Urban planning in Charnea

Closely packed multi-level buildings typical in Charnean cities and towns.

Urban planning in Charnea is influenced primarily by the environmental conditions of the Ninva desert including extreme heat, high winds and airborne sand. The unusual conditions experienced by Charnean settlements have generally encouraged the preservation and reproduction of ancient design principles utilized in the region since antiquity in combination with modern techniques and innovations. Charnea has become an increasingly urban society since the 20th century, imposing the additional pressure of growing urban populations in the millions concentrated in a handful of urban centers such as Agnannet. The modern day urban populations of Charnea strain the existing infrastructure of these cities and has prompted a number of policy measures as well as architectural adaptations and engineering innovations to address the wear and deterioration of urban infrastructure.

Density

Pedestrian alleys and lanes are common in traditional Charnean settlements.

The most visible and influential principle of Charnean urban planning is its remarkable density. Settlements dating back thousands of years show a pattern of buildings being closely packed together, and often built upward several stories rather than spreading out in the open space of the surrounding desert. This is a striking feature of small Charnean towns and villages that house a population of thousands or even hundreds in a small cluster of tightly packed multi-story buildings rather than the widely spaced single or two story structures typical of rural settlements. The purpose of this density is twofold. The first and main function of the high density layout of Charnean urban centers is to protect inhabitants from extreme heat by providing ample shade and protection from the sun, creating a maze-like pattern of narrow alleys and lanes between relatively tall buildings. The second function of the closely packed buildings, particularly in combination with the labyrinthine layout of the lanes, is to shelter the inhabitants from strong winds and sandstorms. A tightly packed facade-like outer profile of the settlement or cluster of buildings acts as a windbreak while the lack of straight, open streets cutting through the city helps to eliminate the venturi effect. These types of structures provide ample shelter from wind and sand and allow the internal parts of a settlement or urban ward to remain relatively comfortable on windy days and during sandstorms. Conversely, the wind is also utilized for cooling through the use of wind catchers that remove airborne sand and redirect airflow down into the shaded lanes to provide passive cooling and ventilation.

Modernization of the Charnean urban density concept and traditional layout has resulted in the segmentation of urban zones into clusters of tightly packed buildings for commercial and residential purposes that are laid out in a dense plan with pedestrian lanes and narrow one-way streets, connected to the rest of the city by open roadways and arterial avenues conveying vehicular traffic across the city. Ancient technology such as the wind catchers used to cool the urban spaces have largely survived using lightweight netting and modern materials, although traditional wind-catchers made from palm fronds are still common in parts of Charnea. Although Charnean cities and towns regularly featured buildings between 6 and 12 stories tall, the advent of the powered elevator and modern construction techniques has made buildings of such height safer, more comfortable and more common across the country. These taller structures allow for the lanes of modern Charnean cities following the traditional cluster pattern of building to be wider, even wide enough for single or two lane streets to run through them, while still providing ample shade to the street thanks to the height of the surrounding buildings. Where arterial avenues and other open spaces are created in the urban plan, shade trees and constructed coverings are used to provide shelter from the sun. Rows of shade trees and shade structures are often also serving the function of a windbreak in the open spaces where they are present.

Earth Sheltering

Earth sheltering is a common practice in Charnea, where earth sheltered structures are known as Ikalifrin (Singular: Akalifri). Such structures can be built below grade, excavated into the surface of the earth, or above grade with displaced earth used on the top and sides of the structure. In both cases, earth shelters take advantage of the thermal mass of soil, sand, rock and earth to insulate their interiors from extreme temperatures. Ikalifrin have been built in what is now Charnea since pre-history, typically following a pattern of a central excavated communal square surrounded by individual akalifri homes cut laterally from the open pit into the sub-surface material. Modern excavation machinery, geological science and geoengineering practices have made the construction of such pit houses faster, easier and safer although not necessarily cheaper. Above-grade earth sheltered structures are generally cheaper than their subterranean counterparts while offering less thermal protection than excavated ikalifrin and occupying more space than typical surface structures made of adobe or other materials. Earth sheltering is less common in modern Charnean cities, traditionally appearing around the outskirts of dense urban settlements and in rural locations where the typical cluster of closely packed multi-story buildings could not be erected due to local conditions or a lack of manpower.

Urban Erosion

The term urban erosion was coined in 1974 by Charnean architect and city planner Younes Ilbak to describe the process through which the flow of advancing windblown sand and sand dunes progressively render parts of the settlement destroyed or otherwise unusable. Younes proposed a variety of planning and engineering solutions to mitigate the phenomenon of urban erosion and desert encroachment, many of which are based in common practices that have existed in Charnea for thousands of years such as the erecting of windbreaks using berms and rows of trees. Such structures, used in by Charnean farmers since antiquity to protect cultivated fields from the detrimental effects of strong winds and sand, can also be used more widely as a simple tool to protect peripheral districts, roads and other infrastructure from advancing dunes and damage from sandstorms and strong winds. Modern urban planning must also account for sandstorm damage and the presence of sand in drainage systems and other infrastructure which can be damaged and even rendered unusable by the presence of too much sand. Filters, sand traps and other minor but significant modifications and pieces of infrastructure are now commonplace across Charnea to protect rail lines, electrical infrastructure, pipes and water infrastructure and even roads, bridges and streetlights and signage from sandstorms and excessive windblown sand.  

Building Materials

A combination of traditional and modern construction techniques and materials can be found in modern Charnean urban centers. Adobe is a very popular building material in Charnea even into the modern era due to its low cost and excellent thermal qualities. Structures made from adobe have thick walls with a high thermal mass, providing excellent insulation and protecting the internal spaces from the extreme fluctuations of daytime heat and nighttime cold typical to Charnea. In the exceptionally dry climate of the region properly maintained adobe structures boast incredible longevity, capable standing for hundreds of years. Building codes dating back to the foundation of the Charnean Empire in the 14th century, largely unchanged into the modern day, regulate the production of adobe bricks and structures and set out the necessary physical properties of the adobe material and design of walls and structures in order to maximize the strength of the structure and the material, as well as its temperature regulating qualities.

The most popular modern alternative to adobe is hemplime, a building material made of fibrous hemp shives and a lime-based binding material. Unlike adobe, hemplime is not weight-bearing and is used in combination with a load-bearing frame of wood or steel. However, the material offers excellent thermal qualities with a greater thermal mass than adobe allowing for walls of supported hemplime to be thinner for the same thermal mass compared to adobe. Many of the more modern constructions in Charnean cities, especially those exceeding 6 floors in height, are often built with a wooden or steel skeleton with insulating walls of hemplime to save on space and avoid the extreme thickness of load-bearing walls required in an adobe structure of equivalent height.