Impacts of Climate Change on a Spatially Distributed Water Balance in the Gaza Strip, Palestine

As Mediterranean coastal area, the Gaza Strip is likely to be at high risk for water scarcity due to climate change, thus hydrological studies are necessary. This study aims to investigate the impacts of climate change on water balance elements of the Gaza Strip and generate future projections. The Water Balance computer model (WetSPASS) integrated with the GIS was used for simulating the hydrological cycle for the Gaza Strip coastal aquifer in this study. The mean annual simulated evapotranspiration were 157.34 mm/year, 156.46 mm/year, 151.85 mm/year and 131.44 mm/year for baseline, year 2020, year 2050 and year 2080 respectively. While  34.88 mm /year, 32.35 mm /year, 26.73 mm /year and 18.71 mm /year were the mean annual  simulated surface runoff for baseline, year 2020, year 2050 and year 2080 respectively. The  mean annual simulated groundwater recharge were 125.33 mm/year, 105.07 mm/year, 64.44 mm/year and 20.14 mm/year for baseline, year 2020, year 2050 and year 2080 respectively. The mean simulated interception values were 8.31 mm/year, 7.71 mm/year, 6.41 mm/year and 4.56 mm/year for baseline, 2020, 2050 and 2080 respectively. The main conclusion from projected water balance elements is that Gaza Strip will be in a condition of severe water scarcity risk. Keywords: water balance, climate change, WetSPASS, Gaza Stri

Modelling Potential Impacts of Climate Change on Groundwater of the Gaza Coastal Aquifer from Ensemble of Global Climate Model Projections

The Gaza Strip is subjected to considerable impacts of climate change that may adversely affect the groundwater resource. A decrease in annual precipitation as well as an increase in temperatures are projected from an ensemble of global climate models. In this study, the impact of climate change on groundwater resources in Gaza coastal aquifer was evaluated. Regional groundwater flow simulations were made by means of a three-dimensional numerical model. The model was calibrated by adjusting model input parameters until a best fit was achieved between simulated and observed water levels. Simulated groundwater levels compared favorably with observed mean groundwater levels measured in observation wells. SEAWAT groundwater transient model with simulated climate change data input without any adaption pumping scenario was developed in order to determine the impacts of climate change on groundwater of the Gaza coastal aquifer. An effective management scenario was developed and examined by the same groundwater transient model. The scenario was generated to adapt with climate change conditions by developing new water resources and managing pumping rates. The results indicated that lack of water is expected to be a problem in the future. Also, the generated and examined solution scenario is a strategic solution for about a thirty year period. Keywords: Gaza Strip, climate change, groundwater, management, modeling, seawater intrusio

Projection of Future Climate by Multi-Model Median Approach under GIS Environment along the Gaza Strip, Palestine

Climate changes over the Gaza strip area as a semi-arid area is a major factor that affects the developing strategic plans for water sector. This study aims to determine the future climate changes over Gaza strip. Fossil energy intensive (A1F1) with high sensitivity is the emission scenario that was used for the prediction process. The median assembly approach was used to get the representative results from multi General Circulation Model (GCM) outputs. The predicted mean annual temperatures for years 2020, 2050 and 2080 were 20.66 oC, 22.48 oC and 25.08 oC respectively, While 0.85 oC, 2.67 oC and 5.28 oC were the mean annual changes from baseline period for years 2020, 2050 and 2080 respectively.  The predicted mean annual precipitation for years 2020, 2050 and 2080 were 294.68 mm/year, 243.70 mm/year and 170.82 mm/year respectively, Hence -7.48, -23.98 and -46.37 mm/year were the predicted mean annual precipitation changes from baseline period for years 2020, 2050 and 2080 respectively. The mean annual sea level rise for baseline period was 1.097 cm, in the other hand 9.04 cm, 28.84 cm and 59.85 cm were the predicted mean sea level rise values for years 2020, 2050 and 2080 respectively. Keywords: Climate Change, Gaza Strip, Climate projection, GCM, Emission scenario

A Land Use Regression Model for Explaining Spatial Variation in Air Pollution Levels using a Wind Sector Based Approach

Estimating pollutant concentrations at a local and regional scale is essential for good ambient air quality information in environmental and health policy decision making. Here we present a land use regression (LUR) modelling methodology that exploits the high temporal resolution of fixed-site monitoring (FSM) to produce viable air quality maps. The methodology partitions concentration time series from a national FSM network into wind-dependent sectors or “wedges”. A LUR model is derived using predictor variables calculated within the directional wind sectors, and compared against the long-term average concentrations within each sector. This study demonstrates the value of incorporating the relative position of emission source and receptor into the empirical LUR model structure. In our specific application, a model based on 15 FSM training sites captured 78% of the spatial variability in NO2 across the Republic of Ireland. This compares favourably to traditional LUR models based on purpose-designed monitoring campaigns despite using approximately half the number of monitoring points in model development. We applied the LUR equation at a high-resolution across the Republic of Ireland to enable applications such as the study of environmental exposure and human health, assessing representativeness of air quality monitoring networks and informing environmental management and policy makers

Air pollution abatement performances of green infrastructure in open road and built-up street canyon environments – A review

Intensifying the proportion of urban green infrastructure has been considered as one of the remedies for air pollution levels in cities, yet the impact of numerous vegetation types deployed in different built environments has to be fully synthesised and quantified. This review examined published literature on neighbourhood air quality modifications by green interventions. Studies were evaluated that discussed personal exposure to local sources of air pollution under the presence of vegetation in open road and built-up street canyon environments. Further, we critically evaluated the available literature to provide a better understanding of the interactions between vegetation and surrounding built-up environments and ascertain means of reducing local air pollution exposure using green infrastructure. The net effects of vegetation in each built-up environment are also summarised and possible recommendations for the future design of green infrastructure are proposed. In a street canyon environment, high-level vegetation canopies (trees) led to a deterioration in air quality, while low-level green infrastructure (hedges) improved air quality conditions. For open road conditions, wide, low porosity and tall vegetation leads to downwind pollutant reductions while gaps and high porosity vegetation could lead to no improvement or even deteriorated air quality. The review considers that generic recommendations can be provided for vegetation barriers in open road conditions. Green walls and roofs on building envelopes can also be used as effective air pollution abatement measures. The critical evaluation of the fundamental concepts and the amalgamation of key technical features of past studies by this review could assist urban planners to design and implement green infrastructures in the built environment