From 1e1a49e116a61477958261176288b5f23be2ee4f Mon Sep 17 00:00:00 2001
From: rekado <rekado@elephly.net>
Date: Sat, 4 May 2013 14:48:32 +0800
Subject: sediments

---
 assignment2/potential-effects.tex | 48 +++++++++++++++++++++++++++++----------
 1 file changed, 36 insertions(+), 12 deletions(-)

(limited to 'assignment2/potential-effects.tex')

diff --git a/assignment2/potential-effects.tex b/assignment2/potential-effects.tex
index 865e6b2..9b6edc0 100644
--- a/assignment2/potential-effects.tex
+++ b/assignment2/potential-effects.tex
@@ -56,9 +56,10 @@ construction in proximity to the river as well as the proposed take
 and discharge activities during operation of the factory have direct
 effects on water quality parameters. Changes to the properties of the
 body of water (e.g. sediment load, changes in flow patterns, increases
-in nutrient levels) affect not merely aesthetical values of residents,
-but are likely to have impacts on the composition of aquatic
-communities and the health of riparian and aquatic ecosystems.
+in nutrient levels) affect not merely aesthetical values held by
+residents of the affected region, but are likely to have impacts on
+the composition of aquatic communities and the health of riparian and
+aquatic ecosystems.
 
 \subsubsection{Construction}
 
@@ -70,13 +71,40 @@ reducing the amount of sediment, excess nutrients and other pollutants
 entering the river \parencite{riparian}. This filtering ability is
 particularly valuable in a region where dairy farming is expanding and
 with it the cumulative impact of non-point sources of farm effluent is
-increasing.
+increasing. The clearing of vegetation may also directly reduce
+available habitat for native species, such as frogs and insects with
+aquatic larvae \parencite{riparian-management}. This impact can mostly
+be avoided by selecting a site that has already been cleared and does
+not serve as important habitat to native species.
+
+During dredging and excavation works on the construction site or
+during the removal of sediments away from the site, sediments may
+spill into nearby water bodies. An excessive increase in suspended
+sediments in the river affects water clarity, thereby reducing
+penetration with sunlight which is needed by aquatic plants and algae
+to grow. Increased turbidity may also make it difficult for fish to
+find food or detect predators \parencite{niwa-sediment}. As the
+sediment load of a river increases, its flow characteristics
+change\footnote{The cascading effects of changes to flow parameters
+are addressed in later sections.} and invertebrate habitat may be
+destroyed.
+
+
+Sedimentation is less of a problem when the construction site and the
+transport routes are chosen to be not in the immediate vicinity of the
+river or other bodies of water.
+
+
 
 \subsubsection{Water allocation}
 
   - Changes in water quality parameters - for example, turbidity and
     temperature levels can increase with reduced flows in rivers.
 
+  - Reduction in habitat - a decrease in water levels reduces habitat
+    for fish and can impact feeding and spawning success.
+
+
 
 \subsubsection{Discharge of waste water}
 
@@ -90,9 +118,8 @@ significantly affect the composition and dynamics of aquatic
 communities around the discharge location \parencite{}.
 
 
-\subsection{Preparation and construction}
 
-- removal of riparian vegetation
+\section{SCRATCH AREA}
 
 
 from NIWA:
@@ -102,22 +129,19 @@ http://www.niwa.co.nz/our-science/freshwater/tools/kaitiaki_tools/land-use/meat-
     alters available mahinga kai habitat and the invertebrates they
     feed on.
 
-  - Reduction in habitat - a decrease in water levels reduces habitat
-    for fish and can impact feeding and spawning success.
-
   - Reduction in specialist habitats - a decrease in water levels
     reduces flow to riparian wetlands, backwaters, and intermittent
     streams.
 
+  - Changes in sediment accumulation - flow reduction affects movement
+    and deposition of sediments in streams and rivers.
+
   - Decreases in species abundance and diversity - aquatic species
     have developed life history strategies in direct response to
     natural flows; for example, diadromous fish species migrate up and
     down the river at various times of the year and rely on preferred
     velocities and depths.
 
-  - Changes in sediment accumulation - flow reduction affects movement
-    and deposition of sediments in streams and rivers.
-
   - Increases in algae accumulation - algae respond to changes in
     temperature and nutrients, which are likely to increase with
     reduction of flow, especially during summer months.
-- 
cgit v1.2.3

