Assessment of the flood hazard arising from land use change in a forested catchment in northern Iran

Abstract

The provinces of northern Iran that border the Caspian Sea are forested and may be prone to increased risks of flooding due to deforestation and other land use changes, in addition to climate change effects. This research investigated changes in runoff from a small forested catchment in northern Iran for several land use change scenarios and the effects of higher rainfall and high antecedent soil moisture. Peak discharges and total runoff volumes from the catchment were estimated using the U.S. Soil Conservation Service “Curve Number” (SCS‐CN) method and the SCS dimensionless unit hydrograph. This method was selected for reasons of data availability and operational simplicity for flood managers. A geographical information system (GIS) was used to manipulate spatial data for use in the catchment runoff modelling. The results show that runoff is predicted to increase as a result of deforestation, which is dependent on the proportion of the catchment area affected. However, climate change presents a significant flood hazard even in the absence of deforestation. Other land use changes may reduce the peak discharges of all return period floods. Therefore a future ban on timber extraction, combined with agricultural utilisation of rangeland, could prove effective as “nature‐based” flood reduction measures throughout northern Iran.

Environmental Scenario Analysis on Natural and Social-Ecological Systems: A Review of Methods, Approaches and Applications

“…The results of the review show that although many papers have analyzed the dynamics and influence of land use change, e.g., [34,[49][50][51] or climate change, e.g., [52][53][54][55] on a particular natural or social-ecological system, the papers that jointly assess both environmental processes are less frequent and very recent (past decade, Figure 1), particularly those that analyze its synergistic effect, e.g., [4,33,[56][57][58]. The evolution of the number of articles on land use change over time has had an upward trend in the past two decades (Figure 1) and more than half of the articles that also take into account climate change analysis have been published in just the last six years of the analyzed period (Figure 1) [33,59].…”

Comprehensive Evaluation of Flood and Flood in the Yellow River Basin Based on Gray Correlation Analysis

“…By using accurate, detailed and reliable digital terrain models (DTMs), Zazo et al have generated more reliable river hazard maps to identify flood-prone areas (Zazo et al, 2018). Of course, there are some other research directions, for example, Hajian et al studied runoff changes in a small forest catchment area in northern Iran, and derived several land-use change scenarios and the effects of high rainfall and high previous soil moisture (Hajian et al, 2019). By using the two-dimensional and one-dimensional hydrodynamic simulation method, combined with the calculation and analysis of the golf hydrological curve, Sattar et al discovered the settlement which may submerge both sides of the river (Sattar et al, 2019).…”

Application of Fuzzy Best Worse Multi Criteria Decision Making Method for Flood Prioritization

“…Despite these descriptions, there are some solutions that can be effective against reducing or preventing flood events (Adhikari et al,2010;Smith and Ward, 1998). The results of studies conducted by the Forest, Rangeland and Watershed Management Organization (FRWMO) in Iran (1986Iran ( -2007 show that 2498 flood events were occurred and resulted in the deaths of 3299 people, injuries of 1733 people, partial and complete destruction of 135092 and 1572 building units (totally 136,664 damaged and destroyed buildings) (Almasi and Soltani, 2017;Hajian et al, 2019;Hooshyaripor et al, 2020;Yadollahie, 2019).…”