Spatio-Temporal Distribution of Greenhouses and Affecting Driving Factors in Al-Batinah South, Oman, Using GIS Mapping

Abstract

Geographic Information System (GIS) tools have been utilized in greenhouse cropping systems for detection, identifying, and mapping. This study aimed to study the spatiotemporal distribution of greenhouses (GHs) and the driving factors affecting this distribution in Al-Batinah South, Oman using GIS Mapping. First, a field survey was conducted between July and December 2017 to all farms with greenhouses (GH farms) in the study area. Second, the required digital and non-digital data were collected from different sources. Third, for 2017, the recorded geographic coordinates of GHs and GH farms were mapped, while the aerial photographs for 2008 using ArcMap 10.1 were used to study the spatial and temporal distribution of GH farms and GHs. Fourth, four main driving factors were selected: distance to various market-outlets, distance to roads, distance to coastline and effects of groundwater quality to observe their significance on the spatial distribution of GH farms in 2017 using simple regression analysis. Fifth, the most driving factors explaining the variance of GH farms spatial distribution in 2017 were extracted using Principle Component Analysis (PCA). The results revealed that, for 2017, the distribution of greenhouse farms varied insignificantly (p>0.05) among the six cities in Al-Batinah South, where 71% and 53% of greenhouses and greenhouse farms were concentrated only in Barka coastal city. For the period 2008-2017, the density of greenhouse farms and greenhouses were shifting towards the inland cities such as Nakhal, Al-Rustaq, and Awabi. Within the same period, there was an average reduction of several greenhouses and greenhouse farms by 16.2 and 2.2, respectively. The total land area occupied by greenhouses shrank by an average of 0.56 ha/year in the same period. Results displayed that only one of the four main driving factors had a statistically significant influence (p<0.05) on the spatial distribution of greenhouse farms in 2017, which was the distance to roads. The most affecting driving factors on this distribution was the distance to local markets and the distance to Al-Mawaleh Central market by accounting for 44.2% and 23.8% of the total variance, respectively. In conclusion, Over the period 2008-2017, there was an overall reduction in the average number of GH farms and GHs due to land use changes, high construction costs (capital cost), high production costs, fuel cost, pests and diseases, water scarcity (in some places), competition due to foreign produce and from high tech domestic, low subsidy by Ministry of Agriculture and Fisheries and/or price fluctuations of fresh produce. The influence of distance to the highway and distance to the nearest paved roads were found significant driving factors (p<0.05). Based on PCA analysis, distance to local markets, and distance to Al-Mawaleh Central market were the two driving factors describing the total variance of GH farms spatial distribution. It is recommended, for future expansion of greenhouse farms, to consider inland areas with low groundwater sa...