A geostatistical model for estimating edge effects and cumulative human disturbance in wetlands and coastal waters     

John M. Humphreys  Amirsassan Mahjoor  Kelly Chinners Reiss  Andres Arias Uribe  Mark T. Brown 《International journal of geographical information science》2020,34(8):1508-1529

ABSTRACT

The modification of landscapes for agriculture, residential housing, and other human uses has the potential to alter ecosystem function, reduce native biodiversity, and to diminish the capacity of natural systems to provide essential goods and services. Resultantly, methods aimed at quantifying disturbance intensity at the intersection of anthropogenic and natural lands are important to applied aspects of landscape planning and natural resource management, as well as theoretical facets of spatial ecology. Tools to appraise human disturbance in wetlands and coastal waters are especially needed because the topographic settings of surface waters make them particularly susceptible to pollutant accumulation, hydrologic alteration, and other influences from the surrounding landscape. Assuming a water resources focus, we developed a novel geostatistical method to quantify and visualize edge effects and cumulative human disturbance for all wetlands and coastal waters in the State of Florida (USA). Model validation revealed that estimated disturbance intensity was strongly correlated to species richness, levels of heavy metal contamination, and persistent organic pollutant concentration. The presented modeling framework offers a flexible means to assess human disturbance across spatial scales and could be readily applied to prioritize conservation land acquisition and to anticipate future impacts from the proposed development.  相似文献   

Environmental impact assessment of air and heavy metal concentration in groundwater of Maheshwaram watershed, ranga reddy district, Andhra Pradesh     

D. Purushotham  Mehnaz Rashid  Mahjoor Ahmad Lone  A. Narsing Rao  Shakeel Ahmed  E. Nagaiah  Farooq A. Dar 《Journal of the Geological Society of India》2013,81(3):385-396

Anthropogenic activities in Maheshwaram watershed have deteriorated water, air and soil quality during the last ten years due to rapid urbanisation and industrial development. Maheshwaram watershed experienced drastic changes in land use pattern, being very close to the Hyderabad city. Base-line data was collected during post monsoon season (October-November) of 2010 in Maheshwaram watershed to assess the impacts of change in land use, urbanisation and industrialisation on air, water and soil quality for Environmental Impact Assessment (EIA). Air samples were analysed for Suspended Particulate Matter (SPM) and Respirable Suspended Particulate Matter (RSPM). Groundwater samples were analysed for pH; EC; TDS; TH; cations, anions and heavy metals viz., Fe, Mn, Al, Si, V, Cr, As, Sr, Rb, Se, Ba, Li, B, Be, Co, Ni, Zn, Cd, and Pb using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Analysed data were compared with the National and International Standards and subjected to Factor Analysis (FA) for six chemical variables to assess and characterise hydro-chemical processes. A comparison of the results of groundwater samples with WHO and BIS guidelines show that most of the groundwater samples are heavily contaminated with heavy metals like lead, chromium, nickel, barium, aluminium, boron and selenium, which was quantified and presented in the form of spatial variation diagrams prepared using ArcGIS. 9.3.1. Similarly the results of air samples compared with the Central Pollution Control Board, Ministry of Environment and Forests, Government of India guidelines show that most of the air samples for residential, rural and industrial areas are contaminated by SPM and RSPM.  相似文献   

Typhoon rainfall impact on drip water δ18O in Xianyun cave,Southeast China     

Yunyue Yang  Tao Xu  Xin Zhang  Le Ma  Mahjoor Ahmad Lone  Xiuyang Jiang 《水文研究》2021,35(2):e14062

Precisely dated high-resolution speleothems may record past typhoon events, however, the state of the art cave monitoring is a prerequisite to identify suitable stalagmites for the reconstruction of such events. With this motivation, we examined the isotopic composition (δ¹⁸O and d-excess values) of rainfall, outside river, cave drip water, and an underground river in the Xianyun cave system, located in southeastern China. Monthly to bi-monthly monitoring of environmental and isotopic conditions was conducted for 1 year, from December 2018 to December 2019, including a typhoon event (August 24, 2019 to August 26, 2019), called Bailu. The δ¹⁸O of rainfall samples over the cave and outside river water ranged from −9.7‰ to −1.9‰ and −8.2‰ to −6.3‰, respectively, while the δ¹⁸O of Typhoon Bailu rainfall and instantaneous outside river water ranged from −19.6‰ to −6.3‰ and −10.4‰ to −7.7‰, respectively. Typhoon Bailu-induced rainfall showed distinctly negative δ¹⁸O values as compared to those of the monthly and bi-monthly rainfall, exhibiting a three-stage inverted U-shaped variation characteristic. Four drip water monitoring sites inside the cave revealed low variations during the studied period with average values of −7.8‰, −8.0‰, −8.0‰, and −8.1‰. However, during the typhoon, the drip water δ¹⁸O values exhibited similar characteristic as outside rainfall but with just 0.2‰ negative deviation owing to precipitation amount and drip water source reservoir. The integration of rainfall amount with drip water source reservoir determines the degree to which a typhoon isotopic signature gets diluted during epikarst infiltration. This study provides the first instrumental evidence of typhoon signal in karst system in southeastern China. Our results imply that the δ¹⁸O of drip water in Xianyun cave can instantaneously respond to typhoon rainfall. However, the 0.2‰ shift in drip water δ¹⁸O is difficult to be recorded by speleothems. We suggest multi-year monitoring to ascertain fully if the stalagmites could be used as paleotyphoon proxy.  相似文献