GIS-based estimation of flood hazard impacts on road network in Makkah city, Saudi Arabia

Makkah city, Saudi Arabia, is periodically exposed to flash floods that result in major human and economical damages. That is due to several factors including its rugged topography and geological structures. Hence, precise assessment of floods becomes a more vital demand in development planning. A GIS-based methodology has been developed for quantifying and spatially mapping the flood characteristics. The core of this new approach is integrating several topographic, metrological, geological, and land use data sets in a geographic information system (GIS) environment that utilizes the curve number method of flood modelling for ungauged arid catchments. Based on the estimated flood volume of sub-basins, a hazard factor has been developed to quantify the expected hazard level for each road. Applying this proposed approach reveals that 21?% of the road network in Makkah city is subjected to low flood hazards, 29?% is facing medium hazards, and 50?% of roads are exposed to harsh flood impacts. The developed approach may be considered a digital precise method that can be easily re-run, in other situations or regions, to estimate flood hazards on roads.     

Assessment of several flood estimation methodologies in Makkah metropolitan area, Saudi Arabia

Estimation of floods in a hydrological basin is essential for efficient flood management and development planning. Several approaches have been proposed to estimate flood peak discharge based on topographic and morphometric characteristics of ungauged hydrological basins. Two global approaches, namely the rational and the curve number methods, along with four national regression models have been compared over Makkah metropolitan area, Saudi Arabia. The curve number methodology has been taken as the basis of comparison due to its precision and wide utilization. Results show that the rational method produces differences equal to 44% in terms of peak discharges. Moreover, the best national regression model gives difference in the order of 18% with respect to the curve number results. Other national models give results very far away from those of the curve number (up to 95%), which can be considered as measures for their awful accuracy. Hence, the curve number is recommended as an optimum methodology for flood estimation, in Makkah city, in case of availability of geological, metrological, land use, and topographic datasets. Otherwise, a specific national regression model (Al-Subai) may be utilized in a simple way.     

Highways protection from flood hazards,a case study: New Tama road,KSA

Natural Hazards - Highways in arid regions are highly exposed to damage by floods. This requires intensive analysis of flood quantity, time and direction that can be used to design the suitable...     

Flash flood hazard mapping based on quantitative hydrology,geomorphology and GIS techniques (case study of Wadi Al Lith,Saudi Arabia)

Flash floods are considered as catastrophic phenomena possessing major hazardous threat to the coastal cities, towns, villages and infrastructures. This study deals with the evaluation of flash flood hazard in the ungauged Wadi Al Lith basin depending on detailed morphometric characteristics of Al Lith basin and its sub-basins. For the detailed study, ASTER data were used for preparing digital elevation model (DEM), and geographical information system (GIS) was used in the evaluation of linear, areal and relief aspects of morphometric parameters. The major parameters such as watershed boundary, flow accumulation, flow direction, flow length and stream ordering are prepared using the ArcHydro Tool. Surface Tool in ArcGIS-10 software, and ASTER (DEM) was used to create different thematic maps such as DEM, contour, slope aspect and hill shade maps. Twenty-five morphometric parameters were measured, calculated and interlinked to produce nine effective parameters for evaluation of the flash flood hazard degree of the study area. Based on nine morphometric parameters which affect the hydrologic behaviour of the Wadi, by influence on time of concentration which has a direct influence on flooding prone area. The flash flood hazard of the Al Lith basin and its sub-basins was identified and classified into three groups (high, medium and low hazard degree). The study provides details on the flash flood-prone area (Wadi Al Lith) and the mitigation measures. This study also helps to plan rainwater harvesting and watershed management in the flash flood alert zones.     

Determination of groundwater availability in shallow arid region aquifers utilizing GIS technology: a case study in Hada Al-Sham, Western Saudi Arabia

A simple, physically based method is developed in this paper to assist in the allocation of areas with high groundwater potential and for the determination of maximum allowed pumping rate to ensure proper groundwater management. This method utilizes the aquifer physical properties as well as GIS technology to accomplish this purpose. The design of this method was considered to be applicable in areas with little data, such as in most arid regions. This technique was applied to a catchment in an arid environment where qualitative as well as quantitative analyses of the results were undertaken. Locations of available groundwater and rates of maximum allowable pumping were compared with observations and experiments in the field and a good agreement was found. It was concluded that the best groundwater location was in the alluvial area, which represents only 16% of the total aquifer, which is a typical case in arid region catchments. The rate of maximum pumping was estimated to be 65 m³/h. However, to benefit 55% of the area, the maximum pumping rate should only be 40 m³/h with an average rate throughout the area (55%) of about 24 m³/h.This revised version was published online in December 2004 with corrections to the category.     

Dam break analysis and flood disaster simulation in arid urban environment: the Um Al-Khair dam case study,Jeddah, Saudi Arabia

Natural Hazards - This study used a simulation methodology for dam break analysis and flood simulation in an urbanized arid region, namely Um Al-Khair dam in Jeddah, Saudi Arabia. The analysis was...     

Chemical evolution of an inland sabkha: a case study from Sabkha Matti,Saudi Arabia

Hydrogeology Journal - Sabkha Matti is a potential discharge point for regional groundwater systems in the Rub’ al Khali topographic basin of Saudi Arabia. The hydrogeochemical evolution of...     

Monitoring and prediction of land use/land cover changes using CA-Markov model: a case study of Ravansar County in Iran

Human‐induced land use/land cover (LULC) changes are among the most important processes that shape the dynamics of the earth’s surface. This phenomenon, which is occurring at an astonishing rate, and its consequential environmental impacts have become an important area of research for scientists.Therefore, a wide range of methods and models have been developed to detect and predict these alterations, among which cellular automata (CA) models such as the CA‐Markov model, due to their affinity to geographic information system (GIS) and remote sensing (RS), are appropriate for detailed resolution modelling and simulating dynamic spatial processes. In Iran, the district of Ravansar has undergone severe LULC changes recently, thus to take the necessary precautions, decision‐makers need to predict and determine the extent of these changes. In this study, using spatial analysis methods the LULC changes in Ravansar were investigated from 1992 to 2015. Subsequently, the CA‐Markov model was applied to simulate the spatial pattern changes of LULC until 2030. Our results indicated that from 1992 to 2015, this region has witnessed a noticeable increase in the areas of the built‐up and agricultural lands (both aquatic and non‐aquatic), resulting in the decrease of the gardens, range, and bare lands. The simulated LULC map showed that this trend will continue due to more urbanization and development of agricultural areas.     

Near-surface foundation level assessment from seismic measurements: a case study of north Jeddah City,Saudi Arabia

In this study, a comprehensive assessment on the generation mechanism, distribution characteristics, and extension rules of structure cracks was conducted by in situ monitoring and field investigation in the Chengchao Iron Mine. Structure cracks are affected by many factors, e.g., surface deformation, structure strength, occurrence position, and machine vibration. They initially occur in a structure when the strength of the structure is not enough to resist the inner strain as surface deformation increases. In contrast, increases in width and length of structure crack exert stress release in the structure and thus decrease structure deformation surrounding the crack. A great ground crack may adversely aggravate structure cracking and release the stress of surrounding rock masses. In addition, micro cracks in rock masses provide favorable conditions for the generation and extension of cracks, resulting that cracks occur in shaft walls more easily and extend towards the deeper. The initial distribution of cracks is generally consistent with such micro cracks. Subsequently, cracks in deep rock masses will extend along the strike of the mined-out area as surface deformation increases. Sensibilities to cracking of structures are changed by their different strain resistances and become stronger from bolt-shotcrete shaft, bolt-shotcrete tunnel, and brick-concrete building to brick wall. Based on distribution characteristics of cracks and wave velocity in rock masses, the overlaying strata affected by underground mining can be divided into four zones: broken zone, broken transition zone, crack generation zone, and micro deformation zone.     

Mapping land limitations for agricultural land use planning using fuzzy logic approach: a case study for Marinduque Island,Philippines

This study demonstrated the use of fuzzy logic approach in mapping land limitations for agricultural land use planning using publicly available data for the province of Marinduque, Philippines. The paper focused only on the two major crops in the province, coconut, and banana. Based on the results, slope is the major factor limiting the production of these two crops. Slope is identified as a limitation in approximately 80% and 18% of the agricultural land of the province for coconut and banana production, respectively. Other land limitations for coconut production in the province include rainfall, soil, and combination of these factors with slope. In the case of banana, soil and combination of this factor with slope were identified as land limitations.

     

GIS based landslide susceptibility mapping using a fuzzy logic approach: A case study from Ghurmi-Dhad Khola area, Eastern Nepal

Landslides cause extensive loss of life and property in the Nepal Himalaya. Since the late 1980s, different mathematical models have been developed and applied for landslide susceptibility mapping and hazard assessment in Nepal. The main goal of this paper is to apply fuzzy logic to landslide susceptibility mapping in the Ghurmi-Dhad Khola area, Eastern Nepal. Seven causative factors are considered: slope angle, slope aspect, distance from drainage, land use, geology, distance from faults and folds, soil and rock type. Likelihood ratios are obtained for each class of causative factors by comparison with past landslide occurrences. The ratios are normalized between zero and one to obtain fuzzy membership values. Further, different fuzzy operators are applied to generate landslide susceptibility maps. Comparison with the landslide inventory map reveals that the fuzzy gamma operator with a γ-value of 0.60 yields the best prediction accuracy. Consequently, this operator is used to produce the final landslide susceptibility zonation map.     

Investigating the effects of land use change on flood hydrograph using HEC-HMS hydrologic model (case study: Ekbatan Dam)

Natural Hazards - Hydrological modeling academic studies have focused on the response to human-caused land use changes. The effects of land use change on flood degree in the catchment basin of...     

基于GIS的岩溶区土地利用的地形梯度分布研究——以酉阳县板溪乡为例

基于 RS 和 GIS 技术,采用地形位指数、分布指数和土地利用程度综合指数,探讨了2002、2011两年重庆市酉阳县板溪乡不同地形梯度土地利用结构的变化特征和定量分析了土地利用程度。结果显示：建设用地、耕地和水域对地形条件的选择性较强;建设用地主要聚集在海拔〈850 m、坡度〈15°176;的区域,耕地主要聚集在海拔〈1050 m 和坡度〈25°176;的区域,5和7级地形位为制约水域分布的地形条件;2011年,灌木林地在海拔650-1250 m、坡度〉15°176;的区域集中增加。总体上,该研究区的土地利用程度较高,但仍然存在耕地分布不合理的现象。     

Impacts of land use and land cover changes upon organic productivity values in Karst ecosystems: a case study of Northwest Guangxi, China

Karst areas are one of the most fragile regions in the world. The Karst environment is very common in southwest China with severe poverty and environmental degradation. Therefore, it is necessary to monitor the Karst ecosystem and its ability to provide goods and services for society. In this paper, we analyzed the spatial distribution of organic productivity values (OPV) in Northwest Guangxi, China in 1985, 1990, 2000, and 2005 using remote sensing and geographic information system techniques. OPV showed a decreasing trend in the last 20 years though there were fluctuations. OPV was 184.85, 117.53, 163.66 and 177.25 million Yuan in 1985, 1990, 2000 and 2005, respectively. Woodland and shrub were the two largest contributors to total OPV. They accounted for 70.51%, 69.13%, 73.92% and 66.23%, respectively, in those four years. Conversely, OPVof residential and barren rock was low with a percentage of 0.70%, 0.56%, 0.57% and 0.90%, respectively. Spatially, OPVis higher in the west than in the east. However, OPV increased in typical Karst areas but decreased in non-Karst areas. Our study indicates that ecosystem conditions in Karst areas had improved because of the application of rocky desertification control policies.     

Geospatial analysis of land use driving force in coal mining area: case study in Ningdong,China

GeoJournal - Geospatial techniques such as remote sensing and Geographic Information System are very important for studying the dynamic process of land use. To analyze the land use change and...