Geoinformatics Techniques Research Articles

MORPHOMETRIC ANALYSIS USING GEO-INFORMATION TECHNIQUES FOR DIFFERENT WATERSHEDS IN NORTHEASTERN PART OF ERBIL CITY, KURDISTAN REGION, NORTH IRAQ

The present research attempts to study detail morphometric analysis of Harrir and Shaqlawa watersheds in the northeastern part of Erbil city, north of Iraq. The areas of the watersheds are 350 Km² and 223 Km² for Harrir and Shaqlawa, respectively. To achieve the aims of this study, the ALOS PALSAR Digital Elevation Model data, and Geo-information (Remote sensing and GIS) techniques were used for determining and analyzing morphometric parameters in terms linear, aerial and relief aspects. Several tools in ArcGIS 10.4 software were utilized for preparing and producing maps, analyzing and assessing various characteristics of the parameters. The main results show that there is a strong inverse relationship between stream order, number and length of the stream in the watersheds of the study area by R² values (R² = 0.78 and 0.81 of Harrir watershed and R² = 0.8 and 0.79 for Shaqlawa watershed, respectively). The watersheds are elongated in shape with dendritic, sub dendritic to parallel drainage patterns. Moreover, detail morphometric analysis shows that the watersheds have a low runoff, low permeable material, and moderate slope. The structural geology and climatic parameters of the study area have influenced the landform development and stream behavior in the watersheds. Hence, the present study is useful and essential for watershed management and planning rainfall harvesting.         

Structure and composition of field margin vegetation in the rural-urban interface of Bengaluru, India: a case study on an unexplored dimension of agroecosystems.

Field margin vegetation (FMV) refers to the plant community in the interface between agriculture and natural environments. Substantial work has been carried out on the management of field margins in European countries with the aim of conserving field-level biodiversity and enhancing agronomic benefits. India, instead, is lagging behind in the assessment of FMV and formulating subsequent management strategies for biodiversity conservation at the field boundaries. This study is a first step to better understand the structural and functional dimensions of field margin vegetation along an agricultural transformation gradient near the megacity of Bengaluru, India. Empirical field studies along with the detection of vegetation change using remote sensing and geo-informatics technique were used to record information on field margin vegetation. The phytosociological study, revealed a total of 81 species, comprising 29 species of trees, 21 shrubs and 31 herbs at the field margins of six selected villages of northern Bengaluru. Randomly selected 355 field boundaries were delineated from high-resolution Worldview 3 images for the year 2018 and from Google Earth images for the year 2004-2005. The FMV area was around to 85.40ha in 2004-2005 but declined to 76.69ha in 2017-2018. The survey also indicated that local farmers have in-depth ecological knowledge on the importance of FMV in ensuring a sustainable flow of resources within the agricultural landscape. The results demonstrate that rural and transition zones of the study area have higher dominance of planted tree species on the margins, whereas urban zone exhibits comparatively uniform dominance for all species. Our study also highlights the need for conservation of FMV to ensure agroecosystem health as a prerequisite for sustainable socioecological development.

Agro-ecological zones delineation based for agricultural development in Sinai Peninsula using geo-informatics techniques

Agricultural development faces many obstacles, such as soil drought, climate change, and human activities, but the main challenge facing Egypt today is the need to develop and better manage natural resources to meet the growing needs of the country. This study aims to map Sinai agro-ecological zones to find out the most suitable environmental condition to growth, development and productivity of agricultural corps using geo-informatics techniques. Nine ground agro-meteorological stations distributed over the study area were used to collect the climatic data from 1986 to 2015. Also, the physiochemical properties of soil were determined. The land capability was carried out using ALES-arid. Model builder with integration of GIS based on an approach using DEM, landsat-8 satellite data, soil analysis and climatic data were utilized to evaluate the agro-ecological zones for agricultural production. The results indicated that land capability was classified as 2.2% belong to C3 (fair), 8.5% belong to C4 (poor), 11.9% belong to C5 (very poor) and 4.4% fits in C6 (non-agriculture). In addition, the Model builder results showed that the study area comprise five zones; i.e. zone (I) high suitable areas (4.1%), zone (II) suitable area (0.1%), zone (III) moderately suitable (15.7%), zone (IV) marginally suitable (7.2%) and zone (V) non-suitable area (9.1%). It could be concluded that, zones I, II, and III were considered the best suitable zones for agricultural development in Sinai Peninsula.

Risk Assessment of Drifting Sand in Agricultural Lands in Basrah Province with the aid of ‘3S’ Techniques

There is a growing need to systematically assessment of drifting sand risk using Geo-information and related technologies for speed and accuracy. The drifting sand map in the southern part of Iraq was established with objective of providing the risk areas of soil loss and the methodology for spatial modeling with Wind Erosion Equation (WEQ) and Geo-information techniques. This analysis was carried out using ‘3S’ technologies [Remote Sensing (RS), Geographic Information System (GIS) and Global Position System (GPS)], with the layers extracted and manipulated from available topographic, climatic and soil maps, as well as satellite image (Thematic Mapping (TM) in 2003 and Enhanced Thematic Mapping (ETM) in 2016) and field survey data analyses. Each of the WEQ factors was digitally encoded in a GIS database to establish each factor’s layers. Simultaneously, the overlay operation with the WEQ model on the factor’s layers was digitally performed to produce the sandy degradation class. The study indicated that the severe erosion class covering an area of about 61.9% of the total area is very high with the degraded vegetation and is located in the southwest part of Iraq. Iraq faces serious environmental degradation problems that must be addressed immediately; failure to do so will greatly compound the cost and complexity of later remedial efforts, with environmental degradation beginning even now to pose a major threat to human well-being, especially among the poor.

Assessing Soil Erosion Hazards Using Land-Use Change and Landslide Frequency Ratio Method: A Case Study of Sabaragamuwa Province, Sri Lanka

This study aims to identify the vulnerable landscape areas using landslide frequency ratio and land-use change associated soil erosion hazard by employing geo-informatics techniques and the revised universal soil loss equation (RUSLE) model. Required datasets were collected from multiple sources, such as multi-temporal Landsat images, soil data, rainfall data, land-use land-cover (LULC) maps, topographic maps, and details of the past landslide incidents. Landsat satellite images from 2000, 2010, and 2019 were used to assess the land-use change. Geospatial input data on rainfall, soil type, terrain characteristics, and land cover were employed for soil erosion hazard classification and mapping. Landscape vulnerability was examined on the basis of land-use change, erosion hazard class, and landslide frequency ratio. Then the erodible hazard areas were identified and prioritized at the scale of river distribution zones. The image analysis of Sabaragamuwa Province in Sri Lanka from 2000 to 2019 indicates a significant increase in cropping areas (17.96%) and urban areas (3.07%), whereas less dense forest and dense forest coverage are significantly reduced (14.18% and 6.46%, respectively). The average annual soil erosion rate increased from 14.56 to 15.53 t/ha/year from year 2000 to 2019. The highest landslide frequency ratios are found in the less dense forest area and cropping area, and were identified as more prone to future landslides. The river distribution zones Athtanagalu Oya (A-2), Kalani River-south (A-3), and Kalani River- north (A-9), were identified as immediate priority areas for soil conservation.

Application of geospatial technologies in developing a dynamic landslide early warning system in a humanitarian context: the Rohingya refugee crisis in Cox’s Bazar, Bangladesh

Since August 2017, more than 744,400 stateless Rohingya refugees – an ethnic Muslim minority group from the Rakhine State – have entered Bangladesh to escape serious crimes against humanity conducted by the Myanmar Army. Extensive level of deforestation and hill cutting activities took place in Cox’s Bazar District (CBD) in Bangladesh to accommodate them. The refugee camps are sitting on hills and loose soil and are highly vulnerable to rainfall-triggered landslides. Notably in June 2017, landslides in the same region killed at least 160 people. From this perspective, the study aims to develop a localised landslide early warning system (EWS) for the Rohingya refugees and their host communities in CBD. A novel method, combining landslide inventory and susceptibility maps, rainfall thresholds and dynamic web-based alert system, has been introduced to develop the landslide early warning system (EWS) by applying advanced geoinformation techniques. Results suggest that approximately 5,800 hectares of forest land cover disappeared due to the 2017 Rohingya influx. Land cover changes through hill cutting andslope modifications, and unplanned urbanisation are predominantly responsible for slope failures and consecutive 5-day periods of rainfall between 95–220 mm could initiate landslides in high susceptible areas. The EWS would support the local authorities and international organisations in reducing disaster risks and saving lives from landslides in a humanitarian context.

Modeling Groundwater Potential Zone in a Semi-Arid Region of Aseer Using Fuzzy-AHP and Geoinformation Techniques

Saudi Arabia’s arid and semi-arid regions suffer from water scarcity because of climatic constraints and rapid growth of domestic and industrial water uses. The growing demand for high-quality water supplies and to reduce the dependency on desalination creates an urgent need to explore groundwater resources as an alternative. The weighted overlay analysis method using the fuzzy-analytical hierarchy process (FAHP) multi-criteria decision making (MCDM) techniques combined with geoinformation technology was used in this study to explore the groundwater potential zones in the Itwad-Khamis watershed of Saudi Arabia. Twelve thematic layers were prepared and processed in a GIS setting to produce the groundwater potential zone map (GPZM). Subsequently, potential groundwater areas were delineated and drawn into five classes: very good potential, good potential, moderate potential, poor potential, and very poor potential. The estimated GWPZ (groundwater potential zones) was validated by analyzing the existing open wells distribution and the yield data of selected wells within the studied watershed. With this quality-based zoning, it was found that 82% of existing wells were located in a very good and good potential area. The statistical analysis showed that 14.6% and 28.8% of the total area were under very good and good, while 27.3% and 20.2% were accounted for the moderate and poor potential zone, respectively. To achieve sustainable groundwater management in the Aseer region, Saudi Arabia, this research provided a primary estimate and significant insights for local water managers and authorities by providing groundwater potential zone map.

Risk modeling of soil erosion under different land use and rainfall conditions in Soan river basin, sub-Himalayan region and mitigation options

Soil erosion is a serious environmental problem impacting soil and water resources of the Himalayan region. To sustain food and fibres requirements of ever increasing population, there is need to rehabilitate erosion affected areas. In the present study, risk of soil erosion was assessed in the Soan river basin of sub-Himalayan region of Pakistan using Revised Universal Soil Loss Equation coupled with geo-informatic techniques. The influential factors leading to higher erosion rates were studied under variable scenarios of environmental change. The study revealed an average soil loss of about 8.4 tons/ha/year in the study area. The intensity of erosion was predicted around 15 tons/ha/year in the open soil and 10.3 tons/ha/year in the agriculture land. The rate of erosion was found maximum over 5°–15° slope, i.e., about 19 tons/ha/year. At steeper slopes (i.e., > 15°), the lower values of erosion rates were observed likely because of presence of exposed rocks lacking extensive soil cover. High risk of erosion was predicted in scenarios of increase in rainfall and conversion of rangeland and scrub forest into agriculture land in the basin. The menace of soil erosion can be controlled through adopting integrated land use planning and soil conservation approach at micro to macro level in this part of the Himalayan region.

Using High-Density LiDAR Data and 2D Streamflow Hydraulic Modeling to Improve Urban Flood Hazard Maps: A HEC-RAS Multi-Scenario Approach

The ability to extract streamflow hydraulic settings using geoinformatic techniques, especially in high populated territories like urban and peri-urban areas, is an important aspect of any disaster management plan and flood mitigation effort. 1D and 2D hydraulic models, generated based on DEMs with high accuracy (e.g., Light Detection and Ranging (LiDAR)) and processed in geographic information systems (GIS) modeling software (e.g., HEC-RAS), can improve urban flood hazard maps. In this study, we present a small-scale conceptual approach using HEC-RAS multi-scenario methodology based on remote sensing (RS), LiDAR data, and 2D hydraulic modeling for the urban and peri-urban area of Bacău City (Bistriţa River, NE Romania). In order to test the flood mitigation capacity of Bacău 1 reservoir (rB1) and Bacău 2 reservoir (rB2), four 2D streamflow hydraulic scenarios (s1–s4) based on average discharge and calculated discharge (s1–s4) data for rB1 spillway gate (Sw1) and for its hydro-power plant (H-pp) were computed. Compared with the large-scale flood hazard data provided by regional authorities, the 2D HEC-RAS multi-scenario provided a more realistic perspective about the possible flood threats in the study area and has shown to be a valuable asset in the improvement process of the official flood hazard maps.

Quantitative environmental impact assessment on groundwater quality using geoinformatics techniques

Availability of quality freshwater is one of the most critical environmental issues of the twenty first century (UNEP, 2002). Urbanization leads to the environmental pollution, i.e., urban growth leads to the increasing of slums, solid waste disposal, provision of transport facilities, conjection and groundwater contamination. Groundwater is an important water resource for domestic and agriculture in both rural and urban parts of India. Pollution of groundwater comes from many sources. Groundwater contamination in a major issue, especially in industrial areas especially like Dindigul. The presence of large number of tanniers and allied industrial unit such as dyeing and bleaching units in and around the town are the main factors, which affect the environmental quality of the town. Dindigul town is not having the physical expansion since 1981 with an area of 14.01sq.km. Only wards are increased by enjoying the rapid growth of population. Dindigul is the main industrial hub for the Tanneries. Effluents from the tanneries are discharged in to streams which drain into ponds, thereby polluting the ground water sources and cultivable land. These values are more than the permissible limit in and around the tannery cluster compared to other parts of the area. The pH,CO3, Na, Ca, Mg, NO3, and SO4 values of all groundwater samples are within the permissible limits but all the EC, TDS, HCO3and K values are exceeding the permissible limit. According to TH and Cl 6 samples are exceeding the prescribed limits. There are about 80 tanneries spread within 4-6 kms radius in the south western part of the town i.e., near Paraipatti, so ground water pollution is very high compared to other places. Madurai road tanneries are located so in Begampur near Annamalayar school pollution is high. R. M. Colony is having the highest household wastages because of its vertical expansion so in that areas also pollution is high.

GIS-based Landform Classification of Eneolithic Archaeological Sites in the Plateau-plain Transition Zone (NE Romania): Habitation Practices vs. Flood Hazard Perception

The landforms of the Earth’s surface ranging from large-scale features to local topography are factors that influence human behavior in terms of habitation practices. The ability to extract geomorphological settings using geoinformatic techniques is an important aspect of any environmental analysis and archaeological landscape approach. Morphological data derived from DEMs with high accuracies (e.g., LiDAR data), can provide valuable information related to landscape modelling and landform classification processes. This study applies the first landform classification and flood hazard vulnerability of 730 Eneolithic (ca. 5000–3500 BCE) settlement locations within the plateau-plain transition zone of NE Romania. The classification was done using the SD (standard deviation) of TPI (Topographic Position Index) for the mean elevation (DEV) around each archaeological site, and HEC-RAS flood hazard pattern generated for 0.1% (1000 year) discharge insurance. The results indicate that prehistoric communities preferred to place their settlements for defensive purposes on hilltops, or in the close proximity of a steep slope. Based on flood hazard pattern, 8.2% out of the total sites had been placed in highly vulnerable areas. The results indicate an eco-cultural niche connected with habitation practices and flood hazard perception during the Eneolithic period in the plateau-plain transition zone of NE Romania and contribute to archaeological predictive modelling.

Appraisal of Land Cover Changes in the Upper Sindh Through Geo-Informatics Techniques

Satellite remote sensing is a useful technique to observe environmental changes which are introduced as a result of man-made activities and physical phenomenon. In this study the land cover patterns of pre-flood period, flood period and post flood period in the year 2015 on upper part of Sindh region have been analysed and difference of vegetation cover, water body and surface temperature before, during and after flood period were observed. Three satellite images of Landsat-8 OLI / TIRS were used in the study acquired on April 11, 2015, August 17, 2015 and October 20, 2015. The land cover classes identify for the study area are healthy vegetation, normal vegetation, wet soil, dry soil and water. Three techniques likelihood supervised classification, Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) were used to get more precise results. Supervised classification and NDVI showed the spatial increase of vegetative cover. Increasing vegetation also witnesses from LST record of post flood period. This result indicates that land cover classes and socio-economy of the study area is under the dangerous threat of climate change, especially flood. In flood period, many socio-economic and landuse/landcover changes especially water, vegetation, land, animal and house are damages. The flood comes approximately every year in the study area. The mean LST of pre-flood period was 30.50C , during flood period was 370C and post flood was 320C.

Land use Dynamics and Landscape Patterns Assessment using Geoinformatics Techniques in Raniganj Coalfield, India

การศกษาครงนมวตถประสงคเพอประเมนมวลชวภาพเหนอพนดนของปาดบเขาตำอทยานแหงชาตดอยอนทนนท จงหวดเชยงใหม จากแปลงตวอยางถาวร 15 ha (n = 375) โดยอาศยสมการแอลโลเมตร และรปแบบความสมพนธของมวลชวภาพเหนอพนดนกบดชนพชพรรณตาง ๆ 4 ตวแปร คอ NDVI DVI RVI และ TNDVI จากภาพถายดาวเทยม Landsat 7 โดยวธ reduce major axis analysis ผลการศกษาพบวา มวลชวภาพเหนอพนดนของปาดบเขาตำ มคาเฉลยเทากบ380.9872 Mg/ha สวนรปแบบความสมพนธพบวา แนวโนมคามวลชวภาพเหนอพนดนมความสมพนธ กบคา NDVI, log(DVI), log(GVI) และ log(TNDVI) ในทางลบโดยมคาเทากบ b = -1.595955e-04**, b = -1.030396e-04**, b = -9.186332e-05**, b = -2.675757e-05** (P < 0.01) ตามลำดบ ซงความสมพนธดงกลาวสามารถนำไปประยกตสำหรบหาคาปรมาณการกกเกบคารบอนได และจะสงผลตอแนวทางหรอนโยบายในการอนรกษทรพยากรปาไมของไทยตอไปในอนาคตใหคงสภาพทสมบรณยงยนตอไป This study aimed to evaluate the above-ground biomass of lower montane forest in Doi Inthanon National Park Chiang Mai province from 15 ha permanent sample plots (n = 375) using the allometric equation. A causal relationship model among above ground biomass and vegetation index in 4 variables: NDVI DVI RVI TNDVI Landsat 7 satellite images by means reduce major axis analysis. The results showed that aboveground biomass in lower montane forest below with an average of 380.9872 Mg / ha. The relationship model that was likely the biomass above ground is correlated with the NDVI, log (DVI), log (GVI) and log (TNDVI) negatively by equal to b = -1.595955e-04**, b = -1.030396e-04**, b = -9.186332e-05**, b = -2.675757e-05** (P <0.01), respectively. Which such relationships can be applied for determining the amount of carbon storage and result can use for guidelines or policy to preserve the forest resources of Thailand in the future to maintain the integrity sustainable.

Spatial analysis of asbestos exposure and occupational health care in Poland during the period 2004-2013.

Asbestos is carcinogenic to humans and exposure to this substance can cause a wide range of diseases. In Poland 1997, a statutory ban was introduced on the production, use and marketing of products containing asbestos. The National Programme for Asbestos Abatement for 2009-2032 includes scheduled activities considering asbestos exposure assessment and health protection. As there are several data sources for asbestos exposure in Poland, which are not linked, the aim of this study was to gather and order them developing a PostgreSQL database, an open-source, objectrelational system. The data gathered combines the following information: the quantity of asbestos-cement products in use, details of asbestos manufacturing plants, the results of the measurements of asbestos fibre concentrations in the air and cases of asbestos-related diseases. The relational database was then used to develop a spatial analysis of asbestos monitoring and exposure in Poland to demonstrate the current state of realisation of the National Asbestos Abatement Programme in the country for 2009-2032 with the use of geoinformation techniques. The use of a database on health aspects of occupational and environmental asbestos exposure was also proposed in Asbestos, Asbestosis, and Cancer: Helsinki Criteria update 2014.

Evaluation of physical and morphometric parameters for water resource management in Gad Watershed, Western Ghats, India: an integrated geoinformatics approach

The selected study area is a coastal watershed which receives high rainfall in the monsoon season. During this period, most of the water input to the watershed drains to the Arabian Sea without any adequate use due to the rugged topography of the watershed. Hence, an attempt has been made to assess the physical properties specifically morphometric parameters of the Gad watershed using geoinformatics techniques along with field evidence for understanding the relationship between fluvial landforms and hydro-physical parameters in the region. Morphometric parameters have been analyzed and integrated with physical parameters like topography, rainfall, soil, land use–land cover, geology, and geomorphology for evaluating the potential water resource availability in the Gad watershed. The results of the study have shown that there is high surface water availability in the watershed with very low water retaining capacity, mainly in the upper region of the watershed due to presence of basaltic bedrock and steep slopes. Based on this work, a water resource management plan has been suggested at a subwatershed level which established on the physical properties and morphological characteristics of the study area.

Mapping spatial urban growth and land use change using geoinformatics technique in Varanasi District, Uttar Pradesh, India

Mapping spatial urban growth and land use change using geoinformatics technique in Varanasi District, Uttar Pradesh, India

Change Detection Analysis Using Surveying and Geoinformatics Techniques

The study was on change detection using Surveying and Geoinformatics techniques. For effective research study, Landsat satellite images and Quickbird imagery of Minna were acquired for three periods, 2000, 2005 and 2012. The research work demonstrated the possibility of using Surveying and Geoinformatics in capturing spatial-temporal data. The result of the research work shows a rapid growth in built-up land between 2000 and 2005, while the periods between 2005 and 2012 witnessed a reduction in this class. It was also observed that change by 2020 may likely follow the trend in 2005 – 2012 all things being equal. Built up area may increase to 11026.456 hectares, which represent 11% change. The study has shown clearly the extent to which MSS imagery and Landsat images together with extensive ground- truthing can provide information necessary for land use and land cover mapping. Attempt was made to capture as accurate as possible four land use and land cover classes as they change through time.

Geospatial Analysis of Changes in Vegetation Cover over Nigeria

Abstract Vegetation cover over Nigeria has been on the decrease recently, hence the need for adequate monitoring using geo-information technology. This study examined the spatio-temporal variation of vegetation cover over Nigeria for thirty years with a view to developing a strategy for enhancing environmental sustainability. In order to predict the spatial extent of vegetation cover in 2030, the study utilised satellite images from between 1981 and 2010 using the Normalised Difference Vegetation Index (NDVI) coupled with cellular automata and Markov chain techniques in ArcGIS 10.3. The results showed that dense vegetal areas decreased in area from 358,534.2 km2 in 1981 to 207,812 km2 in 2010, while non-vegetal areas increased from 312,640.8 km2 in 1981 to 474,436.4 km2 in 2010 with a predicted increase to 501,504.9 km2 by 2030, i.e. an increase of about 27,068.4 km2 between 2010 and 2030. The study concluded that geoinformation techniques are effective in monitoring long-term intra- and inter-annual variability of vegetation and also useful in developing sustainable strategies for combating ecological hazards.

Identification of critical soil erosion prone areas and prioritization of micro-watersheds using geoinformatics techniques

Soil and water come under the category of the most important renewable natural resources on earth. But due to their indiscriminate use, they can be seriously endangered. Hence it is essential to manage natural resources sustainably to preserve them for the future. For soil prevention, Morphometric analyses only drainage pattern. However, Land Use/Land Cover (LULC) and soil characteristics should also be considered. Thus, it is necessary to combine all methods of prioritization to provide reliable results. As the Ganga watershed in India is currently under environmental distress, therefore in the present study, Morphometric, land use/land cover and Universal Soil Loss Equation (USLE) analysis are done in this watershed using ArcGIS and ArcSWAT. To identify the erosion prone areas for effective planning and management of groundwater resources the study area was divided into seventeen sub-watersheds for the analysis. The mainstream of the basin is of eighth order, and drainage patterns of sub-basins are mostly of sub dendritic to dendritic. Various linear, areal and relief parameters of each sub-watersheds have been determined, and sub-watersheds are prioritized by ranking them according to erodibility characteristic. The results reveal that according to Morphometric analysis out of seventeen sub-watersheds, Rajpura Region, Narahi Region and Mughal Sarai Region Sub-watersheds are subjected to more soil erosion, and Sarai Meer Region, Balia Region and Ghazipur Region Sub-watersheds are subjected to least soil erosion. Whereas according to LULC and USLE analysis Narahi Region, Pipra Region, Gahmar Region Sub-watersheds and Rajpura Region and Mughal Sarai Region Sub-watersheds are likely to be subjected to more soil erosion respectively. Sarai Meer Region, Lalganj Region, Pindra Region Sub-watersheds and Sarai Meer Region, Lalganj Region,Magharia Region Sub-watersheds are subjected to least soil erosion according to LULC and USLE analysis respectively. Integrating all the three methods, we found that Chandauli Region, Narahi Region and Mirzapur Region Sub-watersheds are suffering from severe soil erosion problem and Sarai Meer Region, Lalganj Region and Ghazipur Region Sub-watersheds have least soil erosion. These results can be further used for soil erosion and sediment yield modeling projects.

Freshwater fish resource mapping and conservation strategies of West Bengal, India

Explorations and Germplasm estimation of fish biodiversity in the freshwater bodies of India are being gradually updated and analysed with a number of new discoveries though a well-defined figure of existing freshwater fish species at regional and state level remains to be calculated. The freshwater resources of India are currently experiencing an alarming decline trend in term of piscine biodiversity due to several undesired factors and consequences a considerable portion of freshwater fishes have been categorized as Threatened category. West Bengal is now becomes one of the most significant states of freshwater fish producer in India. The research study workout and divide the West Bengal state into six major physiographic divisions along with the help of modern Geoinformatics techniques (ArcGIS 10.2, Google Earth and Global Mapper software for map making purpose). The present study deals with the freshwater fish resource, distribution and biodiversity assessment of entire part of West Bengal. Occurrence of 251 fish species belonging to 15 orders, 50 families have been noted during the study period of 2012–2016. It is evident that the members belonging to Cyprinifomes constitute 37% of the total fish fauna of the river. Fluctuation in occurrence and abundance of the species are influenced by several anthropogenic activities. The demand of proper management of conservation policy is highlights through our research work.