Aviva Peeters

An assessment of regional constraints, needs and trends

This article briefly reviews regional constraints and trends, among them environmental climatic and social ones, existing and developing in the regions of the Middle East and North Africa (MENA) and which should affect planning, design and construction policies and practices. It reviews the current state of legislation regarding energy and other green building issues, as well as the various voluntary tools which are being promoted in the region. This paper concludes that the pace of building practices adaptations is far from meeting the pace of needs and constraints. The repercussions on the livability of buildings and settlements, and the survivability and resilience potential of communities in the arid regions of MENA, may well be at risk. Thus, for many countries in the region, green building (and the standards that encourage this) is not a luxury of developed countries, which they might adopt in the future once more pressing constraints are eased, but, rather, a critical development goal to lessen these constraints and allow a viable path into such a future.

Automated recognition of urban objects for morphological urban analysis

Abstract It has often been suggested that the physical structure of traditional urban settlements represents a time-tested response to the climatic constraints of a given location, particularly in hot-arid or other regions that are characterized by thermally harsh conditions. To test this premise, vernacular urban forms have been analyzed to identify patterns of built morphology which might have developed as a response to prevailing climatic conditions. This approach is often based on visual analysis and subjective and qualitative recognition of climate-related patterns. The current paper presents an alternative approach, using a quantitative methodology to support the systematic and automated recognition of urban morphological patterns. A parametric GIS model was developed for automated recognition of urban objects, employing the ability of GIS to recognize contextual relations among objects and perform a context-based recognition using basic rules that apply to the organization of urban form. The model was statistically tested for its accuracy with satisfying results. A case study is presented to demonstrate the workability of the model and its potential as a quantitative and systematic tool for quantitatively describing the morphology of urban surfaces for urban climate analysis. As a parametric model, it can be modified and applied to a large number of case studies for developing and updating databases of urban morphology, and these can serve as a basis for the recognition of morphological patterns in urban form.

Modeling the Effects of Land-Cover Change on Rainfall-Runoff Relationships in a Semiarid, Eastern Mediterranean Watershed

Temporal changes and spatial patterns are often studied by analyzing land-cover changes (LCCs) using spaceborne images. LCC is an important factor, affecting runoff within watersheds. The objective was to estimate the effects of 20 years of LCCs on rainfall-runoff relations in an extreme rainfall event. A 1989 Landsat TM-derived classification map was used as input for a Kinematic Runoff and Erosion (KINEROS) hydrological model along with the precipitation data of an extreme rainfall event. Model calibration was performed using measured runoff volume data. Validation of the model performance was conducted by comparing the model results to measured data. A similar procedure was used with a 2009 land-cover classification map as an input to the KINEROS model, along with similar precipitation data and calibration parameters, in order to understand the possible outcomes of a rainfall event of such a magnitude and duration after 20 years of LCCs. The results show an increase in runoff volume and peak discharge between the time periods as a result of LCCs. A strong relationship was detected between vegetation cover and the runoff volume. The LCCs with most pronounced effects on runoff volumes were related to urbanization and vegetation removal.

Green Building Standards in MENA: An assessment of regional constraints, needs and trends

The paper reviews briefly regional constraints and trends in the Middle East and North Africa (MENA), among them environmental climatic and social ones, which should affect planning, design and construction policies and practices. It reviews the current state of legislation regarding energy and other green building issues, as well as the various voluntary tools which are being promoted in the region. Covering 20 countries (from Turkey to Yemen, from Morocco to Iran), and based on over 150 documents in Arabic, English, French, Turkish and Hebrew, the paper concludes that the pace of building practices adaptations is far from meeting the pace of needs and constraints. The repercussions on the liveability of buildings and settlements, and the survivability and resilience potential of communities in the arid regions of MENA, may well be at risk. Thus, for many countries in the region, green building (and the standards that encourage this) are not a luxury of developed countries, which they might adopt in the future once more pressing constraints are eased, but, rather, a critical development goal to lessen these constraints and allow a viable path into such a future.

A Semi-automated GIS Model for Extracting Geological Structural Information from a Spaceborne Thematic Image

This paper presents a semi-automated GIS model for extracting structural information from a spaceborne imaging spectroscopy classification of sedimentary rocks by combining the IS classification with a digital terrain model. The output consists of a database with structural attributes, specifically the dip and strike, of the geological layers. The model was evaluated statistically for its accuracy with promising results, which demonstrate its potential to support field surveys, for geological mapping, for 3D modeling of the subsurface, and for geological spatial analysis.

A GIS-based method for modeling urban-climate parameters using automated recognition of shadows cast by buildings

Abstract Projections for the next thirty years predict a rapid growth in urban population, particularly in the less developed regions. Constructing and updating GIS databases of 3D urban form is essential for analyzing spatial phenomena related to urbanization. One of these phenomena, urban climate, is influenced by urban morphology. A prerequisite for representing urban morphology is 3D data including the height of urban features. In cases where no city plans or field survey data are available, a viable option is to use remotely-sensed data for recognition of urban features. Often, the output of automated object recognition consists of footprints of urban features. A known method for calculating a features height for reconstructing 3D urban morphology is to use the shadows cast by those features. A GIS-based method for constructing 3D geodatabases of urban morphology from cast shadows and analyzing geometrical parameters for urban-climate analysis was developed. The method focuses on the aspect-ratio of inner courtyards and its relation to solar access. A case-study is presented to demonstrate the feasibility of this method. Results demonstrate that the method offers a reliable and low-cost process for constructing 3D geodatabases that can be applied to the analysis of urban-climate parameters in less developed regions, where costly data and sophisticated processing practices are less accessible. This method can enhance the understanding of microclimatic conditions and facilitate climate conscious and sustainable future urban planning in sprawling urban centers.

Using Time Series of High-Resolution Planet Satellite Images to Monitor Grapevine Stem Water Potential in Commercial Vineyards

Spectral-based vegetation indices (VI) have been shown to be good proxies of grapevine stem water potential (Ψstem), assisting in irrigation decision-making for commercial vineyards. However, VI-Ψstem correlations are mostly reported at the leaf or canopy scales, using proximal canopy-based sensors or very-high-spatial resolution images derived from sensors mounted on small airplanes or drones. Here, for the first time, we take advantage of high-spatial resolution (3-m) near-daily images acquired from Planet’s nano-satellite constellation to derive VI-Ψstem correlations at the vineyard scale. Weekly Ψstem was measured along the growing season of 2017 in six vines each in 81 commercial vineyards and in 60 pairs of grapevines in a 2.4 ha experimental vineyard in Israel. The Clip application programming interface (API), provided by Planet, and the Google Earth Engine platform were used to derive spatially continuous time series of four VIs—GNDVI, NDVI, EVI and SAVI—in the 82 vineyards. Results show that per-week multivariable linear models using variables extracted from VI time series successfully tracked spatial variations in Ψstem across the experimental vineyard (Pearson’s-r = 0.45–0.84; N = 60). A simple linear regression model enabled monitoring seasonal changes in Ψstem along the growing season in the vineyard (r = 0.80–0.82). Planet VIs and seasonal Ψstem data from the 82 vineyards were used to derive a ‘global’ model for in-season monitoring of Ψstem at the vineyard-level (r = 0.78; RMSE = 18.5%; N = 970). The ‘global’ model, which requires only a few VI variables extracted from Planet images, may be used for real-time weekly assessment of Ψstem in Mediterranean vineyards, substantially improving the efficiency of conventional in-field monitoring efforts.

Time series analysis of vegetation-cover response to environmental factors and residential development in a dryland region

Land-use changes as a result of residential development often lead to degradation and alter vegetation cover (VC). Although these are worldwide phenomena, sufficient knowledge about anthropogenic effects caused by various populated areas in dryland ecosystems is lacking. This study explored anthropogenic development in rural areas and its effects on the conservation of protected areas in drylands, focusing on the change in VC, the reasons, extent, and the drivers of change. We propose a novel framework for exploring VC change (VCC) as a function of environmental and human-driven factors including different types of populated areas in drylands. As a case study, we used a 30-year time series of Landsat satellite images over the arid region of Israel to analyze spatiotemporal VCC. The temporal analysis involved the Contextual Mann-Kendall significance test and spatial analysis to model clustering of VCC. A Gradient Boosted Regression machine learning algorithm was applied to study the relative influence of environmental and human-driven factors on VCC. In addition, we used ANOVA to examine differences between the effects of three types of populated areas on the spatiotemporal trends of VC. The results show that the most influential environmental variable on VCC was elevation (relative contribution of 17%), followed by slope (14.8%) and distance from populated areas (14.6%). Moreover, different types of populated areas affected VC differently with varying distances from residential centroids. The nature reserves increased VC positively and significantly, while livestock settlements had a negative effect. Change in vegetation was mostly confined to the stream network and occurred in lower elevations. The study demonstrates how different land-use practices alter the landscape in terms of VC and differ in their extents, patterns, and effects. With the expected growth in population and residential development worldwide, the proposed framework may assist conservation managements and policy makers in minimizing environmental degradation in drylands.

Predicting the effects of urbanization on runoff after frequent rainfall events

ABSTRACT Urbanization dynamics are commonly subjected to powerful market forces, only partly managed by land-use plans. The density, location and pattern of urbanized areas affect rainfall-runoff relations. Consequently, it is essential to understand future impacts of urbanization on runoff and produce focused regulation. The goal was to analyze land-cover scenarios and their impact on runoff in an urbanized watershed in Israel. Present and predicted land-cover scenarios in a densely populated watershed were produced. The runoff response to rainfall was then simulated using a hydrological model. The impact of implementing afforestation and quarrying national outline plans was considered. By the year 2050, 50% of the watershed will be urbanized with a linear increase in runoff response. Afforestation and quarrying plans show little effect on runoff, although quarries may decrease runoff through percolation. As urbanization is expected to continue spreading in adjacent watersheds, statutory measures should be applied to mitigating runoff.

Effects of land-cover change on rainfall-runoff relationships: a case study of the Yarkon-Ayalon watershed, Israel

Temporal changes and spatial patterns are often studied by analyzing land-cover changes (LCCs) using spaceborne images. LCC is an important factor, affecting runoff regime within watersheds through processes such as urbanization, agricultural activities, quarries and afforestation. The objective of this research was to estimate the effects of 20 years of LCCs on rainfall-runoff relations in an extreme rainfall event, in a sub-basin scale. A Landsat TM-derived classification map was used as an input for the Kinematic Runoff and Erosion (KINEROS2) hydrological model along with precipitation data of an extreme rainfall event. Model calibration was performed by using total runoff volume data based on hydrometric measurements taken during this rainfall event. Validation of the model performance was conducted by comparing the model results to measured data in order to receive output accuracy estimation. A similar procedure was then used with a 2009 land-cover classification map, derived from a Landsat TM image, as an input to KINEROS2 model, along with the same precipitation data and calibration parameters, in order to understand the possible outcomes of a rainfall event of such magnitude and duration after 20 years of LCCs. The results show a slight increase in runoff volume and peak discharge values between the examined time periods as a result of LCCs. In addition, a strong relationship was spotted between vegetation cover along the six sub-basins and the runoff volume. The LCCs that had the most pronounced effects on runoff volumes were related to urbanization and vegetation removal.