic and landscape features such as soil properties, slope gradient as well as orientation and vegetation cover. Soil loss was highest along the shrub transect where the rate of soil erosion was much higher than soil formation. Conversely, the soils on the forest transect were mainly stable although some sediment was also deposited. Both aggradation and erosion were found in the valley bottom. The automated evaluation system and GIS used to identify areas vulnerable to erosion combined with the 137Cs technique have proven to be a suitable approach to assess soil erosion aimed to design effective strategies for soil conservation in Mediterranean mountain environments.

Application of computerized land evaluation systems in Tanzania: a case study in Kilosa District, Morogoro Region

Automated Land Evaluation System (ALES) and Land Evaluation Computer System (LECS) were applied in Kilosa District, Tanzania to test their applicability and adaptability in the area within the context of low-input rainfed maize farming. The study comprised physical land suitability classification of dominant soils identified through reconnaissance soil and land resources survey and comparison of predicted yields with field data. ALES predicted that four soil units had moderate potential with 80% yield, while two soil units had poor potential with 40% yield. Comparison of farmers' reported yields with those of ALES indicates significant correlation (R>0.9, P