Evaluation of Geostatistical Techniques for Mapping Spatial Distribution of Soil PH, Salinity and Plant Cover Affected by Environmental Factors in Southern Iran

Abstract

The study presented in this paper attempts to evaluate some interpolation techniques for mapping spatial distribution of soil pH, salinity and plant cover in Hormozgan province, Iran. The relationships among environmental factors and distribution of vegetation types were also investigated. Plot sampling was applied in the study area. Landform parameters of each plot were recorded and canopy cover percentages of each species were measured while stoniness and browsing damage were estimated. Results indicated that there was a significant difference in vegetation cover for high and low slope steepness. Also, vegetation cover was greater than other cases in the mountains with calcareous lithology. In general, there were no significant relationships among vegetation cover and soil properties such as pH, EC, and texture. Other soil properties, such as soil depth and gravel percentage were significantly affected by vegetation cover. Moreover, the geostatistical results showed that kriging and cokriging methods were better than inverse distance weighting (IDW) method for prediction of the spatial distribution of soil properties. Also, the results indicated that all the concerned soil and plant parameters were better determined by means of a cokriging method. Land elevation, which was highly correlated with studied parameters, was used as an auxiliary parameter.

Land Capability Assessment by Using Geographic Information System in North Delta, Egypt

“…Inverse Distance Weighting (IDW) technique assumes that the (z) value (nonsampled point) is the distance-weighted average of neighbored known points (Zare-Mehrjardi et al, 2010). The neighboring radius and the related power to the distance is a critical matter in this method.…”

Peer Review #1 of "Spatial variability in soil pH and land use as the main influential factor in the red beds of the Nanxiong Basin, China (v0.1)"

“…Many scholars have studied the spatial distribution characteristics of various soil properties by this method (Zhang & Li, 2002;Turgut & Öztaş, 2012;Liu, Shao, & Wang, 2013a). However, most of these studies were limited to a single terrain (Huang et al, 2012;Zhao et al, 2017), vegetation type (Riha, Senesac, & Pallant, 1986;Zaremehrjardi, Taghizadehmehrjardi & Akbarzadeh, 2010), land use (Mao et al, 2014;Miheretu & Yimer, 2017) or other environmental factors, but analysis of them simultaneously is still lack.…”

Spatial Distribution of Some Chemical Characteristics of an Acid Sulfate Soil-Affected Brackishwater Ponds in the Coastal Area of Luwu Regency South Sulawesi Province

“…Spatial distribution of soil types is controlled by a set of environmental factors such as climate, organisms, parent material, and topography as well as time and space (Barthold et al, 2013); in which changes in the environmental factors will change the spatial distribution of soil types. Identification of the spatial distribution of soil characteristics has an important role in many bio-environmental systems (Zuo et al, 2008;Dong et al, 2009;Akbarzadeh & Taghizadeh-Mehrjardi, 2010;Zare-Mehrjardi et al, 2010;Yu et al, 2011). Knowledge of spatial variability on soil characteristics and soil intercharacteristic relationship is important for the evaluation of soil management practices (Huang et al, 2001;Saadi & Athanasopoulos-Zekkos, 2013), and increases the sustainability of land cover/land use (Liu et al, 2006).…”

“…These variations are mainly arise from the factors and processes of pedogenesis and land cover/ land use (Tuzinsky, 1990;Ersahin, 2003;Martin et al, 2011;Beguería et al, 2013) as well as land management practices (Pan Gozalez et al, 2000;Anuar et al, 2008). With classical statistics that take into account the data of land as free data, the implementation often produces unrealistic results (Zare-Mehrjardi et al, 2010). In addition, contrary to the assumption that when used classical statistics is that the soil characteristics on a landscape are not distributed randomly (not just random variability but also not correlated to the spatial location) (Essington, 2004).…”