scholarly journals A Maxent modelling with a geospatial approach for the Habitat suitability of Flamingos in an Evanescing Ramsar site (Sambhar Lake, India) over the changing climatic scenarios

2019 ◽  
Author(s):  
Laxmikant Sharma Kshitij Divyansh ◽  
Alok Raj
Keyword(s):  
Habitat Suitability ◽  
Migratory Birds ◽  
Salt Lake ◽  
Carbon Sink ◽  
Saline Water ◽  
Anthropogenic Activities ◽  
Geographical Information ◽  
Lake Area ◽  
Ramsar Site ◽  
Bioclimatic Variables

AbstractWetlands play a crucial role in the biosphere and provide numerous services. They performed multiple functions such as groundwater recharge, water purification, conservation of biological resources, act as a carbon sink and habitat of amphibians and birds. A Ramsar site-the Sambhar Lake is one of the largest inland saline wetland present in the arid region of Rajasthan, India has unique habitat suitability for the winter avifauna migrants like flamingoes and falcons. The occurrence of suitable climatic conditions and food availability like brine shrimps (Artemia salina) attracts flocks of migratory birds. From the last three decades, Sambhar Lake has been continuously facing degradation due to anthropogenic activities, which disturb Lake’s natural ecology and existence. These cause disturbances in habitat suitability of migratory birds in the Sambhar Lake, which leads to a reduction of population density of migratory birds. Therefore, this study aimed to assess the degradation and vulnerability of Sambhar Lake and the habitat suitability of migratory birds using Maxent Habitat Suitability model. This model provides a platform to integrate the bird’s occurrence data with the bioclimatic variables using remote sensing and Geographical Information System, and provides bird’s habitat suitability as well as predicts future bird’s occurrence scenarios. Landsat-5 and Sentinel-2 imagery for the year 1996 and 2019 respectively were used in this study. Four indicators such as LULC NDWI, MSI and SABI depicts the environmental condition of the Sambhar Lake. Output form Maxent model reveals that the Sambhar lake area with increasing anthropogenic activities has become unsuitable for flamingos. A remarkable loss of breeding sites of animal, particularly avian fauna (flamingos) is seen in the recent years due to different types of threats posed on the Ramsar site. Increase in Salt crust and Vegetation area from 36.8055 to 123.837 Sq. Km. and 26.5347 to 36.857 Sq. Km. respectively have taken place. While a decrease in saline water area from 88.8309 to 19.3256 Sq. Km has been observed, within the vicinity of Sambhar Lake as clearly shown through LULC map. The future prediction of the distribution of species in the region for the year 2050 shows that the most suitable regions will be near to Jhapok and nearby waters of Salt Lake City as the drains from the city opens in the lake where the flamingoes get Algae in the form of food. Active steps are needed for the lake conservation to reduce the risks of migratory bird’s population.

scholarly journals Spatio-temporal modelling for the evaluation of an altered Indian saline Ramsar site and its drivers for ecosystem management and restoration

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0248543
Author(s):  
Rajashree Naik ◽  
Laxmikant Sharma
Keyword(s):  
Migratory Birds ◽  
Saline Soil ◽  
Salt Lake ◽  
Ramsar Site ◽  
Barren Land ◽  
Salt Pans ◽  
Salt Crust ◽  
Decadal Scale ◽  
Salt Pan ◽  
Spatio Temporal

Saline lakes occupy 44% and 23% of the volume and area of all lakes that are tending to suffer from extended dryness, reduced hydro period, or complete desiccation by 2025. The current study is conducted on Sambhar Salt Lake, the largest inland saline Ramsar, site of India, contributing to 9.86% of total salt production. The lake is under threat due to illegal salt pan encroachment, losing brine worth 300 million USD. The objective was to identify the key drivers that affect the lake at a landscape level. Geospatial modelling was conducted for 96 years (1963–2059) at a decadal scale, integrating ground data (birds-soil-water). Land Use Land Cover (LULC) classification was conducted using CORONA aerial imagery of 1963, along with Landsat imageries, using supervised classification for 1972, 1981, 1992, 2009, and 2019, and future prediction for 2029, 2039, 2049, and 2059. Further, images were classified into 8 classes that include the Aravali hills, barren land, saline soil, salt crust, salt pans, wetland, settlement, and vegetation. Past trends show a reduction of wetland from 30.7 to 3.4% at a constant rate (4.23%) to saline soil, which subsequently seemed to increase by 9.3%, increasing thereby the barren land by 4.2%; salt pans by 6.6%, and settlement by 1.2% till 2019. Future predictions show loss of 40% wetland and 120% of saline soil and net increase in 30% vegetation, 40% settlement, 10% salt pan, 5% barren land, and a net loss of 20%, each by Aravali hills and salt crust. Additionally, the ground result shows its alteration and reduction of migratory birds from 3 million to 3000. In the light of UN Decade on Ecosystem Restoration (2021–2030), restoration strategies are suggested; if delayed, more restoration capital may be required than its revenue generation.

scholarly journals Environmental Impact Assessment of the Tidal Link Failure and Sea Intrusion on Ramsar Site No. 1069

2019 ◽  
Vol 9 (3) ◽  
pp. 4148-4153 ◽  
Author(s):  
A. A. Mahessar ◽  
A. N. Laghari ◽  
S. Qureshi ◽  
I. A. Siming ◽  
A. L. Qureshi ◽  
...  
Keyword(s):  
Migratory Birds ◽  
Negative Impact ◽  
Positive Impact ◽  
Drainage System ◽  
Left Bank ◽  
Lake Area ◽  
Ramsar Site ◽  
Ramsar Convention ◽  
Aquatic Biodiversity ◽  
The Impact

This paper presents the impact on the RAMSAR site No. 1069 that receives fresh water by the Kotri drainage system. At present, the complex faces threats by effluents from the Left Bank Outfall Drain (LBOD) system and from saline seawater intrusion during high tides. These threats have destroyed the ecosystem of the lakes Cholari, Mehro, Pateji and Sanhro belonging to the complex. The total present lake area, maintained at the Cholari weir crest level, is about 170km2. The lakes are expanding, available data shows that there is an increase up to 700% in the original lakes’ area, from 6058 to 41220 acres from 1954 to 1977. This is mainly caused by the operation of Kotri Barrage surface drainage system and has positive impact on lakes’ ecology because the drainage effluent is of marginal salinity. The rapid increase in the lakes’ area, of about 40% within 2 years after the functioning of the Tidal Link with saline effluents from LBOD and sea intruded water have changed the ecology of the area. This posed a significant impact on the ecosystem. Conversely, a similar rise in water level due to sea intrusion has nearly doubled the surface area and reposed a negative impact on the system. These lakes were giving shelter to a wide variety of local and migratory birds and had aquatic biodiversity. Hence, parts of Sanhro and Mehro dhands have been recognized by the RAMSAR Convention

scholarly journals A Bioclimate-Based Maximum Entropy Model for Comperiella calauanica Barrion, Almarinez and Amalin (Hymenoptera: Encyrtidae) in the Philippines

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 26
Author(s):  
Billy Joel M. Almarinez ◽  
Mary Jane A. Fadri ◽  
Richard Lasina ◽  
Mary Angelique A. Tavera ◽  
Thaddeus M. Carvajal ◽  
...  
Keyword(s):  
Maximum Entropy ◽  
Habitat Suitability ◽  
Species Distribution Model ◽  
Biological Control Agent ◽  
The Philippines ◽  
Distribution Model ◽  
Field Surveys ◽  
Probability Of Occurrence ◽  
Precipitation Seasonality ◽  
Bioclimatic Variables

Comperiella calauanica is a host-specific endoparasitoid and effective biological control agent of the diaspidid Aspidiotus rigidus, whose outbreak from 2010 to 2015 severely threatened the coconut industry in the Philippines. Using the maximum entropy (Maxent) algorithm, we developed a species distribution model (SDM) for C. calauanica based on 19 bioclimatic variables, using occurrence data obtained mostly from field surveys conducted in A. rigidus-infested areas in Luzon Island from 2014 to 2016. The calculated the area under the ROC curve (AUC) values for the model were very high (0.966, standard deviation = 0.005), indicating the model’s high predictive power. Precipitation seasonality was found to have the highest relative contribution to model development. Response curves produced by Maxent suggested the positive influence of mean temperature of the driest quarter, and negative influence of precipitation of the driest and coldest quarters on habitat suitability. Given that C. calauanica has been found to always occur with A. rigidus in Luzon Island due to high host-specificity, the SDM for the parasitoid may also be considered and used as a predictive model for its host. This was confirmed through field surveys conducted between late 2016 and early 2018, which found and confirmed the occurrence of A. rigidus in three areas predicted by the SDM to have moderate to high habitat suitability or probability of occurrence of C. calauanica: Zamboanga City in Mindanao; Isabela City in Basilan Island; and Tablas Island in Romblon. This validation in the field demonstrated the utility of the bioclimate-based SDM for C. calauanica in predicting habitat suitability or probability of occurrence of A. rigidus in the Philippines.

scholarly journals Assessment of Impacts of Hurricane Katrina on Net Primary Productivity in Mississippi

2010 ◽  
Vol 14 (14) ◽  
pp. 1-12 ◽  
Author(s):  
Shrinidhi Ambinakudige ◽  
Sami Khanal
Keyword(s):  
Natural Disasters ◽  
Hurricane Katrina ◽  
Primary Productivity ◽  
Atmospheric Carbon Dioxide ◽  
Net Primary Productivity ◽  
Gulf Coast ◽  
Carbon Sink ◽  
Anthropogenic Activities ◽  
Remote Sensing Data ◽  
The United States

Abstract Southern forests contribute significantly to the carbon sink for the atmospheric carbon dioxide (CO2) associated with the anthropogenic activities in the United States. Natural disasters like hurricanes are constantly threatening these forests. Hurricane winds can have a destructive impact on natural vegetation and can adversely impact net primary productivity (NPP). Hurricane Katrina (23–30 August 2005), one of the most destructive natural disasters in history, has affected the ecological balance of the Gulf Coast. This study analyzed the impacts of different categories of sustained winds of Hurricane Katrina on NPP in Mississippi. The study used the Carnegie–Ames–Stanford Approach (CASA) model to estimate NPP by using remote sensing data. The results indicated that NPP decreased by 14% in the areas hard hit by category 3 winds and by 1% in the areas hit by category 2 winds. However, there was an overall increase in NPP, from 2005 to 2006 by 0.60 Tg of carbon, in Mississippi. The authors found that Pearl River, Stone, Hancock, Jackson, and Harrison counties in Mississippi faced significant depletion of NPP because of Hurricane Katrina.

Experimental Research on High Performance Concrete under Drying-Wetting Cycles in Saline-Lake Environment

2011 ◽  
Vol 368-373 ◽  
pp. 1561-1565
Author(s):  
Wei Kong ◽  
Yi Hong Wang ◽  
Gang Zhou ◽  
Tian Hua Li
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Saline Lake ◽  
Salt Lake ◽  
Concrete Structures ◽  
Lake Area ◽  
Corrosion Performance ◽  
Dual Action ◽  
Corrosion Problem ◽  
Single Factor Experiment

Aiming at the corrosion problem of concrete structure of bridges in Chaerhan salt lake area, the paper puts forward a new method of using multi-defense lines against salt erosion, helpful to improve the durability of concrete structures. Single factor experiment of salt erosion and a dual-action experiment of salt erosion and drying-wetting cycles were conducted, using 3 kinds of concrete specimens, including simple high performance concrete (HPC), HPC coated with waterproof material outside and HPC mixed with waterproof material. Results of experiments show that high performance concrete prepared in the experiments has good anti-corrosion performance. Moreover, HPC with multi-defense lines application effectively delays salt erosion to concrete, and lengthens service life of concrete structures in saline-lake environment.

scholarly journals KARAKTERISTIK, KESESUAIAN, DAN PENGELOLAAN LAHAN TAMBAK DI KOTA PEKALONGAN PROVINSI JAWA TENGAH

2016 ◽  
Vol 5 (3) ◽  
pp. 505 ◽  
Author(s):  
Rachmansyah Rachmansyah ◽  
Akhmad Mustafa ◽  
Mudian Paena
Keyword(s):  
Land Management ◽  
Paddy Field ◽  
Coastal Area ◽  
Sea Water ◽  
Saline Water ◽  
C:N Ratio ◽  
Land Suitability ◽  
Geographical Information ◽  
Acid Sulfate Soil ◽  
Acid Sulfate

Kota Pekalongan memiliki lahan tambak yang produktivitas tambaknya masih tergolong relatif rendah. Oleh karena itu, dilakukan penelitian untuk mengetahui karakteristik lahan dalam upaya menentukan kesesuaian dan pengelolaan lahan untuk budidaya tambak demi peningkatan produktivitas tambak di Kota Pekalongan. Faktor yang dipertimbangkan dalam mengetahui karakteristik lahan adalah: tanah, topografi, hidrologi, vegetasi, dan iklim. Analisis spasial dalam Sistem Informasi Geografis digunakan dalam penentuan kesesuaian lahan untuk budidaya tambak. Pengelolaan lahan ditentukan berdasarkan karakteristik lahan yang disesuaikan dengan teknologi dan komoditas yang dapat diaplikasikan di tambak. Tanah tambak di Kota Pekalongan tergolong tanah aluvial non-sulfat masam yang tidak memiliki potensi kemasaman tanah yang tinggi dan sebagian kecil tanah sulfat masam. Sumber air laut untuk tambak tergolong agak keruh dan salinitas air tambak cukup bervariasi sebagai akibat adanya sumber air tawar yang berasal dari Sungai Pekalongan dan sodetan. Vegetasi bakau adalah jenis vegetasi yang dominan di kawasan tambak sebab adanya Program GERHAN (Gerakan Nasional Rehabilitasi Hutan dan Lahan) di Kota Pekalongan. Curah hujan di Kota Pekalongan sebesar 2.300 mm/tahun di mana curah hujan yang rendah dijumpai pada bulan Juli sampai Oktober. Di kawasan pesisir Kota Pekalongan dijumpai tambak, sawah, sawah terintrusi, dan pemukiman yang luasnya masing-masing 332,29; 372,53; 183,83; dan 619,73 ha. Dari luas tambak yang ada di Kota Pekalongan, yaitu 331,292 ha ternyata tidak ada tambak yang tergolong sangat sesuai (kelas S1), 191,856 ha tergolong cukup sesuai (kelas S2) dan 140,436 ha tergolong kurang sesuai (kelas S3). Pada areal yang mengandung unsur atau senyawa penyebab kemasaman yang tinggi disarankan untuk melakukan upaya perbaikan tanah terlebih dahulu berupa remediasi, pemberian pupuk yang mengandung nitrogen pada areal yang memiliki rasio C:N tanah yang tinggi serta pemberian pupuk kandang pada tanah yang mengandung liat lebih besar 60% dan bahan organik kurang dari 8%.Pekalongan City has brackishwater ponds with low productivity. Hence, a survey was conducted to know land characteristics as an effort to determine land suitability and land management to increase the productivity of brackishwater ponds in Pekalongan City, Central Java Province. Factors considered to determine the characteristics of land were soil, topography, hydrology, vegetation, and climate. Spatial analysis in Geographical Information System was used to determine land suitability for brackishwater ponds. Land management was determined based on the characteristics of land conditioned to the types of technology and commodity applied in the brackishwater ponds. Soil of brackishwater ponds in Pekalongan City was dominated by alluvial non-acid sulfate soil in large areas and acid sulfate soil in small areas. Source of sea water for brackishwater ponds has high turbidity and high variation of salinity due to presence of freshwater supply from Pekalongan River and man made canals. Mangrove vegetation is dominant in the coastal area of Pekalongan City, because the presence of GERHAN (National Action for Forest and Land Rehabilitation) Program. The average of rainfall in Pekalongan City is 2,230 mm/year, where low of rainfall occurrs in July until October. The result revealed that the coastal area of Pekalongan City had brackishwater ponds, paddy field, paddy field intruded saline water and settlement of 332.29 ha; 372.53 ha; 183.83ha; and 619.73 ha, respectively. From the total brackishwater ponds in Pekalongan City i.e. 331.292 ha, there were no brackishwater ponds classified as highly suitable (S1 class), but it was found moderately suitable or S2 class (191.856 ha) and marginally suitable or S3 class (140,436 ha). It is suggested to conduct improving soil quality first, including remediation of the areas that contain elements or compounds causing the high acidity of soil, fertilizing with fertilizer containing nitrogen in the areas that have high C:N ratio and applying manure in the soils that contain clay more than 60% and organic matter less than 8%. 

scholarly journals Prediction of leopard habitat suitability in Taman Negara main forest complex, Malaysia

2021 ◽  
Vol 42 (3(SI)) ◽  
pp. 806-811
Author(s):  
N.F. Khodri ◽  
◽  
T. Lihan ◽  
M.A. Mustapha ◽  
T.M. Taher ◽  
...  
Keyword(s):  
Land Use ◽  
Habitat Suitability ◽  
Wildlife Conservation ◽  
Environmental Parameters ◽  
Geographical Information ◽  
Urban Habitat ◽  
Suitable Habitat ◽  
Habitat Suitability Modeling ◽  
Presence Data ◽  
Gis Data

Aim: This research assessed the distribution of leopard to predict the habitat suitability in Taman Negara National Park and adjacent forest area. Methodology: Environmental factors for habitat suitability were derived from geographical information system (GIS) data such as elevation, slope, land-use, distance from urban and distance from river. Leopard presence data from 1993 to 2008 were integrated with the environmental parameters using maximum entropy (MaxEnt) modeling to assess habitat suitability across the study area. Results: The results showed that distance from river contributed the most (39.3%) in the habitat suitability modeling followed by distance from urban (31.4%), elevation (12.3%), land use types (10.1%), and slope (6.9%). Distance from river and urban showed highest contribution that influenced leopard distribution in which most suitable habitat occurred in proximity with river and further from urban. Habitat suitability of leopard were distributed among 48% over 2,218,389 ha of the study area. Interpretation: The findings of this study provides knowledge on how the species move and exploit different habitat niches for more effective conservation management. It provide models for future wildlife conservation and urban planning.

scholarly journals Consequences of Anthropic Actions in Cullera Bay (Spain)

2020 ◽  
Vol 8 (4) ◽  
pp. 240
Author(s):  
José Ignacio Pagán ◽  
Isabel López ◽  
Luis Bañón ◽  
Luis Aragonés
Keyword(s):  
Urban Areas ◽  
Anthropogenic Activities ◽  
Aerial Images ◽  
Geographical Information ◽  
General Increase ◽  
Mountain Areas ◽  
Shoreline Evolution ◽  
Sediment Size ◽  
Human Interventions ◽  
A Current

Urbanization and anthropogenic activities have generated significant imbalances in coastal areas. This study analysed the shoreline evolution of the Bay of Cullera (Spain), characterized by strong urban and tourist pressure and with important human interventions during the last century. The evolution of the shoreline was analysed using 60 years of aerial images since the 1950s of the seabed, the maritime climate and the distribution of sediment, as well as anthropogenic actions, such as urban development or the channelling of the Júcar River through the integration of information in a geographical information system (GIS). The results showed: (i) Changes in land-use, in which the substitution of the crop and mountain areas by urban areas was mainly observed. (ii) A general increase in the beach area, although there were important periods of erosion in some points due to anthropic actions. (iii) A significant decrease in the median sediment size in the whole bay since 1987, with a current D50 of 0.125–0.180 mm. The analysis carried out has made it possible to identify trends in coastal accumulation and regression in the different sections of the sector, as well as to demonstrate the usefulness and advantages of GIS.

scholarly journals Migratory Connectivity in Bicknell's Thrush: Locating Missing Populations With Hydrogen Isotopes

The Condor ◽  
2004 ◽  
Vol 106 (4) ◽  
pp. 905-909 ◽  
Author(s):  
Keith A. Hobson ◽  
Yves Aubry ◽  
Leonard I. Wassenaar
Keyword(s):  
North America ◽  
Dominican Republic ◽  
Migratory Birds ◽  
Geographical Information ◽  
Source Population ◽  
Catharus Bicknelli ◽  
Breeding Grounds ◽  
Early Fall ◽  
Bicknell's Thrush ◽  
Two Populations

Abstract The measurement of the abundance of naturally occurring deuterium (δD) in feathers grown in North America can provide geographical information on location where the feather was grown. Previously, we used this technique to link populations of Bicknell's Thrush (Catharus bicknelli) breeding in northeastern North America (to 46°N) with wintering grounds in the Dominican Republic. That study indicated the presence of a subpopulation of wintering birds with more depleted feather δD values than those measured on their known breeding grounds. This suggested either a more northerly or a higher altitude breeding source population than previously measured. We located two populations of Bicknell's Thrush in Quebec, Canada, at Mine Madeleine (49°N) and at Mont Gosford (45°N). The Mine Madeleine birds had feather δD values overlapping those of the unidentified subpopulation found wintering in the Dominican Republic. At Mont Gosford, hatch-year birds were more depleted in their feather δD values than after-second-year birds suggesting their more northerly origins and capture during the early fall migration period. Our study demonstrates how the stable-isotope approach can be used to document connectivity between breeding and wintering populations of migratory birds. Conectividad Migratoria en Catharus bicknelli: Localización de Poblaciones Perdidas con Isótopos de Hidrógeno Resumen. La medición de la abundancia de deuterio en estado natural (δD) en las plumas formadas en América del Norte puede brindar información geográ fica sobre la localización en donde se formó la pluma. Anteriormente usamos esta técnica para relacionar las poblaciones de Catharus bicknelli que se reproducen en el noreste de América del Norte (hasta 46°N) con las áreas de invernada en República Dominicana. Ese estudio indicó la presencia de una subpoblación de aves invernantes con valores de δD en las plumas por debajo de los valores medidos de los sitios conocidos de cría. Esto sugirió la presencia de una población reproductiva proveedora de individuos localizada más al norte o a mayor elevación que las registradas anteriormente. Localizamos dos poblaciones de C. bicknelli en Québec, Canadá, una en Mine Madeleine (49°N) y otra en Mont Gosford (45°N). Las aves de Mine Madeleine tuvieron valores de δD en las plumas que se superpusieron con aquellos de la subpoblación no identificada encontrada invernando en República Dominicana. En Mont Gosford, las aves del primer año de edad presentaron valores más bajos de δD en las plumas que aquellos encontrados en aves del segundo año de edad o mayores, sugiriendo un origen más boreal y que fueron capturadas durante el inicio del período de migración otoñal. Nuestro estudio demuestra como el mé todo de isótopos estables puede ser usado para documentar conectividad entre poblaciones reproductivas e invernales de aves migratorias.

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