Erosion and Landslips

In Mediterranean regions, erosional soil degradation is of particular interest (see, for example, Grimm et. al. (2002), Gonzalez-Hidalgo et. al. (2007)) because soil resources will continue to deteriorate as a result of climate change, land use and human activities in general (Gobin et. al.

(2004), Koulouri and Giourga (2007) and Blavet et. al. (2009)). Therefore, the same concerns apply to Albania as a Mediterranean country and more specific to River Fani Catchment where soil erosion is a problem. Despite the fact that the country’s mountainous topography (60 per cent of the territory) and weather patterns are natural causes of erosion, human activities (i.e. the dredging of rivers for construction materials, logging, overgrazing, the abandonment of terraced land, poorly designed terraces, roads and channels) are exacerbating the problem and decreasing agricultural soil productivity (United Nation, (n.d.) [online]). These natural and anthropogenic disturbances affect the equilibrium between the soil, geologic, and topographic conditions with the vegetative systems that ‘allow’ a base level of erosion. In effect, accelerated erosion could result.

Generally, in temperate Mediterranean climates, where precipitation may be in the form of either rain or snow, the parameters that most often exacerbate the erosion processes are: slope steepness, lack of soil aggregation and high detachability, as well as vegetation cover (Wischmeier and Smith (1978) and Koulouri and Giourga (2007)). Slope and slope-length directly affect the acceleration of runoff waters (Fosters and Wischmeier (1974), Arnau-Rosalen et. al. (2008)). Soil aggregation and shear strength affect the ability of soil to resist detachment as runoff volumes and velocities increase (Elliot and Ward (1995), Knapen et. al. (2007)). Other factors that also cause soil erosion include wind and rainfall. Topography and rainfall duration dictate the importance of wind or rain in contributing towards erosion. These factors, at different extent levels, also contribute towards soil erosion on River Fani Catchment. Intense rainfall for example, on this mountainous catchment as well as the lack of vegetation cover in some areas are the significant contributing factors of soil erosion.

Poor management, illegal cutting of forests and overgrazing, as well as inappropriate methods of forestry and soil management are additional factors that result in erosion in River Fani Catchment. The hilly, mountainous topography of the Catchment, with steep slopes and generally irregular relief, intensifies the problem. The high erosive power of intense rainfall (1800 -2000mm/year) contributes significantly to soil erositivity. Plates 3.5 and 3.6 show the erosion of the River Fani banks across different locations along its length as well as an example of the many landslides that occur in the Catchment.

(a) (b) (c)

Plate 3.5: Soil erosion and bank instabilities along the banks of the River Fani (a) upstream Rubik town. The arrows show landslips and the erosive force of the River flow, (b) landslips, upstream of the River Fani at Rubik town, (c) landslips, downstream of the River Fani at Rubik town (Source: AIA Porthcawl).

Plate 3.6: Soil erosion and landslide problems in Lesja (situated near Rubik town) in North Albania.

Mitigation measures underway (concrete piles) to stabilise the landslide (Source: AIA Porthcawl).

3.4.3 Flooding

Floods are a natural phase of the hydrologic cycle and are manifested as extreme events of excess water of varying magnitudes. They are one of the most catastrophic forms of natural disasters,

and are responsible for high fatality levels and economic damage. Recently this global problem has been observed to be increasing at a more rapid rate, thus posing very serious threats to human lifes and properties. For example: (i) in France, 42 people died in 1992 during flash floods in the town of Vaison-la-Romaine; (ii) basin wide floods caused widespread disruption and losses in the Rhine and Meuse basin in 1992, 1993 and 1995; (iii) exceptional flooding struck the Po Valley in Italy in 1994, (iv) in 1999, in Venezuela, torrential rain and mudslides killed 15,100 people, (v) in UK, 8,000 properties have been flooded during October 31 to November 16, 2000 (vii) in 2004 flash floods have devastated Boscastle village in UK causing damages to properties worth of millions of pounds while the same year the Tsunami in Indonesia killed 295,600 people (vii) in 2005 Carlisle flooding three people were killed, many homes and businesses were flooded and schools were closed. There was widespread transport disruption with all of Carlisle's buses damaged. Appleby, Cockermouth and Keswick also had flooding. This was the worst flood to affect Carlisle since 1822.(viii) Hurricane Katrina in 2005 was the 3^rd most intense and one of the most deadliest storms (1,836 people lost their lifes) ever to hit the U.S. The flooding caused widespread disruption to the transport network in England and Wales, but damage was the most severe in northeastern England, North Wales, the Midlands and southern England (Risk Management Solutions (RMS), 2000). (ix) in 2007 floods in UK killed 6 people and caused disruption to Yorkshire transport system (road and rail closures), power system leading to evacuations with Sheffield the worst hit (x) Morpeth Flood in UK in 2008 caused River Wansbeck to burst its banks causing damage to 995 properties costing £40 million (xi) Winter 2009-2010 was devastating not only for UK but the whole of Europe. In UK heavy rain resulted in flooding with the worst concentrated in Cumbria which let to the death of four people. The prolonged period of snowfall and sub-zero temperatures caused disruption and at least 22 deaths in the UK and at least 90 across Europe. Some of the causes of these floods are due to global warming conditions, failure of drainage systems, flash floods or increased runoff caused by

frequent rainfall. Consequently some flooding events can be predicted and other cannot, causing additional problems such as: siltation of the rivers, degradation of land, and failure of drainage systems. On a trans-continental level, thousands of lives have been lost directly or indirectly from flooding in many countries including Bangladesh, China, Guatemala, Honduras, Somalia and South Africa (Samuels (1999)).

In Albania, 40,000 hectares of land is affected by flooding (United Nation, (n.d.) [online]).

During September 2002, intense rain (which usually occurs in the period from November to March), caused flooding in most parts of Albania, (see Plate 3 .7). Northern Albania was particularly affected, leading to the country being placed in a state of emergency requiring external assistance, e.g. from Japan (The Ministry of Foreign Affairs of Japan (2002)).

In the River Fani Catchment, frequent flooding affects the local populations, particularly Rubik residents. The tranquillity of their livelihood, as stated before, is being disturbed with economic, social and environmental issues raised due to flooding and its effects. Catchment management strategies are a necessity and can be achieved and supported with the aid of modelling.

Hydrological modelling could be used as a DSS to provide solutions to these problems as has been reported in Chapter 2. These tools, require certain datasets in order to be build successfully and consequently data precision and accuracy are often unavoidable prerequisites. Such data are usually retrieved from archives. In cases where these do not exist, alternatives but useful sources need to be explored.

Plate 3.7: Flooding in Kruje in Albania, 30^th September 2002 (Source: Co-operative Program on Water

& Climate (CPWC), UNESCO-IHE (2002)).