Ecohydrological responses to surface flow across borders: Two decades of changes in vegetation greenness and water use in the riparian corridor of the Colorado River delta

Hydrological and bioclimatic processes that lead to drought may stress plants and wildlife, restructure plant community type and architecture, increase monotypic stands and bare soils, facilitate the invasion of non-native plant species and accelerate soil erosion. Our study focuses on the impact of a paucity of Colorado River surface flows from the United States (U.S.) to Mexico. We measured change in riparian plant greenness and water use over the past two decades using remotely sensed measurements of vegetation index (VI), evapotranspiration (ET) and a new annualized phenology assessment metric (PAM) for ET. We measure these long-term (2000–2019) metrics and their short-term (2014–2019) response to an environmental pulse flow in 2014, as prescribed under Minute 319 of the 1944 Water Treaty between the two nations. In subsequent years, small-directed flows were provided to restoration areas under Minute 323. We use 250 m MODIS and 30 m Landsat imagery to evaluate three vegetation indices (NDVI, EVI, EVI2). We select EVI2 to parameterize an optical-based ET algorithm and test the relationship between ET from Landsat and MODIS by regression approaches. Our analyses show significant decreases in VIs and ET for both the 20-year and post-pulse 5-year periods. Over the last 20 years, EVI _Landsat declined 34% (30% by EVI_MODIS) and ET_Landsat-EVI declined 38% (27% by ET_MODIS-EVI), overall ca. 1.61 mm/day or 476 mm/year drop in ET; using PAM ET_Landsat-EVI the drop was from 1130 to 654 mm/year. Over the 5 years since the 2014 pulse flow, EVI_Landsat declined 20% (13% by EVI_MODIS) and ET_Landsat-EVI declined 23% (4% by ET_MODIS-EVI) with a 0.77 mm/day or a 209 mm/year 5-year drop in ET; using PAM ET_Landsat-EVI the drop was from 863 to 654 mm/year. Data and change maps show the pulse flow contributed enough water to slow the rate of loss, but only for the very short-term (1–2 years). These findings are critically important as they suggest further deterioration of biodiversity, wildlife habitat and key ecosystem services due to anthropogenic diversions of water in the U.S. and Mexico and from land clearing, fires and plant-related drought which affect hydrological processes.     

Identification and determination of PAHs compounds in Anzali International Wetland

The worst environmental pollutants in Anzali International Wetland are oily hydrocarbons especially aromatic and poly aromatic compounds (PAHs). The existence of oily compounds with approximate limit of concentration of 0.1 μg/l in aquatic environment bans the growth of fish larva and causes the generic state manner of animals. Anzali International Wetland, which is situated in the west — southern part of Caspian Sea where has environmental importance in life of living organisms and ecosystems. In this reseach, four sites, Pirbazar, Pasikhan, west and central parts, where are situated in Anzali International Wetland, have been studied in 2002. Waste sedimentation soil Sampling was performed during winter and spring in the above-mentioned regions. In the first stage, the purpose of sampling was to access optimum instrumental conditions and correct and precise procedures. Oily pollutants were extracted from water and it was done by using CC1₄ solvent after cleaning and concentrating. The extracted samples were identified with gas chromatographic method with using polyaromatic standard solutions. By the powerful GC/MS method; results of qualitative analysis were confirmed. Also by GC/MS using SIM mode quantitative analysis were performed. Quantitative study of polyaromatic compounds has also been done by luminescence spectrophotometry. Some compounds which were identified in the water samples were: olifinic, aromatic and poly — aromatic compounds such as: antracene, fluourine, xylene, methylbenzene, naphthalene and acenaphtylene. Finally, the degree of biodegradation of compounds such as pristan (C₁₉H₄₀) and phytan (C₂₀H₄₂) in water samples was integrated.     

Effect of spatial resolution of satellite images on estimating the greenness and evapotranspiration of urban green spaces

Urban green spaces (UGS), like most managed land covers, are getting progressively affected by water scarcity and drought. Preserving, restoring and expanding UGS require sustainable management of green and blue water resources to fulfil evapotranspiration (ET) demand for green plant cover. The heterogeneity of UGS with high variation in their microclimates and irrigation practices builds up the complexity of ET estimation. In oversized UGS, areas too large to be measured with in situ ET methods, remote sensing (RS) approaches of ET measurement have the potential to estimate the actual ET. Often in situ approaches are not feasible or too expensive. We studied the effects of spatial resolution using different satellite images, with high-, medium- and coarse-spatial resolutions, on the greenness and ET of UGS using Vegetation Indices (VIs) and VI-based ET, over a 780-ha urban park in Adelaide, Australia. We validated ET with the ground-based ET method of Soil Water Balance. Three sets of imagery from WorldView2, Landsat and MODIS, and three VIs including the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI) and Enhanced Vegetation Index 2 (EVI2), were used to assess long-term changes of VIs and ET calculated from the different imagery acquired for this study (2011–2018). We found high correspondence between ET-MODIS and ET-Landsat (R² > 0.99 for all VIs). Landsat-VIs captured the seasonal changes of greenness better than MODIS-VIs. We used artificial neural network (ANN) to relate the RS-ET and ground data, and ET-MODIS (EVI2) showed the highest correlation (R² = 0.95 and MSE =0.01 for validation). We found a strong relationship between RS-ET and in situ measurements, even though it was not explicable by simple regressions; black box models helped us to explore their correlation. The methodology used in this research makes a strong case for the value of remote sensing in estimating and managing ET of green spaces in water-limited cities.     

Evaluation of WaPOR V2 evapotranspiration products across Africa

The Food and Agricultural Organization of the United Nations (FAO) portal to monitor water productivity through open-access of remotely sensed derived data (WaPOR) offers continuous actual evapotranspiration and interception (ETIa-WPR) data at a 10-day basis across Africa and the Middle East from 2009 onwards at three spatial resolutions. The continental level (250 m) covers Africa and the Middle East (L1). The national level (100 m) covers 21 countries and 4 river basins (L2). The third level (30 m) covers eight irrigation areas (L3). To quantify the uncertainty of WaPOR version 2 (V2.0) ETIa-WPR in Africa, we used a number of validation methods. We checked the physical consistency against water availability and the long-term water balance and then verify the continental spatial and temporal trends for the major climates in Africa. We directly validated ETIa-WPR against in situ data of 14 eddy covariance stations (EC). Finally, we checked the level consistency between the different spatial resolutions. Our findings indicate that ETIa-WPR is performing well, but with some noticeable overestimation. The ETIa-WPR is showing expected spatial and temporal consistency with respect to climate classes. ETIa-WPR shows mixed results at point scale as compared to EC flux towers with an overall correlation of 0.71, and a root mean square error of 1.2 mm/day. The level consistency is very high between L1 and L2. However, the consistency between L1 and L3 varies significantly between irrigation areas. In rainfed areas, the ETIa-WPR is overestimating at low ETIa-WPR and underestimating when ETIa is high. In irrigated areas, ETIa-WPR values appear to be consistently overestimating ETa. The relative soil moisture content (SMC), the input of quality layers and local advection effects were some of the identified causes. The quality assessment of ETIa-WPR product is enhanced by combining multiple evaluation methods. Based on the results, the ETIa-WPR dataset is of enough quality to contribute to the understanding and monitoring of local and continental water processes and water management.     

Utilization multi attribute decision making models for spatial prioritization and environmental decision making in new towns

This study was conducted to determine some important factors of site selection for Esfahan 4th new town-Iran, with quantification of importance index for each factor and the effect of selected criteria in determination of the prioritized location for urban development. The study followed an explanatory analytical method based on field studies, analytical hierarchy process and technique for order preference by similarity to ideal solution model. This means that after defining the criteria and the significant parameters using Delphi technique and filling out the questionnaires by experts in environmental sciences and urban constructions, the rate of effectiveness of each factor and also the significant criteria in site priority and environmental decision making for new towns were determined by analytical hierarchy process model and “Expert choice” software. The results revealed that among the main defined criteria (i.e. physical, biological, economical-social, political and pollution dispersion) and sub-criteria selected by the experts for location of Esfahan 4th new town, the physical criteria with a weight of 0.453 designated nearly 45 % of the importance index to itself, standing at the first priority. Accordingly, the economical-social and pollution dispersion criteria were ranked at the second and the third place with weights of 0.307 and 0.116, respectively. The technique for order preference by similarity to ideal solution model, which is one of the methods for multi-criteria decision making, was then used to determine the best location scenario. Comparing the three proposed locations, alternative 1 was found to be more suitable as it was well-fitted to the defined criteria.     

Development of industrial waste disposal scenarios using life-cycle assessment approach

In this study, environmental impacts of industrial waste disposal of used lubricating oils and sulphur wastes scenarios have been investigated and modeled. The life-cycle assessment methodology was selected among the environmental impact assessment methods. In this method environmental issues and burdens were quantitated in order to facilitate the comparison. In this regard, options with the least adverse impacts were suggested. Functional unit of the study has also been defined as amount of used lubricating oils and sulphur wastes in terms of kilograms based on capacity of transitional barrel. Accordingly, the system boundaries were selected for life cycle of the wastes produced in sulphur unit of Tehran Oil Refinery. Since the main disposal method applied in Tehran Oil Refinery was transference to the municipal landfill, two incineration and landfilling scenarios were modeled for used lubricating oils and sulphur wastes by means of Simapro-7.1 software. Then, the outputs of these scenarios were compared in terms of the least environmental impacts by EDIP 2003 and Ecoindicator 99 methods. Finally, incineration scenarios were recommended as the most efficient ones.     

The performance evaluation of information value,density area,LNRF, and frequency ratio methods for landslide zonation at Miandarband area,Kermanshah Province,Iran

Landslide is one of the natural disasters which causes a lot of annual damage directly or indirectly in the world. Many planned areas, especially in hilly regions, are prone to different types of landslides; therefore, landslide susceptibility maps become an urgent issue, so that landslide damages and impact can be minimized. The best method for studying landslides, which has long been of interest to researchers, is hazard zonation. In this method, due to the affecting factors in landslide occurrence, study areas are classified into areas with low to very high risk. Different methods have been developed for this purpose. In this paper, the four bivariate statistical methods namely information value, density area, LNRF, and frequency ratio are used to investigate the hazard zonation of landslide in Miandarband located north of the Kermanshah Province. The density ratio (D _r) and Qs values for information value, density area, frequency ratio, and LNRF methods used in this study were calculated to be 2.245312, 0.98146; 2.857816, 1.071185; 2.858085, 0.783945; and 2.418375, 1.070928, respectively. The results indicate that although there are minor differences, the frequency ratio method compared to the density area method that was used for the study of landslide zonation presents better results.     

Evaluation of ecotourism potential in the northern coastline of the Persian Gulf

This research has identified areas located in the northern coastline of the Persian Gulf in the south of Iran, as strategic and ecological sites, based on tourism potential assessing criteria. To this end coastal limits were identified by satellite imagery in terms of shorelines and the maximum extent of water approach into the land and taking into consideration the characteristics of the nearby coastal villages. The studied region was then compared to similar international criteria and experiences. The original criteria were then divided into three main and four sub criteria. The Kangan region was found to have a potential for tourism industry according to the mentioned criteria. Naiband Gulf with a score of 20 was ranked first followed by Asalouyeh with a score of 18 and finally Taheri and Kangan Ports with scores of 16 and 15, respectively. With a high tourism industry potential in the studied region the necessity of ecotourism quality enhancement and environmental management planning for the northern shoreline of the Persian Gulf becomes of vital importance.