The document has been prepared after detailed study of three main landslides areas in Daeen, Shulja and Dilkhushan Villages adjacent to Chatorkhand Town, District Ghizer, Gilgit-Baltistan. The study was carried out by a consultant ground GEO BAND. The field exertion was leaded by senior Geologist Mr. Tehseen Uallah Qureshi during July 2018. The same study was submitted to earth sciences department, Karakuram International University GIlgit as assignment.
Geology of district Ghizer, land slides, geology, Chatorkhand, Ghizer, GB
Land Slides in Chatorkhand Town, District Ghizer, Gilgit-Baltistan, Pakistan,
1. ASSIGNMENT # 01
ON
“CREEPING AND SUBMERSING OF LAND IN DAEEN VILLAGE,
CHATORKHAND, TEHSIL PONIAL, DISTRICT GHIZER” GB.
SUBMITTED BY:
Tehseen Ullah Qureshi (Bounjivi)
MS Geology, Semester # 01,
Department of earth sciences,
Karakorum international University, Gilgit.
July-2020
SUBMITTED TO:
Professor Dr. Hawas Khan
Earth Sciences, Karakoram international University, Gilgit
SUBJECT:
Land Slide
2. TABLE OF CONTENT:
1.01 INRODUCTION TO THE TOPIC: 1
1.02 BACK GROUND OF THE STUDY AND ISSUE: 1
1.03 PURPOSE OF THE STUDY: 2
2.0 GENERAL INTRODUCTION TO THE STUDY AREA / DAEEN SLIDE 3
2.1 ACCESSIBILITY TO THE EFFECTED AREA / DAEEN 3
2.2 PHYSIOGRAPHY 4
2.3 GENERAL TOPOGRAPHY OF THE AREA 4
2.3.1 Drainage 4
2.3.2 Climate 4
2.4 REGIONAL TECTONICS 5
2.5 REGIONAL GEOLOGY 5
2.6 GEOLOGY OF CHATORKHAND AND DAEEN AREA 6
2.6.1 Gneiss 6
2.6.2 Alluvium (QAL) 6
2.6.3 Moraine Deposits / Overburden 7
2.6.4 Daeen Nullah 7
2.7 DAEEN SLIDE, CHATORKHAND, DISTRICT GHIZER: 8
2.7.1 Agents causing its downward creep: 8
2.7.2 Remedial measurements suggested: 9
2.7.3 PERMANENT SOLUTION: 9
2.8 PHOTOGRAPHS: 9
3. Assignment # 01. Land Slides 1
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By Tehseen Ullah Qureshi and team
1.01 INRODUCTION TO THE TOPIC:
Creeping of Land in Daeen Village, near Chatorkhand, Tehsil Ponial, district Ghizer, Gilgit-
Baltistan.
1.02 BACK GROUND OF THE STUDY:
Daeen village is located along the right bank of Ponial / Ishkoman River and in front of
Chatorkhand Village of Tehsil Ponial, district Ghizer, Gilgit-Baltistan. Daeen village is located
in higher elevation and across the Ishkomen River. The whole village is located on an uneven
alluvial fan which is consist of different Nullahs, terraces, cliffs and mountains. The village is
divided on the basis of elevation and division of terraces having different local names with rich
in fertility and people cultivate different crops in different seasons. Our area of focus is the
“Goshaar” area in Daeen village, which comprises an area of approximately 300 acers on a
mild to medium slope angle from West to east direction. This area is bounded by two Nullahs
from its North and south.
ISSUE:
The issue reported here is that the whole land of “Goshaar” section is creeping gradually from
east to west direction and hence large crakes have been developed in the whole area. Several
houses have been damaged and fertile, cultivated lands have been disturbed in large scale.
A large area of the cultivated land has been submerged and other is damaged by developing
of crakes. People life and property is at risk.
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Fig-.1.01: A Bird eye view of Daeen Village and the effected portion in white polygon with Nullahs in red lines.
1.03 PURPOSE OF THE STUDY:
Purpose of the study is to find out following phenomenon’s and their active influence on the
issue
A- Geological setting of the area i.e. geological formations, tectonic activities, hydrology
and other erosional features.
B- Type of land mass movement and submerging
C- Parameters of area effected
D- Causes of the mass movement i.e. Water, Fault line, slope angle, material type etc.
E- Direction of the mass movement
F- Rate of mass movement per month/year
G- Effect of current situation on settlement area
H- Types of geotechnical or geophysical investigation needed to explore the actual issue
I- Remedial measurements
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2.0 GENERAL INTRODUCTION TO THE STUDY AREA / DAEEN SLIDE
A landslide, also known as slope failure, landslip or slump, is a geological process in which
gravity causes an uncontrollable downhill flow of rock, earth, debris or their combination.
Landslides are among the many natural disasters causing massive destructions and loss of
lives across the globe. Natural causes of landslides include
A- Climate changes and weathering
B- Earthquakes
C- Flooding and erosion
D- Volcanoes eruption
E- Forest fires and steeper slopes
F- Gravitational force
G- Mining through blasting / vibrations and
H- Cutting of trees from the slope area.
These can trigger a massive landslide. Communities living at the foot of hills and mountains
are at a greater risk of loss and death by landslides. A substantial landslide carries along huge
rocks, heavy debris and heavy soil with it which result in loss of life, destruction of property,
decimation of infrastructure, affects beauty of the landscapes, impacts on river ecosystems
and river water supply for household activities and irrigation.
In Gilgit-Baltistan region of Pakistan, landslides events are frequent. For landslide hazard
management and mitigation measures in Chatorkhand area, B&R Division (PWD), Ghizer,
intends to conduct Feasibility Study of Slope Failure Shulja, Dilkhsan and Daeen area of
Chatorkhand through Power Aim Engineering Services (Pvt.) Limited. Chatorkhand is located
in Gupis–Yasin District of Giligit Baltistan. Gupis–Yasin District was created in June 2019, from
the three western tehsils of Ghizer District, namely Gupis, Ishkoman, and Yasin.
2.1 ACCESSIBILITY TO THE EFFECTED AREA / DAEEN
Gilgit-Baltistan is the northernmost province of Pakistan located along the international borders
of India, China and Pakistan. Gilgit is the capital of Gilgit-Baltistan and easily accessible from
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Islamabad via roads and by air. Karakoram Highway is the main road which connects Gilgit-
Baltistan with the other parts of the country and China.
Ishkoman Valley / Tehsil Ponial and Chatorkhand area lies in the NE of Ghizer District in Gilgit-
Baltistan. The Valley is approachable by all-weather road round the year. Due to peculiar
topography and climate condition, the roads to Ishkoman Valley are frequently exposed to land
sliding and mass movement resulting suspension of traffic during landslide events.
The Project is located in Daeen area of Chatorkhand, about 100 km from Gilgit city and 30 km
from Gahkuch City. Daeen Nullah is a right bank tributary of Ishkoman river A good road is
available from Gahkuch to Project area.
2.2 PHYSIOGRAPHY
The slopes in the Project areas are unstable, chemical weathering and frost action is
predominant. Suspended sediments and bed loads are high. The valley from its upper reaches
to downwards is narrow gorge type but widens considerably in its lower reaches.
2.3 GENERAL TOPOGRAPHY OF THE AREA
The topographical structure of the project area is desert landscape with high mountains, high
altitude plains, rivers, lakes, glaciers and snowcapped peaks. The altitude of area ranges from
6000 ft to even more than 7000 ft. People often make terraces to stabilize their land and to
make it feasible for cultivation.
2.3.1 Drainage
The drainage pattern in all over the Ponial and specifically in Daeen village is dendritic. Small
tributaries feed large Nullahs and the Nullahs feed the main Ishkoman river which combines
with Phunder river near Gahkuch. This river then meets with Hunza river in Gilgit which then
meets river Indus near Bunji Village District Astore.
2.3.2 Climate
The Project areas fall in semi-arid climate zones of Pakistan. The most significant features are
the low overall precipitation (on average over 130 mm per year) and a large range of mean
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monthly temperature values. The low winter temperatures and severe frosts during the period
early December to Late February. Temperature regimes are variable. In the valley shade
temperatures can exceed 35°C on a number of occasions each year and exposed surface can
have still greater temperatures. During the winter months, freezing conditions extend down to
the valley floors with snow falls. At highly elevations, snow fall on the exceedingly steep upper
slopes results in the widespread and frequent avalanching.
2.4 REGIONAL TECTONICS
A regional fault Main karakuram thrust fault “MKT” crosses the affected area “Daeen Village”
in east west direction.
2.5 REGIONAL GEOLOGY
Rocks exposed in the project area are mostly metamorphic with small intrusions of igneous
rocks and some outcrop of sedimentary rocks. Two major Crete-Tertiary granitic belts
intruded meta sedimentary rocks and a meta-volcanic complex in Hunza River valley up to
Sarat are Ladakh-Kohistan granitic belt and Karakoram granitic belt. The lithological units
exposed in the area are from the oldest to the youngest are given
ssu slates
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Quaternary deposits
2.6 GEOLOGY OF CHATORKHAND AND DAEEN AREA
In Chatorkhand and Daeen village, the rocks appear are slightly metamorphosed sedimentary
sequence of the Yasin area. These rocks, mostly cover the valley slopes of the area, are black
Slates and Granitic gneiss. Graded bedding erinaceous material horizons also observed in the
Black Slate. However, further toward the north the rocks become arkosic and contain several
pebbles and have a conglomeratic appearance.
On the basis of Surface geological mapping and field observations, the project area is
divided into following units described hereunder;
2.6.1 Gneiss
Moderately to highly fractured rock surrounding with alluvium. Three sets of Joint observed in
the rock unit mostly filled with clay and fine material. Slope of the whole rock body is steep and
faces towards Nullah.
2.6.2 Alluvium (QAL)
Light brown to brown colour rounded to sub rounded boulders and gravels intermix with clayey
silt and sand matrix. The material is moderately to highly cement together and is stable as a
whole in slope.
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2.6.3 Moraine Deposits / Overburden
Moraines in Daeen village are composed of heterogeneous material including boulder,
cobbles, pebbles, gravels, sand grain rock chips and silty clay soil. The lateral moraine material
(glacial remnant) in combination with fallen material from high elevation make them more
heterogeneous in composition. The terminal moraine material deposits represent more
glaciated than fluvial in origin. Boulder, cobble and other material are angular in shape and
less spherical.
2.6.4 Daeen Nullah
Daeen is a steeply sloping Nullah that confluences at right bank of Ishkoman River. The bed
slope in this study reach is about 0.1 m/m. The modeled reach is mostly confined by high
mountains on either bank. The study reach widens as the Nullah fans out before its confluence
with Ishkoman River.
There are settlements at either bank of Daeen Nullah. Most settlements along right and left
bank are located where Nullah fans out near Ishkoman river. In upper part of the study, where
the natural stream flows between mountains, scattered settlements are present. Mostly
cultivated fields and agricultural lands have been developed by locals.
The active river creek of Daeen Nullah meanders within the river edges. Historic satellite
images show that active creek sometimes meanders close to, or at the stream banks. This can
result in cutting and erosion of unprotected banks due to high velocity flows. There is almost
zero protection at either bank of Daeen Nullah against erosion.
2.7 DAEEN SLIDE, CHATORKHAND, DISTRICT GHIZER:
Daeen slide is the large slide along the right bank of Main Daeen Nullah and along left bank of
a local flood Nullah. The sliding portion of the Daeen area is sandwiched between these two
Nullahs. (Fig-01.) It is an active slide and its creeping rate is increasing daily (6 inches/Day as
quoted by Locals. Depth of slide varies at different locations but the average depth anticipated
at site is more than 200 m. Bed rock anticipated at site is at more than 300m in depth as no
outcrop observed even along Nullah beds. Along left bank of the Main Daeen Nullah, there is
rock exposed with dip angle more than 70° towards Nullah.
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The surface area of the vulnerable has been cultivated by locals and a number of houses are
present on it. Trees have been moved from their actual locations. The rate of creeping along
heights is higher than along the Nullah bank.
The actual phenomenon occurred here is that the surface thick alluvium cover has been
detached as a whole from its bed rock. This is due to the percolation of the Nullahs water from
both side of the village into the deep alluvium beds. Due to which the material cannot sustain
and creeps down ward. The alluvium can be defined as gravely, sandy, silty Clay/Calyey Silt
with subordinate cobbles, pebbles and boulders of sub angular to angular in shape. Close
picture of the representative material is given in photographs section
2.7.1 Agents causing its downward creep:
Percolation of rain, Nullah and springs water from different parts into the slide material.
Material own huge weight,
Slope angle ≥40°,
Toe erosion by both Nullah’s (especially during floods) and
MKT
As the area lies along MKT, so small and medium sized earth quacks also play their role in
downward movement of the mass.
The creeping of the material has been increased in 2020 which was at its maximum during
2010. The phenomenon was started during 2010 when initial cracks were developed at
different places. Average slope angle of the slide portion is between 20° to 40°. Although large
sized horizontal and vertical cuts in the form of slices along the whole slide can be observed
abundantly. Width of an average cut is 3-5ft and depth is 5ft to20 ft. Maximum width of the
cracks calculated is 20 ft. and depth anticipated is 50 ft. But it can be much more at different
places. Because most of the cuts have been filled by eroded material.
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2.7.2 Remedial measurements suggested:
Strengthening it from toe along both Nullahs,
Preventing of water seepages from both Nullahs, Springs and rains into it by concrete
channels and concrete Walls along Nullah beds.
Dewatering and benching along different places can prolong its creeping and down flow
rate.
It recommended to convince locals to leave cultivation and gardening as they use excess water
for it. This water percolates deep into the cracks and makes slush. The same phenomenon
occurred in the formation of Aataabad Lake Hunza, where such an issue was created. Locals
did not realized the issue and continued their cultivation. As a results large cracks developed
and water percolated very deep into the earth and slided down as a whole at once creating a
disaster.
2.7.3 PERMANENT SOLUTION:
Total area effected is between 35 Acers to 45 Acers. If government shifts the locals of the
specific area and compensate their land and other immovable property, it will cost
approximately 15 cores. This is the only permanent solution. Otherwise engineering practices
will not be long lasting and will cost equal to the total land compensation.
2.8 PHOTOGRAPHS:
Labelled photographs have been annexed in next pages.
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Fig-2.01: Large vertical and horizontal crakes developed along cultivated land.
Fig-2.02: House damaged as a result of submerging and creeping of land.
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Fig-2.03: Dislocation of plants from their actual location due to creeping of land in one year.
Fig-2.04: A bird eye view of the affected area “Goshaar” in Daeen Village.
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Fig-2.05: Size of crakes in Daeen Village in cultivated lands.
Fig-2.06:Due to frequent crakes in all over Goshar of Daeen village, locals use large pipes to transport water
from one place to another instead of ground channels.