Stream II: Watershed Management

(a) Jagir

Jagir land was assigned to government employees (civil and military) in lieu of salary, and the holder enjoyed its income during service. Guthi was land for religious and charitable trusts, Kipat was communal land of indigenous groups such as Limbu, and Rakam was land held in return for compulsory labour services.

(c) 70-1000 msl

Nepal's tropical zone lies from the lowest point (about 70 m in the Terai) up to about 1000 m above mean sea level. The subtropical zone follows from about 1000 to 2000 m.

(d) All

Microclimate is shaped by local slope and aspect, soil type and moisture, air movement, vegetation cover and nearby water bodies, so slope, soil and air all affect it.

(d) All

Participatory Rural Appraisal uses focus group discussions (FGD), key informant interviews (KII) and surveys, along with tools such as transect walks, resource mapping and seasonal calendars.

(a) Dolpa

Dolpa is a high Himalayan district. The Chure (Siwalik) range runs along the southern foothills, and includes Dadeldhura, Udayapur and Saptari.

(a) 1990

Nepal's watershed programmes moved from a purely technical, top-down approach to a people's participation approach around 1990, with local user groups involved in planning and implementation.

(c) 0.9

Impervious surfaces such as roofs and pavements have a runoff coefficient of about 0.9 (typically 0.9-0.95), since almost all rainfall becomes runoff. A value of 1.0 is only a theoretical limit.

(d) High rates of fog drip and soil evaporation

Cloud forests are frequently immersed in cloud. Their foliage intercepts fog droplets, which drip to the ground as extra "occult" precipitation (fog drip). Low radiation and high humidity keep transpiration low.

(c) The source of a river

Headwaters are the upper reaches of a stream, where it originates, such as springs, glaciers or small first-order streams in the uplands.

(b) Slope

A watershed is delineated on a topographic map by marking the outlet point, tracing the ridge lines across contours (perpendicular to them), and using the drainage lines to see where water flows. Slope is not needed for the boundary.

(b) Gandaki

Among Nepal's large rivers, the Gandaki (Narayani) has the highest mean annual discharge, about 1,700 m$^3$/s at Narayanghat. The Koshi (about 1,500 m$^3$/s) and Karnali (about 1,400 m$^3$/s) follow, and the Mahakali is much smaller (about 570 m$^3$/s).

(b) Revival of springs

The springshed approach manages the recharge area of a spring (geology, land use, infiltration) to sustain and revive spring discharge. Soil conservation and productivity gains are by-products, not the main focus.

(c) 4-7 mm/hr

Hydrological soil group B has moderate infiltration (about 4-7 mm/hr when thoroughly wetted), for example silt loams. Group A is above this (high), and groups C and D are lower.

(d) Rip-rap

Palisades and fascines are bioengineering measures using live plant material (rows of stakes or cuttings, bundles of live brushwood). Rip-rap is a structural measure of placed stone, a civil engineering rather than a vegetative technique.

(b) Stream order

The bifurcation ratio is the number of streams of a given order divided by the number of streams of the next higher order:

$R_b = \frac{N_u}{N_{u+1}}$

It therefore derives from stream order (Horton-Strahler).

(d) Conglomerates

Conglomerate is a sedimentary rock made of cemented rounded gravel. Slate, marble and quartzite are metamorphic, formed from shale, limestone and sandstone respectively.

(b) Relief

Relief is the difference in elevation between the highest and lowest points of an area. Altitude is the height of a single point above sea level.

(b) Erodibility

Erodibility is the inherent susceptibility of a soil (resistance to detachment and transport) to erosion, as in the K factor of USLE. Erosivity is the capacity of rainfall or runoff to cause erosion.

(b) 12.78%

The Chure (Siwalik) range covers about 12.78% of Nepal's total land area, running along the southern foothills from east to west.

(b) Food access

Food access means households have enough resources to obtain adequate food through purchase, home production, barter, gifts, borrowing or aid. Food security also needs availability and utilisation, so it is broader.

(c) Watershed

A watershed (catchment) is the land area that drains to a common outlet, bounded by a ridge line or divide.

(d) All of above

An alluvial fan forms where a steep stream enters a flatter, wider valley or plain. It suddenly spreads out, slows and loses energy, and drops its sediment load in a fan-shaped deposit.

(b) Filtration

Filtration removes suspended particles and dust from water by passing it through a filter medium such as sand, gravel or cloth. Sublimation is the change from solid directly to gas.

(b) Rain water harvesting

Rainwater harvesting is the collection and storage of rainfall from roofs or land surfaces in tanks, ponds or natural reservoirs, or its recharge into the ground, for later use.

(b) DEM

A Digital Terrain Model (bare-earth surface, free of vegetation and buildings) is a kind of Digital Elevation Model. A DSM, by contrast, includes surface features such as trees and buildings.