Determination of potentially irrigable agricultural lands using remote sensing and geographic information system: case study of Yamula Basin

Dynamics of Utah's agricultural landscapes in response to urbanization: A comparison between irrigated and non-irrigated agricultural lands

The resolution of digital elevation model (DEM) used for watershed delineation and data extracted from the delineated watershed relevant to hydrography plays an important role in the calibration of hydrological models. The effect of DEM resolution on the drainage length, watershed area and average slope are studied in many earlier works. DEM resolution can have impact on hydrologic modeling parameters, water quality simulation results. The impacts of DEM resolution on results of the watershed response and water quality modeling are studied using HSPF (Hydrologic Simulation Program Fortran) model applied to a watershed in Kentucky in this study. Three major streams in this watershed are impaired due to pathogen pollution according to the current state of Kentucky water quality standard set for recreation. The effects of DEM resolution on water quality modeling and calibration for fecal coliform bacteria are studied using a HSPF model. Results from this study indicate that the DEM resolution affects hydrography parameters of the delineated watershed, influence the calibration process, and the non-point and point source loadings to the streams in the watershed.

Introduction: Landslides are one of the critical natural processes, which cause enormous damage to life and property..Uttarakhand Himalaya is vital to sustainity of region. This region is very fragile due to topographic and climatic condition. Landslides in the mountainous terrains are natural derivational processes and one of the most. There is a need for Landslide Hazard Zonation for identification of potential landslide areas. Keeping this in mind one hilly district, Pauri district of Uttarakhand, India was selected. Materials and Methods: The present study is an attempt towards development of a landslide model by using multi-criteria decision analysis in GIS and remote sensing techniques for landslide hazard zonation. The IRS LISS-4 satellite imageries, Survey of India topographical maps, and ancillary data were used as inputs to the study. The data layers of land use–land cover and geology were interpreted from satellite image and available ancillary data. Other raster thematic layers, i.e., slope, aspect, elevation, and drainage density, have been generated in Arc info three-dimensional analyst tool using ASTER DEM of 30 m resolution. A numerical rating scheme for the factors was developed for spatial data analysis in GIS. Results and Decision: Using high-resolution LISS-IV and Cartosat-2A, merged data of 2011–2012 landslides were mapped by visual interpretation of satellite image. A total of 167 landslides have been identified. Elevation map of Pauri district was prepared by classifying digital elevation model into 5 elevation categories. Distribution of landslides in different elevation categories is also done. Maximum landslides have occurred in elevation category (710–1134 m) and (185–709 m). Slope map has been generated and classifi ed into 6 slope classes, i.e. 0°–5°, 5°–10°, 10°–20°, 20°–30°, 30°–40°, and more than 40°. Distribution of landslides in different slope categories is also done. Maximum landslides have occurred in slopecategories (10°–20°), (20°–30°), and (30°–40°). Aspect map has been generated and classified into 8 aspect classes. Maximum landslides have occurred in aspect categories South-West (14.37%), South (35.97%), and South East (15.57%) directions. The Southern aspect (SW-S-SE) contributes to 65.91% of total landslides. Drainage density map has been generated from ASTER DEM using three-dimensional Analyst tool and classified into 6 classes, namely 0–2, 2–4, 4–6, 6–8, and more than 8 (km/sq.km). Geological map of Pauri district has been adopted from Geological map from Geological SOI. Rock types such as phyllites, quartzites, slates, siltstone, sandstones, graywacks, granitoids, alluvium, crystallines and metamorphics, and limestones are present in the district. Distribution of landslides in different drainage density categories is also done. Maximum landslides have occurred in drainage density category 2–4, 4–6, and 6–8 (km/sq.km). LULC map of Pauri was classified into various classes such as water body, forest scrub, wasteland/scrub, tree-clad, forest evergreen, agriculture land, built up, forest deciduous open, and forest deciduous dense/close. Maximum landslides have occurred in forest deciduous open category (84) followed by agriculture land (22), forest scrub (14), forest evergreen and forest deciduous dense/close (13 each), and water body. Conclusion: The above-mentioned 6 layers were integrated in the weighted overlay model of Arc Info and weights were assigned corresponding to landslide occurrence in these layers. The influence of the layer in causing landslide has also assigned. The final LHZ map generated after processing 6 themes. The final map has been classified into 3 categories, namely high, moderate, and low hazard categories. Of a total of 167 landslides, 110Landslides fall in the high HZ and 43 landslides fall in moderate HZ category while only 14 landslides fall in the low HZ category. 34.01% of the district falls under low HZ category and 40.73% falls under moderate HZ category while 25.26 under high HZ category. More layers need to be added in the model to obtain more precision. This map is not checked in the fi eld ground truth.

We analyse historical land use/land cover changes beginning from 1996 to 2013 and apply an agent-based model to simulate potential agricultural land use change scenarios in Uganda. The model incorporates farmers’ decision-making processes into biophysical and socioeconomic factors and uses these to analyse the effect of farmers’ decisions on agricultural land use changes. Geographic information system tools are employed to build spatial relations between farmers and land cover systems. Satellite images are used to represent the initial land cover conditions and serve as observed land cover datasets to calibrate the simulated results. Significant agricultural and grassland cover and urban land uses are experienced in 72 and 36% of the regions, respectively, while wetland land uses increased significantly in 82% of the regions. On the other hand, 91% of the regions experience reductions in forest cover except for Teso region which reports gains of 62% in forest cover. Acholi is the only region (extreme outlier) that reports dramatic gains in wetlands of over 880%. The results of the simulation model are promising, and the model was successful at representing historical and future scenarios of agricultural land use patterns at a national level.

This paper discusses the methods and process of Geographic Information System (GIS) applied in soil spatial analysis, involving the collection of soil spatial data that GIS required, spatial analysis method of soil nutrient, land use, slope and exposure of geography, crop yield and other factors, and also including acquiring soil spatial information and creating thematic map, and so on. Taking Hengjing Town in Wuxian County of Jiangsu Province as a case study and the maximum income as a principle, and applying the GIS methods and their interrelated models, we have calculated the most optimized agricultural land and the possible maximum income of Hengjing Town. According to the method, we can rationally regulate local agricultural production, and put forward some scenarios for optimizing agricultural structure of Hengjing Town. The paper puts forward an evaluation method of land adaptability based on soil spatial analysis, and offers some research clews to optimize agricultural land use constitution, so the paper will be have important reference value for soil study.

This study focuses on detecting, mapping and analyzing the conversion of forests into agricultural uses and agricultural uses into urban/peri-urban uses in Nzega district, Tabora Region - Tanzania over a period of 28 years since 1978. Land use classes were from multitemporal and multi-sensor satellite images and aerial photographs. Topographical maps at a scale of 1:50000 and onsite information gathered in the field were used for interpretation and ground truthing purposes. Land use changes were detected using land use change matrices and land use change maps. Four land use maps were compiled from Aerial photographs dated 1978, Landsat TM satellite imagery dated 1986, Landsat ETM+ satellite imagery dated 2000 and IRS satellite imagery dated 2006. The maps show agricultural areas are concentrated along road networks generally expanding towards neighboring grasslands and unprotected forested areas. Land use changes were detected from land use maps for three change periods: 1978 - 1986, 1986 - 2000 and 2000 - 2006, with emphasis on agricultural and forest land uses. The change maps and change matrices show that despite abandoned farms agricultural land increases with time. Change in the opposite direction was also common where abandoned agricultural land gradually regenerated back to grasslands and forests. An average of 16% of agricultural land has been maintained during the 1978 - 2006 period compared to 67% of forests that have been maintained in the same period of time.

This study aimed to evaluate the landslide risk map in the Algerian Western coasts. This evaluation was based on three steps. The first step requires evaluating the landslide hazard. To reach this, a field surveys data, combined with Geographical Information System (GIS) analysis and Remote Sensing (RS) image processing were carried out. Seven controlling factors were considered: lithology, geomorphology, slope, land use, distance to stream, rainfall and distance to fault. A topographic map of 1/ 25 000 was used to generate a Digital Elevation Model (DEM) with 15 × 15 m of resolution. From this DEM, the slope was extracted. Based on knowledge approach, the different factors were weighted according a scale value ranging from 1 to 9. The lowest values were assigned to the factors which have a minor influence on landslide triggering, and the highest values were given to the important parameters for landslide occurrence. These factors were combined using weighted linear combination (WLC). The landslide hazard map was classified into five levels: very low, low, moderate, high and very high. The landslide vulnerability was evaluated through the identification of the elements at risk. Three vulnerabilities aspects were considered: physical, environmental and socio-economic. The weights of each factor were given depending on the magnitude and the rate of landslide. Landslide Vulnerability Map (LVM) for Algerian western coasts was generated by the combination of the physical, environment and socio-economic vulnerability maps. Landslide risk was evaluated by combining the hazard map and the vulnerability map, and it was divided into four classes: very low, low, moderate and high.

Land use and land cover (LULC) analysis is a vital component of geographical studies as it reflects the dynamic interaction between human activities and the natural environment. The present study examines the spatial and temporal patterns of land use and land cover changes in Amethi District of Uttar Pradesh from a geographical perspective. Amethi, a predominantly agrarian district located in the eastern part of the state, has experienced noticeable transformations in its land use structure due to population growth, urban expansion, infrastructural development, agricultural intensification, and changing socio-economic conditions. The study aims to analyze the distribution of major land use and land cover categories, assess their changes over time, and identify the driving factors responsible for these transformations. The analysis is based on secondary data obtained from district statistical handbooks, agricultural surveys, census records, and satellite-based information supported by remote sensing and Geographic Information System (GIS) techniques. Various land use categories such as agricultural land, forest cover, fallow land, barren and wasteland, water bodies, and built-up areas have been systematically examined. The results indicate a gradual decline in agricultural and forest land, accompanied by an increase in non-agricultural uses such as residential, commercial, and infrastructural development. Expansion of built-up areas, reduction in water bodies, and an increase in fallow and degraded land in certain blocks highlight emerging environmental and resource management challenges. The study reveals that rapid urbanization, pressure on land resources, inadequate land management practices, and climatic variability have significantly influenced land use and land cover patterns in the district. The findings of this study can serve as a valuable base for planners, policymakers, and researchers concerned with sustainable land management and regional development.

In basin researches, quantitative data available from Topographical maps and Digital Elevation Model (DEM) make significant contributions to researchers in line with database created making use of Geographical Information Systems (GIS). Technological developments in the last 10 years, in particular, rendered GIS and Remote Sensing methods fit-for-use to achieve the objectives in geology-related applications. To identify applications of GIS in relation to basin researches, we selected the basin of the Kazandere Stream Basin of the castle located in Marmara Region as the field of study. In this study, we generated drainage network features of the basin using Arcinfo 9.2 GIS software from streams on 1/25000 scaled topographical map and from 10 m grid spaced DEM. We used Archydro Tool in line with the objectives of study. We obtained parameters in relation to stream directory analyses such as branching rate, drainage density and stream frequency of the field of study making use of topographical maps. And for DEM-related applications, we obtained information about sub-basins by way of Flow Accumulation and Flow Direction model. DEM's are a general source of data for field analyses and 3-dimensional applications. Such basin characteristics as basin field, sub-basin fields, water running directions, drainage networks, catchment centreoid etc., are easily generated through DEM. Stream morphometric features found using such two data sources provide reliable information on drainage characteristics of the stream basin and its lower branches. Analyses and applications conducted within the framework of database created on GIS environment indicated that GIS could be used for multi-purposes under scope of geographical researches.

The use of geographic information systems (GIS) allows for a very efficient analysis of spatial hydrologic data for water resources projects especially for water control studies. In this respect, flood hydrographs for Mogan basin, Turkey for different durations and return periods are determined by using Soil Conservation Service (SCS) method. The basic parameter of the SCS method, curve number (CN), is evaluated by using GIS employing digital land use and hydrologic soil group data derived from analog maps. A Digital Elevation Model (DEM) of Mogan basin is constructed by making use of topographic maps with a scale of 1:25,000. Flood hydrographs for these three productive subbasins of Lake Mogan are attached and superimposed to obtain the total flood hydrographs. Total flood hydrographs entering into Lake Mogan are routed by Puls Method to determine the outflow hydrographs from the lake; then, associated lake levels are computed. Furthermore, inundation maps of Lake Mogan are obtained; these results are presented by GIS techniques.

Drought occurrence is influenced by a complex interplay of natural and anthropogenic factors, with human activities significantly shaping the frequency and severity of such events. Among these, land use change is a critical driver, as it alters the geographical and environmental characteristics that determine regional drought vulnerability. This study focuses on land use as a manageable and controllable factor in spatial development, with implications for minimizing the adverse impacts of human-induced environmental change. The research assesses the impact of land use transitions on drought vulnerability in the Lam Ta Kong watershed, emphasizing projected changes over the next decade. Drought vulnerability was evaluated using the Analytical Hierarchy Process, while future land use for 2032 was simulated using the Cellular Automata-Markov model, integrated with Geographic Information System tools. The projection was grounded in historical land use dynamics from 2000 to 2021, which revealed substantial shifts due to socio-economic growth. The transition was characterized by a decline in agricultural and forested land and a significant expansion of built-up areas. By 2032, urban areas are projected to expand by 33.11%, predominantly encroaching upon agricultural and forested lands. Current assessments indicate that 35.09% of the watershed is highly vulnerable to drought, with this figure anticipated to rise by 10.55% under future land use scenarios. High vulnerability zones are primarily concentrated in the midstream region of the watershed. These findings underscore the substantial influence of land use change on drought risk and highlight the urgent need to integrate land use planning into comprehensive drought mitigation strategies. Graphical Abstract This graphical abstract illustrates an assessment of the impacts of land use conversion on drought vulnerability in the Lam Ta Kong Watershed. The study employed spatial transition analysis using Geographic Information System (GIS) tools to identify historical land use change patterns. Building on this, the CA-Markov model was applied to project land use distribution for the year 2032. The projected scenario served as a basis for evaluating future drought vulnerability, integrating ten critical drought-related criteria, which are grouped into four factors, through the Analytical Hierarchy Process (AHP) within a GIS framework. This approach generated a spatially explicit drought vulnerability map, revealing that land use conversion substantially increases susceptibility to drought. The results underscore the urgent need for integrated land use planning and sustainable water resource management to mitigate escalating drought risks in the region.

BackgroundSoil is a basic natural resource for the existence of life on earth, and its health is a major concern for rural livelihoods. Poor soil health is directly associated with reduced agricultural land productivity in many sub-Saharan countries, such as Mali. Agricultural land is subjected to immense degradation and the loss of important soil nutrients due to soil erosion. The objective of the study was to diagnose the spatial distribution of soil erosion and soil nutrient variations under different land use in two agroecological zones of Southern Mali using the Geographical Information System (GIS) software, the empirically derived relationship of the Revised Universal Soil Loss Equation, in-situ soil data measurement and satellite products. The soil erosion effect on agricultural land productivity was discussed to highlight the usefulness of soil and water conservation practices in Southern Mali.ResultsThe results of the land use and land cover change analysis from 2015 to 2019 revealed significant area reductions in water bodies, bare land, and savanna woodland for the benefit of increased natural vegetation and agricultural land. There was significant variation in the annual soil loss under the different land use conditions. Despite recordings of the lowest soil erosion rates in the majority of the landscape (71%) as a result of field-based soil and water conservation practices, the highest rates of erosion were seen in agricultural fields, resulting in a reduction in agricultural land area and a loss of nutrients that are useful for plant growth. Spatial nutrient modelling and mapping revealed a high deficiency and significant variations (p < 0.05) in nitrogen (N), phosphorus (P), potassium (K), and carbon (C) in all land use and land cover types for the two agroecologies.ConclusionsThe study highlighted the inadequacies of existing field-based soil and water conservation practices to reduce soil erosion and improve landscape management practices. The findings of the study can inform land management planners and other development actors to strategize and prioritize landscape-based intervention practices and protect catchment areas from severe erosion for the enhanced productivity of agricultural fields.

Since 2006, the interdisciplinary project “Leventina – Prehistoric Settlement Landscape”, funded by the Swiss National Foundation, is being conducted under the coordination of the Department of Pre- and Protohistory of the University of Zurich with researchers from further disciplines. The project investigates prehistoric settlement and economy in various altitudinal zones of the Alpine Ticino valley. One of the aims is to reconstruct the agricultural, pastoral and forestal land use in the Bronze and Iron Ages, and to evaluate the influencing factors on the spatial distribution of subsistence economy areas. A wide range of spatial and archaeological data as well as literature and field data describing properties in particular of the ancient economic plants was available for the purpose. Based on these data, a factor analysis and a subsequent prediction were conducted in order to evaluate the variables with a likely impact on agricultural land use at prehistoric times, and to detect potential agricultural land. Additionally, using predictive modeling, we aimed at extracting factors with impact on the spatial distribution of Bronze age settlement sites and generating a potential map of areas used for settlement. Furthermore, a cost path analysis was conducted to investigate different traffic routes across the main ridge of the Alps in terms of travel time.

Spatio-temporal evolution of agricultural land use change drivers: A case study from Chalous region, Iran

The extent of anthropogenic land use in watersheds determines the amount of pollutants discharged to streams. This indirectly and directly affects stream water quality and biological health. Most studies have therefore focused on ways to reduce non-point pollution sources to streams from the surrounding land use in watersheds. However, the mechanistic pathways between land use and the deterioration of stream water quality and biological assemblages remain unclear. This study estimated a structural equation model (SEM) representing the impact of agricultural and urban land use on water quality and the benthic macroinvertebrate index (BMI) using IBM AMOS in the Nam-Han river systems, South Korea. The estimated SEM showed that the percent of urban and agricultural land in the watersheds significantly affected both the water quality and the BMI of the streams. Specifically, a higher percent of urban land use had directly increased the biochemical oxygen demand (BOD) and total phosphorus (TP), and deteriorated the BMI of streams. Similarly, higher proportions of agricultural land use had also directly increased the BOD, total nitrogen (TN), and total phosphorus (TP) concentrations, and lowered the BMI of streams. In addition, it was observed that the percent of urban and agricultural land use had indirectly deteriorated the BMI through increased BOD. However, we were not able to observe any significant indirect effect of the percent of urban and agricultural land use through increased nutrients including TN and TP. These results indicate that increased urban and agricultural land use in the watersheds had directly and indirectly affected the physicochemical characteristics and benthic macroinvertebrate communities in streams. Our findings emphasize the need to develop more elaborate environmental management and restoration strategies to improve the water quality and biological status of streams.