Plant growth processes and productivity of agroecosystems depend highly on evapotranspiration from the land (soil-crop cover complex) surface. A study was carried out using MODIS TERRA optical and thermal band data and ground observations to estimate evaporative fraction and daily actual evapotranspiration (AET) over agroecosystems in India. Five study regions, each covering a 10 km610 km area falling in agricultural land use, were selected for ground observations at a time closest to TERRA overpasses. The data on radiation and crop parameters in paddy (irrigated and rainfed), cotton (rainfed), groundnut (residual moisture) crops were recorded at 14-day intervals between August 2003 to January 2004 from 2 km62 km homogeneous crop patches within each study region. Eight MODIS scenes in seven optical (1, 2, 3, 4, 5, 6, 7) and two thermal bands (31, 32) level 1B data acquired from the National Remote Sensing Agency, Hyderabad, India and resampled at 1 km, were used to generate surface albedo (a), land surface temperature (T s, MODIS ) and emissivity (e s ). Evaporative fraction and daily AET were generated using a single source energy balance approach with (i) ground based observations only ('stand alone' approach), and (ii) 'fusion' of MODIS derived land surface variables on cloud free dates and coincident ground observations. Land cover classes were assigned using a hierarchical decision rule applied to multi-date Normalized Difference Vegetation Index (NDVI). The exponential model could be fitted between 1-EF ins, ground (ground based evaporative fraction) and difference between T s, MODIS and air temperature (T a ) with R 2 50.77. Linear fit (R 2 50.74) could be obtained between 1-EF ins, ground and temperature vegetation dryness index (TVDI), derived from T s, MODIS -NDVI triangle. Energy balance daily AET from the 'fusion' approach was found to deviate from water balance AET by between 4.3% to 24.5% across five study sites with a mean deviation of 11.6%. The root mean square error (RMSE) from the energy balance AET was found to be 8% of the mean water balance AET. The satellite based energy balance approach can be used to generate spatial AET, but needs more refinements before operational use in the light of progress in algorithms and their validation with huge datasets.
Background:Air pollutants of iron- and steel-making operations have historically been an environmental and health hazard. These pollutants include gaseous substances such as sulfur oxide, nitrogen dioxide, and carbon monoxide. The Iran National Steel Industrial Group beam rolling mills factory has two production lines viz. line 630 and line 650, with different beam production capabilities and is capable of producing different types of beams.Materials and Methods:A retrospective cross-sectional study on 400 workers in different exposure levels to environmental pollution was performed during 2005 to determine the mean value of respirable particulate matter (RPM) concentrations and its effects on the health status of workers. To elicit information regarding the health status of the worker, the National Institute for Occupational Safety and Health standard questionnaire was used. Fisher's exact test was performed to assess the relative risk (RR) of exposure to air pollution on cardiovascular diseases, chest tightness, cough, difficulty in retention, i.e. loss of memory, tension, occupational fatigue, and occupational stress in exposed workers.Results:There was significant difference in RPM pollution level between two product lines. The RR of exposure to air pollution on cardiovascular diseases, chest tightness, cough, difficulty in retention, i.e. loss of memory, tension, occupational fatigue, and occupational stress in exposed workers were 2.78, 2.44, 2.15, 1.92, 1.57, 3.90, and 2.09, respectively.
Drought frequencies during the years 1901–2010 were investigated over three spatial units – All India, 5 Homogeneous Regions (HR) and 36 Meteorological subdivisions (MSs). The All-India rainfall trend is in fact indicative of no trend, while the Northeast HR (NER) shows a significant decrease. Furthermore, a significant decrease in rainfallis to be observed over Himachal Pradesh, Madhya Pradesh, Maharashtra and the Southern Peninsular region, and a significant increase over West Bengal, Punjab, Haryana, Coastal Karnataka, North Interior Karnataka and Rayalaseema. There have been 21 All-India drought years during the last century, of which 13 were linked to El Niño. When compared with HRs, the WCR is highly prone to El Niño while the NER is not affected by this global tele-connection. Western Uttar Pradesh, Eastern Rajasthan, Uttarakhand, Vidharbha and Telangana shared 11–10 drought occasions with El Niño. Maximum frequencies of droughts (21) were reported for East Madhya Pradesh within the WCR and Orissa within the Central Northeast Region (CNER), while Andaman, Nicobar and Rayalaseema experienced minimum drought episodes (12) over the last century. Sixty percent of the MSs in the West Central Region (WCR) and the Northwest Region (NWR) were coherent with All-India droughts. During the years 1918, 1972 and 2002, the majority of HRs (except NER) witnessed normal or below-normal rainfall. Western Madhya Pradesh within the WCR saw maximum drought events (13). The highest degree of simultaneous occurrence of drought years between the MSs and all-India concern Eastern Rajasthan, Western Madhya Pradesh, East and West Uttar Pradesh. The study also found that the MSs in HRs highly affected are East Rajasthan (NWR), West Madhya Pradesh (WCR), West and East Uttar Pradesh (CNER), NER and Coastal Karnataka (Peninsular Region). Western Uttar Pradesh, Eastern Rajasthan, Vidarbha and Telangana had 10–11 occasions when El Niño and Drought years occurred.
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